Whittle Programming Pty Ltd have developed a unique new software
program for mining companies to obtain the cut-offs which
maximise the value of a mine.
The theory of increasing the net present value (NPV) of a mining project by optimising cut-off grades has been in circulation for some time. But until Whittle Programming developed software for this theory to be realised, there were no practical tools available.
Taking theories developed by Kenneth Lane, author of The Economic Definition of Ore (1988), which detailed the NPV theory, Whittle Programming advanced the concepts considerably and created a range of software that has changed the operations of the mining industry around the world.
The latest software created by the company was developed over a three year period. Called Opti-Cut, it is applied to a mine that has an operating life of more than two or three years. When provided with a scenario describing the economic conditions, mining and processing throughput capacities and the resource to be mined, Opti-Cut will determine the most efficient way to mine and obtain the best quality ore in order to maximise the NPV. It will also manage stockpile utilisation and mining and milling throughputs.
Raising the processing cut-off above the marginal cut-off in the early years of a project can increase the average grade into the mill and, consequently, the cash flow. This increased cash flow in the early years can more than compensate for the consequent reduction in cash flow at the end of the project.
If the material between the marginal and the raised cut-off is stockpiled for later use in the project, this can increase the NPV still further, even after allowing for extra handling costs and possible reduced recovery.
Opti-Cut software will run with data from a generalised mining package, from Whittle Four-D, or stand-alone from a manually produced mining package. The software is capable of handling multiple cut-offs, rock types, processing methods and stockpiles, and has been acclaimed by the world's major mining companies as an important innovation in natural resource procurement.
Fastflo to optimise complex
fluid flow dynamics
Advances in computing mean that complicated industrial problems
involving fluid flow, temperature and chemical reactions,
can now be tackled on workstation computers, with the appropriate
software. Available from Compumod Pty Ltd, Fastflo is a new
software for solving complex fluid flow problems common in
the metals and minerals processing, as well as in engineering,
manufacturing and food processing industries.
The research and development team lead by Dr Nick Stokes at the CSIRO Division of Mathematics and Statistics gave priority to solving problems that could not be adequately solved using existing software, such as the realistic three-dimensional modelling of mineral processing, which can be prohibitively time consuming.
The team developed a high speed computing core section using modern algorithms to overcome the solution time problem, while other modules treat special applications such as flows with bubbles and suspended particles, flows of liquids involving melting or freezing, and flows where liquids are reacting chemically. These applications are common in metals and minerals processing where for example, flows of molten metal are frequently encountered.
Mapping a model of the real
world
Ever since primitive man first drew lines in the sand to
put his fellow man on the right track, maps have been important
to us. Today, that sand has been processed into silicon chips
and the lines are drawn on computer screens to create maps
used by modern people in many walks of life.
But modern mapping is a complex business, so the enormous amount of mapping data must be co-ordinated and integrated into a system - a geographical information system (GIS). Dr Robert Starling of Genasys II Pty Ltd spent two years developing GenaMap. It is, as he puts it: "A system to 'model' the real world, graphically and quantitatively, in 3 dimensions and time." This was the first GIS created for use on the sophisticated UNIX multi-computer platform operating system.
GenaMap incorporates a seamless topological database capable of handling very large data sets and sophisticated geoprocessing algorithms for spatial analysis. It is now used by major multinational companies for oil exploration activities. In Australia, many municipal councils use the software to help map out projects such as garbage collection routes and disaster control planning.
Australia's Commonwealth Environmental Planning Agency's new national State of the Environment reporting system will be based on GenaMap. This reporting is aimed at documenting both positive and negative changes to the conditions of Australia's atmospheric, freshwater, marine and urban environments.
Multi-source geological data
integration software
Developed by Stuart Nixon in 1988, ER Mapper is the most
advanced image processing software in the world for processing
earth sciences datasets from varying multiple sources. Commercialised
in 1989 by Earth Resource Mapping Pty Ltd, ER Mapper runs
on X-Windows based Unix workstations and can integrate raster
images with vector GIS/LIS data, and has an easy to use graphical
interface. ER Mapper is a breakthrough in interactive image
processing. The easy to learn software includes a complete
library of algorithms to process a wide variety of data, including
seismic, aero magnetic, aerial photographic, satellite and
radar data.
The extensively used, highly flexible, and powerful image processing system has many applications including agriculture, forestry, land information, disaster management and recovery, mineral exploration, oil and gas, oceanography, surveying and water resources.
Detecting magnetic rocks
with a portable meter
Rocks containing ilmenite, haematite and magnetite have very
slight magnetic properties, which can give vital clues regarding
the mineral ore bearing potential of a given site. Until now,
measuring this magnetism presented time consuming problems
for geologists and prospectors.
A new pocket-sized instrument commercialised in 1992 by Geo Instruments Pty Ltd made the process faster and more efficient. The GMS-2 Magnetic Susceptibility Meter is the world's first combined analog and digital meter. Held against the rock surface, it automatically records the magnetic properies of the rock. Because of advanced microprocessor technology, this data can be transferred to a computer, either in real time or at a later stage for storage and further analysis, if required. And because it analyses digital data 2 times per second and the analog data 10 times per second, it provides the user with virtually instant results in the field. When high magnetism is sensed, the GMS-2 gives out a high-pitched audio signal - one of the many features of the meter. The meter is usually employed in the field before magnetic surveys, to measure outcrops of surface rocks or to measure the drill core at close range, to determine from what rock types and at what depths the observed magnetic responses have originated.
The innovative instrument can also be used for biological and agricultural research purposes.
Superior transient electromagnetic
mapping
Electromagnetic (EM) methods are employed in geophysics to
map subtle changes in electrical conductivity below the surface
of the earth. These readings are used by geologists to locate
deposits such as massive sulphides, which are good electrical
conductors compared with the rocks around them.
However, one of the major problems encountered with using EM is the presence of weathered overburden covering the deposits. Because the overburden may itself be electrically conductive, its EM response can obscure the detection of the deposit beneath it.
Investigations into overcoming the problem by a team led by Dr Ken McCracken at the CSIRO Division of Mineral Physics (later Exploration Geoscience, and now Exploration and Mining), led to the development of SIROTEM, an instrument based on the transient electromagnetic (TEM) technique. The original instrument developed in the late 1970s was 50 times more sensitive than other TEM instruments available at the time.
After continuous development, the much improved SIROTEM Mk3 was released in 1990. This latest version, manufactured by Mineral Control Instrumentation Ltd and marketed worldwide by Geo Instruments Pty Ltd, is considerably more versatile than the original instrument. Adapted also for shallower mapping of conductivity changes in the first 50 metres below the surface, the new model has also been used to map salinity and monitor potential groundwater contamination around waste disposal sites. The portable instrument is a combined digital transmitter and receiver with internal solid state memory and a large LCD screen, housed in a rugged compact carrying case. With two microprocessors, the instrument has considerable data processing power, to provide the user with data and statistics in the field.
SIROTEM has an impressive global user list that includes large mining companies as well as the national geological survey organisations of Australia, United Kingdom, United States, Germany and China.
Qualitative evaluation of
materials by SEM
A unique system has been developed for the automated mineralogical
examination of ore samples and concentrates. Based on a scanning
electron microscope (SEM) fitted with energy dispersive x-ray
detectors, it uses image analysis techniques to rapidly generate
reliable, repeatable data for the mining industry.
After initial collaboration in the 1970s with the University of Queensland, the QEM*SEM system was developed with support from the Australian Mineral Industry Research Association (AMIRA), by a team of scientists led by Dr Alan Reid at the CSIRO Division of Mineral Chemistry (now Minerals). It scans specially prepared polished sections of sub-samples, and creates an image of each particle sampled on a computer screen.
QEM*SEM is a fully automated computer controlled scanning electron microscope which can distinguish minerals and their attributes in individual ore particles sampled at any stage of a mineral processing operation. It provides important mineralogical information that enables mineral companies to improve their plant operations, design and feasibility studies.
Apart from selling the equipment, the CSIRO has also set up a mineral analysis bureau to provide services to domestic companies operating or planning mineral concentration plants.
It provides data on mineral type, mineral content, mineral locking information, size and shape of grains, exposed mineral surface areas, mineral liberation and intergrowths, the accuracy of which exceed those from conventional mineral analysis techniques. For the first time, all this reliable data can be obtained automatically, and used to together with other mineralogical and physical information in the development of processing strategies.
QEM*SEM is being used extensively by companies to analyse complex sulphides such as lead, zinc, silver ores; copper ores; copper, lead, zinc ores; nickel ores, as well as tin ores, beach sands, fluvial sediments, coal mineral matter, ash products of combustion and phosphate.
Computer aided open cut mining
Architects and engineers have been routinely using computers
for decades, but it is only recently that the computer has
seriously entered the world of open cut mining, with revolutionary
software programs that assist companies in reducing their
economic risks when mining. Called the Four-D Package, the
software was written by Jeff Whittle in 1987 and co-ordinates
raw data about the geology of the proposed mine, the sites
where the ore has been found and relevant economic factors
about the viability of establishing a mining operation. From
the data the projected size, shape, and locations of the ore
body are worked out and from this information a range of optimal
pits is calculated, typically 40 to 100 with a varying set
of economic ratios, mining schedules and cash flows for each.
Developed by Whittle Programming Pty Ltd the Four-D Package replaces time-consuming and elaborate manual calculations. The information generated by the software can be produced in graphic form allowing management to readily make informed decisions about the economic life of the mine.
Environmental concerns are included in the programming outcomes for Four-D, in particular it can suggest mining operations which reduce the amount of overburden or rock that has to be removed in order to mine a deposit. The program can also indicate the point at which it is more profitable to proceed to underground operations.
The package is used by some of Australia's biggest mining companies with great success. With Four-D Package, miners now have a very proficient tool with which to design open pit mines. Gone is much of the guesswork, and with it comes the security of knowing that economic risks are significantly reduced and therefore investment optimised.
Optimising computer-aided
mine modelling
The mining industry uses computer-aided modelling techniques
to simulate how the rock will behave during excavations. If
they can predict the stability of various types of excavation
before mining begins, a great deal of time, and possibly lives,
may be saved. Computer-aided modelling is also important in
planning both underground and open cut mines, to determine
the maximum amount of ore that can be extracted, without endangering
workers or unnecessarily diluting the ore with the surrounding
waste rock.
CSIRO Division of Geomechanics (now Exploration and Mining) developed graphics software to help the mining industry make best use of these models, feed data and interpret results. Two of these programs are FEMCAD and FEMVUE.
FEMCAD is a powerful program for generating and editing finite and boundary element meshes. The program is an indispensable design tool for civil and mining engineers. FEMVUE is a dynamic program that displays the results of modelling packages and includes unique features such as 3-D stereoscopic vision.
Whereas many graphical postprocessors are tied to a particular hardware configuration, like FEMCAD, FEMVUE is a fully portable program which can operate on a range of hardware from a 386 PC to a supercomputer. The program takes full advantage of the original graphics language of specific systems and produces faster and more sophisticated images. Both of these smart programs are on the leading edge of innovation in their fields.
Transforming 2D pictures
into 3D information
Photogrammetry has been used for over 150 years - it is
a recognised measurement technique for defining or monitoring
the shape of complex structures or shapes. It is used in professions
such as surveying, mining and architecture. It also has potential
in the field of medicine for such things as facial reconstruction
work.
Surveyor Michael Elfick and electronics engineer Michael Fletcher worked with Advanced Design and Manufacturing Pty Ltd, trading as ADAM Technology, to produce a simplified system which transforms two dimensional photographs into three dimensional digital information. This information can then be measured, manipulated or displayed on a computer monitor as perspective illustrations.
The system is called the MPS-2 Three Dimensional Digitiser. Using tried and tested photogrammetric methods, the MPS-2 transforms 2D photographs into 3D digital information. It can utilise simple photographs you can take with virtually any camera. Once the photographs have been taken, the operator uses a stereo microscope to view the photographs and the system will then provide measurement data of any point selected.
MPS-2 uses the revolutionary self-contained microelectronics developed by the company to perform all computations and corrections without the need for multiple computers and screens. Using the system's sophisticated surface modelling software you can then display, manipulate and store the data acquired much faster than was previously possible. The host personal computer used can be virtually any fully compatible MS DOS system, from an early model 'XT' to the latest 486 system.
FRP rock bolts for mine wall
reinforcement
A need for a low cost, light weight, high strength, corrosion
resistant rock bolts for use in long-wall underground mining,
led researchers to look for alternative composite materials
and new moulding techniques. Two years of research and development
involved exhaustive investigation of glassfibre types, resin
compositions, catalysts, fillers, fibre percentages, moulding
temperatures and releasing agents.
Chemical engineer Peter Hastwell, Managing Director of Applied Research of Australia Pty Ltd invented and commercialised the 1.2 metre long fibre reinforced plastic (FRP) rock bolts in 1992. FRP has the same strength of steel, but is a quarter of the weight. It is also resistant to corrosion and can be cut easily by machine excavation.
The development utilises a patented matched-die moulding process, which now allows surface deformations and threads to be formed as an integral part of the bolt during moulding. This world first gives the new rock bolts greater strength than previous FRP bolts which required bonding a thread either by gluing or moulding, resulting in a substantially weaker thread/nut combination.
Coal mines are using the new rock bolts to support the ribs in their long-wall panel extraction method, whilst hard rock mines are using the bolts in areas where corrosion problems render steel bolts ineffective after a few months.
Paging people underground
and on the move
Communicating with miners underground has always been difficult
because of the dependence on aerials, wires or cables underground
which are subject to damage from rockfall or fire. As well,
existing telephone and cable systems can be unreliable and
limited in their coverage.
The PED Communication System is the world's first message paging and control system for underground mines that solves these, and other communication problems. Designed and developed by Mine Site Technologies Pty Limited PED has significantly improved mine safety and productivity, and is now utilised in both coal and metal mines in Australia, Canada and South Africa. Based on low frequency communication, the "through the earth" transmission capability of the innovative system eliminates dependence on extensive leaky feeders or cables underground and achieves reliable, mine-wide coverage.
Messages can be sent directly from people on the surface down to individuals or vehicles, regardless of their location underground. In emergency situations, messages can be broadcast to all units. Personal receivers are integrated with the miner's cap lamp battery. On receipt of a message, the cap lamp flashes and the message is displayed on top of the receiver. In most mines, PED receivers are worn by shift bosses, deputies, electricians, surveyors and other roving personnel. They can receive messages wherever they are underground, and respond immediately to changes in operating conditions.
AutoPED units can be mounted on production, transport and maintenance vehicles.
Many major mining companies have found that in addition to its undeniable contribution to safety, the PED has also proved to be a valuable day to day management communications tool. The same PED transmission system has also been used to remotely control ventilation fans, pumps and underground lighting circuits, and significantly reduce energy consumption and costs.
Mobile miner automatically
mines hard rock
Mining in hard rock has been a complicated cyclic process
punctuated by the need to blast the rock, but now an innovative
mobile mining machine is able to continuously mine the hardest
rock efficiently and automatically.
The Robbins Mobile Miner MM130 was developed to mine mechanically what until now could only be done by drilling and blasting, and to bring increased speed, safety and efficiency to underground mining operations. The extraordinary machine employs disc cutter technology for the most efficient excavation of the hardest rocks. The Mobile Miner's patented cutting system produces a clean tunnel with a flat floor and roof and a variable width. It can tunnel in a straight line, around corners as well as iincline and decline on a 1 in 7 gradient.
Originally conceived by engineer Dave Sugden back in 1978 and subsequently developed jointly by Rick Willoughby's team at Pasminco Limited and engineers at Robbins Pty Ltd, the world's first automatic mining machine which can excavate hard rock is now commercially available.
The innovation is making hard rock mining safer, cheaper, faster and easier.
Three dimensional measurement
of rock stress
The measurement of rock stress provides information that
can be used in predicting how large masses of rock will behave
in the future. This information is critical for people working
in the mining industries. It can help to improve the design
of tunnels and shafts, which can lead to greater safety for
workers and cost-saving methods of production.
In 1973, research scientists George Worotnicki and Robert Walton of the CSIRO's Division of Geomechanics (now Exploration & Mining) set about to develop a device which would provide reliable measurements of stress using the, so-called, overcoming stress relief technique. The results of their two year research was the Hollow Inclusion (HI) Stress Measurement Cell commercialised by Mindata Pty Ltd in 1978. HI Cell measures the three-dimensional state of stress in rock. Primarily designed to measure absolute values of rock stress, it may also be used to monitor stress change.
The Hl Cell is installed into a small hole in the rock and the hollow body of the cell surrounded with an epoxy cement when the cell is at its target depth. After the cement sets, a section of the rock containing the cell is drilled. During this drilling (called overcoring), a cable from the buried HI Cell transmits stress information to a monitor outside of the borehole.
A significant improvement of an existing concept, the Hl Cell from Mindata has been successfully employed for taking measurements in underground coal and metal mines, and around tunnels and caverns excavated for civil engineering projects around the world.
The pump that knows when
to switch off
When Mount Isa Mines Ltd recognised that they were confronted
with huge energy and maintenance costs because of their double
diaphragm dewatering pumps, engineer Paavo Laukannen developed
a prototype pump that would automatically turn off when there
was no water to be pumped. Together with Mine Site Technologies
Pty Limited, the company has now developed an energy efficient,
lightweight and corrosion resistant pump.
The PP50 is the world's first air operated pump which performs only when needed - whether it be dirty water or chemical fluids, the pump will automatically stop working when it is not required. Made from a special engineering plastic, the lightweight new pump weighs just 6kgs. It utilises an "Air over Fluid" positive displacement principle controlled by a magnetic float operated pilot valve, ensuring a complete ON-OFF function. The PP50 is a major breakthrough that will result in significant savings in energy and pump maintenance costs for the mining, agricultural, construction and petrochemical industries.
Small hydraulic fracture
tool tests stress in rock
Knowing the stress in rock at any given place is important
for the design of mining projects. This knowledge can have
a major impact on decisions regarding mining methods, size
and orientation of excavations and the size of supporting
pillars in tunnels.
In 1986, research scientists with the CSIRO's Division of Geomechanics (now Exploration and Mining), James Enever, Michael Wold and Graeme Crawford began working on the world's first small hydraulic fracture system for the measurement of rock stress in small diameter bore holes. Over the next two years they developed the Minifrac System.
Compared with existing methods, the new tool is fast and easy-to-use. It has a test-section length of only 150mm in a 38mm diameter borehole, making it more suitable for selecting test sections in jointed rock than larger tools of similar type. Once the Minifrac device is inserted into the borehole, a straddle packer is inflated which seals off the section to be tested. Water is used to increase the pressure in the sealed-off section until the surrounding rock fractures. A pressure recorder or data logger records the relevant data for later analysis.
The tool and associated equipment is manufactured and marketed internationally as the Minifrac System by Mindata Pty Ltd.
Minifrac has the advantages of simplicity and low cost over other methods of rock stress measurement - and it's size makes it easier and more convenient to use. An intrinsically safe version is available suitable for use in hazardous areas such as underground coal mines.
Smelting technology improves
efficiency and reduces costs
It took a scientific team led by metallurgist Dr John Floyd
at CSIRO Division of Minerals 10 years to come up with a revolutionary
new way to improve metal smelting techniques using top submerged
lancing.
The process, which can be used to treat a wide range of metals including zinc, lead, copper, nickel, tin, antimony, gold, silver and platinum is being commercially developed by Ausmelt Pty Ltd.
AUSMELT is a bath smelting process carried out in a high temperature metallurgical furnace system in which concentrates are fed into a molten bath of slag or matte, while the fuel is burned within the bath to provide the process heat. The submerged combustion principle enables high-heat and mass-transfer rates to be attained and therefore, high production rates per unit volume of the reactor to be achieved.
The key to the process is the lance design which permits the fuel to be burned below the surface of a molten bath using a relatively simple and cheap air-cooled lance. The submergence of the lance creates a highly turbulent environment which promotes fast chemical reactions, excellent fuel efficiency and higher metal recoveries than in conventional technologies.
While the technology will revolutionise the smelting process worldwide, it has wider applications than metallurgy. AUSMELT is capable of being used to upgrade wastes and residues deposited by other process technologies, producing environmentally acceptable products amenable to discard, or recycling in the form of feedstock or building materials. This means that governments and industries now have access to technology which, at reasonably low cost, can convert stockpiles of slag and unacceptable toxic wastes to cleaner environmentally friendly materials.
Cathode technology for refining
and winning copper
In traditional copper refining, thin copper cathode plates
(starting sheets) were used to 'grow' cathodic copper in electrolytic
tanks. Making and handling these starting sheets was labour
intensive, and because the sheets became part of the cathode
which went to the furnace for melting, they needed to be replaced.
Whilst the concept of using permanent starting blanks was
well established in the zinc industry, a number of problems
prevented its use in the copper industry.
In 1987, a team of metallurgists led by Jim Perry at Copper Refineries Pty Ltd, a wholly owned subsidiary of MIM Holdings Limited, developed a unique new process called the Isa Process for refining and winning copper by continuous use of permanent stainless steel cathode plates. Their success was due to the choice of cathode blank material, the perfection of a patented edge masking system, and the unique method of stripping the deposited copper.
In the stripping machine, cathodes are washed and stripped of their copper. A wax coating is applied to the edges of the stainless steel plates which are then returned to the cells. The edge masking prevents the copper growths on either side of the blank from joining up, which would prevent the stripping process.
The technology and its associated specialised equipment, provides cost effective operation for new electrowinning or refining plants, as well as for existing plants requiring modification to increase productivity.
The cleaner high intensity
smelting process
To reduce operating costs and to maintain or improve smelter
hygiene standards, a team of researchers led by Jim Fewings
at MIM Holdings Limited, developed a revolutionary high intensity
smelting process jointly with the CSIRO Division of Minerals.
The Isasmelt process is based on the Sirosmelt lance developed by the CSIRO in 1973, and has many advantages over the more conventional technology. The process requires a simple refractory lined furnace and operates with a single submerged combustion lance to create a highly turbulent bath. The lance is coated with a protective layer of frozen slag. Internal swirlers enhance the heat transfer from the lance wall to the process air, promoting the formation of this slag coating.
The concentrate feed to the furnace requires minimal preparation and is moist. The turbulence of the Isasmelt bath ensures rapid incorporation of feed materials and a high rate of reaction. This subtantially reduces dust problems associated with conventional sinter plants.
Isasmelt plants are economical to build, cheap to run, simple to operate and easy to maintain. The process is highly automated, requires fewer people and can accept a wide variety of material for processing. It is also a clean process, offering improved plant hygiene for workers and its ability to eliminate impurities from slag is particularly important in areas where legislation requires the slag to be taken to toxic waste dumps. The slag from the Isasmelt process can be used for land fills and road construction. The enclosed nature of the furnace also allows for the efficient removal of gases.
The process can be incorporated into conventional smelters and provide an increase in capacity with relatively low capital expenditure. Another important benefit is the use of cheap coal instead of metallurgical coke.
Column flotation technology
improves mineral recovery
Froth flotation is the method of separating and extracting
mineral ore from rock crushing, where the liquid or slurry
is aerated, causing tiny particles of ore solids to rise to
the surface where they are collected for processing. Developed
in Australia in 1903, the process has been described as one
of the most significant advances in metallurgy. A recent innovation
has improved on this process.
The new major breakthrough in column flotation technology is the Jameson Cell, invented in 1985 by Professor Graeme Jameson from the University of Newcastle and commercialised in conjunction with MIM Holdings Limited and Newlands Coal Pty Ltd in 1987.
The cell is about one quarter of the height of a conventional column, has a rapid throughput, taking only two minutes to float off solids compared with about a quarter to half an hour for conventional columns.
In the revolutionary new design, both the air and the feed are introduced at the top of the cell via a downcomer. This downward movement of air and feed creates more numerous and closely packed bubbles, increasing the likelihood of bubble contact with the mineral being recovered, and considerably speeding up the flotation process. The Jameson Cell has proved successful in a range of applications including lead, zinc, copper, gold and coal.
Reduced capital outlay, shorter installation time, lower operating and maintenance costs are among the benefits of the new cell, which is able to recover the fine component of mineral slurries which until now were not able to be recovered.
On-the-spot analysis of minerals
To maintain competitiveness in the mineral industries, companies
needed a faster process of analysis during the recovery of
metals in their processing plants.
In the past, the mineral industry had to wait up to 24 hours for assay results to assess the performance of their plant. To speed-up this process, the instrumentation division of Amdel Limited developed a range of on-the-spot analysis equipment, for the processing of minerals such as copper, zinc, lead and platinum.
Over a three-year period, Amdel and the CSIRO Division of Minerals developed a Thickener Interface Gauge for use in the large tanks in which minerals are separated from the liquid used in the mineral washing process.
In thickening tanks, minerals sink to the bottom and are extracted while the washing liquid floats to the surface and is drained off. To avoid overloading the process in these tanks, operators must know the rate at which thickening is occurring inside the tanks - at various levels.
The Thickener Interface Gauge - a long probe which extends into the tank - uses a unique measuring method: the gauge measures the naturally-occurring radioactivity of the mineral - at different levels within the tank. The higher the reading of radioactivity level, the greater the concentration of minerals.
Amdel's unique Thickener Interface Gauge provides the minerals industry with a more accurate and continuous measurement of minerals/liquid ratio for washing and thickening plants.
Coal slurry analyser for
accurate coal grading
During its processing, coal must be washed to remove most
of the ash to ensure that the customer gets maximum energy
from the product. Higher efficiency in the coal washing process
results in a 'cleaner' coal. However, some ash always remains
with the coal, so it is in the interest of both the producer
and the purchaser to know the exact percentage of ash that
remains to establish the grade of the coal.
Until recently, the flotation section of a coal washing plant had been difficult to control because the plant operators were unable to see how well the process was operating. In 1988, physicists and electronic engineers led by John Watt at the CSIRO Division of Mineral and Process Engineering and Andrew Toop at Amdel Limited developed and commercialised the Coal Slurry Analyser system, which provides continuous on-line analysis of the percentage of ash and solids in the flotation circuit.
The system can measure coal with a particle size of up to about 2mm. Three probes are connected to a signal analyser which processes the signals from the probes and transmits them to the central computer. This enables immediate action to be taken to keep the plant running at optimum by maximising the yield while maintaining the quality of the product within the required specifications.
On-line measurement of coal
quality
Coal from the same mine may look the same, but its quality
can vary enormously. High grade, quality coals have much less
ash than low grade coal and up until recently, obtaining accurate
measurements to determine the ash content, and therefore the
quality of coal, was a time consuming and lengthy process.
The inability to quickly measure the quality of coal led to
wasteful practices by coal producers and wide coal quality
variations for consumers.
Whilst the physical principles required for on-line coal quality analysis had been known for some time, researchers at the CSIRO Division of Minerals developed a range of new techniques from existing technology, that were industrially practical as well as precise for use in the coal industry. The team responsible for the developments included Dr John Watt, Dr Brian Sowerby and Dr Nick Cutmore. The CSIRO innovations were licenced to Mineral Control Instrumentation Ltd, who in 1982 commercialised the Coalscan range of on-line coal analysis systems.
The four models in the Coalscan range: 1500 Natural Gamma Ash Monitor, 3500 Through Belt Ash Monitor, 4500 Ash and Moisture Monitor and the 9000 Series Coal Analysis Systems.
The first three models only measure ash content of the coal. The need for information about the elemental composition of coal led to the development on the 9000 Series, which are the most precise and sophisticated in the range, and are for use in demanding applications such as coal preparation plant control, product specification monitoring and power station feed monitoring. Using this system, the quality of coal can be accurately gauged, allowing more efficient use of one of the world's most useful natural resources.
Suite of PC software for
automatic ash control
The proportion and consistency of ash content of coal is
a quality indicator which has a significant effect on coal
price and marketability.
In most modern coal preparation plants the operator establishes an ash level set point which is monitored by an on-line ash analyser in the product coal stream. Deviations from the set point are then manually adjusted in the plant process circuits.
Dr Tom Romberg and his colleagues at the CSIRO Division of Minerals developed the unique algorithm for Coaltrol - a suite of PC-based software developed and commercialised by BHP Engineering Pty Ltd in 1992, which functions to add value to coal preparation plant operations by replacing the manual control of ash content with automatic closed loop control.
The Coaltrol is interfaced with the plant's existing control systems and with the on-line ash analyser monitoring the product coal stream. The software monitors the deviation of ash from its specification value and automatically trims the set points of the density controllers. Its unique characteristic is its ability to adapt to changing conditions, both in the plant and the coal. The innovation reduces the need to constantly monitor and adjust media density in response to changes in ash content and improves the consistency of ash quality of washed coal.
Comprehensive coal quality
assessment in a single test
Some bituminous coals fuse when heated above approximately
350C, become plastic to a greater or lesser extent and then
solidify to form a semi-coke by about 500C. This property
is critical for coke manufacture where the temperature is
further increased to about 1,000C to produce strong coke for
metallurgical purposes. In many other uses, the thermoplasticity
of coal can be a problem due to agglomeration of particles
and its interference with particle and gas flows. In each
case however, it is important to measure the extent and related
parameters of the coal's thermoplasticity.
A group of research scientists led by Dr Leo Lynch at the CSIRO Coal and Energy Technology and Joint Coal Board (the New South Wales coal authority) have developed a unique new instrument to test the coking power of coals.
Proton Magnetic Resonance Thermal Analysis (PMRTA) is a technique that allows changes in the molecular properties of organic solids, such as coal to be monitored. These changes can be detected and recorded as the solids are heated to high temperatures and then decompose.
The benchtop apparatus is linked to a computer and uses signals from the protons of the coal sample to determine the degree and extent of molecular mobility attained during the heating of the coal. It can distinguish between the fused or 'plastic' material and the unfused or rigid material. By measuring the mobility of coal molecules as the sample is heated, the instrument provides data to indicate the different temperatures and temperature ranges at which the coal will soften, become most mobile or plastic, and become solid as a semi-coke.
Commercially available from the CSIRO since 1992, PMRTA is a major leap forward on previous tests and offers industry an efficient means to obtain coal quality data from which to characterise coals and indicate their suitability for particular processes.
Although the instrument was developed primarily for analysing coal, it has also been used for other materials studies. PMRTA has wide applications anywhere where information on the thermal properties of organic and hydrated inorganic materials are sought, such as in the plastics, rubber, fibre, food and pharmaceutical industries.
Upgrading Cameca microbeam
electron microprobe
Many research laboratories around the world use an instrument
called the Cameca "microbeam" electron microprobe. These are
analytical electron microscopes with very sensitive x-ray
spectrometers enabling the analysis of small solid materials
1 millionth of a metre in diameter. While the latest version
of the US$600,000 instrument is still the best of its kind,
the computer used to control the older model, a DEC PDP-11,
is now dated and often difficult and costly to maintain. As
well, only a few models were fitted with an energy dispersive
(ED) spectrometer integrated with the wavelength dispersive
(WD) spectrometers for quantitative analysis.
Developed by Ian Harrowfield and his team at CSIRO Division of Mineral Products, PC Microbeam is a software and hardware package which upgrades Cameca "microbeam" electron microprobes. Commercialised in 1992 by Microbeam Services, a division of Aberbrook Pty Ltd, PC Microbeam runs on an IBM compatible PC, and replaces the obsolete digital PDP-11 computer with an extremely user friendly platform, capable of fully integrated ED and WD analysis.
The kit containing interface cards and software makes the IBM 486 PC plug compatible with the interfaces installed in the original computer. To install the kit, the parallel and serial cables are removed from the old computer and plugged into the PC Microbeam interface card. The original control and data processing software has been emulated in the PC so users can resume work with familiar software immediately after installation.
PC Microbeam which can run in either a DOS or Windows environment, has not only modernised the very expensive Cameca "microbeam" electron microprobe, it has also improved its operational speed, reduced maintenance costs, and improved the manipulation of acquired data and results.
Many PC Microbeam systems have already been successfully installed and are operational in Europe and the United States, and further installations are expected in other parts of the world.
Powerful wind turbines for
all conditions
Wind power has been harnessed by man in many ways for many
centuries. It powered the windmills of early industry and
propelled the great sailing ships that discovered new worlds.
Today, energy from the wind has the capacity to produce a
quarter of the electricity requirements of most nations. The
problem has been to find efficient and effective ways to capture
and convert the ceasless power of wind.
The problem with wind power is that because the average wind speed (and range) varies from one place to another, to achieve optimum performance in low wind speeds, wind turbines require a large rotor area to capture the energy, and a small rotor area in high wind speeds to avoid damage.
The average global wind speed over land is 4.5 metres per second (16kph). Most wind turbines require between 9 and 12m/sec to produce their rated output and at least 6m/sec to start producing usable power. This means that their output performance is only an average of 17% of what they could produce if they worked at 4.5m/sec.
An innovative solution to the problem, invented by expatriate American engineer Ralph Belden and commercialised by his company Synergy Power Corporation Pty Ltd, is making wind power generation at normal global wind speeds a viable and often alternative in many regions of the world.
The three blade Survivor Wind Turbines are designed to reach their rated power output at 4.5m/sec, giving them a comparative rating of 65% output. The success of the new turbines is due to the unique variable axis which allows the rotor blade to adjust to all wind conditions, utilising more of the potential energy from the wind than ever before.
Developments are now in progress to build a large turbine model.
For people living in remote parts of the world or for people who want to get away from it all, the innovation has far reaching benefits resulting from viable self sufficiency, particularly when combined with an integrated remote area power system.
The world's most efficient
solar cells
Solar cells convert sunlight directly into electricity using
the photovoltaic effect in semiconductors. They provide one
of the best alternatives for sustainable energy in the future.
The commercial challenge in photovoltaics has been to increase
the efficiencies of solar cells suitable for high-volume,
low-cost production.
The first modern silicon cells were a by-product of the silicon electronics industry reported in 1954 at Bell Laboratories in the United States. Today, Australia is the largest manufacturer of silicon solar cells per head of population.
Dr Stuart Wenham and Professor Martin Green from The University of New South Wales are the innovators behind the laser grooved buried contact solar cells - the world's most efficient solar cells, commercialised by Unisearch Limited in 1990. The first commercial sale of the cells was in 1990 by licensee Telefunken System Technik, for the Swiss solar car The Spirit of Biel, which won the 1990 World Solar Challenge, a 3,000 kilometre race in Australia from Darwin to Adelaide.
Recently, independent tests in the United States confirmed that a module of 16 silicon cells achieved an efficiency of 20.5% - the first time that the 20% milestone was passed by any photovoltaic module in the world. Although the silicon cells are still very expensive, they are vastly cheaper than their competitors made from gallium arsenide used mainly in spacecraft, which have efficiencies around 18%.
It may be a many years before we can all look to the skies for our daily source of power and energy, but every little step towards a sustainable energy source is one new step towards self sufficiency on earth. In the interim, the annual World Solar Challenge held in November, is worth watching - not only for entertainment, but also to take a glimpse into the future of solar energy utilisation.
Mains-quality electricity
from alternative energy
Mains quality electricity is something most people take for
granted. However, for many isolated communities around the
world, the only source of power is often from fuel and wind
generators, solar panels, deep-cycle batteries or mini-hydro
systems. Whatever the power generating system, inverters are
used to convert alternative energy to usable household electricity.
In 1989, the world's first bi-directional sine-wave inverter that replicates the quality of power obtained from public power grids was developed by Mechanical engineer Dale Butler, of Butler Solar Systems Pty Ltd, and commercialised by Siemens Ltd in 1992.
The Sunsine Green Grid sine-wave inverter, converts the DC voltage supply to sine-wave electricity like mains-quality sinusoidal AC output voltage. This means that appliances can operate more efficiently, with lower noise levels, and avoid problems with appliance malfunctions.
The solid-state unit is virtually maintenance free and conforms to stringent international safety standards. The innovation won the "Most Outstanding Contribution to the Electrical Industry for 1990".
The new inverter can operate all household appliances without difficulty, including microwave ovens, low efficiency fluorescent lights, sewing machines, radios, stereos and televisions. It's unlimited power factor operation and a very high surge capability, makes it particularly suitable for induction motors, refrigeration systems, power tools, washing machines, dishwashers and vacuum cleaners.
The product has subsequently been developed into various interactive versions which contain system control software. A 'generator interactive version' integrates diesel generator sets and renewable resources to provide a 24 hour power supply. The green grid system provides improved quality of supply to consumers on rural networks.
Smokeless briquettes from
ancient coal dust
In 1987, Rockhampton Country Brickworks was approached by
CSR Ltd who wanted to make briquettes from the low value coal
dust at their Yarrabee mine. Attempts to bind the dust failed
and the project was abandoned by CSR.
Owner of the brickworks, Russell Anderson, continued his search for a suitable economical binder, and eventually found the solution in a cheap agricultural by-product, which when combined with the coal dust resulted in a unique, inexpensive smokeless and odourless briquette that burns up to five times longer than others.
Engineer Barry Ryan built the prototype briquetting machine capable of producing one ton of briquettes every three hours, which is now produced by Anderson's other company, Yarraboldy Briquette Company Pty Ltd.
The briquettes are made from anthracite coal which is the oldest form of coal, and because it has been buried deep beneath the Earth's surface for many millions of years more than other coals, all the "nasties" have been filtered out long ago. The binder contains two naturally occurring products, one of which retains any sulphur which may be present. Therefore the fuel has no smoke, no odour, and the product is totally environmentally friendly, from the time it is dug out of the ground until the ash is returned back into the environment.
Isolating faults in electricity
networks
Electricity. Without it, modern day life comes to an abrupt
halt. We only appreciate the importance of reliable constant
supply of electricity to our homes and offices when we are
deprived of it for a period of time. Reliable power systems
are essential and prevent problems such as loss of computer
data, VCR recordings, perpetual clock resetting for consumers
and expensive production down time for industry.
If a fault develops on the overhead lines or underground cables of an electricity distribution network, a large section of the line and many customers may be without power until the fault is found and the section isolated for repair. And although fault indicators have been around for many years, they have not been used very widely because of their limited reliability.
A new solar powered fault indicator developed by Campbell Keenan, electrical engineer and Managing Director of CHK Engineering Pty Limited has overcome the reliability problems with conventional products and is now being used extensively by many electricity distribution authorities, and in the harshest conditions from the Australian outback to the Canadian Yukon. The RPU fault indicator, which was commercialised in 1992, was awarded the Electrical Development Association Memorial Award in the same year.
Whereas traditional fault indicators need to be mounted live on each of the conductors, only one RPU is mounted on each pole. A line fault will cause the LED's to flash on all indicators from the isolating circuit breaker along the circuit path up to the fault, but not beyond it for easy visual location. For distribution automation systems, the RPU can provide remote indication of a fault directly to a central control room where the faulty section can be isolated and power restored to the rest of the network within seconds.
The housing is custom moulded and filled with insulating foam to minimise heat cycling problems which plagued older electromechanical and disposable battery designs. The line configuration, voltage, pole materials and the mounting height do not affect the reliability of the unit. Because the RPU has one universal model for each of three wire and single wire systems, the user does not need to calculate fault levels and stock a variety of trigger levels.
Plasma igniters replace fuel
oil at power stations
A world first technology has been developed by a project
team led by engineers Peter Vierboom and Craig Foreman at
Pacific Power (The Electricity Commission of New South Wales)
to replace the need for expensive fuel oil consumption in
pulverised coal fired utility boilers. The innovation was
prompted by the need for a more flexible, dependable and cheaper
ignition system to overcome the high and often volatile price
of petroleum products. The old fuel oil igniters are being
replaced with a new plasma igniter which runs on electricity
and pulverised coal which is both cheaper and avoids the storage
of fuel oil at the power station. Electricity is used to produce
plasma with temperatures in excess of 11,000C which is then
used to ignite the pulverised coal in the plasma igniter.
Each plasma igniter contains a plasma torch in which a direct
current electric arc is maintained between two electrodes.
The plasma is created by nitrogen gas being heated as it is
blown through the arc.
Initial investigation and demonstration of principle test was conducted at the University of Sydney. After 11 years of intense research and development at Pacific Power, the plasma igniter was finally commercialised in 1993.
Pacific Power's plasma ignition system has the potential to be cleaner, safer, cheaper and more reliable than the conventional oil fired systems.
A new technique for diamond
exploration
A new technique developed by a team headed by Dr Bill Griffin
at the CSIRO Division of Exploration Geoscience (now Exploration
and Mining), can cheaply and quickly assess the viability
of prospective diamond exploration areas.
The technique relies on using a particle accelerator to study trace elements in garnets taken either from rocks that may contain diamond, or from stream sediment and soil samples collected during exploration. The nickel content of garnet is a reliable indication of the temperature at the time the garnet was picked up by the volcanic magma. This in turn is an indication of whether diamonds are present, and if so, their likely quality. This 'nickel thermometer' provides an estimate of the depth of origin, which is a critical factor in the formation of diamonds.
Because the technique only requires a small number of garnets to be analysed, and avoids bulk testing of obviously barren prospects, it results in substantial savings to prospectors.
Currently, the analysis can only be carried out by the CSIRO on the division's proton microprobe, which is the only instrument capable of producing sufficiently accurate trace element data.
The remarkable laboratory
grown emerald
The natural resources of the world are gradually being depleted.
Precious stones are no exception, and deposits of natural
emeralds are rapidly depleting. Gem quality stones are becoming
increasingly rare and expensive. And while synthetic emeralds
have been available for some time, they have never really
been close to the real thing.
All that changed in 1980, when geologist Artur Birkner developed a unique technique for replicating the natural crystallographic processes of emeralds in a laboratory, and produced man-made emeralds with exactly the same physical, chemical and optical characteristics as natural ones. Commercialised by Biron International Limited, the laboratory grown Biron emeralds are made from rough natural beryl emeralds which are dissolved with a mineraliser under high pressure and temperature, and recrystallised by a slow hydrothermal process into perfect crystals with true crystallographic form. As with natural emeralds, the green colour of the Biron emerald is controlled by the addition of chromium oxide and vanadium.
An affordable alternative to expensive natural stones, Biron emeralds can duplicate the beautiful hues of even the finest Muzo, Chivor, Zambian and Afghani emeralds.
Identifiable only by expert gemologists, Biron emeralds provide an opportunity to own a flawless gem quality emerald at an affordable price.
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