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By Z. Hyder, M. Karmis

Underground or In-situ Coal Gasification (UCG or UICG), though not a new concept, is now attracting considerable global attention as a viable process to provide a "clean" and economic fuel from coal. Applying improved UICG technology to gasify deep, thin, and low-grade coal seams could vastly increase the amount of exploitable reserves. However, it is imperative that further development of this technology is based on integrating UCG practices and potential environmental impacts with accepted sustainability frameworks and processes. This paper evaluates the potential of UCG to conform to frameworks such as MMSD (Mining, Minerals and Sustainable Development), Natural Step and Green Engineering, in order to define its "sustainable" potential. The paper also discusses the potential contributions of UCG to sustainability during its design, operation, closure, and post-closure phases.

Jan 1, 2011

By M. J. Farrell

Mining is a significant emitter of greenhouse gases and is the focus of increasing attention from green groups and regulators. Miners need to know their own carbon emissions and how they compare with the rest of the industry. Miners and mining companies need to know where they fit in the emissions curve. Who is in the bottom quartile? This article is based on research report data from minecost.com and Metalytics Pty Ltd which detail the specific carbon dioxide emissions for 208mines producing 90% or more of western world copper, zinc, lead and nickel in 2007. The copper and nickel mines also include Norilsk in Russia, KGHM in Poland and Kazakhmys in Kazakhstan. This is the first time that such information has become available.

Jan 1, 2009

By D. A. Larson

The Bureau of Mines conducted research to develop preliminary engineering data necessary if the cobalt-rich manganese crusts that occur in the Exclusive Economic Zone (EEZ) of the Hawaiian Archipelago are to be mined. The research was divided into the following sections: (1) physical, mineralogical, and chemical descriptions; (2) mechanical property testing, such as compressive strength, tensile strength, and a rippability index; and (3) mechanical cutting characteristics, including average and peak cutter forces, the specific energy, and cuttings size distribution. Section 1 utilized microscope, X-ray powder diffractometer, and electron microprobe analyses. Section 2 utilized standard mechanical property testing techniques. Section 3 utilized a converted planer mill with full-size coal cutters to fragment the crust and substrate samples. The manganese crust samples were mainly manganese and iron oxides and hydroxides with an average cobalt content of 1 pct and had a nucleus or substrate of rock or sediment. The significant results shown by the mechanical property and cutting tests are that the crust and all but two types of substrates (basalt and trachyte) are weak materials and easily cut with standard drag cutters. The crusts are generally comparable to medium hard coal in strength and in their resistance to cutting.

Jan 1, 1987

By C. C. Merrill

The Bureau of Mines beneficiated the wastes generated by commercial titanium chlorination operations to reclaim metal values and reduce the problem of disposing of solid wastes. A water leach solubilized about 40 percent of the dry weight and over 75 percent of the metallic impurities. The residue from the water leach was rich in titanium dioxide and carbon; it was combined with rutile and recycled to a laboratory chlorinator. The contained carbon was used in lieu of part of the coke requirement.

Jan 1, 1969

By Oliver Bowles

The manufacture of lime is one of the oldest industries. Plants are distributed widely and furnish an essential raw material for numerous industries. The use of lime by the building trades, in agriculture, and in hundreds of manufacturing and chemical processes has created demands for a large production and has necessitated exhaustive research on methods of manufacture and uses. The bibliography of lime is an extensive one, but for the most part each publication has dealt with only certain operations. The purpose of this paper is to present a general picture of the industry as a whole. The abundant literature has been abstracted and quoted freely, and the National Lime Association has rendered valuable assistance in furnishing data for certain sections. Publications containing more detailed information on the various branches of the industry are referred to in the footnotes and in the bibliography.

Jan 1, 1936

By Pierre Pelletier, Christian Pichetie, Dany Pelletier

"IntroductionDuring 1994, Barrick Gold Corporation, or American Barrick at that period, acquired Lac Minerals Ltd. properties. One of them was the Bousquet Complex. The Bousquet Complex is divided into three distinct sites: one mine (Bousquet 2), one mill (Est-Malartic Division) and one analytical chemistry laboratory (Les Terrains auriferes).The Bousquet 2 orebody was discovered in 1986. An extensive drilling program was initiated during 1987. Its purpose was to define the orebody extent. At the end of 1997, gold production from Bousquet 2 mine reached 1 290 000 oz of gold from a cumulative tonnage processed of 4 175 000 M t.From 1980 to 1990, the Est-Malartic mill was used for the treatment of ore from the following mines: Bousquet 1, Doyon, Francoeur (Richmont mines), Buckshot and 1-20 stope. At present, the mill receives ore from the Bousquet 2 mine.HistoryThe Est-Malartic mill is located close to the town of Malartic in northwestern Quebec. The mill has been in production since the mid-1930s processing mainly clean, free mill gold ore. Active mining from the Est-Malartic mine ceased in 1979 and the mill was switched to custom processing of ore from La Mine Doyon located some 45 km to the west. This custom processing arrangement continued until 1987 when the expanded mill at Doyon became available to process all of the Doyon production. In 1987, Lac Minerals commenced development of a second mine at the Bousquet site located 40 km west of Malartic. This mine, Bousquet 2, is the down dip extension of the La Ronde mine developed by Agnico Eagle. During pre-feasibility evaluations, it was determined that it would be economically more attractive to modify the existing Est-Malartic mill than building a new facility on site. The Est-Malartic mill modifications for processing the high-copper/gold ore from the Bousquet 2 mine began in late 1989 and new circuits were commissioned in mid-1990. Modifications included the addition of both gravity and flotation concentration circuits to recover coarse, free gold and the copper. The existing leaching circuit continued to operate on the copper flotation tailings with some minor modifications to the solution handling systems. A S02/Air cyanide destruction circuit was also added at that time."

Jan 1, 2000

By Rees J. Llewellyn

High chromium white irons can be formulated to provide required combinations of abrasion and erosion wear resistance, toughness and capability to withstand corrosion attack. As a consequence, they are used widely in casting form throughout the mining/mineral processing industry, particularly as components for slurry pumps and also as mill and crusher liners, laminated wear plates in chutes and hoppers and in valves, nozzles and cyclones. Traditional cast chromium molybdenum and high chromium white irons for wear applications are covered in ASTM A532 Classes 11 and 111 and are also available as comparable proprietary alloys. They rely on heat-treated, hypoeutectic microstructures containing a high volume fraction of very hard eutectic/secondary metal carbides and martensite to provide extremely high wear resistance. The ability to increase the carbide volume fraction and hence achieve higher wear resistance, has been limited because of severe casting difficulties encountered when carbon and chromium contents are raised and hypereutectic alloys with structures also containing coarse acicular primary metal carbides are produced. The limitation has been overcome and cast hypereutectic chromium white iron pump components have established themselves in a wide variety of mineral processing service applications. Comparisons will be made between the microstructures and wear test performance data for the various alloy types and details will be provided of the service performance improvements that have been achieved through the use of hypereutectic chromium white irons.

May 1, 2004

By P. Bissert, M. Klein, L. Yan, D. Yantek, R. Matetic

"U.S. Mine Safety and Health Administration (MSHA) regulations require underground coal mines to use refuge alternatives (RAs) to provide a breathable air environment for 96 hours. One of the main concerns with the use of mobile RAs is heat and humidity buildup inside the RA. The accumulation of heat and humidity can result in miners suffering heat stress or even death. MSHA regulations require that the apparent temperature in an occupied RA not exceed 95 °F. To investigate this, the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted testing on a 23-person tent-type RA in its Experimental Mine in a test area that was isolated from the mine ventilation system. The test results showed that the average measured air temperature within the RA increased by 9.4 °C (17 °F) and the relative humidity approached 94 percent at the end of a 96-hour test. The test results were used to benchmark a thermal simulation model of the tested RA. The validated thermal simulation model predicted the volume-weighted average air temperature inside the RA tent at the end of 96 hours to within 0.06 °C (0.1 °F) of the average measured air temperature. IntroductionIf an accident occurs in an underground coal mine, miners who fail to escape from the mine can enter a refuge alternative (RA) for protection from adverse conditions, such as high carbon monoxide levels. One of the main concerns with the use of mobile RAs is the potentially adverse thermal environment inside an RA from the metabolic heat of the occupants and the heat released by the carbon dioxide (CO2) scrubbing system. Moreover, the humidity within the RA will increase through occupants’ respiration and perspiration, and from the chemical reaction within the CO2 scrubbing system. The accumulation of heat and humidity can result in miners suffering heat stress, heat stroke or even death."

Sep 1, 2016

By D P. Sainsbury, B L. Sainsbury, A Vakili, H-D Paetzold, P Lourens

The cave propagation behaviour of a jointed rock mass is strongly governed by the unique nature of joints and discontinuities, together with the intact strength of rock bridges that make up the rock fabric. A discrete finite difference (DFD) modelling technique has been developed to allow for the detailed consideration of the rock mass structural fabric at many scales and through many different stress paths that can be used for complex mine-scale analysis. The DFD methodology uses interfaces to explicitly represent large-scale structures and ubiquitous joints embedded within the simulated rock mass matrix to characterise intermediate structures. Through simulated testing of DFD materials, properties such as strength anisotropy and scale effects can be obtained. This paper discusses the successful application of implementing a DFD modelling technique for the back-analysis of caving-induced subsidence behaviour of Lift 1 at the Palabora mine.CITATION:Sainsbury, D P, Sainsbury, B L, Paetzold, H-D, Lourens, P and Vakili, A, 2016. Caving-induced subsidence behaviour of Lift 1 at the Palabora block cave mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 415–426 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By E. C. Lane

[This Is the ninth in a series of reports on properties of commercial motor fuels, made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the United States Department of the interior. The first report gave data on motor gasoline sold during the winter of 1935-36.3/ The Present report presents analytical data for 2,033 samples, representing the products of approximately 80 companies, which, as in previous surveys, include both large and small suppliers. In addition, the Pacific coast is represented by data that were average by the Pacific Coast Technical Group before 'being submitted and are published exactly as they were received. As in previous surveys, the data are divided into the three groups of samples of regular-price, premium-price, and third-grade gasolines, and each group has been averaged separately. The cumber of samples, items, and brands comprising each group, exclusive of those of the Pacific coast, arc as follows: Regular price, 1,066 samples, 208 items, and 49 brands; premium price, 575 tamales, 154 items, and 38 brands; third-grade gasoline, 7;4 samples, 150 items, and 53 brands. The meanings of these terms as used in the surveys tar as follows: Sample: The individual supply of gasoline obtained at the filling station and analysed in the laboratory.]

Jan 1, 1940

By Mark Colwell

As per most other earth science engineering problems, the underground coal geotechnical environment and the way in which roof and rib support interacts with the rock mass are complex issues. While the problem should not be oversimplified (i.e., the dominant failure mechanisms or critical data input parameters should not be ignored), without question judicious simplification is at the heart of all good engineering design. Engineers play a vital role in supplying the world with solutions and products; however it is crucial that engineers make practical and readily useable contributions. One way to ensure this is to employ simplification in the engineering process.

By AIME AIME

WHEN "Chief" Buehler in mid-September set out on his official 10,000 mile swing-around-the-circle visiting Local Sections he decided not to tell his audiences how to organize and operate a state geological survey. As the director for 28 years, of the Missouri Bureau of Geology and Mines (which, he concedes, is the best in existence) lie could have done this to good advantage; but he preferred to discuss affairs of the Institute. In 25 speeches made to member and student groups, he dwelt on sonic or all of the following phases of activities. He stressed the vital importance of the Local Sections in providing the opportunity for members to associate under pleasant auspices with others in their profession. The benefits of Institute membership he classified as tangible and intangible. Of the two lie felt that the latter were more important. A man's progress in his profession depends in large measure upon a broad acquaintance and friendship with others. The Institute is incomparably the best medium for meeting fellow engineers. The primary, function of the new enlarged Membership Committee is to obtain a comprehensive list of engineers eligible to be members, always hearing in mind that the standards of membership must not be lowered in any degree. These men are to be invited by individual letter to apply for membership. Whether they become members or not is of less importance; but it is vital that no qualified man should be outside the fold for the reason that membership had never been suggested to him. Dr. Buehler emphasized repeatedly his feeling that the younger man that had never had Institute membership brought specifically to his attention had been cheated:

Jan 1, 1935

By Robert L. Marovelli

The major mining health and safety problems of concern to United States Government and private industry researchers in 1981 included the difficulty experienced by longwall operators in complying with the Federal 2 .0-mg/m3 respirable dust standard, the accident rate associated with falls of ground and materials handling hazards, and the upsurge in the incidence of disasters after the steady decline in recent years. Although the many mines and manufacturing companies involved in the research projects to be described are not specifically identified, it is important to note their significant involvement. This is not by way of acknowledgement, but rather to establish that these projects, using mostly Federal funds, represent close cooperation between the U.S. Government and the mining industry. The ongoing work to be described on the development of critical longwall dust control technology is a classic example of Government-industry participation through the phases of problem identification, planning, cost-sharing, and implement at ion.

Jan 1, 1982

By Y. Pokhvisnev, S. Vandariev, A. Yatshenko-Juk, V. Valavin, V. Romenets

The technology of the liquid-phase reduction process known as Romelt was developed in the Moscow Institute of Steel and Alloys in 1979. The pilot plant was constructed at the Novolipetsky Steel Works (Russia) in 1984. Investigations into processing zinc-containing blast oxygen furnace dust and slag from the Lead and Zinc Works at the pilot Romelt plant proved the perspective of using this technology for processing zinc and lead-containing materials. In this article, the description of Romelt technology, basic technological information of trials at the Romelt plant using zinc-containing materials, compositions of charging materials, metal, slag, gas and dust are presented. The influence of flue gas composition on the composition of zinccontaining dust is shown.

Jan 1, 2000

By Charles P. Lazzara, Alex C. Smith, Richard W. Pro, Mark W. Ryan

The U.S. Bureau of Mines conducted a study to determine if commercially available automatic sprinklers could withstand the high static pressures in deep underground coal mines without leaking and if exposure to the mine environment affected their leak pressures. New sprinklers and sprinklers exposed to the mine environment were subjected to increasing pressures until leakage occurred. The average leak pressures of the new sprinklers ranged from 640 to 2,300 psig and were significantly different for sprinklers from different manufacturers and for different types of sprinklers. Different for sprinklers from different manufacturers and for different types of sprinklers. Generally, standard-response sprinklers withstood higher pressures than fast-response sprinklers. The results indicated that most commercially available sprinklers would withstand the high static pressures in deep underground coal mines; however, they would not provide the same reliability and safety factor as sprinklers used aboveground at or below their rated pressure of 175 psig. The average leak pressures of the sprinklers exposed to the mine environment ranged from 740 to 1,180 psig. The mine environment affected the ability of 66% of the sprinklers to withstand high static pressure New sprinklers were also evaluated at pressures of at least 500 psig for 30 days to determine their ability to withstand long-term exposure to high static pressures; no leakage was observed.

Jan 1, 1993

The geologist is often called upon to give judgment on the possibilities of reviving a former mining field presumably worked out as far as the evidence then available indicated. From time to time, scarcity and consequent high prices of metals has led to there-examination of many old fields. The possibility of resuming investigation on them where the practical miner ceased work, even where he had the aid of the trained geologist, has long since disappeared.Means of access to mines have been removed and water fills the workings. Hence an indirect mode of attack becomes essential.This method depends mainly on past history, and may be described as a reaching out by faith supported by shrewd guessing from the known to the unknown. Apart from whatever general intelligent observations may be made in situ of the evidence of former mining activity, the method depends largely on the examination of the past history of the field as revealed in the official records, company reports, plans of underground workings, local newspaper accounts, and the testimony of practical miners formerly employedon the field, the' reliability of which has to be carefully sifted. The matter derived from the examination of these sources must next be rigorously collated and correlated where possible. When the review of all individu!1l features and aspects has been completed, tentative and speculative conclusions may be drawn which, though not verifiable before the event, will usually prove to be more serviceable guides in exploratory operations than mere "blind stabbing."As an actual illustration of what is involved in the mode of procedure outlined above, the following is the description of an investigation in which the writer took part.In 1937, during the course of the Commonwealth Aerial, Geological and Geophysical Survey of Northern Australia, a detailed geological investigation was undertaken of the Croydon gold field, situated near the south-eastern. extremity of the Gulf of Carpentaria in North Queensland.The history of the field briefly is as follows: It was discovered in 1885, reached its peak of production 1896, declining thereafter till 1906, when operations ceased. The total production was about 1,000,000 ounces of gold bullion, containing approximately 40 per cent. of silver. The gold bullion was won from flat-dipping quartz reefs, which yielded an average of 2.oz. to the ton, and the maximum depth to which production occurred was 500 feet. Subsequent prospecting below this depth failed to locate further ore.In consequence of the inaccessibility of the mines and the almost total masking of the' surface by alluvium, the investigation of future possibilities became largely an. office ,study, which was conducted under the following headings:-1. Recording of factual data of each mine separately.

Jan 1, 1950

By W. M. Jansen

In many mineral processing operations, the reported production figures for an accounting period may not make the best use of available data. While most of the mathematical approaches, such as check-in/check-out, mass balancing, used in effective metallurgical accounting strategies are well understood, the sources and magnitude of measurement errors generally are not. As part of the 'AMIRA P754-Metal Accounting and Reconciliation' project, a study was undertaken at the Northparkes copper/gold concentrator near Parkes, New South Wales to examine the data used in their concentrator metallurgical accounting system. This paper summarises the results of a detailed examination of the mass measurement systems around the concentrator as well as the primary sampling system used for grade estimation. The goal of this work was to develop practical techniques to quantify the error (ie both accuracy and precision) of the measured metal accounting information. With this information, statistical confidence levels for this data can then be calculated. If the errors are small, the effect of error in each piece of measured data can then be propagated to other calculated production figures such as recovery and feed grade using a statistical technique called `the propagation of error'.

Jan 1, 2007

By S. Hamm

Elevated total dissolved solids (TDS) content in waters downstream from surface coal mines in Central Appalachia is an increasing concern, as unnaturally high TDS and/or associated specific conductivity (SC) may contribute to deteriorated stream ecosystem health. The aim of this preliminary study was to explore the efficacy of accelerated leaching as a means of minimizing long-term TDS/SC generation by problematic overburden materials. Five spoil samples were collected and leached using simulated rainwater solutions under ambient and acidified pH conditions. SC and pH were monitored during each leach cycle, and ICP-MS was used to determine how leaching conditions affected release of specific ions. This paper highlights the results of both jar and column leaching tests. Among the most significant findings was that, for certain spoil materials, SC in leach column effluent was effectively reduced when spoil was leached first with acidic rainwater followed by ambient rainwater (vs. ambient rainwater leaching alone). This suggests that accelerated leaching might aid in long-term stabilization of some materials.

Feb 23, 2014

By Gerard de Vries

pipeline industry and are still growing in size. Liquid epoxy and polyurethanes are an excellent choice for whatever the aggressiveness of the substance transported and whatever the harmful outside influences, maximum protection is required. They can be used as coatings on all kind of pipelines varying from the mainline coating to the field joint coating. Compared with traditional systems like dual layer FBE and 3-layer polyolefin there are some benefits to be considered like easiness of repairs, amount of coats, application temperature and film thickness. The interior coating renders the pipe surface so much smoother that considerable savings can be realized in pump stations. Apart from the interior of the pipeline, the industry is faced with new challenges like higher operating temperatures of lines and an emphasis on product benefits in order to save money. Key words: liquid epoxy, liquid polyurethane, phenolic epoxy, pipeline, field joint coating, internal coating, corrosion control

Jan 1, 2006

By M J. Daniel

The diamond industry is no newcomer to High Pressure Grinding Rolls (HPGR) as it has used the technology for more than 20 years, predominantly in secondary crushing and recrushing roles. In fact it could be argued that the diamond industry has led the way for the wider minerals industry to consider its application. In existing conventional secondary cone crushing applications, large valuable diamonds are" won" through meticulously managing the recovery process within defined particle size ranges. Conventional crushers operate with relatively large closed side settings, but have the potential to damage diamonds by making direct contact with the sides of the crusher. Cone crushers also result in steep product size distributions that run a high risk of losing many of the smaller, unliberated but more abundant diamonds from the rock. This current comminution paradigm of particle size reduction management results in recrushing processing applications or plants where HPGRs are often used.

Jan 1, 2010