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By A. E. M. Warner, I. E. Hills, C. L. Harris

Since the late Dr. Keith Brimacombe, et al, performed tests at the now-closed Asarco Tacoma smelter and the Inco Copper Cliff Smelter on Peirce-Smith copper converters almost thirty years ago, many Pyro-metallurgists have investigated using the technology. To the best of the authors knowledge, except for shrouded tuyere technologies using substantial oxygen enrichments, the core idea of using high pressure air injection has not been implemented anywhere in the world. This paper reviews the fundamentals of this technology and summarizes the basic economic considerations. It also presents the circumstances of where and when high-pressure injection might be justified.

Jan 1, 2007

By Laurence A. Dahners

As part of the strategic minerals program, the Bureau of Mines conducted a diamond-drilling project on three barite properties in eastern Tennessee and western North Carolina during the summer and fall of 1944. These properties, the Moccasin Gap prospect and the Krebs property in Cocke County, Tenn., and the Sandy Bottom mine of the Stackhouse group in Madison County, N. C. (fig. 1), are known to have produced some barite. The Bureau of' Mines project was planned to prospect for extensions of the ore bodies. A total of 3,169 feet of diamond drilling was done in 15 holes on the three properties. Tabulations of sample analyses and drill-hole logs are presented in this report. Two other mines of interest in the area are the McCoy and the Williams in Cocke County, Tenn. The Williams adjoins the Krebs. No drilling was done by the bureau in either of these properties.

Jan 1, 1949

Atlas Copco Construction and Mining Australia identified a number of issues in regard to the skill levels, labour turnover and productivity of our service technicians. In 1994 we were experiencing a labour turnover rate of 42 per cent per annum amongst our technicians. Exit interviews were held with each individual and one of the major areas of dissatisfaction was the degree of product training provided on our equipment, compared to what is required to be competent across the range of our products. These tradespersons were prepared to accept the reduced remuneration that an OEM offers, for the benefit of comprehensive, professional training that, in theory, could be provided. The truth is that we were achieving approximately 40 per cent of our target for training hours because of the demands of field service, pre-deliveries, etc. So, the summary was the same as the industry was experiencing at that time because of skilled labour shortages, production demands, etc people were employed and thrown in at the deep end. A recipe for failure that will be successful every time.

Jan 1, 1998

By O. C. Blade

Consumption of Diesel fuel oil in the United States has increased very rapidly during recent years. At the present time approximately 5 percent of the crude oil refined in this country is said to be processed for this purpose. This figure represents approximately 20 percent of the total distillate-type fuel oils now being produced in the United States. One factor contributing greatly to the recent increase in consumption of Diesel fuel oil has been the conversion from steam locomotives to Diesel engines by a number of railroads. Other contributing factors are greFl.ter use of Diesel engine8 in buses, trucks, tractors, water craft, and stationary power plants. The growing importance of Diesel fuel oil has resulted in a need by the petroleum industry, engine manufacturers, and consumers for more information regarding the types and quality of Diesel fuels currently being marketed. To supply this information, the American Petroleum Institute and the Bureau of Mines, United states Department of the Interior, under a cooperative agreement, have conducted a survey of Diesel fuel all produced in refineries in this country during 1950. Under the agreements, samples of Diesel fuel oil, representative of actual shipments, were analyzed by the manufacturers in accordance with instructions issued by the Fuel Survey Panel of the Automotive Research Committee of the American Petroleum Institute. Results of the analyses were transmitted to the Bureau of Mines, and that agency has studied the data and compiled them by groups in comparable form as shown in the tables of this report.

Jan 1, 1950

By Lynn Alcorn, Jeffrey Shawn Peterson

Data collected by the Mine Safety and Health Administration (MSHA) has shown that roof bolting machine (RBM) operators are the second most likely type of underground mining machine operator to be are over exposed to noise, per the MSHA Permissible Exposure Limit. In response to this, the Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) has initiated a project to develop engineering noise controls for roof bolting machines. Key to this research is an evaluation of the duty cycle of a typical roof bolting machine operation and this paper presents the results of such an exercise for data collected at two cooperating coalmines. The evaluation entails a time motion study of an operators' shift, logging each activity for time (e.g., tramming the machine, drilling holes, installing the roof bolt, etc.) and the noise levels associated with each task with a Larson Davis Spark 705+ dosimeter. NIOSH post processed the data to determine which tasks the operator devotes the most time to and the noise dosage accumulated during those tasks. These results provide insight into which portion of the operators' duty cycle is the most prominent contributor to noise exposure and thus, where research activities for the development of engineering noise controls should be focused. It was determined that the task of drilling holes is the most significant source of the operators' noise exposure and project research has focused on engineering noise controls to reduce the noise emissions generated during the drilling portion of the machine duty cycle.

Computation is believed to be a powerful tool in scaling-up chemical processes and in designing materials, however, is being challenged by low predictability and limited scalability. This presentation will discuss the promising future of multi-scale computation in solving these two problems to realise the real-time simulation of industrial processes. Multi-scale structures are a common nature of most chemical systems and the meso-scale phenomena are believed to be the road blocks not only in improving the predictability of physical modeling but also in extending the scalability of computation. Focusing on the meso-scale phenomena, a series of research has been carried out at the Institute of Process Engineering, Chinese Academy of Sciences, for the past three decades. Starting with a simple idea of modeling the meso-scale clusters in gas-solid two phase flows, the so-called EMMS (Energy-Minimisation Multi-Scale) model was established. In verifying the stability condition of the model, the pseudo-particle approach was proposed to explore the micro-mechanisms in particle-fluid systems, and the strategy of the EMMS model was extended to other six different multi-phase systems, resulting in a unified conceptual formulation of multi-phase complex systems expressed by a multi-objective variational problem. In applying this model to different multi-phase systems and to industrial problems, it was recognised that the EMMS model defined a new paradigm of multi-scale computation by realising the structural similarity between software, hardware and the problems to be computed. This paradigm of computation was implemented on a multi-scale supercomputer with a capacity of 1.0 petaflops by integrating CPUs and GPUs (Graphic Processing Units), showing high efficiency and low cost. Running the EMMS model on this computer, the simulation of hydrodynamics of multi-phase systems can be speeded up very much, indicating a promising future of virtual reality of process engineering. The presentation will review this series of work, introduce successful applications in industries, and will be concluded by emphasising the critical importance of the meso-scale phenomena as the bridge between macro-dominants and micro-mechanisms. This is an ABSTRACT ONLY. No full paper was prepared for this presentation.

Sep 13, 2010

Frother-Depressant Interactions in Two and Three Phase Systems

Sep 13, 2010

By G. St. J. Perrott, G. W. Jones

"In the course of its investigations pertaining to the promotion of safety the Bureau of Mines is actively engaged in investigating all promising materials that may be of value in rendering methane or other combustible gases, vapors, or solids less inflammable.Added substances are of value if such additions narrow the limits of inflammability, raise the ignition temperature, lower the speed of propagation of flame, or reduce the maximum pressure developed. Of major importance is the effect of added materials on the limits of inflammability, because methane is the chief combustible s liberated in mines, considerable work has been done with extinguishing agents on methane flames. For obvious reasons, a substance to be of value for the extinction flames should be a gas, or a liquid having a sufficient vapor pressure to give concentrations of the vapor in sufficient amounts to extinguish the flames or markedly narrow the limits of inflammability. The substance should be nontoxic, cheap, and noncorrosive and must be incombustible. Solids, such as rock dust, are undesirable and of little value for combustible gases because they soon settle out of the atmosphere, and their flame- extinguishing value is thereby lost. There are at present only a few gases and vapors-for example, nitrogen, carbon dioxide, and carbon tetrachloride-which meet these requirements.The extinction of methane flames by nitrogen, carbon dioxide, and argon has been reported by Coward and Hartwell 4; the extinction by water vapor by Coward and Gleadell 5, and the extinction by helium and carbon tetrachloride by Coward and Jones 6."

Oct 1, 1930

A record $19.7 billion in minerals was produced by United States industries in 1963. This was some $800 million above the previous high established in 1962. Preliminary statistics compiled by the U.S. Bureau of Mines show that most metals, nonmetals, and fuels gained both in value and volume of production. The 1963 total represents the largest value increase since 1956 and continues an upward trend begun in 1959. Product.ion and value of all mineral fuels rose, with anthracite registering a remarkable 20% value increase. Nonmetals advanced 591 in value, gains exceeding losses by 213 to 1 among individual commodities. Heavier industrial demand and the settling of labor difficulties were among the factors contributing to increased output of such materials as iron ore, bauxite, molybdenum, lead, and zinc, which accounted for most in€ the growth in metal output. Silver prices continued to rise and, as a result, production value of that metal gained 132,.

Jan 2, 1964

By M. H. Dunn, T. P. Danehy, C. F. Denholm, S. L. Busler

The problems associated with abandoned minelands are so extensive that neither federal, state, or local governments nor the mining industry nor watershed groups can adequately address these problems individually. By combining talents and resources, however, these problems are being solved efficiently, effectively, and economically. Utilizing existing water monitoring data, local public-private partnerships have successfully designed and built passive systems within five weeks to six months which treat discharges up to hundreds of gallons per minute that vary in quality from net alkaline to highly acidic, containing as much as 200 mg/L dissolved iron and 70 mg/L dissolved aluminum.

Jan 1, 2002

By C. L. Kosmoski, B. M. Eiter, B. P. Connor

"In the recent past, the mining industry has witnessed a substantial increase in the numbers of fatalities occurring at metal and nonmetal mine sites, but it is unclear why this is occurring. One possible explanation is that workers struggle with identifying worksite hazards and accurately assessing the associated risk. The purpose of this research was to explore this possibility within the mining industry and to more fully understand stone, sand and gravel (SSG) mine workers’ thoughts, understandings and perceptions of worksite hazards and risks. Eight mine workers were interviewed and asked to identify common hazards they come across when doing their jobs and to then discuss their perceptions of the risks associated with those identified hazards. The results of this exploratory study indicate the importance of workers’ jobrelated experience as it applies to hazard identification and risk perception, particularly their knowledge of or familiarity with a task, whether or not they had personal control over that task, and the frequency with which they perform that task. IntroductionAccording to the U.S. Mine Safety and Health Administration (MSHA, 2015a), 37 mine workers were fatally injured in accidents at metal and nonmetal mine sites between October 2013 and January 2015, following a record low of 16 in 2012 and in 2011. In 2014 alone, 29 mine workers were fatally injured at a metal or nonmetal mine site, and 52 percent of these fatalities occurred at a surface stone, sand or gravel (SSG) mine. In January 2015, Joseph A. Main, Assistant Secretary of Labor for Mine Safety and Health wrote to stakeholders in the metal and nonmetal mining community and identified several areas where improvement was necessary to promote the health and safety of mine workers. One area identified was an increased focus on “daily and effective workplace exams to find and fix hazards” (MSHA, 2015b).Hazard detection is challenging in the mining industry, despite the existence of regulation. Mining is a major undertaking involving the use of complex heavy machinery, equipment and processes as well as numerous and diverse worker activities that take place in a dynamic, challenging environment (Scharf et al., 2001). In other industries that are similarly dynamic and unpredictable, such as the construction industry, a large proportion of hazards go undetected (Carter and Smith, 2006). It is critical that miners are able to both recognize worksite hazards and accurately assess the risk associated with the hazards, because their health and safety depend on their deciding whether and how to remove hazards and mitigate risks."

Nov 1, 2016

By William E. Lardner

Interlocking caisson walls developed from conventional "soldier pile and lagging" shoring. In the latter, the soldier piles receive directly most of the soil load. Natural arches form in the soil behind the shoring; the lagging supports little more than the segment of soil inside the arch. Fig. 1: A typical layout of a lagged wall [ ] Fig. 2: A typical layout of an interlocking caisson wall [ ]

Jan 1, 1987

By Gábor Csicsovszki

We have developed a novel method - at the laboratory scale - comprising an ion-exchange separation and a membrane-electrolysis step for the purpose of zero-waste regeneration of spent HCl pickling liquors originating from hot-dip galvanizing of common steels. It is aimed at the parallel regeneration of HCl and iron. Experiments revealed that iron can be electrodeposited at high current efficiencies by maintaining the following conditions: 0.04-0.08 M HCl, 500-1000 A/m2, 20°C and stationary electrolyte in a conventional cell. Zinc in the solution did not disturb the deposition of iron, however it contaminated the product and it poisons the anion-exchange membrane required to tackle acidity during electrolysis. For a preliminary separation, anion-exchange tests were carried out to produce pure iron solutions. Beyond the equilibrium studies, column experiments were carried out showing that low flow rates of the loading solution and the ~1.5 M HCl eluent are essential for separation.

Jan 1, 2006

The extraction of minerals and coal at greater depth, employing higher-powered machinery to improve production levels, imposes an increased burden on the ability of a ventilation system to maintain an acceptable mine climate. Hence, mechanical mine cooling systems are often adopted, which can be expensive in terms of both their associated capital and operating costs. Consequently, in order to optimize the total mining costs, it is essential to provide the mine operator with a method with which to determine the most cost effective and efficient mine cooling system. In a previous paper1a novel energy analysis employing the concept of exergy was proposed and applied to cooling systems applied to two conceptual model mines, representative of UK deep coal operations, and their resultant subsurface thermal environ-mental conditions predicted. This paper presents an analysis of the results obtained from the application of this novel technique to assess the performance of various cooling systems applied to a current UK colliery that is experiencing climatic problems due to its depth and highly mechanized production and development workings. To perform this analysis, ventilation and climatic data collected at the case study mine were used to construct balanced mine ventilation and climatic network models to replicate the subsurface environment. Where air conditions exceeded specified climatic limits within identified climatically control zones, mechanical mine cooling systems were employed. A number of cooling system configurations were applied to these model to investigate the potential to satisfactorily regulate the thermal environment. The heat energy transferred out of the air stream by the various cooling methods was absorbed using a variety of chilled water systems, which were designed to operate at various water flow rates and temperatures. Models of various cooling system were developed and applied to control the underground climate within this mine network to within pre-set climatic limits. The results of a comparative analysis of the energy transfers that were produced by the application of the different cooling systems are presented in the form of exergy performance indices. The results produced by simulation models constructed to represent chilled water distribution networks to supply the various air coolers, are designed and balanced. The results of the exergy analyses applied to the operation of the various chilled water pipe networks are discussed and used to assess the exergetic performance of the application of each proposed cooling system to the mine ventilation network.

Jan 1, 2004

By Gary E. Sherman

Preliminary economic mining feasibility studies were conducted by the Bureau of Mines to estimate mining costs in the Juneau gold belt area of the Juneau Mining District, southeastern Alaska. Investigations were conducted on the economics of two mineral deposit types: (1.) Berners Bay vein gold deposits, and (2.) stockwork gold deposits containing gold, silver, and lead. Cost estimates were developed using the Bureau of Mines Cost Estimating System (CES). Discounted cash flow return on investment (DeFROI) was calculated using the Bureau's MINSIM computer program. Underground mining of a Berners Bay vein gold deposit was found to be economic (15 pct DCFROI) at a recoverable metal value of $353.67/mt for a 100 mtpd shrinkage stoping mine with a 10 yr mine life, $324.76/mt for a 20 yr mine life, $138.63/mt for a 500 mtpd longhole stoping mine with a 10 yr mine 1 ffe, and $127.50/mt for a 20 yr mine life. Block caving mining of a large stockwork gold deposit was found to be economic at a recoverable metal value of $15.28/mt for a 18,000 mtpd mine with a 20 yr mine life.

Jan 1, 2011

By Robert Stefanko

A series of workshops were conducted -with invited participants from the coal mining industry to identify the most pressing research and development needs of the industry. Six workshops were held on the following subjects; Research Priorities for Mining-Oriented Universities, R&D Needs-for Surface Coal Mining, R&D Needs for Deep Coal Mining, R&D Needs for Anthracite Coal Mining, R&D Needs for Coal Mine Health and Safety, and R&D Needs far Environmental Control in Coal Mining.

Jan 1, 1975

Phelps Dodge Mining’s Bagdad, AZ copper facility uses a large series of cone crushers and ball mills to reduce copper ore to very fine particles. The solids are mixed with water to create a slurry. Milk of lime is added to this slurry to raise the pH. Small amounts of reagents are also added, including a frother to make bubbles, as well as a collector chemical that causes the copper minerals to stick to those bubbles. This material is pumped to a series of froth flotation cells to concentrate the copper. Air is blown into the flotation cell tank and the pulp mixture is vigorously agitated. Rising bubbles carry the copper particles over the edge of the flotation tank. The bubbles break after they flow over the edge.

Jan 1, 2005

By J. S. Dunning

One Federal Bureau of Mines research goal, to minimize requirements for domestically scarce mineral commodities through conservation and substitution, can be accomplished by utilizing more abundant elements such as iron, molybdenum, and titanium. An example of this research is the study of precipitation-hardening, iron-base alloys containing molybdenum and titanium, as substitutes for the high-tonnage stainless steels that are high in imported nickel and chromium. The precipitation hardened iron-base alloys are strengthened by a dispersion of the ternary Laves phase, Fe2 (Mo, Ti). Aluminum and chromium additions changed the solid solubility limits of molybdenum and titanium in a-iron and affected the composition of precipitating phases. A baseline composition of Fe-7Mo-2Ti was selected to study the effects of aluminum and chromium additions on the precipitation-hardening mechanism and microstructure and was also used in studies of mechanical properties and oxidation resistance. The study yielded workable, precipitation-hardening alloys, with elevated temperature strengths equivalent to or superior to types 304 and 316 stainless steels. Chromium and aluminum additions in combination were more effective in providing oxidation resistance than either addition was alone.

Jan 1, 1980

By V. R. Miller

The Bureau of Mines developed and evaluated a detecting and sorting device to separate the copper-bearing portion from the barren portion of Michigan native copper ore in the minus 4- plus 1-inch size range. Small-scale sorting tests were also conducted on minus 1- plus 1/2-inch material from the Centennial No. 6 mine, using a previously developed system that was modified to increase sensitivity. Results showed that, with the added sensitivity, 85 to 90 pct of the copper in the minus 1- plus 1/2-inch material could be recovered in about 50 to 60 pct of the fraction. Sorting tests on minus 4- plus 2-inch and minus 2- plus 1-inch fractions from the Centennial mine were conducted with the large sorting system. Results showed that 86 to 93 pct of the copper was recovered in 43 to 64 wt-pct of the sorted fractions. Combining of concentrates from the two fractions resulted in a recovery of 90 pct of the Popper in 55 pct of the weight. The composite concentrate contained 2.40 pct copper, and the tailing analyzed 0.33 pct Cu; the head sample assayed 1.46 pct Cu.

Jan 1, 1978

By John Dasher

In 1980, some US cars were designed and built to metric dimensions; wine and gas were sold by the liter; and the March of Dimes Walkathon was measured in kilometers. Although the US Congress has taken a ''soft" approach to metrication, and public resistance to the idea remains strong, the use of metric units is becoming more and more widespread. As the minerals industry becomes more international in scope, US mining companies are converting to the metric system-particularly those companies with business interests overseas.

Jan 2, 1981