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ISSUE 13 • MAR/APR 2007

C S I R O E X P L O R AT I O N & M I N I N G M A G A Z I N E

Sensing & Sensors

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Industry partners
Embedded research success

The road ahead
metal production, more in-situ mineral processing, and the minimisation of waste production from processing by using waste streams for useful purposes. The industry will become far more uniformly committed to scientific and engineering R&D than it is at present, and there will be massively increased levels of automation. This will enable us safely and efficiently to access deeper, hotter and more stressed ore bodies, and minimise the exposure of workers by taking them out of hazardous situations, yet safeguarding jobs by placing them in remote monitoring and control roles. These new jobs are likely to be knowledgebased roles, ideal for highly skilled employees. Through all these forward visions can be woven the thread of sensors and sensing. Smaller, ‘smarter’, safer and more accurate sensing devices are being developed by CSIRO Exploration & Mining and its collaborative partners in science and industry to lead us into a new automated age. These technologies cover everything from down-hole geochemical tools for pre-mining assays to predicting roof collapse in operational and well established coalmines. Many of these systems are already here and being used – they are scientifically proven and either already commercialised or on the cusp of being manufactured. They are our new eyes and ears, our ‘future senses’ which will allow us to look and move underground with accuracy and confidence, and allow us to maintain and strengthen our industry for years to come. Dr Peter Lilly Chief [email protected]

Looking down-hole
Towards rapid coal assays

Longwall advance
Sensing the coal seam

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Interview
Xstrata’s Peter Henderson

Safer mines
Predicting roof-falls

Future mapping
Mineralogy empowerment

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Sensor skills
Old tech has new applications

ow is the time to look in detail at what awaits our industry 20 or even 25 years down the track and calculate how the innovative multiple-solution technologies we are developing are going to serve us best. We know for certain that significant skills shortages, HSE governance, greenhouse gas mitigation, water-use and related societal demands will all have major impacts on exploration and mining. Undoubtedly we will need to shift towards using more predictive rather than empirical exploration methodologies as a matter of routine. We will become more dependent on technology for discovery, particularly the use of remote and low impact sensing, to find the deposits of the future. Low footprint mining methods will need to be adopted across the board to meet stricter environmental and societal legislation. This will include a large reduction in net energy and water consumption in mineral processing and

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In the field
Down under Japan

Ask our scientists
Jeremy Thompson

Publications
Key scientific papers

Metalmorphosis
Changing face of metals

e a rt h m a t t e r s is produced by CSIRO Exploration & Mining. Views expressed do not necessarily reflect those of CSIRO Exploration & Mining management.
ISSN 1448-336X Managing Editor: Matthew Brace - [email protected] Design: Liz Butler - [email protected] Cover image: Ryuichi Okano/GettyImages CSIRO Exploration & Mining www.csiro.au
© 2006 CSIRO Exploration & Mining All rights reserved. No part of this document may be reproduced, stored in a retrieval system, photocopied or otherwise dealt with without the prior written permission of CSIRO Exploration & Mining

For your own copy of
To be added to our mailing list please email: [email protected] For electronic version: www.em.csiro.au/earthmatters

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e a rt h m a t t e r s MAR / APRIL 2007

PETE TURNER/GETTY IMAGES

COVER STORY

New sensor and sensing technology is taking us to the next stage in industry development

Finding the sixth sense
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nowledge is power in the exploration and mining industry, and much of that knowledge comes from detailed geological information. This gives scientists and exploration companies sets of eyes beneath the surface, displaying what lies down there, where it is, whether or not the deposits are mineable, and if so how to get them out. This information is equally crucial during mining to display the efficiency and safety performance of the process, for instance whether a longwall shearer is staying within the seam and maximising coal delivery. Inaccurate data can prompt misinterpretation of results and that can cost dearly. So, more accurate and detailed data is a key goal. But where does this information come from, and how is it gathered? The answer is sensors, the devices that read and see geology, geochemistry and a host of other physical aspects of a rock mass or deposit. If the information is wrong at this raw data stage then the errors are going to spread dendritically throughout the operation, which is why CSIRO Exploration & Mining (CEM) is collaborating with a wide range of research organisations, state geological surveys and progressive companies to build better, ‘smarter’ sensing devices to ensure the highest levels of accuracy the industry has yet known. It’s about working towards that ‘sixth sense’ which will make exploration and mining safer and more profitable. In many cases it means examining existing sensing technology and making it many times more accurate: being able to measure accurately to within 50mm rather than 1-5m, for example. Sometimes non-mining technology is employed as the basis for building new sensing machines, such as using cameras very similar to a standard digital compact to take pictures at intervals and relay them back to the control room. New and ingenious developments include down-hole geochemical tools to provide rapid and accurate geochemical coal assays. Such determination would result in a geochemical model containing a high level of confidence in the distribution of key element concentrations prior to mining. In sand mining where pond dredges are used, sensors can now be used to enhance safety and increase production. And in coal mines sensors are allowing us to predict post-mining roof falls with more accuracy than ever before. Thermal infrared cameras and optical marker band detectors combine with other sensors mounted on the longwall shearer to monitor a coal seam during extraction. They build up an accurate panoramic image which shows operators whether the shearer is staying within the seam or whether its position should be changed. CEM is at the forefront of this technology and is helping to make Australian mines the most advanced, ‘sensed’ and automated in the world. And then there is the added safety element when using electronically operated sensors in a gassy mine, so all equipment has to be made either intrinsically safe or at least explosionprotected. As Xstrata Coal’s automation and sensing guru Peter Henderson says in the Interview (p10-11), the generally accepted strategy for sensing is “to remove people more and more from hazardous areas and change their roles to observation and correction”. “Although it is unlikely that all people will be removed from all parts of a mine in 20 years, it is possible that within 10 years people can be removed from an operating longwall face, but they will still be underground close to the longwall machine for quick response to exception conditions that only humans can handle,” he said.

e a rt h m a t t e r s MAR / APR 2007 3

EMBEDDED RESEARCHERS

Sensing an opportunity
PHOTO COURTESY OF BHP BILLITON

Night moves: After dark at the Mt Keith mine

Solutions are being found through a groundbreaking industry-science programme, says Matthew Brace

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ignificant strides are being made in the field of spectral sensing and sensor technologies through a unique collaborative initiative. The Embedded Researcher (ER) programme places scientists from industry and research organisations into each other’s camps to share and transfer knowledge, and solve problems. The latest benefits are being seen in Western Australia, where five ERs are working on gold, nickel and iron ore exploration projects. Three are based in the Kalgoorlie goldfields region, striving to solve the riddle of how to map the chemical gradients that control the location of deposits, and testing a new Hydrogen Flux theory of how metals were transported from the deep Earth to the surface by hydrogen-rich fluids. Drs Tony Roache, Carl Young and Mark Pirlo are all researchers employed by the University of Melbourne (through the Predictive Mineral Discovery CRC, pmd*CRC) working respectively at St Ives Gold Mining Company (part of Gold Fields), Barrick Kalgoorlie Operations, and Barrick Granny Smith Operations. According to their coordinator (and one of the founders of the ER programme), CSIRO Senior

Principal Research Scientist at the Australian Resources Research Centre (ARRC), Dr John Walshe, the ERs are focusing on “defining the spatial evolution of fluid chemistry within the gold mineralising system by mapping alteration (minerals, mineral compositions, rock compositions, and S, C and O isotopes) at scales from near ore (within hundreds of metres of known deposits) to district scale (up to 20-50 kms from known ore)”. “They are looking to define parts of systems where critical changes in fluid chemistry occurred that are favourable for gold deposition. “In the past the focus of exploration has been on physical processes such as finding the structure that the ore fluid flowed along and then identifying some suitable trap site like a structure or specific rock type. “This current work is novel because it is dealing with a completely revised understanding of the chemistry, which is more complicated than we previously thought, reflecting multiple fluids, pathways and processes,” Dr Walshe said. The ERs drive the collection and interpretation of new data sets. They admit many datagathering tasks are not complicated but

interpreting the data on site and teaching others how to see what they see from the results is driving a change in perspective. Exploration geologists are now looking to the ERs to facilitate targeting exercises, thereby training explorers to interpret data and better predict deposit locations.

Building success
Dr Walshe said perhaps the most obvious successes are from St Ives. “The impact at St Ives is both at deposit scale and district scale,” he said. “At deposit scale the work is providing practical testable targets close to known lode horizons. And at district scale, defining the locations of chemical gradients through use of the hyperspectral data and multi-element geochemistry helps to significantly reduce the search domain.” Similar benefits are being reaped in nickel and iron ore. BHP Billiton has embedded Project Geoscientist Dr Annamalai Mahizhnan with the ARRC to optimise ore processing at the Mt Keith Mine north-east of Perth (operated by BHP Billiton subsidiary Nickel West) by quantifying the mineralogy of ore and waste material using reflectance spectroscopy.

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Talc and serpentine minerals commonly occur in the komatiite-hosted, serpentinised, disseminated Ni-sulphide Mt Keith (MKD5) deposit. These minerals adversely affect the grinding circuit, ore froth-floatation system performance and, in turn, nickel recovery. ARRC research team member, CSIRO Senior Research Scientist (Discovery Technologies), Dr Martin Wells, said company talc quantification models and methods are “time consuming and at best only semi-quantitative but previous CSIRO research had demonstrated that talc can be detected using reflectance spectroscopy”. “The role of the ER in this case was, under CSIRO guidance, to develop a quantitative spectral method to detect and determine the talc content in powdered samples to meet the operational needs for grade control and mineral processing at the Mt Keith mine. “Initial development of spectral prediction models were developed using the portable infrared PIMA™ and ASD spectrometers, but these instruments were not sensitive enough for the level of accuracy required. Further investigation by Dr Mahizhnan identified a suitable spectrometer (whose name has not yet been released) that has the sensitivity needed to further the development of a reliable spectral prediction protocol,” Dr Wells said.

Nickel West heeded Dr Mahizhnan’s advice and purchased the spectrometer and it is under trial as e a rt h m a t t e r s goes to press. The iron ore sector of the project involved two ERs from Rio Tinto: Senior Projects Geologist, Ms Danielle Robinson, and Geologist, Mr Glenn Kirkpatrick. According to their coordinator, CSIRO’s Commodity Leader for iron ore, Dr Erick Ramanaidou, their roles covered a much broader range of areas including ore type evaluation and characterisation, trace element contaminants and mineral association, and the facilitation of technology transfer particularly in the areas of exploration and applications to resource evaluation. “The close ties established with Robinson and Kirkpatrick were pivotal in establishing a 10-month, extended field-trial of the Fe-Hylogger™ at Hamersley Iron’s Bungaroo exploration camp near Pannawonica, just south-east of Karratha,” Dr Ramanaidou said. This trial follows on the success of a shorterterm trial at the camp featured in the Nov/Dec 2006 e a rt h m a t t e r s issue. One of the advocates of the ER concept, BHP Billiton’s Senior Resource Geologist, Dr Bob Morrison (formerly with Gold Fields Ltd St Ives), said “ERs provide direct evidence that the research is out of the Ivory Towers; it’s

on-site, it’s pragmatic, practical, focussed, responsible and realistic”. And Mike Christie, General Manager – Exploration for Resolute Mining (formerly with Placer Dome Asia Pacific), said: “Traditional ore deposit research has typically ended up gathering dust on a bookshelf at the mine site with little buy-in from the exploration team on the ground”. “The ER programme has provided a fertile environment to share ideas and concepts that have benefited both the researcher and the explorer. When the embedded researcher leaves site they leave an educated and empowered team with a set of practical tools and ownership of the new ideas.”

LINK
Dr John Walshe +61 8 6436 8643 [email protected] Dr Martin Wells +61 8 6436 8812 [email protected]

History of the ER
CSIRO’s Embedded Researcher programme is managed by CSIRO Exploration & Mining’s (CEM) Minerals Down Under (MDU) initiative. It was established to engage industry and research organisations, and to allow the ERs to be the main catalysts for maintaining the momentum of research on targeted projects. The programme works symbiotically: scientists from industry are embedded within CSIRO (including at ARRC), while CSIRO and university researchers move out to work within companies. ERs from industry learn the workings of their host research organisation and can return ‘home’ with valuable insights which will benefit their company and enhance future relationships. From CSIRO’s point of view the value is a better understanding of the day-to-day operations, restrictions and demands of industry. Having an industry-sourced ER on-site has enabled organisations to adopt more suitable approaches to meet ongoing R&D issues as they occur. The shared vision is for more ERs. Co-founder of the programme, Dr Walshe, has proposed a consortium-funded programme aimed at developing the ER Initiative. This would establish the ER system firmly within the exploration and mining industry,
e a rt h m a t t e r s MAR / APR 2007 5

with the support of funding from AusIndustry’s Industry Cooperative Innovation Program (ICIP). “It is proposed the focus would be on multiscale mineral mapping research projects, including deposit-scale to district-scale and new technologies based on gold, iron and base-metal extractive industries, and operational in 5-6 mineral provinces across Australia,” he said. The MDU initiative has agreed to fund a further 5-7 ERs.

DOWN-HOLE DETERMINATION

Towards a rapid geoch
geochemical logging tool would offer “a rapid assay estimate in a continuous fashion, which would provide substantially more information on the vertical and lateral element distributions than is currently available”. The result would be a geochemical model containing a “high level of confidence in the distribution of key elements prior to mining”. One of the favoured technologies for in-situ down-hole determination of element concentrations would be next-generation Prompt Gamma Neutron Activation Analysis technology (PGNAA), which will include the use of neutron generators (neutron sources that can literally be turned on and off at the throw of a switch) and advanced neutron detectors. PGNAA has the capability to estimate a number of the ‘problem’ elements present in coal (see table opposite). However, as most previous PGNAA technology was designed primarily to estimate the abundance of major elemental constituents of coal ash and host rocks like silicon, iron and aluminium, this approach needs to further development and adaptation. According to Fraser: “Other techniques that the team will evaluate include laser-induced breakdown spectroscopy (LIBS), laser-induced fluorescence (LIF) and down-hole X-ray fluorescence (XRF). All of these techniques have proven application for the elements in the table opposite but their implementation in the borehole environment has complex engineering issues.”

Fine tuning: Scientists could soon have a new way of assaying coal

Scientists are heeding industry’s call for in-situ determination of element concentrations

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nowing the fine chemical make-up of a coal deposit before mining is something the industry yearns for.

Faster and more accurate
According to the project leader, Principal Research Scientist in CEM’s Mining Geoscience Group, Stephen Fraser, the only method available for gaining information on a suite of major, minor and trace elements is laboratorybased analysis performed on borehole samples; and these are often composited over inappropriate sampling intervals. “Sampling and laboratory assay techniques are expensive, turn-around can take months rather than days for off-site commercial laboratories, and detailed sampling is often restricted to the coal seam only,” he said. “Consequently, this process often provides sparse information about the in-situ lateral and vertical zonation of elemental distributions. Fraser said in-situ determination of element concentrations using a down-hole

TIPP HOWELL/GETTY IMAGES

One way of vastly improving the accuracy of an assay estimate is to employ in-situ determination of element concentrations using a down-hole geochemical logging tool. There are various technologies that can help, each with its own particular advantages and disadvantages in terms of how easily the technology can be employed ‘down-hole’ and how readily particular elements are determined. But according to recent industry canvassing, companies also wants to assess the feasibility of such a tool, so CSIRO Exploration & Mining (CEM) has proposed a 12-month project to develop and assess the requirements for such technology here in Australia.

Getting results
The CEM project will define the coal industry’s specifications for borehole logging estimates of major, minor and trace elements; their deemed importance; specifications in terms of accuracy, precision and detection limits; as well as a review of what additional requirements are likely to be important for the industry in the next 10 years due to OH&S, environmental and utilisation issues. The scientists believe it is unlikely that a single technology will fulfil all industry requirements, so technologies will need to be identified that offer the best chance of success in detecting and measuring the various required elements.

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VIXXXN

emical coal assays
Main aims
The project aims to conduct three main activities: • to determine further the specifications required by the coal industry in order to be able to separate ‘must-have’ elements from ‘nice-to-have’ elements, to collaborate with industry to assess and recommend equipment specifications and how the new technology would be best implemented, and to review potential technologies that may be capable of delivering the requirements identified by industry in a borehole logging configuration.

ELEMENTS
P

POTENTIAL DETECTION LIMIT
0.001 – 0.01%

COMMENTS
Affects steel making. Can be erratically distributed within coal seams, both laterally and vertically.

C, O, H S, N

0.1% 0.1%

Can be used to provide estimates of yield, washability and contained energy Affects coking performance and produces SO2 and NO2 emissions. S contributes to acid mine drainage.





Si, Al, Fe, Ti, Mn, Ca, Mg, Na, K, P

0.01 – 0.1%

Affects coking coal and thermal coal performance, as well as usability of waste ash.

The team believes a new borehole tool would be able to offer same-day analysis of a wide range of elements in exploration and production boreholes, to order. “The major outcome will be a clear direction for the development of a prototype down-hole instrument capable of performing to specifications determined by the coal industry,” said Fraser. “When such a next generation down-hole geochemical logging tool is developed, it will supplement the existing suite of tools already provided by the major commercial logging contractors, and provide a capability to quantitatively estimate the content of major, minor and trace elements important to coal producers. “That would be a major step forward for the Australian coal industry.” It would provide cost effective measurement of elemental abundance throughout the coal seam and host rock stratigraphy, delivering data coverage that is virtually unachievable via existing sampling and laboratory analysis techniques. Also beneficial to industry would be the detailed knowledge of lateral and vertical zonations of important elements, enabling a comprehensive understanding of 3D elemental distributions within coal seams, overburden and interburden materials. Fraser said the tool would also “increase confidence and reduce risk by allowing companies to mine coals and interburden materials with known characteristics and performance”. •

Sb, As, B, Be, Cd, Cl, Co, Cr, Cu, F, Hg, Mn, Mo, Ni, Pb, Se, Th, U, V, Zn

0.001 – 0.1%

Minor and trace elements emitted to atmosphere during thermal coal burning and to a lesser extent coking.

Coal concerns: Preliminary assessment of elements of interest relevant to the coal industry. Source: CEM’s 2006 ACARP LONG PROPOSAL – Borehole Tool for Quantitative Elemental Analysis.

These expected benefits should include: • Same day analysis of a wide range of elements in exploration and production boreholes as required Cost effective measurement of elemental abundance throughout the coal seam and host rock stratigraphy, delivering an order of magnitude greater data coverage than available now using existing sampling and laboratory analysis techniques Detailed knowledge of the lateral and vertical zonation of major, minor and trace elements important to the coal industry, enabling a comprehensive understanding of three dimensional elemental distributions within coal seams, overburden and interburden



However, the operational performance of existing mines can also be influenced by localised knowledge of coal seam variability, such as the effects of phosphorus hot spots, oxidised areas, lower volatile zones, and erratic sulphur and iron distributions.

LINK
Stephen Fraser +61 7 3327 4544 [email protected] Craig Smith +61 7 3327 4150 [email protected]

These outcomes would benefit miners in the exploration/feasibility stage where investment decisions are strongly controlled by the interpretation of coal quality parameters, utilisation performance and environmental implications.

e a rt h m a t t e r s MAR / APR 2007 7

LONGWALL TECHNOLOGY

Sensing the future for
in turn cuts costs by limiting the need for downstream washing and separating. Although this Coal Utopia is still some way off, recent developments in four areas of sensing have brought it several steps closer.

e a rt h m a t t e r s can reveal that two of these areas – thermal infrared cameras and optical marker band detection - should be in commercialisation with manufacturers within six months.
This is the most recent stage in a long-term project by CSIRO Exploration & Mining (CEM). Traditional assessment methods cannot measure the coal seam 3D location accurately enough prior to mining to enable on-line navigation and control of mining equipment, so these measurements that keep mining equipment working within the seam must be made as we mine. According to the leader of CEM’s Mining Automation Group, Dr David Hainsworth, the common denominator in all four development areas is the desire to detect where the longwall extraction equipment sits relative to the coal seam, and to keep the shearer working to maximum efficiency within the seam. His group’s work has been to develop sensors to do this in real time. However, the major problem in sensing coal seam location is that the properties of coal seams vary widely and all sensors won’t work at all sites. So having a suite of methods that utilise different coal properties offers better odds that at least one method will work at any given site. “Ideally, before you start mining you would like to know exactly where the coal is - where the roof and floor of the seam are accurately across the longwall face. With this fixed reference you can drive the machine based on those survey points,” said Dr Hainsworth.
Close watch: New sensing systems combine to maximise longwall production

“If you can’t do this, you have to try to guide the cutting process to stay in the seam while you are doing it”. He said the process was not dissimilar to the sensors used by the human brain when driving a car. “You can use a GPS navigator to tell you how the road snakes ahead in front of you but you still need to have the steering wheel in your hands so you can watch the centre line of the road and keep the car steered in real time,” he said.

Four coal-face systems are providing a suite of information that will allow miners to maximise coal extraction
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erfect measuring and mapping of the 3D shape of a coal seam is a major industry goal. It would give mine managers the ability to ‘drive’ a longwall shearer to cut the seam only, avoiding all the surrounding rock. This would maximise the use of equipment and minimise the presence of non-coal elements in the final extracted product, which

coal
Similarly, mining equipment operators look for features in the freshly uncovered seam that give them an idea of its structure. They then position the cutting drums to keep those features in the same relative position as they mine. “Traditionally sensing systems have been able to tell us where the coal is to within 1-5metres of accuracy so we know roughly where we are going. The sensing we are developing shows you in real time where you need to be cutting to an accuracy of 50mm, and is going to let us take our hands off the steering wheel.” the roof and floor cutting horizons to give good seam following. “The fact that thermal infrared sensing could detect this reference reliably meant that there was now a consistent feature in the exposed face that could be reliably detected by machine and that could be used to generate consistent roof and floor cutting horizons.” There is confidence that the method will be viable and the team is collaborating with equipment manufacturers on commercialising the system. accurately predicting coal thickness immediately at the cutter head. Dr Hainsworth said CEM is “currently looking at applications for GPR in surface mining in coal and iron ore but commercialisation is not so straightforward”. “We are still in the science area and the implementation issues are huge,” he said.

Ultra wide band technology (UWB)
In addition to ground penetrating radar, the team has also investigated the use of freespace radar systems for navigational purposes. New research in the field of ultra wideband (UWB) radar is being undertaken which allows targets to be identified and localised despite background clutter. As bolting and other features of a mine’s infrastructure must be surveyed and logged by law, there is a wealth of information on hand to assist navigation. As a Senior Project Engineer for CEM’s Mining Automation Group, Chad Hargrave, pointed out, “identifying and tracking the movement of mining equipment relative to these features provides a complementary sensor to locate the inertial path of the equipment in relation to the mine infrastructure”. A preliminary trial of the technology at Beltana in October 2006 demonstrated that rib-bolts could be identified by radar, and work is now under way to develop a robust position sensor based on the technology.

Thermal infrared camera (TIR)
Anyone familiar with televised cricket will have seen the thermal infrared camera which picks up hotspots when the ball hits a bat, glove or pad. The same science is being employed underground to sense when a shearer is starting to cut into surrounding harder rock rather than the coal. The picks heat up when hitting the harder rock. The cameras, which comprise a series of sensors, can see these hotspots and can alert operators to change the shearer’s direction to stay within the coal seam. Such cameras were originally trialled unsuccessfully due to their size and complexity. The latest TIRs are compact in size and housed in small flameproof enclosures with a window transparent to thermal infrared radiation, meaning they can be mounted safely and efficiently on the shearer. The first compact camera trials, carried out at Beltana mine in the Hunter Valley two years ago were the most comprehensive of their type and a success. And there was a bonus: a scientific first. As well as the expected hotspots at the hard rock boundary, the cameras also picked out heat differences within the exposed coal face itself, which intrigued the team. They did not align with clearly visible features (or marker bands) in the seam yet they were strongly related to the layered structure of the coal (or plies). “This immediately indicated great promise for thermal infrared sensing use in horizon control,” said Dr Hainsworth. “Interfaces between coal layers within a seam are often subtle and difficult to detect visually but give valuable information about the structure of the seam and are used by experienced operators to give a reference against which they offset

Optical marker band detection
One of the most effective ways of guiding a coal mining machine is to find visible features in the seam, often bands of clay, known as ‘marker bands’. If a marker band is dipping closer to the floor shearer operators can adjust the cutter heads to follow the seam. A CEM-ICT Centre sensor development is aiming to automate this principle. A series of small lightweight sensor array-based video cameras is mounted along the longwall face. Each camera takes a still image (snapshot) of its section of coal face. When combined they produce a panorama computer image or ‘mosaic’ which shows which marker bands are present. Image processing software is then used to calculate the position of the bands relative to current roof and floor. This is translated into a correction signal and fed into a control system which alters the shearer’s position.

LINK
Dr David Hainsworth +61 7 3327 4420 [email protected] Dr Chad Hargrave +61 7 3327 4523 [email protected]

Ground penetrating radar (GPR)
Beneficial as the thermal infrared and optical methods are, you only know if you have gone out of the seam once the shearer is already cutting foreign matter at the boundary of the seam, so there will inevitably be some noncoal material in the extracted product as the corrections are applied. The beauty of GPR is that it can see through an amount of roof and floor material so operators can measure directly how close the shearer picks are to non-coal material. It can tell the difference between coal and rock from a distance of up to 1m, allowing a shearer’s ‘driver’ or automation system to alter course before foreign rock is struck. Rather than ‘looking’ ahead into the seam, the GPR penetrates material at right angles (into the roof and floor of the seam) thereby
e a rt h m a t t e r s MAR / APR 2007 9

INTERVIEW

Interview
It seems Beltana is a most progressive coalmine, mainly because you are so advanced with sensing and automation. Why has the mine decided to pursue this path so vigorously?
Beltana started longwall production in 2003 after the closure of the adjacent South Bulga mine. South Bulga was a strong supporter of automation but technologies just did not exist to allow South Bulga to take advantage of higher levels of automation. The initial driver for automation at South Bulga was to remove the workforce from the dusty workzones mainly on the tailgate side of the shearer. Beltana is a world leader in longwall automation but a mine can only run automation if it has high standards in all areas such as engineering, maintenance, training, industrial relations, community consultation, etc. Automation is almost like the cream on top of a multilayer cake of high standards and good people.

How has that progressive (even aggressive) approach to sensing and automation translated into efficiency?
A good comparison is the 2005 annual production figures for all underground longwall mines. Beltana uses 1994 vintage equipment first used at South Bulga and produced 7.050Mt ROM (run of mine). The second highest producing mine in the country produced 4.8Mt. Other mines with higher capacity and newer equipment came nowhere near Beltana. While there are many factors that influenced this result the positive attitude to automation across the entire workforce is a major influence. The 2006 production figures have not yet been released but I feel a similar result will show that Beltana is first and Daylight is second.

JASON STARR

Xstrata Coal’s sensing and automation guru, Peter Henderson, tells e a rt hma t t e r s that he can see a fully ‘sensed’ future for mines

Although Beltana has gone down the automation route, this has not precipitated a reduction in employees. How has this worked?
There are many jobs that keep a longwall mine operating. Our longwall automation strategy is to have on-face observation of an automated longwall. The machines do the repetitive tasks very well and humans like to handle exception or error conditions. So the normal production cycle is automated but closely observed and

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adjusted by the technicians. This has resulted in higher production levels which then leads to a need for higher mine development rates, higher maintenance required on the machines because they wear out in proportion to tonnes mined, and extra mine support activities such as conveyor belt work and services support. All this has resulted in extra employment.

complication of underground mining is that the electrical equipment must be explosionprotected. The current process to certify that electrical equipment is explosion-protected is very expensive, time consuming and bureaucratic. Governments need to streamline this process so that new sensors and other technology can be accessed by the mining industry.

new bigger more efficient operations have opened near Singleton and Mussellbrook. Until someone can perfect cold fusion coal will power the Hunter.

What’s next? What is Beltana and Xstrata Coal planning next in terms of sensing and automation?
Longwalls overall have very poor basic mechanic reliability compared to other surface industries. I believe improvements in machine heath sensors and high speed data networks will allow algorithms to detect failure modes and slow down or even stop the equipment before it has a major failure.

What have been the most significant advances in sensing and/or automation in mining in the past five years?
The introduction of the inertial navigation system (INS) to the longwall has by far made the biggest impact. It has enabled automation that was only dreamed of in years gone by. This sensor has allowed the automation of the shearer ranging arms to finally be accurate enough that the technicians now accept that the shearer will produce a better cutting horizon than they ever could. Also the navigation aspect of this system has allowed us to automatically control overall longwall steering without impacting on production. Because the longwall is one big machine over 260m long all the moving parts have lots of tolerance. The INS surveys the face alignment and geometry and then the algorithms developed by the CSIRO ‘correct’ the face alignment and steering.

Do you think the prospect of a fully ‘sensed’ and automated mine is a reality in the next, say, 10-20 years?
My strategy is to remove the people more and more from the hazardous area and change their roles to observation and correction. I think it is unlikely that all people will be removed from all parts of a mine in 20 years. It is possible that within 10 years people can be removed from an operating longwall face but they will still be underground close to the longwall machine for quick response to exception conditions that only humans can handle.

PETER HENDERSON
Born in 1963 in Cessnock, Australia EDUCATION 1983 1985 1986 1993 1999 CAREER 1980 - 1997 1997 - 2003 2003 - 2006 Electrician, Electrical Engineer Pelton / Ellalong Collieries Mine Electrical Engineer South Bulga Colliery Mine Electrical Engineer Beltana No1 Mine Electrical Trades Certificate Electrical Engineering Certificate Certificate of Competency as a Mine Electrical Engineer Bachelor of Computer Science, University of Newcastle Master of Technology, Deakin University

In world terms, would you say Australia is the leader in mining ICT and automation?
I visited a number of large producing mines in the USA during 2006 and found that in general they are miles behind Australian longwall mines in terms of automation. The US mines are all keen to flow the path Beltana has taken but they don’t know how. I was amazed at the strength of the unions in these US mines; they are that strong that the union decides who does what job, on what shift, and management just stands back and watch. They have to overcome these industrial issues before they could even consider the introduction of high levels of automation. San Juan mine in New Mexico is the exception and they will introduce some of this technology over the next few years. The German coal industry has sent a team to Beltana to look at the automation and they are also keen to introduce our systems into their mines.

Are you using knowledge, skills and innovation in sensing and/or automation to reduce emissions from coalmines, or deliver any other environmental improvements?
All the major drives in a longwall mine are powered by electricity at voltages up to 11000V. It is Xstrata’s policy to always investigate the most energy efficient motors or drive systems. We have also planted thousands of trees on company land that was previously farm land or overburden from old open cut mining. Investigations are now underway to generating electricity from the methane gas released during mining.

2006 - present Engineering Coordinator Beltana Highwall mining POSITIONS 2007 Member of Engineers Australia, and National Register of Professional Engineers (MIEAust CPEng)

Is enough being done by science, industry and government to advance the disciplines of sensing and automation, in education and industry contexts?
Automation of mining equipment can only occur if good sensors are available. If we are to continue improving automation then new and better sensors are a must. An extra

You have grown up in the Hunter Valley – how have the region’s coalfields changed in significance?
Coal has always been king in the Hunter and will continue to be a very important industry. As the mines closer to the coast have closed

e a rt h m a t t e r s MAR / APR 2007 11

INTEGRATED SAFETY SYSTEM

Making mines safer

New research is providing a real-time roof monitoring system to save lives and maximise productivity, says Matthew Brace

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new integrated roof collapse monitoring system is making underground coal mines safer and less susceptible to losses in productivity. The system, developed by CSIRO Exploration & Mining (CEM) and jointly sponsored by CEM and Japan Coal Energy Centre (JCOAL), is improving industry’s understanding of roof behaviour and the failure process, and

highlighting early warning signs of imminent roof falls. The project was established by the leader of CEM’s Sustainable Mining Systems Theme, Dr Hua Guo, with the seismic component managed by CEM Project Scientist/Geophysicist, Dr Andrew King. Three key components in the integrated system are a displacement monitoring device, a stress monitoring device, and a system of seismic sensors. The system’s benefits stem from its ability to provide (in real-time) more accurate and comprehensive data on rock deformation, stress change and seismicity from deep inside the rock. These monitoring results help mine engineers and managers to get a much clearer picture of what happens to a roof prior to and during failure, and the likely mechanisms and precise timing of a collapse. According to the current project leader, CEM Principal Research Scientist, Dr Baotang Shen, “numerous studies have been done in the past to investigate roof behaviour related to underground coal mining activities, which have all lead to increased safety and productivity”.

Integrated CSIRO roof monitoring system

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e a rt h m a t t e r s MAR / APRIL 2007

Rock solid science – how the system works
“However, it is still a major challenge to effectively predict an imminent roof fall early enough for preventative actions,” he said. This is where the CEM system comes into its own, by integrating displacement, stress and seismic monitoring in one package.

The three key components which make up the integrated system include a displacement monitoring device, a stress monitoring device, and a system of seismic sensors. The displacement monitoring device used is the GEL Multipoint Extensometer (from GEL Instrumentation Pty Ltd, who contributed to the research). According to Dr Shen it is a “simple yet reliable device, composed of a potentiometer, anchors, and anchor wires”. When the anchors move, this leads to a change of voltage which can then be measured by a readout unit, or logged by a data logger. The stress monitoring device is called a Vibrating Wire Stressmeter. It works on the principle that any change of the stress around the borehole will lead to a change in tension of a vibrating wire in the stressmeter. This, in turn, leads to a change in the wire vibration frequency. Again, a readout unit or data logger will measure the frequency change and reveal the results.

Four types of seismic sensors are used: uniaxial and triaxial microseismic (MS) sensors, acoustic emission (AE) sensors and AE transmitters. The system locates microseismic events with an accuracy of 0.2m and acoustic emission events with accuracy of 0.04m. The extensometers and the stressmeters, along with an array of seismic sensors are installed in the roadway roofs well ahead (minimum 100m) of where the actual mining is taking place. The data acquisition component of the system collects the roof deformation, stress and seismic data in real-time and transmits the data to the surface through a communication cable such as an optical fibre cable. The data are then analysed and displayed in real-time on a mine site computer. The monitoring data can also be sent in real-time, via internet, to other off-site research centres worldwide for analysis.

Live tests
To test the system, two field experiments were conducted at Xstrata’s 250m deep Ulan coal mine in New South Wales where longwall mining is the preferred method of extraction. Roof displacement, stress change and seismicity were monitored in several different locations in roadways. “Although the displacement rates are always checked in actual mining practice, they are often not quantified in detail,” said Dr Shen. “We found that the roof displacement rate is an important roof fall indicator as it tells us the trend of the roof deformation, so a roof with accelerating movement is likely to fall soon. “The stress change in the roof is very interesting. It responds to the mining progress remarkably well. When mining stopped over the weekend the roof stress change was minimal but when it resumed on Monday morning, the roof stresses began to vary again almost simultaneously. Prior to roof falls, the horizontal stresses reduce. “Seismic activity intensifies before major roof displacement or stress changes are evident, and subsides in the later stage of roof failure when large roof displacement is visible. “Also, the seismic resonance frequencies decrease during roof failure development. “To identify the key precursors, the total roof displacement and the displacement rate for all the monitored roof locations are examined.” The field monitoring studies at the Ulan mine (the first of their kind in underground Australian coal mines) also identified a number of quantitative and site-specific roof fall precursors potentially useful for roof fall prediction and prevention. Dr Shen said the scientists were “intrigued to see that the stressmeters could even ‘feel’ mining activities as far as 400m away”. The team also noted that roof falls in the mine followed a clear time sequence: first seismicity, then stress change, then displacement.

“This process is believed to be applicable to most roof fall failures,” said Dr Shen, “but the timing and intensity of each stage will vary according to site-specific conditions. Seismicity and roof stress signals appear to provide warnings for the imminent roof falls earlier than the roof displacement signals.”

enabling our geotechnical design people to further understand some of the issues related to longwall mining in this area”. “Xstrata Coal remains committed to working with organisations such as the CSIRO to help test and implement new technology in the interests of the health and safety of our employees. The testing of new technology to more effectively and efficiently help our crews monitor and evaluate working conditions both prior to and during their shift underground, will ultimately help ensure Xstrata Coal maintains the highest safety standards possible,” said Mr Wood.

New warning system
The results of the CEM trials suggest that displacement monitoring alone may not be enough to provide adequate warning of a roof fall because roof damage is likely to have already occurred by the time extensometers show any noticeable deformation. However, once combined with stress and seismic monitoring the results can reliably warn of caving events, and could be part of a mine’s routine safety monitoring. According to the Operations Manager at Ulan Coal, Murray Wood, the project “provided valuable information for the Ulan operation,

LINK
Dr Baotang Shen +61 7 3327 4560 [email protected] Xstrata Coal www.xstrata.com
e a rt h m a t t e r s MAR / APR 2007 13

MINERALOGY

Making sense of minerals
New mineral products and methods have also been developed and are being tested, including carbonates, smectites, epidiote and amphibole. The Predictive Mineral Discovery Cooperative Research Centre (pmd*CRC) and the CRC for Landscape Environments and Mineral Exploration (CRC LEME) are helping to interpret the significance of these mineral maps. And Geoscience Australia is collaborating with the CSIRO-GSQ team on how best to process and use Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) multispectral satellite data for geological mapping in the same area. According to GSQ’s Senior Geologist – Remote Sensing, Mr Mal Jones, the benefits for the exploration industry are significant. “Exploration companies can improve their prospect targeting, enabling more efficient evaluation of their tenements,” he said. “The mineral maps also support the development and evaluation of mineral emplacement models that lead to greater understanding of mineralising systems. “Because the system is remote, all terrains can be covered, no matter how inaccessible or environmentally sensitive.” It is hoped this will re-invigorate exploration activity in Queensland among junior explorers and well resourced companies, and lead to significant new mineral discoveries. These promising early results, combined with strong Queensland Government support, spawned the establishment of Stage 2 of the NGMM project, which involves the collection of a further 16000km2 of airborne HyMap™ data from across the state. This will also develop a prototype version of CEM’s software for mineral mapping processing and web-based delivery for testing by GSQ, available later to all geological surveys. The final report and the GIS maps will be released in July 2007 (Stage 1 – Mount Isa) and July 2008 (Stage 2 – Mount Isa and northeast Queensland).
JOHN HAY/GETTY IMAGES

Mapping Australia: Empowering geologists with more knowledge

Sensing leads the way to an Australia-wide 3D mineral map

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xploration and mining companies are to benefit from recent, long-awaited advances in mineral mapping technologies. The data-gathering systems are becoming available with operational airborne sensors, including the Australian HyMap™ system, providing calibrated hyperspectral Visible to Short Wavelength InfraRed (V-SWIR) spectra from the Earth’s surface. Operational satellite systems are expected within five years. The next step is to take this data and extract the mineralogy, empowering exploration geologists with it, so they can get the maximum benefit from the maps; so they can see what they are really looking at from the mines-scale to the continental-scale. This has been a major challenge mainly because data itself is compromised by natural factors such as vegetation cover, and atmospheric and solar effects. Also, it has been so expensive that only the cashed-up resources giants have been able to consider it. Now CSIRO Exploration & Mining (CEM) is developing solutions with its Next Generation Mineral Mapping (NGMM) project. The project’s aim is to develop mineral mapping capabilities so that they become a standard part of the pre-competitive geoscience data offered by the government geological surveys. To do that, scientists are working with geological surveys across Australia to research and develop hyperspectral mineral processing

software, mineral product standards, geological case histories, efficient web-based information delivery and technology transfer systems that can be efficiently accessed and valued by all exploration companies. According to CEM Geologist and Stream Leader for Spectral Sensing, Dr Tom Cudahy, “NGMM aims to empower the exploration industry with mineralogy”. “The vision is a mineral map of Australia which, when combined with the HyLogging™ of every drill core’s mineralogy, can provide a 3D mineral map of the continent.”

Origins out west
NGMM falls within the Minerals Down Under (MDU) initiative but its origins are in the Kalgoorlie goldfields where in 2005 a MERIWA research project (M370) was established to create mapped mineral products that were accurate, reproducible and traceable. In 2006, NGMM established the first stage of the mineral mapping project with the Geological Survey of Queensland (GSQ), which plans to assess the value of mineral mapping for exploration around Mount Isa. More than 8000km2 of airborne HyMap™ data were collected from five structural corridors, and processed using CEM’s software. White mica and kaolin processing methods generated for the M370 project were successfully applied to the Mt Isa HyMap™ data, which revealed exciting new information about regolith and alteration patterns, subsequently validated by a field campaign.

LINK
Dr Thomas Cudahy +61 8 6436 8630 [email protected]

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e a rt h m a t t e r s MAR / APRIL 2007

SAFETY CONTROL

Sensors add value
A pleasant surprise met scientists working on solving a sand mining dredge problem
combining bow-mounted sonar sensors and GPS data. So the sonar sensors had now proved valuable in measuring both pond depth and rope position. “When the dredge approaches the limit of its swing, one rope passes under the bow sonar and is detected. The GPS heading is recorded simultaneously and the location of the rope is calculated using the known geometry of the dredge and cutter,” Dr Cavanough said. “The same happens at the opposite extent of the swing. From then on, the system can track the location of the cutter and ropes, and activate an alarm if a collision is imminent. “The system can also accommodate changes in the anchor position because it automatically updates each time the dredge swings to the limit of the slew. No manual inputs are required when the anchor positions are changed.”

In solution: Answers found to make sand mining safer

Monitoring lean

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ecent sensor system trials proved that valuable new information can be obtained from the novel use of existing technology A team of CSIRO Exploration & Mining (CEM) scientists was working on a dredge research and monitoring project with the sand mining company Consolidated Rutile Limited (CRL), a subsidiary of Australian mining company, Iluka Resources Limited. The objective of the project was to develop, install and trial a system to monitor all of the critical sensory activities required if the dredge was controlled remotely, and to provide a high level design and plan for installation of a dredge remote control system. According to CEM’s Stream Leader for Metalliferous Mining, Mr Jock Cunningham, the trials “proved that off-the-shelf instruments can be used to measure things for which they are not specifically designed, thereby providing new applications and information”.

processing thickener tanks were trialled and shown to be successful in measuring the depth of the pond. They also provided a graphical display of the sonar intensity scan which was useful to interpret the nature of the material at the bottom. “Even though at first it looked difficult to measure pond depth using this equipment, which is made for a different application, it proved successful and gave us the bonus of added information,” said Mr Cunningham. Pond depth information, sonar plots and alarm warnings were displayed on a computer screen near the dredge operator, giving a clear ‘picture’ of the pond bottom and mine face.

The project also developed a non-contact method to simultaneously measure the depth (the height above the deck) and location of the spuds using scanning lasers. Two spuds are mounted at the stern and driven into the bottom of the pond to ‘walk’ the dredge and to provide a pivot point about which the dredge sweeps. Unintended operation can cause the spuds to slip, stick or even shear off, causing significant production delays and damage. One laser, mounted to scan vertically, was used for each spud. The system also measured the angle of lean in the fore-aft direction and can provide an indication of whether the spud was leaning significantly in the port-starboard direction. The positions of the spuds were displayed on the computer screen near the operator. “It’s very satisfying when we find solutions to problems through using equipment designed specifically for that purpose, but when we find technology has additional, unforeseen benefits …that’s a major bonus,” said Mr Cunningham.

Maximum control
Mining is carried out by the operator sweeping the dredge back and forth across the pond in a regular arc about an anchored point. The front of the dredge is swept using two steel ropes that are connected between the submerged cutter and anchor points either side on the shore. The operator controls this movement by shortening one line while lengthening the other in order to swing the nose of the vessel. They must be careful to avoid running over the ropes with the cutter. CSIRO’s Dr Gary Cavanough, who supervised the trials, conceived an idea to measure the position of the slew ropes accurately by

Depth gauge
CRL was using a 50 tonne dredge floating on an artificially created freshwater pond. The depth of mining within the pond was set at approximately 15m below water level, and the production rate was between 3000 and 4000 tonnes per hour. A series of sonar devices that were designed to measure the depth of slurry in mineral

LINK
Jock Cunningham +61 7 3327 4699 [email protected]
e a rt h m a t t e r s MAR / APR 2007 15

IN THE FIELD

Shake, rattle and roll

Going underground: CSIRO scientists succeed in Japan, despite the elements

Electronics engineer Stuart Addinell tells Matthew Brace about a groundbreaking trip to Japan

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xploration and mining scientists do not just need large brains and considerable vision; they need more than the average human quota of courage and resilience too. This was proved recently when a CSIRO Exploration & Mining (CEM) team flew up to the small fishing village of Kushiro on the eastern coast of Japan’s northern island of Hokkaido. Little did they know they were in for an earth-moving experience. The team consisted of CEM electronics engineers Stuart Addinell and Lance Munday, with Tai Johnsen in hardware support and Olivier Fillon and Kerstin Haustein looking after the software installation. The team was conducting the final stages of the five-year Nexsys™ project, a collaboration between CEM and Japan Coal Energy Centre (JCOAL).

Nexsys™ Real Time Risk Management Project involves a unique mine communications and data management system, which is delivering great advances for mine safety and efficiency. It is a key element in developing hardware systems to bring Ethernet-based high-speed data communication to underground coal mines that can be used during all phases of mine operation and emergency conditions. “Kushiro Coal Mine (KCM) is the last operating coal mine in Japan and is used extensively for trialling new technology. Our aim was to install the latest versions of hardware and software systems that we had been developing,” said Mr Addinell. “With funding from JCOAL and other industry partners, our team has developed a suite of products that allows underground coal

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KEVIN WILTON

producers greater access to modern technologies such as WLAN, web-based cameras, personnel and equipment tracking systems, and sophisticated software systems for monitoring real-time critical safety aspects of mining operations.” While carrying out the latest implementation and tests in Japan during the November 2006 trip, the team was bluntly reminded of the necessity for such safety systems. “The earthquake came at around 5pm,” said Mr Addinell, “and it was the timing that was so concerning, because we had only just arrived back at the surface from a day in the mine. “I hate to think what it would have felt if like if it had happened just slightly earlier and we had been underground. “We had been about 300m down in the mine, and what makes KCM ever more unusual is that it extends out under the Pacific Ocean by several kilometres – out in the direction of the earthquake’s epicentre.” Mr Addinell is no stranger to mines – as well as being a electronics engineer for CEM he has been a member of the Queensland Mines Rescue Service Inertisation team, the same team that flew to West Virginia in the United States in 2003 to help extinguish a coal seam fire in the Loveridge coalmine. “I have been underground many times in Australia and the US but being so far underground and beneath the ocean was somewhat of a novelty.” But there was no guarantee of safety even on the surface. As the earthquake had happened out at sea, it was only minutes before the tsunami sirens were wailing across the mine and the little fishing village. “They sounded like air raid sirens and the mine control room told us we could expect a tsunami in about an hour. When it arrived it was not several metres tall as we had imagined but 30cm, but nevertheless the threat was very real.” In Japan even when the earth is not shaking and sending tsunamis to threaten fishing villages, mine scientists and engineers are still frequently tested by the wilds of nature.

This is particularly common up in Hokkaido. The island sits between 41oN and 45oN and its proximity to the wastelands of Siberia means Arctic winds and perishing winter weather can blow unrestricted across the Russian plains and over the icy northern extremes of the Sea of Japan. And off the island’s eastern coast are thousands of miles of Northern Pacific Ocean, with barely any landfall until Russia’s far north Kamchatka Peninsular and the Bering Strait between Russia and Alaska. During a previous trip in March 2006, the above ground temperatures were down to 12oC, quite a shock to the system for the scientists who had arrived fresh from a steamy Brisbane summer. Underground the temperatures plunged to 20oC with windchill as the ventilation system channelled frozen air at high velocity through the roadways. “We had to limit our exposure to these temperatures underground to about 20 minutes working and about 20 minutes resting in a heated timber hut that was placed nearby,” he said. “We operated like this for about three days while we were installing and testing our equipment underground.”

Roughly 1.5m of snow lay on the ground and was added to by regular falls, and just beyond the harbour large ice sheets lay on the ocean. Despite the planet throwing just about everything it could at the team, they completed their work and made it home. “Despite some unusual challenges the field trip was a resounding success and was a great opportunity to showcase CEM’s expertise and innovation on an international stage,” said Mr Addinell. The experience may prove invaluable as the next stop for the technology could be China, a nation blighted with ferocious weather similar to Japan’s. Unlike Japan, China has very high coalmine fatality statistics and is well suited to take advantage of this type of technology, increasing both mine safety and mine operational awareness. Meanwhile the technology is making Australian coalmines safer too. It is installed at the Grasstree underground mine north of Emerald in Queensland, and the Beltana High Wall mine just outside Singleton in New South Wales.

LINK
Stuart Addinell +61 7 3327 4171 [email protected]

e a rt h m a t t e r s MAR / APR 2007 17

Project Engineer Jeremy Thompson is working at the cutting edge of mine sensor communication

Ask our scientists
What is your academic background? I graduated with a degree in Engineering (Software) from the University of Queensland in 2004. The degree also provided a complete grounding in general engineering skills, which has been extremely beneficial while working in a broad engineering environment like CEM Mining Automation Group. How did your path lead to CSIRO? University of Queensland requires engineering students to complete a number of days under the supervision of a practicing engineer. I was lucky enough to have a contact in CSIRO and had always found the description of their projects to be really interesting. I thought CSIRO would offer me the ideal environment to get some exciting engineering experience. I joined the CEM Mining Automation Group in 2004 as a vacation student and apparently they liked me so much they didn’t want me to go so I have continued on as a project engineer. How do you describe your position? The best description is a Project Engineer because my work covers more than just straight software development. A project will often require a range of different engineering skills, for example designing and constructing the hardware for controlling a sensor and also developing the processing software for it. What interesting and important projects have you worked on? The Landmark longwall shearer guidance system involved developing the real-time visualisation of mining equipment. This involves highly complex sensor communications, processing, display and integration, as well as developing crossplatform graphical user interfaces customised for industry. The Landmark automation project is focused on achieving a more consistent and safer production environment. I am also involved in research in the sensor environment as part of a team investigating how software can interface with a range of high-end sensors, including laser scanning range sensors, inertial navigation systems, and thermal infrared imaging. What are you working on today? Right now my work is focusing on research into emergent technologies, such as intelligent processing of video streams for mining automation applications, algorithm development for fusion of sensor data for increased system performance, and integration of emergent web-based services into a classical mining environment. New technology means that we can do things faster and more accurately. This means we are able to find solutions to previously insurmountable problems: for industry that means higher, safer and more consistent production. Why is this such an exciting time to be in this field? The advance of technology allows us to do things better, faster and cheaper, and gives us the freedom to apply technology in new areas. For example where we previously required a bulky, expensive and complicated system adapted from a standard PC, we can now use a cheap single board computer to process sensor data. In the Landmark project it’s been really exciting to be able to take new technology and apply it to the problem and actually see the results on the ground at the mine sites. What do you see as the future for sensor technology in exploration and mining? Sensor technology has always played a major role in exploration and mining and with the advancement of technology this role is only going to expand. Coupled with the new sensor technology is the advancement of sensor data processing because in the end it’s what you do with the data that counts. I think that the Landmark project is a great example of how a wide range of sensors, some of which had previously never been considered in a coal mining context, can be integrated and fused to produce excellent results. Where do you want your career to go now? I really enjoy working at CSIRO and in particular the CEM Mining Automation Group as it has a wonderful working environment. In the future I would like to refine and extend my skills and I would also like to start bringing my own project and research ideas to the table. What would be your dream project? In a lot of ways I am already living the dream as one thing I couldn’t see myself doing was writing code day in day out. My current projects give me the opportunity to work with new and exciting technology in interesting and challenging environments.

LINK
Dr Jeremy Thompson +61 7 3327 4769 [email protected]

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e a rt h m a t t e r s MAR / APRIL 2007

JASON STARR

Publications
A selection of key CSIRO Exploration & Mining scientific papers

Numerical investigation of the effect of heterogeneous permeability distributions on free convection in the hydrothermal system at Mount Isa, Australia
Kuehn, M., Dobert, F.*, and Gessner, K Fluid flow patterns due to free thermal convection in permeable rock masses have been investigated for the 3D geological architecture around the Mount Isa lead–zinc–silver and copper deposits. Key results for the range of parameters explored here are: (1) Flow pattern and temperature distribution in stratigraphic units with homogeneous permeability are similar to those in units with the same average permeability in a heterogeneous distribution. (2) The geometry of one highly permeable stratigraphic unit governs fluid flow to an extent where it spatially attracts a convection cell, irrespective of the volume of adjacent permeable units. (3) Even in a complex and heterogeneous system with patches of low permeability along the fluid pathways, the Rayleigh number can be used to determine whether free convection will occur or not. Numerical simulations in 3D of coupled fluid flow and heat transfer were carried out using the finite difference computer code SHEMAT. Two different levels of permeability heterogeneity were investigated. Firstly, heterogeneity introduced by stratigraphy and

secondly, various heterogeneous permeability distributions within geological units. Further complexity was created by defining patches with very low permeability within those stratigraphic units. The results show that free convection in hydrothermal systems is highly sensitive to the 3D permeability distribution in the geological architecture. Earth and planetary science letters 244, 655671. 2006.

wavelength/thickness ratios, nonconcentric fold shapes, and axial plane crenulations. This contrasts with classical folding theory that emphasizes large mechanical contrasts between a weak matrix and strong embedded layers leading to periodic concentric fold systems with no formal link to axial plane structures. Geology 35(2), 175-178. 2007.

Thermodynamics of folding in the middle to lower crust
Hobbs, B., Regenauer-Lieb, K., and Ord., A. A new theory of folding is described in this article, in which a team of CSIRO scientists show that the folding process in the middle to lower crust differs significantly from the classical Biot approach. Instead of a single dominant wavelength, folds develop at a range of scales. Folds formed at the kilometre scale are governed by the thermal diffusivity, but folds also develop at smaller scales governed by the heterogeneous distribution of thermal conductivity arising from fluctuations in mineralogy. The abstract states: We show that dissipative processes involving thermal-mechanical coupling produce fold systems with characteristics observed in the middle to lower crust. These comprise folds in layers with little strength contrast, scale invariance, no strict periodicity, small

Optimal and robust noncausal filter formulations
Einicke, G. A. The paper describes an optimal minimumvariance noncausal filter or fixed-interval smoother. The optimal solution involves a cascade of a Kalman predictor and an adjoint Kalman predictor. A robust smoother involving H/sub /spl infin// predictors is also described. Filter asymptotes are developed for output estimation and input estimation problems which yield bounds on the spectrum of the estimation error. These bounds lead to a priori estimates for the scalar /spl gamma/ in the H/sub /spl infin// filter and smoother design. The results of simulation studies are presented, which demonstrate that optimal, robust, and extended Kalman smoothers can provide performance benefits. © 2006 IEEE. Reprinted, with permission, from IEEE Transactions on Signal Processing 54(3), 1069-1077. 2006.

World authority praises new geology publication
A newly released volume called the Society of Economic Geologists (SEG) Special Publication 13, Nickel Sulphide Deposits of the Yilgarn Craton; Geology, Geochemistry and Geophysics Applied to Exploration, is edited by CSIRO’s Dr Stephen Barnes. The volume has received praise from the world’s foremost authority on the geology and origin of nickel-copper-platinum group element deposits, Dr Anthony J. Naldrett. Dr Naldrett said the volume “represents an excellent, timely summary of our understanding of these deposits and their associated rocks, along with the methods developed over the last 40 years for their exploration”. “It will serve as the ‘Bible’ for those exploring in other areas for similar deposits. Publication is particularly timely, 40 years after the initial discovery, since exploration and geological mapping in the area is waning. In a few years, much of the intimate understanding of this deposit style could have been lost. This publication will preserve this understanding for future generations.” Chapter 1 outlines the story of the emergence of the eastern Yilgarn Craton as a major global nickel province. It is written by Dr John Hronsky and Dr Richard Schodde, formerly of WMC Resources and now with BHP Billiton Ltd. Chapters 2 and 3 by the Editor provide the geological underpinning for understanding the nature and distribution of komatiite-hosted nickel sulfide deposits. Chapter 4 by Dr Ben Grguric and co-workers, formerly of WMC Resources and now with BHP Billiton Ltd, includes accounts of the giant lowgrade Mt Keith and Yakabindie deposits. Chapter 5 is an account by Dr Charles Butt and Dr Ernie Nickel of CSIRO Exploration & Mining (with Dr Nigel Brand of ioGeochemistry Inc) of the consequences on nickel sulphide deposits and their host rocks of prolonged and complex lateritic weathering. Chapter 6 is an account by Dr Bill Peters of Southern Geoscience Consulting of the geophysical methodologies in common use in nickel exploration in Western Australia. Chapter 7, written by Dr Mick Elias, also formerly with WMC Resources, a consultant with several decades of experience in nickel laterite deposits, covers the geology and mineralogy of the large nickel laterite deposits which have come into prominence with the advent of high pressure acid leach (HPAL) processing technology in the late 1990s. The volume can be ordered online at https://store.agiweb.org/seg/pubdetail.html? item=SP13
e a rt h m a t t e r s MAR / APR 2007 19

www.csiro.au
is the 50th element of the Periodic Table. It is silvery-white and one of the few metals that has been used and traded for more than 5000 years. One of the oldest uses is its combination with copper to form bronze. Its success has come from its advantageous combination of properties – a low melting point, significant malleability, and resistance to corrosion and fatigue. It can resist distilled water, sea water, and soft tap water, but is unable to withstand strong acids, alkalis, and acid salts, and if oxygen in solution is involved the destruction is faster and more severe. Tin is also non-toxic, readily alloyed with other metals, and easy to recycle. Tin is found mainly in the ore cassiterite (SnO2), although small amounts are recovered from sulphide minerals such as stannite (Cu2FeSnS4). The metal is obtained by reducing SnO2 with carbon in a furnace at between 1200°C and 1300°C.

Tin

Sn
Ordinary tin is malleable (yet brittle when heated), ductile, and has a highly crystalline structure. There are two forms of tin, the characteristics of which are dictated by temperature. Above the 13.2°C figure it appears as white (or ∝) tin and possesses a tetragonal structure. When cooled below 13.2°C it transforms into grey (or ß) tin, which boasts a cubic structure. This ‘metalmorphosis’ (known as ‘tin pest’) was first seen in Europe where the tin pipes of the mighty organs in churches and cathedrals appeared to develop growths on them. It was eventually discovered that - rather than an act of God, the Devil or a biological disease of some sort – this change was caused by the altering of impurities such as aluminium and zinc.

Tin has had a long history as a Tin popular and useful metal, chiefly • was found in Egyptian tombs, and as an outer coating applied to later mined and exported from other metals, such as iron, lead, Cornwall in England zinc and steel, to prevent corrosion • was so popular that it was traded and other forms of chemical decay.
on the London Metal Exchange from the market’s beginnings in It has been employed to plate steel 1877 and make ‘tin cans’ to preserve foodstuffs (hence the phrase • in small amounts is found in food ‘tinny’ for a can of beer), and it can cans and is harmless. The agreed limit of tin content in US foods is be highly polished. However, the 300 mg/kg largest uses for tin are the production of solders and for tin • was used to coat steel in the massproduction of the popular tin whistle plating to make iron and steel products more attractive. • price rocketed on the back of a bull market, rising by 150 per cent Major tin-producing countries between August 2002 and May include China, Malaysia, Bolivia, 2004, and then another 73 per cent Indonesia, Thailand and Brazil. in 2005. The price on February 28, Australia’s production collapsed 2007, was US$13,545/tonne between 2002 and 2004 to just • alloys include soft solder (tin and 800 tonnes of tin-in-concentrates, lead), type metal (tin, lead and according to the Australian Bureau antimony), fusible metal, pewter, of Agricultural and Resource bronze, bell metal, Babbitt metal, Economics. In 2004 Australia White metal, die casting alloy, and phosphor bronze produced 1306 tonnes from its tin mines. • miners in Australia were originally

More than 85 per cent of Australia’s tin resources are at the Renison Bell deposit in Tasmania but the mine has been in care and maintenance since October 2005.

expats from Cornwall

for your

diary
AMEC National Mining Congress
7 – 9 June 2007 Perth Convention Exhibition Centre
A number of concurrent sessions will include company presentations with the following themes: • Commodity focus – iron ore, gold, nickel, zinc, copper, uranium • New discovery case studies • Technical, environmental, socio-economic challenges in international exploration • Emerging IPOs Core technical sessions will feature issues that impact geologists and operational staff within mining and exploration companies, including: • CSIRO seminar on innovative high impact research • Geochemical practices • Environmental and land access issues • Regulatory issues More information: www.ameccongress.com.au

AusIMM New Leaders’ Conference 2007 ‘Mining – The Big Picture’
2 – 3 May 2007 Sofitel, Brisbane
The conference will take a big picture view of the mining industry and highlight situations, locations and innovation that tomorrow’s leaders may encounter. Possible topics include multidisciplinary inputs to mining, legal obligations from statutory requirements to socioenvironmental aspects, technical problems and solutions, development of new technologies during a boom, planning involved in greenfield sites, project risks, growth strategies and corporate mergers, infrastructure, logistics, safety, buffering against an industry downturn, and dealing with climate change concerns. More information: www.ausimm.com

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e a rt h m a t t e r s MAR / APRIL 2007

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