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By A. J. Kraemer

This paper is the third and concluding report of the results of the United States Bureau of Mines twenty-third semiannual survey of motor fuel marketed in the United States. The first paper, reporting data relative to gravity, vapor pressure, and distillation range of the samples, was published as Report of Investigations 3129.7 The second report dealt with the data of the twenty-third survey in accordance with the revised specifications for United States Government Motor Gasoline. These data were published as Report of Investigations 3142.8

Jan 1, 1931

Rock mass classification systems are extensively used in rock engineering design work, and mine design is no exception. Among the systems most widely used for mining-related design work are the NGI 0-system (Barton et al., 1974), the RMR system (Bieniawski, 1976), the MRMR system (Laubscher and Taylor, 1976) and, more recently, the GSI system (Hoek et al., 1998). Classifying the rock mass is widely seen as being the fieldwork required to characterize the rock mass and enable the application of empirical design methods associated with the different classification systems. This paper argues that it is fundamentally important to recognize the distinction between rock mass characterization and rock mass classification. These two processes should, in most cases, be separated from each other. Rock mass characterization should be used to determine the intrinsic properties of the rock mass independently of the application; i.e. independent from the infrastructure to be designed, the size, shape, and orientation of the excavation(s) or pillar(s), etc. Rock mass characterization should also be compatible with most classification systems and empirical design methods to be used. Rock mass characterization is the background fieldwork required to perform rock mass classification and/or engineering design work. Rock mass classification is the subsequent step to the characterization, and an integral part of the design process. Parameters that vary according to the design, such as the relative orientation of geological structures compared to the opening or the mine-induced stresses, should be calculated as part of the rock mass classification and design process, rather than during the rock mass characterization process. The failure to distinguish between rock mass characterization and rock mass classification can lead to major design errors and poor results.

Jan 1, 2012

By Madan M. Singh

This report presents the results of an investigation of inclined roof bolts, anchored over pillars, in room-and-pillar coal mines susceptible to shear failures of the roof. Although the field data do not support this contention, it is believed on the basis of analyses and other work that inclined roof bolts do offer potential under some circumstances.

Jan 1, 1978

By H. W. Gillett

This bulletin is issued by the Bureau of Mines as a contribution to the increase of safety and efficiency in the preparation and utilization of the mineral resources in the United States. Notable among the drains on these resources are the demands made by the nonferrousmetal industries, and in these the losses occasioned in melting brass and bronze are worthy of particular attention. This statement will be better appreciated by a consideration of the size of the brass industry. MAGNITUDE OF THE BRASS INDUSTRY. According to the Thirteenth Census, in 1909 there were in the United States 1,021 fu-ms that dealt mainly in brass and bronze. This total included jobbing foundries, manufacturing plants that both cast and machine a brass or bronze product, and rolling mills, but did not include iron foundries having nonferrous departments nor the numerous large brass-foundry departments of manufacturing plants that produce the castings used in the manufacture of electrical apparatus, cash registers, pumps, and the thousands of machines that require brass castings for their construction. Penton's Foundry List for 1910 gives about 1,150 exclusively nonferrous foundries and about 2,300 iron or steel foundries that also melt brass. If the rolling mills and. jobbing foundries in manufacturing plants be included, and if due credit be given to the rapid growth of the industry in the last few years, largely through the stimulation of the automobile busi¬ness, it is probable that not less than 3,600 plants are to-day melting brass or bronze.

Jan 1, 1916

By P. N. Anyalebechi

The effects of solidification rate on the cast microstructures of aluminum alloys 6009 and 6016 have been investigated with directionally cooled laboratory-size ingots, at 0.2-10.1 K/s and 0.4- 23.1 K/s, respectively. These ranges of solidification rate are within those observed in commercial-size ingots. In both alloys, the average dendrite cell size and second phase particle size decreased with increase in average solidification rate and with a decrease in average local solidification time. However, at comparable solidification rates, the dendrite cells and second phase particles are finer in the shorter freezing range alloy 6009 than in the longer freezing range alloy 6016. This is provisionally attributed to the earlier formation of second phase intermetallics at higher temperatures during solidification and to the formation of greater amount of the relatively coarse plate-like ß -phase (Al9Fe2Si4) phases in alloy 6016. In general, in both alloys, the types and relative amounts of the second phase particles in both alloys are independent of solidification rate.

Jan 1, 2006

By John Marsden

Despite the recent pullback in metal and mineral prices, and the associated market adjustments, the mining industry is still facing a serious issue with the declining availability of graduate expertise. This is due to a combination of an aging workforce, retirements and retrenchments, coupled with a lack of suitably qualified graduates entering the workforce. The issue has certainly improved since 2004 when the industry picked up the rates of hiring graduate engineers and mining/mineral school enrollments picked up in response. This hiring effort has helped to cover the ?gap? years from about 1985-2000, when industry demand for graduates was particularly poor. However, the recent market pullback is likely to set back this progress, as recruitment and hiring wavers as a result of cost cutting measures and economic uncertainty. A key issue for the mining industry is how to ensure the survival and growth of relevant ?core? degree programs. Such programs include mining, metallurgical, mineral processing and geological engineering. The mining industry needs a healthy, high-level education program to ensure an adequate supply of appropriately qualified graduates for the mining industry. Two-thirds of the professionals entering the minerals industry who graduated within the past 40 years graduated prior to 1985. Since 1985, we have been living off the legacy of graduation classes from the mid-1970s and early 1980s. It is estimated that we have been producing graduates at approximately 40 to 50 percent of the sustaining rate since about 1985. Further growth in the domestic industry would increase graduate requirements significantly, and the export of U.S.-graduates to other parts of the world (as is currently occurring) also impacts the total graduate requirements.

By B Olsson, B Reynolds, R Norman

An unprecedented growth in demand for coal exports has placed pressure on multi-user coal chains to guarantee that their capacity expansion projects will meet the required demand. These projects, however, are taking place in an increasingly complex commercial and technical environment - competing rail and coal terminal service providers as well as a myriad of competing mine operators, all needing to operate in an increasingly integrated manner to get the most out of expensive shared assets.Increasing system complexity and integration has driven the need for more holistic and sophisticated analysis tools. The capacity of coal chain subsystems, such as mine, rail and port, can no longer be determined effectively in isolation. Understanding the nature of the interactions between these subsystems, their sensitivity to uncertainty and the resultant capacity of the integrated system is the key to both maximising value and minimising risk.Recently, TSG has worked closely together with the Integrated Logistics Company and a number of key stakeholders in the Dalrymple Bay Coal Chain to develop independent system master plans. These master plans have provided a quantitative and rational assessment of coal chain capacity in its current state and a prediction of its capacity once a pipeline of committed capacity improvements is in place. This paper provides an overview of the study and a comprehensive guide to the process required to effectively achieve valuable strategic insights in a challenging multi-user stakeholder environment.CITATION:Reynolds, B, Olsson, B and Norman, R, 2012. Using independent system simulation to mitigate risk in the Dalrymple Bay Coal Chain, in Proceedings Project Evaluation 2012 , pp 77-84 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 24, 2012

By Zbigniew Zurecki

The selection of atmosphere composition is critical for controlling surface quality of reactive aluminum alloys during solution treatments. An improper selection of annealing atmosphere can result in surface blistering in AI-Mg and sub-surface depletion of lithium in AI-U ingots. To determine optimum atmosphere compositions for homogenizing A1-Mg and Al-Li alloys, Ii number of exploratory experiments were carried out in air, nitrogen, and carbon dioxide based atmospheres including reactive impurities or additive such as moisture and sulfur hexafluoride. This paper describes the influence of these atmospheres on high-temperature oxidation and sub-surface defects. The results are discussed in terms of the change in Pilling-Bedworth ratio.

Jan 1, 1996

By Roberto Busato Belger

- Fertilizer Business Overview - Supply -Demand Balance in the World - Supply -Demand Balance in Brazil - Brazilian Market Growth Opportunities - Fosfertil Operations - Fosfertil Expansion Plan - Salitre Project - Project Characteristics - Technical Challenges and Solutions - Technical Support Studies Conclusions

May 1, 2010

By J. A. Jr. Carpenter

Expanding world economic prosperity, probable peaking of conventional petroleum production in the coming decades and environmental concerns require efforts to increase the efficiency of, and the development of alternatives to, petroleum-based fuels used in automotive transportation. In January 2002, the U.S. Department of Energy (USDOE) and the U.S. Council for Automotive Research (USCAR) of the "Big Three" traditionally-USA-based automakers, DaimlerChrysler, Ford and General Motors, formed the Freedom Cooperative Automotive Research (FreedomCAR) Partnership to fund high-risk, high-payoff research into advanced automotive technologies with the potential for eventually lowering the USA's nearly complete (95%) dependence on petroleum, 55% imported, for its transportation fuels. FreedomCAR replaced the Partnership for a New Generation of Vehicles (PNGV) which existed from 1993 to 2001. In January 2003, the energy-supply industry joined with the FreedomCAR Partnership forming the FreedomCAR and Fuel Initiative (FC&FI) to develop the technologies needed for the mass production of fuel-cell vehicles using hydrogen as fuel and the infrastructure needed to deliver the hydrogen to the consumer. The goal is to enable the automotive and energy-supply industries to make commercialization decisions in 2015 on large-scale introduction of such vehicles and on developing the infrastructure beginning in 2020. In addition to work on fuel cells and hydrogen infrastructure, the FC&FI conducts research on technologies with the potential for nearer-term energy efficiency and environmental benefits, such as new engine concepts, lightweight materials, and engine-electric hybrid propulsion systems. Lightweighting is seen as crucial for shorter and for longer term benefits because hybrid and fuel-cell powertrains are expected, at least in the early stages of adoption, to be heavier and more costly per unit of power than the standard internal-combustion, gasoline- or diesel-fueled powertrains they replace. Research and development (R&D) on casting of aluminum automotive components were major parts of the PNGV and R&D on casting of magnesium automotive components have been and are so under FreedomCAR. This presentation will review those efforts.

Jan 1, 2006

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 P. L. Crouse, S. J. Lubbe, M. J. Kabangu

A selective extraction and separation of zirconium by solvent extraction with 1-octanol is proposed. The process is based on the dissolution of the metal basic carbonates in hydrochloric acid in the presence of potassium fluoride, using 1-octanol as extractant. The effect of several process parameters, including hydrochloric acid and potassium fluoride concentrations, reaction time, and phase ratio between the aqueous and the organic phase was investigated. Zirconium is enriched in the organic phase. The best extraction and separation results were obtained with the basic carbonate dissolved in 10% hydrochloric acid and 1.5 M potassium fluoride. The optimum reaction time was 15 min with an organic to aqueous phase ratio of 2:1. Based on the selectivity of zirconium over hafnium in the organic phase, a McCabe-Thiele diagram was constructed. A near complete stripping of zirconium from the organic phase was achieved using a 3 M sulphuric acid solution. Additional studies are required in order to determine the reaction mechanism and the chemical speciation of the current investigation.

By G. K. Rogers

The portal, which is the near-horizontal, surface point of entry to an underground excavation, can often be an exceedingly difficult area in terms of ground control. Surface and subsurface failures at portals, as discerned during a study involving over 300 case histories, are unfortunately, common. To aid in the engineering evaluation of portals, the Geomechanics Classification System was appended with discontinuity orientation assessment values and support/excavation guidelines. Also, a design model utilizing RMR predicted rock loads in conjunction with half-dome theory is proposed for the most common type of portal failure. Other pertinent comments and recommendations relating to portal stability are included.

Jan 1, 1989

By Michael Harley, E. Guy Charlesworth

"Abstract - Bedding-parallel thrust-hosted gold veins are developed in the Sabie-Pilgrim's Rest goldfield, eastern Transvaal, South Africa. The reefs display a complex history characterized by temporally and spatially overlapping events of similar mineralization and deformation. Recognition of the episodic reactivation of these low angle (5° to 10°) thrust faults implicates high fluid pressures (equalling or exceeding lithostatic pressures). Geochemical constraints limit the amount of fluid-rock interaction and the occurrence of transgressive mineralization within the Archaean granitoid basement suggests that the high pressure fluids originated at depth beneath the Transvaal Basin.Similarities exist between gold deposits of Sabie-Pilgrim's Rest and Telfer, Western Australia as well as Passagem de Mariana, Minas Gerais, Brazil. All deposits are sub-parallel to the enclosing bedding which is shallowly inclined. Furthermore, they are also hosted by contractional deformational structures and are clearly epigenetic in origin."

Jan 1, 1994

By Terry A. Lee

The grade of mineral resource estimates underpin all major economic considerations of mining prospects. While there are reporting requirements to satisfy when stating a mineral resource estimate, an examination of NI 43-101 style reports suggests that authors believe that there are a number of ways of addressing these requirements. As a reader of these reports, some processes are helpful and others are not so in getting a real appreciation of how realistic is the mineral resource estimate. Critical to the quality of the mineral resource estimate is how realistic is the economic mineral concentration component. In many cases, this parameter is called grade. The industry experiences increased difficulty in achieving realistic grade estimates as the sample grade variability increases. The level of transparency in a mineral resource estimate is very much a function of the competence of the author. An objective presentation of the critical data, such as grade sampling variability can assist a reader in determining if the geology of the mineral concentration is adequately understood and how realistic is mineral resource grade estimate. This paper has considered 75 NI 43-101 style reports released in the past 2 years. The review demonstrates features that were helpful in determining how realistic the mineral resource grade estimate is. If there is insufficient transparency in a report, there is a high probability that the mineral resource grade estimate will not be realistic.

Apr 1, 2005

By R. R. Oder, R. E. Jamison, E. D. Brandner

This paper presents preliminary test results obtained with a 0.38 kg/s (3000 lb-hr) beta prototype MagMill™. In processing Upper Freeport coal the beta prototype recovered 82% of the weight of the feed and 91% of the heat content while reducing the potential emissions of sulfur, kgSO2/GJ(lbSO2/MBtu), by 61%. Pyritic sulfur in the MagMill™ product was reduced by 78% compared to that in the feed. For all runs, the mill product was controlled between 70 to 80% finer than 74 µ particle size. Recoveries of mercury, arsenic, and selenium ranged from 35 to 45% of that in the feed. Power draw was reduced by 26% and mill throughput was increased by 9% compared to the pulverizer operating with no magnetic separator attached.

Jan 1, 2000

By B Powell

Coastal acid sulfate soils (ASS) are wetland soils and unconsolidated sediments that contain iron sulfides which, when exposed to atmospheric oxygen in the presence of water, form sulfuric acid. ASS form in protected low energy environments such as barrier estuaries and coastal lakes and commonly occur in low lying coastal lands as Holocene marine muds and sands. When disturbed, the iron sulfides in these soils can oxidise and produce large volumes of sulfuric acid (essentially similar chemistry to acid rock drainage with mines) resulting in the subsequent release of toxic levels of iron, aluminium, manganese and possibly heavy metals. This results in detrimental effects on aquatic biota, plants, animals and steel/concrete structures and on human health in the surrounding environment. There are an estimated 2.3 million ha of ASS located along 6500 km of the Queensland coastline. In contrast to many mineral sulfides encountered in the mining industry, the pyrite crystals in ASS can be as small as 2 mm and commonly occur as framboids with extremely large surface area per unit mass, substantially increasing their reactivity if exposed to air (oxidation). Highly reactive iron monosulfides can also occur, particularly in drains and shallow lakes. Many coastal areas, where some 80 per cent of the population of Queensland reside, are coming under pressure for agricultural and urban development. Construction of canal estates, marinas, housing/industrial estates, roads, golf courses, aquaculture ponds, sand/gravel extraction and drainage for sugar cane can disturb ASS and release sulfuric acid, which may then drain into adjacent waterways with heavy rain. As development continues to encroach on coastal lowlands, the identification, quantification and management of ASS must be addressed as part of a commitment to the principles of Ecologically Sustainable Development (ESD). ASS can be successfully managed by adopting best practices and following guidelines, but government, community and industry must collaborate to raise awareness, avoid æhot spotsÆ and develop more cost-effective solutions. Scientists led the education and public awareness program showing infrastructure and environmental damages arising from ASS in Queensland. Using results from mapping and research, they convinced policy makers, industry and polititians to accept the need for legislation founded on good science. The resulting æState Planning Policy 2/02: Planning and Managing Development Involving Acid Sulfate SoilsÆ identifies the StateÆs interest in acid sulfate soils. The Queensland Government considers that development involving acid sulfate soils in low-lying coastal areas should be planned and managed to avoid potential adverse effects on the natural and built environment (including infrastructure) and human health. SPP 2/02 states where the policy applies and when a development application will trigger the policy. It can also be used to assist local governments in preparing their planning schemes under the æIntegrated Planning Act 1997Æ. The SPP 2/02 comes with a æState Planning Policy 2/02 GuidelineÆ to provide advice and technical information on interpreting and implementing the SPP 2/02. This guideline has legal status in assisting in the interpretation of SPP 2/02. Those seeking more detailed technical information can now also access the æSoil Management GuidelinesÆ and ASS æSampling GuidelineÆ, available from the Department of Natural Resources and Mines website. These are some of a series of chapters being developed for the æQueensland Acid Sulfate Soil Technical ManualÆ.

Jan 1, 2003

By S. D. Hill, G. E. McClelland

To maximize productivity and improve minerals processing technology, the U. S. Department of the Interior, Bureau of Mines, is investigating a particle agglomeration technique as a means of increasing the percolation rate of leaching solutions through heaps of clayey or finely crushed, low- grade, gold-silver ores. Bench-scale and pilot-scale experiments conducted on different ores indicated that the percolation rate of cyanide leaching solution was enhanced markedly by mixing the ore with a binder, such as lime or portland cement, moistening the mixture, then mechanically agglomerating and aging the feed prior to heap building and leaching. In addition, the rate of silver and gold extraction markedly increased without sacrificing total recovery of values. The use of concentrated cyanide solution instead of water during the agglomeration procedure substantially decreased the leaching time required to obtain maximum recovery. Results from bench-scale and pilot-scale experiments using the particle agglomeration technique are discussed.

Jan 1, 1981

By Gianni Bartolacci, Patrice Nadeau, Szatvanyi. Gerard, Carl Duchesne, Claude Chrétien

"Combustion is used throughout the mineral processing industry to produce steam in boilers, to dry concentrates in rotary dryers, and to apply heat treatments in pyrometallurgical furnaces. Tight combustion control is very important in latter type of furnace since the combustion conditions directly affect final ore quality. However, achieving tight combustion control is not straightforward since most of the flames encountered in industry are turbulent non-premixed flames, they are affected by several unmeasured disturbances and are often produced by burning several types of fuel simultaneously, some of them coming from other parts of the plant. A novel method is proposed in this paper to improve process and product quality control as well as to optimize the combustion conditions based on digital flame color images. Multivariate Image Analysis and Regression is to used extract the flame color characteristics from images to predict the solids discharge temperature of an industrial rotary kiln. It is shown that this method yield extremely good 10 minutes ahead forecast of the temperature and should lead to a substantial reduction in product quality variability as well as in fuel consumption.INTRODUCTIONFuel-fired furnaces are often used in the mineral processing industry for various purposes, such as for the production of steam (utility boiler), in conjunction with rotary dryers to dry mineral concentrates or in pyrometallurgical processes for induration, roasting, and so forth. These furnaces are necessary in the supply chain from the mine to the metals, but their operating costs are constantly rising due to the fluctuations in fuel prices. Moreover, these processes are now targeted by the Kyoto Protocol since they are energy intensive and they produce significant amounts of CO2 and other pollutants such CO, NOx and SO2. To achieve both a reduction in operating costs (i.e. fuel consumption) and in pollutant emissions while maintaining or improving product quality, one needs to have a very good control of the combustion process."

Jan 1, 2005

By X. Louw

"This paper examines the change in surface properties of the Polyurea used on spirals at different operational times: unused spiral, 28 months in operation and 58 months in operation. This is being done to investigate the alleged statement that spirals have a decrease in spiral separation efficiency after a certain period of operational time. Observing the surface characteristics under 1.5x and 36x magnification it can be concluded that the surface roughness decreases with increased operational time. This may be explained by a decrease in air inclusions and streak lines as the spiral surface wears. Decreased surface roughness should in theory have a beneficial effect on spiral separation performance. This leads to the conclusion that if a decrease in spiral separation performance is observed after a certain period of operation, it can’t be attributed to the change in surface properties. Uneven wear of the spiral surface, material creep or application of force to the spiral will change the profile of the spiral and could cause an adverse effect on spiral separation performance. The metallurgical test work showed that the best results are obtained at 30 - 35% solids by mass in the spiral feed. The iron recovery was significantly higher in the new spiral in comparison to the 2012 and 2010 spirals. The mass yield to concentrate in the new spiral was approximately three times more than for the older spirals. In conclusion, the yield combined with the grade, which equals the recovery was the best for the new spiral.IntroductionAn investigation was launched to research the common belief that spirals experience a decrease in efficiency, and therefore recovery, after a certain period of operation (a period of seven years has been used in the industry). The properties of the spiral that may have an effect on the efficiency are:"

Jan 1, 2017