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By N Haque, S Northey

Water in mining, mineral processing and metal production on a life cycle basis has been at the top of agendas for various industries, government agencies, research organisations, academic institutions and communities. As a result, a number of water footprint assessment methodologies have been developed. However, their practical applications in mining and mineral processing industries with specific case studies are still rare.A key objective of the Minerals Down Under Flagship is to contribute to the long-term sustainability of the Australian mining and mineral industries. Researchers in the Mineral Futures theme have developed robust assessment methods to evaluate the impact of mining and minerals technology development on the environment. The future of mining and the mineral industry is strongly linked with its sustainability - better water management strategies will need to be implemented.Life cycle assessment (LCA) has been a recognised method for measuring the environmental impacts of products, processes and services. It provides a scientifically sound method of comparing products and processes using a common basis and identifies so called æhot spotsÆ and opportunities for reducing environmental impacts. The water footprint of mining, mineral processing and metal production using an LCA basis is still scarce in the literature. Research methodology is now being applied in detail for copper, gold and nickel. A primary focus has been the relationship between ore grade and water use for which mathematical models are being developed. These types of models provide inputs for LCA of mining and mineral processing plants and can identify water saving opportunities through scenarios and process route analysis.CITATION:Northey, S and Haque, N, 2013. Life cycle based water footprints of selected mineral and metal processing routes, in Proceedings Water in Mining 2013 , pp 35-50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

Explosives are used to mine coal. Any blast results in three size categories of products, namely over-, middle-, and under-size. Boulders can still be broken smaller in further operations after blasting. The under-size, for instance coal fines, negatively affects the mining efficiency. Their reduction ensures better returns. The paper concerns investigations aimed at reducing coal fines' generation. Inherent fractures are identified as one of source of fines. The discussion is therefore centered on establishing a relationship between the fracture occurrence, the explosive properties and the blast outputs evaluated in terms of the fines generated.

Jan 1, 1996

By James D. Brown

The Bureau of Mines has written a computer program in FORTRAN to facilitate the calculation of concentrations from X-ray intensities in electron probe microanalysis. Philibert's absorption and Castaing's secondary fluorescence corrections are used; no atomic number correction is included. Background and dead time corrections are applied to the data before calculating the relative intensities. Data from any type of electron probe microanalyzer can be used with the program.

Jan 1, 1965

By George A. Savanick

The objective of this paper is to review advances in the art of borehole (slurry) mining made by the Bureau of Mines. The introduction gives historical and general background information on borehole mining. The borehole mining concept is defined and justified in terms of economics, health and safety, the environment, and resource conservation. This is followed by a description of the design of a prototype borehole mining tool (BMT) developed by the Bureau of Mines. Included are design drawings and performance specifications. The next section describes the application of the BMT in the extraction of metallurgical coal from steeply pitching seams near Wilkeson, Wash., during 1975-76. The field test showed that the BMT produced coal at the rate of 8 tons per hour (tph) (7,272 kg/hr) from a depth of 88 feet (26.8 m) and was effective in producing coal as far as 15 feet (4.6 m) from the center of the borehole. The data are used as a basis for an economic analysis of borehole coal mining and for the suggestions for the design of a second-generation borehole coal mining tool. The following section describes Bureau efforts in applying borehole mining to the extraction of uraniferous sandstone at Rocky Mountain Energy Corp.'s Nine-Mile Lake site, Natrona County, Wyo. BMT design changes appropriate to uranium mining are described along with production, reliability, and reclamation data taken during 1977-73. The field test revealed that the BMT produced 900 tons (81.8x105 g) of uraniferous sand at an average race of 8 tph (7,272 kg/hr) from a depth of 75 (22.8 m) to 90 (27.4 m) feet and created a cavity 25 feet (7.6 m) in radius. These data are used as the basis for an economic analysis of borehole mining of shallow uraniferous sandstones. Reclamation data included will be the results of backfilling experiments conducted at Nine-Mile Lake during 1978. The most significant of these data were that backfill was emplaced at the rate of 16 tph (14.5x103 kg/hr) and that 90 percent of the material extracted from a cavity can be backfilled.

Jan 1, 1979

The Fosterville Goldfield has a modest past production (0.3 Moz), but is now emerging as a significant goldfield (2.6 Moz resources, including 1.1 Moz reserves) with implications for exploration within the orogenic gold provinces of the Lachlan Fold Belt in Australia and the Buller Terrane on the West Coast of New Zealand. Fosterville is located 20 km east of the 22 Moz Bendigo Goldfield and is geologically similar to other Victorian goldfields, however the nature of the gold mineralisation differs significantly. Unlike other Victorian goldfields there is no primary free gold at Fosterville. The gold occurs in as sub-SEM resolution particles, in fine grained arsenopyrite and pyrite crystals disseminated through the wall rocks in fault controlled quartz-carbonate vein stockworks. The Fosterville Goldfield comprises several subparallel fault systems striking 340¦ over an exposed strike length of 28 km. The Fosterville Fault system comprises the west dipping (~75¦), reverse Fosterville Fault and several less steeply west dipping splay faults formed in the footwall. The splay faults extend through east dipping beds from the Fosterville Fault across a syncline hinge into stratigraphically controlled positions on the west dipping limb of the syncline. The predominant control on gold mineralisation is the intersection of the bedding on the east dipping limb of the syncline and faulting which, is in turn controlled by the orientation of bedding in the west dipping limb of the syncline. The mineralised shoots are thus subparallel to the plunge of the syncline and show a plunge reversal about a culmination in the footwall syncline. This provides a very powerful exploration tool with bedding û cleavage intersection lineations measured in outcrop and oriented core indicating the plunge of mineralisation. Mineralisation is also, albeit less commonly, controlled by local variations in strike and dip of the host fault and at metre scale by host lithology. As the faults and mineralisation are stratigraphically controlled, detailed stratigraphic interpretations are essential to provide control on structural interpretations for resource modelling. Compared to other Victorian goldfields, the Fosterville Goldfield formed later (385 Ma to 360 Ma cf 440 Ma), at lower temperatures and at shallower depths (fluid inclusion studies of Au associated veins suggest vein formation at ~270¦C (range 140¦C to 385¦C) and at depths of 2.6 - 5.7 km).

Jan 1, 2005

The utilization of computer assisted tomography (CT or CAT-scan)as general non-destructive examination (NDE) technique and as research tool for scientists in South Africa, is limited due to the relative unavailability or nonexistence of such specialized analytical equipment. Many medical hospitals are equipped with X-ray CT scanners for the diagnostic examination of patients but do not easily allow paleontologist or other scientist to utilize their very expensive equipment. As from 2003, Necsa hosts the South African Neutron Radiography (SANRAD) and tomography facility where neutrons from the SAFARI-1 nuclear research reactor and their penetrating power as well as X-rays as a complementing tool, are utilized in many R&D applications. This facility is being made available to HEI and specifically utilized by postgraduate students as part of their studies and/or by industry on an ad hoc commercial basis. The capability of these radiation imaging facilities at Necsa will be demonstrated in areas such as paleontology, geosciences and specifically the physical properties of rock and the distribution of minerals in borehole cores, petrophysics to predict the percentage tar/oil/water content within sandstone samples and others. The penetration capability of neutrons through specimens with a matrix of high atomic number (dense materials) and their ability to be attenuated by low atomic number material (light density) makes neutron imaging complementary to X-ray imaging. The capability of X-ray and gamma radiation for relatively easy penetration through specimens of low atomic number allows for viewing of imbedded high atomic number materials and density variation. X-ray micro focus radiography is capable of resolving objects of micro scale size that are micro distances apart whereas X-ray phase contrast radiography utilizes the wave properties of the electromagnetic spectrum of X-rays to clearly define edges of the specimen under investigation. Many applications with neutrons as imaging probe are successfully applied at several facilities across the globe such as at NIST in USA, Neutra at PSI in Switzerland, and ANTARES at FRM2 in Germany, etc, are documented 4?9, through world conferences on neutron radiography, for example. This is achieved through very well thought through and implemented instrumentation from the production of neutrons to their detection and interpretation of the images. The need arose at Necsa to upgrade the current facility from 42-year-old technology, which was successfully applied in neutron imaging over the past 10 years, to state-of-the-art technology found at European facilities. This initiative started under the auspices of an IAEA-TC programme for the period 2007?2010.

Jan 1, 2008

By R. D. Currie

The practicability and dependability of two permissible methane-indicat- in detectors recently developed were proved conclusively by extensive tests in the return airways of all mines operating in the anthracite region in most of which samples and readings were taken with one or the other of the two in- dicating detectors. These detectors roved dependable and accurate within practical limits, and their general use should be encouraged as an aid to bet ter ventilation, more accurate control of air currents, and greater safety in mines.

Feb 1, 1936

Arguably the SMC Test® has become the most popular laboratory hardness test in the world with over 17,000 tests having been completed to date, covering over 650 different ore bodies. It is now routinely used in design, optimisation and orebody profiling projects. The test is unique in that from relatively small amounts of drill core it simultaneously provides parameters that are used in simulation modelling of AG/SAG and crushing circuits as well as work indices that are used in power-based equations for predicting the specific energies of AG/SAG/Crushing and HPGR circuits. The very large data base that has been accumulated has provided the opportunity to study the differences in variability from deposit to deposit. This paper describes and discusses the trends that have become apparent from the study of this data base. Recommendations for appropriate selection of sample numbers are also made which are based on these trends.

Jan 1, 2012

By M. M. Oosterveld

"In South West Africa diamonds are mined from ancient beach deposits by the Consolidated Diamond Mines of South West Africa, Limited.To improve the control of mining production, a computer is used for the calculation of statistically more accurate and homogeneous ore blocks. Geological and sampling information has been digitized and stored on magnetic files.The figures derived for each block entail the calculation of the diamond size frequency distribution, the diamond density distribution and the ore reserve by using the density distribution.The diamond size frequency distribution is used for estimating the revenue in an ore block.A description is given of how a linear programming system can be used for production planning."

Jan 1, 2014

By S. Esfahani, M. Barati, Y. Kauwachi

"Heat recovery from slag has gained attention due to its high potential in lowering energy intensity of metal extraction processes. A direct method to recover the thermal energy of slag is to use countercurrent air flow that extracts the heat from falling droplets. Often, the solidified slag is aimed to be used as a substitute for Portland cement, thus high cooling rates are required to form an amorphous slag with sufficiently strong hydaulicity. Rapid cooling however involves using large gas flow rates that in turn lower the thermal efficiency of the process. This article presents a mathematical model that was developed to determine the optimum conditions in the heat recovery process and to investigate the effect of the air flow and granule diameter on the cooling rate of the droplets as well as the thermal efficiency of the heat recovery system. INTRODUCTIONMetallurgical slags are the largest by-product of high temperature materials refining and extraction processes. The total amount of metallurgical slag produced in the year 2008 has been estimated at up to 422 million tonnes containing up to 222 TWh/y (Barati and Esfahani, 2011) of thermal energy. Over the past four decades attempts have been made to recover this substantial amount of energy as heat, electricity, or fuel, while none of the proposed method has been commercialized yet.During slow cooling the slag tends to crystallize the constituents (CaO, SiO2, Al2O3, etc.) into a hard, heavy solid. In the past, over 90% (Bengt, 1983) of the molten waste was discharged onto heaps and allowed to cool slowly, then crushed and used in road construction or land filling or as coarse aggregate for concrete. However, later it was found if cooled rapidly, the slag can be used as a substitute for Portland cement. As a result, processes such as wet granulation were created in which molten slag is fragmented with water, forming amorphous (glassy) phases. Despite its effectiveness in producing a suitable material, heat would not be recovered through this process. Thus, dry granulation was introduced in 1930’s and was developed further in 1970 – 1980’s."

Jan 1, 2012

By Zhenfeng Zhou, Qingguo Xue, Jingsong Wang, Guang Wang, Yuanyuan Zhang

The oxygen blast furnace is a new technology for ironmaking, where the oxygen and CO2-stripped blast furnace top gas are blown into the blast furnace replacing the conventional hot air. The oxygen blast furnace could reduce the consumption of coke and emission of carbon dioxide. In this chapter, a three-dimensional numerical model was developed to simulate the lance-blowpipetuyere-raceway region of a blast furnace, and the flow and combustion behaviors of coal particles were investigated based on an oxygen blast furnace. Compared with the traditional blast furnace, the combustion characteristics in the raceway of the oxygen blast furnace were different. In addition to the combustion of coal and coke, the combustion of large amounts of reducing gas was included. The coal combustion of different oxygen content (70, 80, 90, 100%) were investigated. The simulation results indicated that the coal burnout was only 21.64% at an oxygen content of 70%, a decrease of 51.52%, compared with a traditional blast furnace. The coal burnout was increased with the increase of oxygen content. When the oxygen content is 100%, the coal burnout was 90.38%, an increase of 17.22%.

Mar 1, 2017

By Douglas W. Huber

During the past decade, a general awareness of the need for and subsequent development of increased safety in United States coal mines has taken place. Government and industry alike were stimulated into accelerating their actions through unacceptable accident statistics and costs (in terms of human misery dollar values). Those of us who work in the United States coal industry are aware of the development of governmental controls on nine safety. Both Federal and State regulations have placed increased responsibility upon mine owners and operators to insure a safe working environment and to provide training for miners. No other industrial group of workers has received such attention or, in our opinion, deserves it more.

Jan 1, 1982

By Thomas G. Langton

The demand for mineral raw materials, especially in the major industrialized nations, has grown rapidly during the past three decades. One consequence of this growth has been an increasing reliance by the large industrialized countries upon nondomestic mineral supplies. These mineral supplies, to a large extent, have been developed by capital from the major industrialized countries. Until recently, most foreign mining ventures were either wholly-owned subsidiaries or joint ventures between two or more mining companies. The recent rise of economic nationalism has substantially changed the business climate and parameters under which foreign investors operate. This paper describes some of the underlying reasons for this change and notes how investors have adapted to the new business conditions.

Jan 1, 1974

By G. Purcell, S. C. Sun

The objective of the present study was to detennine the role played by double bonds in the flotation of a very pure mineral using 18-carbon unsaturated fatty acids as collectors. Streaming potential measurements were made on a plug of pure synthetic rutile in solutions of inorganic electrolytes and unsaturated 18-carbon fatty acid soaps. Experimental results from these tests are detailed in the paper. The collector effectiveness of oleic acid with one double bond, linoleic acid with two double bonds, and linolenic acid with three double bonds has been a matter of speculation for many years, and conflic- ting experimental evidence1-8 has not clarified the issue. The overall objective of the present study was to determine the role played by double bonds in the flotation of a very pure mineral using 18-carbon un-saturated fatty acids as collectors. Since zeta potential is dependent on adsorption and orientation of ions at the solid-liquid interface, its variation under different conditions of pH and collector concentration should throw some light on the behavior of unsatu-rated fatty acids in flotation pulps. Titanium dioxide, in the form of rutile, was chosen for the investigation because it is now available in a very pure, synthetic, crystalline state, and despite the fact that it is one of the most important synthetic inorganic chemicals in commercial use, its electro-kinetic properties have not been closely studied. Electrokinetic properties of rutile in various aqueous solutions are discussed in this paper. Adsorption information gained from the streaming potential measurements enabled the flotation resultsg to be explained in a qualitative way, thus providing a clearer

Jan 1, 1963

By James Arthur

In deep coal mining the support of the underground roadway is fundamental and without knowledge of the mechanics of ground control a mine is unlikely to be operating safely and efficiently. It is therefore important for the support system to be designed sat¬isfactorily for the size of the excavation required and to do so an understanding of the behaviour of the surrounding strata is re¬quired. Over the last 15 years there has been a major change in the industry and the support systems adopted. The industry has been privatised, legislation has been updated, a comprehensive research programme has been carried out and guidance docu¬ments produced. The paper will show how privatisation has not allowed support standards to deteriorate, highlight research, the legislation and guidance documents updated and how this has led to a reduction in accidents and falls of ground..

Jan 1, 2002

By J. R. M. Hill

The U.S. Bureau of Mines is involved in research to improve geological sensing (or geo-sensing) techniques. This paper presents results from field trials of two research projects concerned with new technologies for geosensing. The goal of the first project was to develop a "smart" roof bolter drill so that it could probe into roof rock to evaluate rock conditions. The goal of the second project was to modify an existing mine-wide monitoring system in a continuous mining operation so that the system could interface with geotechnical instruments to provide near real-time geosensing. Integration of this mine-wide monitoring system with the smart roof drill to collect, reduce, and analyze geotechnical data and the potential applications of the resulting technology in mining, are described.

Jan 1, 1992

By T. A. E. Breen

A new high intensity grinding technology has been developed and is now being commercialized by Hicom International of Australia. This has led to the development and manufacture of Hicom 120 grinding mills which are now being sold internationally for a range of mining industry applications. The first commercial process application has been for the diamond sector, where the ability of the mill to remove host kimberlite rock by attritioning, with no damage to the thereby liberated diamonds, is seen to be a most beneficial attribute. There are, however, many other mineral industry applications for this mill.

Jan 1, 1999

By K. Trybalski

Facing the optimization activities, which purpose is to minimize the copper processing costs, the main sources of their occurring were presented. In this purpose, the costs analysis was performed, divided to individual standings, for one of the polish copper beneficiation plants. It was proved, that the main component of the copper beneficiation costs is energy consumption, generated mainly in grinding and classification node, particularly by operating mills. The technological system ? grinding and classification node ? in KGHM Polska Miedz S.A., ZWR region Lubin was then selected to investigation. To evaluate the grinding and classification node, the energetic factors W were proposed, calculated on the basis of the energetic-technological data of process, given by node monitoring system. The correctness of the energetic factors selection to evaluate the work of this node and their practical application in industrial conditions was experimentally proved in other technological object. The selected technological object ? grinding and classification node ? was then mathematically modeled and optimized. The calculated energetic factors were the basis to build mathematical models, identifying industrial copper grinding and classification process. The models described correlation and character of dependency between factors and energetic-technical data of the process. These were regressive and neural networks models. On the basis of factors models, the optimization tasks were determined, which purpose was to select the optimal points of grinding and classification node work. Also, the estimated economical effect, possible to achieve after introduction of given monitoring values to grinding and classification node optimization system, was presented.

Jan 1, 2014

By N. S. Dalal, Xianglin Shi

"Electron spin resonance (ESR) measurements provide direct evidence for the involvement of Cr(V) in the reduction of Cr(VI)· by NAD(P)H. Addition of hydrogen peroxide (H2 O 2) to NAD(P)H-Cr(VI) reaction mixtures suppresses the Cr(V) signal and generates hydroxyl (·OH) radicals (as detected via spin trapping), suggesting that Cr(V) reacts with H2O 2 to generate the ·OH radicals. Reaction between H2O 2 and a Cr(V)·glutathione complex, and between H2O 2 and several Cr(V)-carboxylato complexes also produces ·OH radicals. These results suggest that Cr(V) complexes catalyze the generation of ·OH radicals from H2O 2, and that ·OH radicals might play a significant role in the mechanism of Cr(VI) cytotoxicity. KEY WORDS: ESR. spin trapping, Cr(VI) reduction, Cr(V), hydrogen peroxide, free radicals.INTRODUCTIONThis communication reports an ESR spin trapping detection of hydroxyl ( OH) radicals.in reactions between some Cr(V) complexes containing biologically important ligands and hydrogen peroxide (H2O 2 ). This work was undertaken because while the reduction of Cr(VI) to lower oxidation states has been suggested as a key step in the mechanism of Cr(VI) toxicity, the reaction· mechanism is not yet clear. 1 Mutagencity has been well documented for Cr(VI) via various bacterial assays, while Cr(III) has been shown not to be mutagenic.2 • 3 Since it has been reported that compounds containing Cr(VI) do not react with isolated DNA,4 the reduction of Cr(VI) by other cellular constituents has been thought to be important in the mechanism of Cr(VI) induced DNA alteration.1·4 • 5 For cellular systems earlier studies include those on the reduction of C~(VI) by microsomes,6-8 rat liver DT-diaphorase,9 and aldehyde oxidase. 10 Regarding the reduction mechanism, Jennette used ESR spectroscopy to show that a long-lived Cr(V) complex is formed as an intermediate in the microsomal reduction of Cr(VI) in the presence of NADPH.8 She postulated that Cr(V) is the ""ultimate"" carcinogenic form of chromium compounds. This conclusion has led to many further investigations of the formation of Cr(V) in the reduction of Cr(VI) under biologically relevant conditions.11 - 19 More recently, however, it has been suggested that oxygen-derived radicals generated during the Cr(VI) reduction are the species responsible for the DNA alteration.20.2• To the best of our knowledge, however, no information is available on the generation of such radicals in the reduction of Cr(VI) under biologically relevant conditions, except some preliminary results on the glutathionyl (GS·) radical formation in the reduction of Cr(VI) by glutathione (GSH). 11 - 19 We, therefore, undertook a systematic investigation of the reaction of Cr(VI) with NAD(P)H, GSH, ix-hydroxycarboxylic acids, and H2O 2 • NADPH was chosen as a model reductant because of its ubiquitous existence inside the cells, its critical role in the enzymatic Cr(VI) reduction,1·6-9 its representation of important cellular Cr(VI) reductants, and its ability to reduce other metal ions.22 GSH was chosen as another model Cr(VI) reductant because GSH also exists inside cells, it represents another important category of cellular Cr(VI) reductants, the thiols, and it also plays an important role in the Cr(VI) toxicity .1• 1 ""- 19.i3.i4 For further clarification, we also studied the reaction of Cr(VI) with several '1'.-hydroxycarboxylic acids in the presence of H2O 2 since these acids are definitively known to reduce Cr(VJ) to form stable, isolable Cr(V).25 .2 6 The results obtained indicate that Cr(V) complexes, produced in the reduction of Cr(VJ) by cellular reductants, react with H2 O 2 to generate ·OH radicals, which might be the initiators of primary events in Cr(VI) carcinogenicity."

Jan 1, 1990

By Albert F. S. Seboukens

A 5;6 MVA pyrometallurgical demonstration-scale pilot plant was commissioned at Mintek, South Africa, in 1994, using lead blast-furnace slag and coke as raw materials. The plant included a.d.c. power. supply, two plasma-arc furnaces' and an ISP lead-splash condenser. Slags containing typically 12 per cent zinc oxide and 3 per cent lead oxide are produced as a waste during the smelting of lead in a blast furnace. These slags are a potential: resource for the recovery of lead and zinc. During 1994, about 600 t of lead blast-furnace, slag was proceced through the pilot plant using the Enviroplas process. Zinc and lead oxides were reduced to their respective metals, volatilized, and collected in an. ISP lead splash condenser. Prime Western grade zinc and slags disposable in accordance with current US legislation, were produced. Zinc condensation efficiencies of about 80 per cent were achieved.

Jan 1, 1995