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By Madgwick J. C

Four manganese dioxide leaching microorganisms, an Achromobacter spp, Aspergillus niger, Elllerobacter cloacae and Elllerobacter agglomerails were purified from sucrose enriched crude mixed cultures which contained at least sixteen, non-leaching, morphologically different, colony types. Fastest leaching rates were obtained from the original enrichment's mixed cultures (1.26 g Mn++ I/d) while best yields of Mn++ m terms of sugar use came from Achromobacter and A. niger being 0.84 and 0.89 g Mn++/g sucrose respectively. The peak efficiency in manganese reduced, per carbohydrate used, coincided with the exponential growth phase for Achromobacter. The two Elllerobacter species performed better in stationary or senescent growth phases.

Jan 1, 1985

Computers and other microprocessor technology lead the world of technological change. Nevertheless, the real advances in the world at large are not necessarily in the computer industry, but in the industries whose economics benefit most by the advances that this computer revolution makes possible. The minerals industry has always been in the forefront of this advance. Technological change in the era preceding the industrial revolution, and the mining industry's part in it, provides an instructive lesson for what is happening today. Strong parallels can be drawn for predicting future advances. With each technological advance allowing more efficient production comes a re-alignment of economics - absolute and relative changes to prices, to quantities demanded, and to other market characteristics. This re-alignment applies not only to the mineral industry, but also to the world at large. Adaptability, rather than technical advancement per se is the key to survival and growth in a changing world. 'Adaptability' as a concept is easy to support. As an operational philosophy it is not so easy to implement. As a goal for planning, it is much harder to quantify. A fixed scenario of a future world may provide helpful guidelines, but a scenario that demands adaptability to an uncertain future world is much less definite. Of course, everyone else in the world is also uncertain about the future, and they are making their plans using different assumptions. This virtually guarantees that our future will turn out different to our expectations. This is in part what Hayek (1945) calls the 'knowledge' problem. Until now, most of the planning and technical research undertaken in the world has ignored this problem. This ignorance is a luxury that we can no longer afford. The paper looks at the history of technological change and highlights the characteristics of successful technological revolutions. 'Adaptability' to unforeseen circumstances is the key to success in this environment. The paper examines the knowledge problem from the perspective of the mineral industry, and suggests a number of directions for maximising the returns from application of computer technology in this important area.

Jan 1, 1995

By O N. Savassi

A rigorous methodology for prediction of flotation plant performance is presented, which is based on a standardised batch flotation test called the MFT. The work is part of the FLEET program, developed by MinnovEX with the support of seven large mining firms. The methodology is divided into three key steps: direct measurement of the kinetics of true flotation in the pulp, independent of hydraulic entrainment and other froth effects in the batch cell; benchmarking of the industrial plant over a broad range of ore types and operation conditions; and model calibration to describe froth effects in the plant, with a minimal number of parameters. To date, the methodology has been applied with success at several industrial plants, encompassing copper, gold, nickel, iron, lead, zinc and coal operations. This paper includes a description of the laboratory testwork procedure and scale-up to full industrial circuits. Examples of industrial application are also presented.

Jan 1, 2005

SEVERAL serious accidents, which had occurred owing to the platman leaving the plat without first withdrawing the "chairs" from the shaft, set the writer scheming to devise a mechanically operated system which would obviate such accidents and be "fool-proof". It was obvious at the outset that some means of indicating to the engine-driver by the movement of the "chairs" themselves, whether they were "in" or "out" of the shaft, was necessary.An arrangement of signalling similar to railway semaphores was considered, but was rejected owing to the difficulties accruing from the large number of communicating wires which would be required down the shaft-viz., 2 for each level. After several experiments, a comparatively simple and efficient electrical system was devised, and which is covered by Commonwealth Patent TO. 10,402.One of the chief features of the apparatus is its simplicity, and its strongest point is the fact that both the engine-driver and platman receive visual indication of the position of the "chairs." The arrangement consists of a miniature coloured glow lamp, one for each level of each shaft compartment, arranged and placed beside the numbers and arrows corresponding to the various levels, on the winding engine indicators. Also a large indicating glow lamp is installed at each compartment in the various levels, in proximity to the levers for operating the "chairs." Upon operating the various levers for the "chairs," an electrical current...

Jan 1, 1909

By D J. Bradshaw, B Lottermoser, A Parbhakar-Fox

"Best practice for acid rock drainage (ARD) risk assessment still relies solely on the geochemical properties of sulfidic rocks and mineral processing products, despite the fact that a rockÆs tendency to produce acid also depends on mineralogy and texture. Consequently, there are a plethora of geochemical tests routinely utilised by the mining industry to predict ARD formation. Due to limitations associated with these tests and their relatively high costs, analysis of recommended best practice sample numbers is rarely achieved, reducing the accuracy of waste management plans. Our research addressed this through examining the application of geometallurgical data for predicting acid formation, and led to the identification of potential environmental geometallurgy indicators.Samples obtained from an iron-oxide copper gold deposit were subjected to the geochemistry-mineralogy-texture (GMT) approach, an improved methodology for classifying acid forming potential. GMT results were compared against geometallurgical and assay data sets to evaluate: relative carbonate content measurements (measured by HyLogger) and identify how these could be used to calculate effective acid neutralising capacity mineral hardness (measured by EQUOtip) to determine application of this data for calculating lag-time to acid formation opportunities to automate the acid rock drainage index (ARDI) using classified images produced by a GEOTEK logger and automated microscopy.Links between the GMT approach and geometallurgical data sets were identified. Classified mineralogy data has application at stage one, HyLogger and EQUOtip at stage two and computer-based ARDI evaluations of classified images at stage three. Through such integration, ARD characterisation costs can be reduced, with value added to geometallurgical data sets. Furthermore, deposit-wide ARD domaining is possible, and acquisition of total-orebody knowledge more likely. Through adoption of this environmental geometallurgy approach, a better informed waste management plan can be formulated, allowing for best practice ARD sampling in a more cost-effective manner.CITATION:Parbhakar-Fox, A, Lottermoser, B and Bradshaw, D J, 2013. Cost-effective means for identifying acid rock drainage risks - integration of the geochemistry-mineralogy-texture approach and geometallurgical techniques, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013, pp 143-154 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 29, 2013

Mining companies often view water quality as an environmental issue. The importance of water quality as a production related issue in mineral beneficiation is greatly underestimated at many mineral processing operations. While most mine sites have comprehensive water balance data for water quantity, the information regarding the quality of water supplies available on site is limited, inadequate or non-existent. The seasonal variations in process water quality and changes in the composition of various water streams are not known. Despite the fact that water represents about 80 to 90 per cent of the volume of mineral pulp processed in a flotation plant, the influence of process water composition on flotation performance is often poorly understood. The process water used at mineral processing operations is made up from a number of available water sources, which can be classified as recycled water streams or make-up waters. The recycled water streams are commonly the tailings and concentrate thickener overflows, filtrate from the concentrate filtration plant and tailings dam return water. Make-up waters can originate from a variety of sources: surface waters (rivers, lakes, reservoirs, dams), groundwater (wells and springs), mains water (potable water), treated and untreated sewage waters and industrial effluents. Mineral processing plants are increasingly recycling water to reduce demand for fresh water and minimise the discharge of wastewater to the environment. However, increasing water recycling can have adverse effects on process water quality and ultimately on the performance of mineral separation processes. The main reasons for reduced plant performance due to water recycling are the accumulation of organic and inorganic compounds in the process water and increased microbiological activities. Other detrimental effects of water recycling can be increased reagent consumption and inefficient dewatering of tailings and concentrates. Recycling of water also tends to accumulate very fine suspended particles. Excessive amounts of slimes in the process water can also have an adverse effect on mineral beneficiation processes. The main constituents of process water are dissolved gases (oxygen, nitrogen, carbon dioxide), colloidal and suspended solids of inorganic and organic nature (including micro-organisms: dead or alive), dissolved organics (natural organic matter, residual reagents, reaction and decomposition by-products of chemical reagents, impurities in the reagents and metabolites originating from microbiological activities) and inorganic compounds (acids, alkalis, inorganic salts, metal ions, anions and heavy metals). Inputs to the chemical composition of process waters are: dissolution of soluble mineral phases present in the ore, surface oxidation followed by dissolution of mineral particles during grinding and mineral processing, the chemical composition of various make-up waters and recycled water streams, and reagent additions during mineral processing. The beneficial or detrimental impact of process water quality on flotation performance can be attributed to a number of subprocesses: adsorption and/or precipitation of inorganic and organic species present in the process water onto the surface of mineral particles, chemical reactions between process water constituents and the chemical species present on the surface of mineral particles and interactions between the chemical and microbiological species present in the process water and the various reagent species added in solution during mineral processing. Dissolved chemical species such as calcium, magnesium, iron, copper, lead, zinc, nickel, sulfates, phosphates and carbonates can have a strong effect on the electrokinetic properties of oxide and sulfide minerals, at certain pH ranges. Several reactions can occur at the solid-liquid interface that can play an important role in determining surface adsorption of reagents. Solid-liquid interfacial properties of mineral particles can be significantly affected by the conformation of adsorbed and precipitated reagent layers, which in turn are determined by solution chemistry. The chemical and microbiological constituents of process water can have a significant effect on liquid-gas interfacial properties and have a strong influence on froth height, strength and stability during flotation. Water chemistry can play an important role in determining the interactions between minerals present in the ore and the chemical reagents added in the mineral processing plant by altering the reagent-solution and mineral-solution equilibria. These interactions can include dissolution, micellisation and precipitation of reagents, dissolution of minerals contained in the ore followed by hydrolysis, complexation, adsorption and precipitation of dissolved chemical species and reactions between dissolved ions and various reagent species present in solution. All of the above mentioned subprocesses can ultimately have a significant effect on the efficiency of mineral processing operations. In this presentation, a systematic approach for assessing the composition of water supplies available at the mine sites and for investigating the influence of process water quality on the efficiency of mineral processing operations will be discussed. The consequences of mixing different quality water streams to produce the required volumes of process water for some flotation plants will be highlighted. To substantiate the water quality issues described in this paper some examples are given from a metalliferous processing perspective. However, the topics described in the paper are not only relevant to metalliferous processing but to all other type of mineral processing operations as well. In fact the principles described in this paper have also been successfully applied to the coal flotation industry.

Jan 1, 2006

THIS SYMPOSIUM ON AUSTRALIAN BEACH SANDS IS MOST TIMELY; WHEN WE ARE APPROACHING PEAK PRODUCTION FROM THESE RESOURCES AND WHEN PRICES ARE GOOD, BUT THE RESOURCES CAN BE SEEN TO BE COMING TO AN END IN THE LIFETIME OF OUR YOUNGER COLLEAGUES - 20 TO 25 YEARS AS WE HEARD FROM ROY TOWNER TODAY. THE SPREAD OF PAPERS HAS BEEN 15 PERCENT EACH ON GEOLOGY AND THE MINERAL RESOURCES, WITH 25 PERCENT ON LAND USE AND ENVIRONMENTAL PROBLEMS. I AM PLEASED TO SEE 20 PERCENT HAS BEEN ON TREATMENT PROCESSES AND 25 PERCENT HAS BEEN CONCERNED WITH DOWNSTREAM USES. I SUSPECT THESE RATIOS ARE DUE IN PART TO THE WAY PAPERS WERE CALLED FOR, BUT THEY ALSO SUMMARISE CLOSELY THE BALANCE OF INTERESTS IN THE INDUSTRY. NOTE AGAIN; 30% CONCERNED WITH SUSTAIN -ING RESOURCES, BUT 25% WATCHING LAND USE AND IMPOSING CONTROLS; 20 % IMPROVING THE PRESENT PROCESSING, AND A HEALTHY 25% WITH AN INTEREST" IN WHAT HAPPENS TO THE MINERAL CONCENTRATES. I SHALL RETURN TO THIS FOURTH POINT AT THE END OF MY REMARKS. THE POSSIBILITY OF ADDITIONAL HEAVY MINERAL SANDS IN NEW AREAS WAS HINTED AT BY M.S. SHEPHERD (EG TERTIARY SHORELINES OF THE MURRAY BASIN). OLD FOSSIL SHORELINES, WELL REMOVED FROM PRESENT SHORES ARE AN IMPORTANT MINERAL SOURCE IN CHINA AND IT WOULD HAVE BEEN INTERESTING TO HEAR FROM THE SEVERAL COMPANIES EXPLORING IN THE MURRAY BASIN. I ALSO NOTICED THAT WHILST OUR MONAZITE

Jan 1, 1986

By B Dold

"Mining has still today high potential for improvement in the exploitation efficiency. Especially low-grade ores have very low recoveries. In Cu bioleaching operations from porphyry copper deposits extraction of only five and 15 per cent with maximum of 40 per cent are reached. This means that 60–95 per cent of the resource is not exploited. Consequently, any metal not extracted will end up in the waste material, therefore increasing the risk of environmental pollution. This inefficiency is mainly due to the use of element concentrations for decision-making on the daily basis of a mining operation (eg cut-off ore grade, acid-base accounting – ABA). If, instead, quantitative mineralogical and geochemical data together with information on the bioleaching behaviour of the ore assemblage (the biogeometallurgical approach), is used for decision-making right from the beginning of the exploitation, higher recoveries and less environmental impact can be achieved, ie an increase in sustainability can be reached.CITATION:Dold, D, 2016. The Biogeometallurgical Approach – the Information We Need to Increase the Sustainability of Mining, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 169–172 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

IN a mine with any considerable output the economical handling and transport of ore underground is a matter of prime importance, and in the design or lay-out of a trucking system the question of what form the points and crossings are to take should be one of the first considered. Trucks may be moved from one line of rails to another by the following means: by flat sheets, with which may be coupled turn-tables, or by points and crossings. The latter class may be further divided into fixed and movable points.Flat sheets and turn-tables, owing to the time and skill needed by the trucker in using them, are seldom of great value with large tonnages, unless for purely temporary work, and the choice narrows down to one between fixed and movable points andcrossings. Both systems have their disadvantages - movable points being liable to jamb with dirt and get out of order, whilst with fixed points trucks may sometimes run over the points and capsize, or go on to the wrong line, though this is not of frequent occurrence. On the other hand. the fixed points are simple, easily laid, and strong, and there is no necessity for the trucker to work any levers, the truck being guided on to its new direction by screwing.Cast-iron points and crossings were first introduced into the North mine during the opening-up of the 950-ft. level, and the first arrangement was designed for a double turn-out in the main crosscut. Since then both the points and crossings have beenmodified several times, and it may be interesting to briefly outline the various forms through which they have passed, showing the reasons for the retention of some features and the rejection of others.

Jan 1, 1915

By M M. Collisson

The Synthetic Rutile (SR) plant operations, North Capel, produce electrostatic precipitator (ESP) fume and kiln scrubber residue. Typically ESP contains about 18 per cent Ti, 13 per cent Fe, 0.5 per cent Mn, eight per cent Si, six per cent Al, 16 per cent C, 0.9 per cent Zn, 0.6 per cent Pb, 300 ppm As, 300 ppm Cr and 5 ppm Cd. These wastes are held in a storage dam together with neutralised acid effluent (AE) liquor. A project was initiated to treat the fume and produce a benign residue that could be delivered to landfill, reducing dam space storage. Plant AE, containing free acid (9 - 14 g/L), Fe (6 - 7 g/L) and Mn (1 g/L), was used to leach ESP. The degree of extraction achieved for various elements include about 20 per cent Zn, almost 50 per cent As, five per cent Al, 0.4 per cent Pb and 15 per cent Cd. Extraction was most effective at pH The residue from AE leaching still contained Pb. TCLP tests of the leach residue produced Pb extraction significantly higher than the 0.1 ppm stipulated by Class 2 landfill guidelines. Other elements (eg As, Cd, Cr) successfully met the limits. Further leaching of the residue with EDTA extracted up to 65 per cent of Pb content. TCLP tests on treated residue showed Pb leaching potential of Lead was removed from the leach circuit as the sulphate by acidification of EDTA leach liquor, allowing EDTA to be recycled. The study showed that one waste stream can be used to treat another and help reduce plant waste.

Jan 1, 2001

During the period 1981 - 1991, Esso Australia and their Joint Venture partners have discovered about 180 MB of liquids (crude and condensate), 60 MB natural gas liquids and 800 - 1000 GCF of gas. A total of 48 wildcat wells were drilled including 12 new pool discoveries drilled from platform facilities. Significant discoveries include the West Tuna, Kipper, Blackback and Terakihi fields. These four discoveries, contribute to 75 per cent of the total reserves discovered in the last decade and were all high-risk plays. The Kipper discovery, in the pre-Latrobe Golden Beach Group top sealed by volcanics, and the Blackback-Terakihi discoveries, located on the present day continental slope in water depths ranging from 300-700 metres are both the result of successful drilling outside the traditional exploration bounds for the basin. During the last decade, Esso and its partners have spent about A$400M on wildcat exploration activity. The exploration success rate, excluding platform based drilling, has been 50 per cent for wildcat wells. On a technical front, the last decade has heralded substantial improvements in seismic data quality. Peak frequency content in seismic data at the Latrobe Group target levels is now double that of the early 1980s. Significant advances have also been made in our understanding of sequence stratigraphy, geochemistry and geohistory of the basin.

Jan 1, 1992

At Bulong, the mineralised (>0.8 per cent nickel) ore exists within numerous lithologies, which can and do occur coincidently. It is very important to discriminate between the different host units for estimation purposes, stockpiling and scheduling. This allocation of host unit has relied upon visual interpretation by the geologist recording the information, which can be very subjective by its nature. By using quantified constraints, such as assayed magnesium oxide and iron, the subjectivity of describing the host material of nickel laterite ore is reduced. The constraints permit consistent identification of the various host units, which improves the confidence in the overall estimation and scheduling of the ore.

Jan 1, 2000

By C M. Zammit, N Cook, F Reith, C L. Ciobanu, J Brugger

The role of biological agents in the gold mining industry is currently limited to the use of microorganisms in bioleaching and bioremediation. However, there is a variety of possibilities in which biotechnology could aid the mining industry in the future. In this article we discuss the potential for the development of these novel biotechnologies and the role they can play in the exploration for new gold deposits, the processing of ores and the post-mining remediation of sites. The development of these biotechnologies has been enabled by rapid advances in our molecular-level understanding of the role microorganisms play in the solubilisation, dispersion and precipitation of gold. An understanding of the distribution of microbial species in soils overlying mineralisation can be utilised to develop bioindicator systems that assist with gold exploration. An in-depth knowledge of how microorganisms interact with gold complexes is being used to develop in-field biosensors, supporting exploration. Processing technologies may be improved based on advances in our understanding of the interactions between microorganisms, ore minerals, cyanide and gold. For instance, cyanide-producing microorganisms are being investigated for use in in situ leaching of gold. In turn, the use of cyanide-utilising microorganisms for the degradation of cyanide is being explored. Combined, the implementation of these biotechnologies in the gold mining sector may revolutionise the industry, leading to greener, more efficient exploration for and extraction of gold.CITATION:Zammit, C M, Cook, N, Ciobanu, C L, Brugger, J and Reith, F, 2013. Possible future applications of biotechnologies in the gold industry - a prospective approach, in Proceedings World Gold 2013 , pp 233-244 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Sorentino C

Mineral valuation may appear to be a special field of financial valuation when in fact it is a subset of general investment decision theory. The only significant difference in mineral valuation is that in the case of valuing an on-going mineral asset, ie a mine, often there is no initial capital outlay involved. One is required to determine what the mineral asset as it stands is worth. But this is the same problem as determining the maximum one could pay today and not incur a loss over the life of the asset. In other words one needs to determine the Net Present Value (NPV) of the asset. The two most widely used discounted cash flow methods, NPV and Internal Rate of Return (IRR) came of age with the rapid adoption of the personal computer and spreadsheet programs. The two methods are directly related as the IRR is a special case of NPV. NPV measures the absolute increase in real wealth that can be expected from a certain investment, which makes it particularly suitable for mineral asset valuation, but ignores the efficiency of the investment. In contrast, IRR gives the expected efficiency of the investment but ignores the increase in wealth aspect. IRR has two serious theoretical weaknesses; multiple IRR's and a very rigid assumption about the rate of return of reinvested proceeds, plus if no initial equity expenditure is involved there is no IRR. The choice of the ""hurdle"" rate can also be a problem and in certain circumstances one can obtain different rankings of mutually exclusive projects using IRR and NPV. Although NPV and IRR supposedly measure financial risk, in fact they only address a very narrow area of risk, namely the time value of money given the real discount rate. They side step the issue of what the real discount rate should be and varying degrees of risk. The classical way to establish the real discount rate is to use the weighted average cost of capital.

Jan 1, 1994

By B Klein

This paper stems from research and development in sensor and sorting technologies towards future sustainable mining undertaken by the UBC Mine-Mill Integration group in collaboration with MineSense Ltd. Sensors and sensor-based technologies such as ore telemetry and sorting are envisioned to be a significant component in achieving such ‘invisible’ future sustainable mining. Such technologies offer high flexibility and power in use: delivering valuable information from the very preliminary stages of mining exploration through to final upgrading of the ore preceding the fine comminution stages. This paper reviews sensors and sorting as enabling technologies towards a future smart mining operation and introduces a model in which sensor-based exploration (down-the-hole sensing), ore exploitation (smart-shovels), transportation (smart-conveyors) and preconcentration (sensor-based sorters) are effectively integrated to increase the present value of operations. It is anticipated on the basis of several case studies that an effective use of sensor technologies through tomorrow’s ‘smart mine model’ should lead to several positive impacts ranging from increased mining production, to reductions in transport costs, overall energy use and waste generation. In this way sensors can be used to maximise the profitability and present value of the mining operation from the exploration stage through to mine closure.

Nov 22, 2011

By H Waterer, L Zheng, T Kalinowski

The Hunter Valley Coal Chain (HVCC) consists of mining companies, rail operators, rail track owners and terminal operators, together forming the worldÆs largest coal exporting facility. In 2008, the throughput of HVCC was about 92 million tonnes, or more than ten per cent of the worldÆs total trade in coal for that year. The coal export operation generates around $15 billion in annual export income for Australia. As demand has increased significantly in recent years, and is expected to increase further in the future, efficient supply chain management is crucial. The Hunter Valley Coal Chain Coordinator Limited (HVCCC) was founded to enable integrated planning and coordination of the interests of all parties, thus improving the efficiency of the system as a whole. One of the many planning challenges faced by the HVCCC is that of annual maintenance planning. Different supply chain elements, such as trains, railway track, terminal equipment and load points, must undergo regular preventive and corrective maintenance, leading to significant reductions in system capacity (up to 15 per cent). However good alignment of the maintenance tasks can reduce their impact, and the HVCCC undertakes an annual process to ensure the impact of maintenance on the supply chain capacity is as small as possible. This is achieved in an iterative negotiation process between HVCCC and individual service providers. In the past, maintenance schedule optimisation was largely manual, which for the more than 1000 tasks involved is quite labour-intensive.In this paper the authors describe an approach developed at the University of Newcastle in partnership with the HVCCC to automate this schedule optimisation process. We will discuss our experience in applying exact (mixed integer programming) and heuristic techniques from mathematics and computer science to address the problem. This work is anticipated to lead to new decision-support tools for the HVCCCÆs capacity planning team.

Sep 26, 2011

By Branagan D. F

The geology of the area studied is briefly described, together with the prospecting methods used in the search for copper, lead, zinc and uranium ore bodies.Four prospects, Mt. Corella, Yanasinga, Lawlor's and Greenmount, which were diamond-drilled, are described in detail and geochemical results are discussed in relation to the mineralization found. Copper anomalies were found wherever intrusive rocks were mapped, and showed a much closer relation to geology and mineralization than did the predominantly lead and zinc anomalies.Geochemical prospecting aids in the overall mineral search programme because of its speed and economy, as it helps to pinpoint areas worthy of detailed geological examination. Geochemical anomalies are a guide to favourable zones but may not indicate the presence of ore.INTRODUCTIONDuring 1953-55 the National Lead Company of New York carried out a search for minerals in an area south and west of Cloncurry (Fig. 1) in rocks of Precambrian age. After reconnaissance mapping, a number of prospects were chosen for closer examination by detailed geological mapping and geochemical sampling, and from these prospects, five sites were selected for drilling.This paper records the salient features of the exploration programme and discusses the geology and geochemistry of four of the prospects-Mt. Corella, Yanasinga, Lawlor's and Greenmount. Practically all the prospects examined showed high zinc "anomalies" or "dispersion" trains. Greta, Mt. Corella and Lawlor's prospects showed some copper anomalies and, to a lesser extent, lead anomalies. In particular, Greenmount exhibited striking copper anomalies.

Jan 1, 1960

Australia is not capitalizing on the raw gems and precious minerals that it produces in abundance. In particular, there is an unrealised value for diamonds due to lack of processing after mining. Australia could enhance the value of its raw jewellery products by developing and integrated jewellery industry. For instance, initiation of a diamond industry would require training programmes to educate people in the requisite skills, such as diamond sorting, cleaving, sawing, bruting and polishing. Equally important would be the training of people in design jewellery, manufacturing, and appropriate diamond grading and sales techniques. Future technological advances in diamond processing will decide where the major diamond processing centres of the world will be. Australia, for a relatively small investment, could develop a highly productive diamond processing capacity using the new technology available. Australia's geographical position, and advanced banking and communication facilities provide the potential for this country to become a major trading centre for diamonds. KEYWORDS: Argyle Diamond Mine, Diamonds, Diamond Production, Diamond Sorting, Jewellery Industry

Jan 1, 1989

I have chosen this subject in view of the fact that, while there are many and ample opportuuities of getting reliable assays made, there are but few who are in a position to obtain reliable data on the sampling of minerals and metals my long experience at Port Pirie, where, for five years, I had charge of the Refining and Sampling Mill, showed me how important it was that a correct sample should be taken.Weighing; This, to the ordinary layman, seems so simple that no expert knowledge is needed, but in actual practice there are hundreds of pounds to be lost by the lack of knowledge in this department.(1.) There is the matter of weighing in large or small quantities.(2.) The class of weighing machine used.(3.) The accuracy of weights used.We all know that, say, 1000 tons of ore cannot be weighed in one parcel; but the fewer the weighings the less loss to the seller (and usually wishes it weighed in small lots carefully) for it is a well known fact that the most sensitive scales take a certain weight to show distinctly the indication of the balance, or, in other words, what is known as "the pull of the scales." As for instance, 1000 tons weighed in lots of 1 c. each, taking the pull of the scale as being equal to 1 lb., would give a result of 9 tons loss to tbe seller, and as most of the ore sent to Customs works is worth 5. -£20 per ton-this would mean £180 loss to the careful man.

Jan 1, 1901

By Z Li, D Chalmers, J M. Tenney

This paper presents the findings and analysis of the investigation of effectiveness of thin spray-on liners (TSLs) as a gas management tool in underground coalmines. The project involves spraying TSL on the area surrounding gas drainage holes whereby the TSL acts as a thin membrane decreasing the permeability of the coal. This restricts air migrating through the coal seam and diluting gas from the drainage holes. There are a number of potential benefits from this technique but key points are that gas drainage holes produce gas with higher concentrations of methane. The design and execution of a field trial to investigate the effectiveness of a TSL on purity of in situ methane from gas drainage holes is presented in this report. For eight drainage holes, the results show an average increase in methane purity by 9.14 per cent and a reduction in air contamination by an average 7.93 per cent. Overall methane flow rate decreased by 27.6 L/s; however, flow rates were unreliable due to poor measuring equipment. For most holes, methane purity was not changed significantly; however, certain boreholes were responsible for most of the variation in methane purity. The boreholes showing a dramatic improvement in methane purity were likely those with intersecting cleats covered by the TSL. If the TSL was sprayed over more area, specifically in areas where the cleats are intersecting with holes, it is likely that purity of methane in the drainage holes will increase.CITATION:Tenney, J M, Chalmers, D and Li, Z, 2015. Thin spray-on liners potential in reducing dilution of in situ gas in underground coalmines, in Proceedings The Australian Mine Ventilation Conference, pp 323–328 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015