Search Documents

By J. H. Crary

This report summarizes the results of a one-year agreement for research on the electromagnetic environment in coal mines, which was conceived as the beginning of a long term cooperative program between ITS and the Bureau of Mines. The concepts on which it was originally based are a result of the report on mine rescue and survival by the Committee on Mine Rescue and Survival Techniques of the National Academy of Engineering, dated March 1970. This report drew particular attention to the need for improved communications during and following mine disasters. In particular, the outstanding problems identified were the location of, and communication with, trapped miners. Some tentative solutions, generally involving long-wave electromagnetic signals, were offered. Consideration of the problems of disaster location and communication soon leads to consideration of the communications techniques (or lack of them) for use under normal mining conditions. In particular, if a disaster communication and/or location system is to be readily available and operable under disaster conditions, it should also be usable during mining operations. In this way operators can become familiar enough with the system to operate it during disaster conditions, as well as provide a mechanism for regular testing.

Jan 1, 1972

By Sam S. Taylor

"INTRODUCTION This report deals with a comparatively simple application of some of the engineering principles involved in the evaluation, installation, and operation of air- or gas-injection projects and well-clean-out and repair methods to increase the producing rates of oil wells in partly depleted pools during the war. The methods suggested for developing gas-injection projects take into consideration that in general no new wells will be drilled because of wartime restrictions of equipment and manpower and that only existing wells and second-hand machinery will be used. Because air will be employed as the injection medium in secondary-recovery operations where natural gas is scarce and expensive, the disadvantages and hazards accompanying, its use are discussed. Engineering techniques recognized as best modern practice are discussed in relation to the effect of simple air-injection development of properties on postwar operations and Probable ultimate recovery of oil. The report is an introduction to where, when, why, and how an air-injection project should be installed and operated; it is not intended to be an engineering manual for technical guidance in the selection, development, and operation of simulative methods of oil recovery.The report is intended mainly for these thousands of operators in the Appalachian region owning a few wells prodding small quantities or oil daily. Many such operators are anxious to increase their production rates by simulative means and to rehabilitate their wells so that they will produce more oil to help win the war but, in general, are unfamiliar with secondary-recovery operations and cannot afford to hire technical assistance."

Sep 1, 1944

By R. L. Levens

The Underground Injection Control program was promulgated in 1981 by the U.S. Environmental Protection Agency under the provisions of the Safe Drinking Water Act. Placement of mine waste backfill underground is considered underground injection under the provisions of this program. A major issue is whether mine waste that is regulated as a contaminant source on the surface should be disposed of underground. The U.S. Bureau of Mines conducted research to investigate the impacts of mine waste sandfill on the quality of ground water. Analyses of water samples collected before and after contact with sandfill in a 10-year-old stope, as well as samples of the sandfill itself, were used to ascertain the influence of the sandfill after mine closure and subsequent flooding. Computer models supported the hypothesis that oxidation of pyrite by oxygen, accompanied by dissolution of carbonates, was the predominant reaction controlling the quality of the water being discharged from the stope. Concentrations of metals released as a result of acid production remained near or below detection limits. Metals release after mine flooding is expected to remain low as a result of the buffering by the sandfill and the reduced rate of oxidation.

Jan 1, 2010

By S. R. Knowles, R. J. McDonough

"The purpose of this paper is to introduce to the minerals processing marketplace a viable alternative to conventional mechanical agitation and pachuca airlift agitation. What follows is a brief introduction to the Atara Corporation and the fundamentals of how an Atara ""cannon"" mixer operates. The main body of the paper is concerned with the results of a study to evaluate the cannon mixer for a gold cvanide leach application. A brief summary of research and testing for other metallurgical applications is also presented.1. 1 THE COMPANYThe Atara Corporation is a privately owned Canadian company, headquarted in Dorval, Quebec. Its subsidiary, Atara Incorporated, located in Paramus, New Jersey services the municipal wastewater treatment market in the United States. Dorval focuses on industrial mixing applications in Canada and the US. The Atara Corporation provides design, engineering and specifications of agitators for mineral land other) processing applications. Fabrication of mixers is pursued in either Canada or the US, depending on the ultimate destination.Although Atara and its unique static in-tank mixer are relative newcomers to the mining industry, the cannon mixer has demonstrated its value over the past 20 years in municipal wastewater treatment services. In the past four years the Atara unit has been developed for industrial applications; the bulk of the development work has been for metallurgical applications. To-date the cannon mixer has been evaluated for mixing slurries in the following applications: nickel-copper concentrate storage, copper concentrate storage, coal slurry storage, gold cyanide leaching, uranium acid leaching, silver leaching and zinc acid leaching. Atara mixers have been installed with successful performance in full scale tanks containing nickel-copper concentrate slurry (Falconbridge) and gold cyanide leach pulp (Dome"

Jan 1, 1984

By Kunihiko Takahashi, Gjergj Dodbiba, Hisayoshi Umeda, Toyohisa Fujita

"An increasing number of mobile phones is increasing the number of the discarded mobile phones. Many efforts are thus being made to collect and recycle these devices. This paper is a short introduction of the recycling system of precious metals from the discarded mobile phone, currently available in Japan. Moreover, an attempt has been made to compare the energy recovery and the mechanical recycling of plastic wastes from the discarded mobile phone. The assessment has been carried out in the context of the life cycle assessment methodology (LCA). The environmental impact of each option was assessed by calculating the following impact indicators: depletion of abiotic resources (ADP), and global warming potential (GWP). 1. Introduction In 2003, the demand for mobile phones was increased since the camera was included in a mobile phone and the 3rd generation of mobile phones was introduced. In turn, the number of discarded mobile phone is rising sharply. Generally speaking, all the metallic parts of mobile phones can be recovered and recycled by using smelting and purification techniques. The recycled materials are then used to fabricate other new products."

Jan 1, 2008

By H. R. Banks

IF you have ever travelled in the valley lying between the Selkirks and the Rockies in the East Koorenay district, you will have noted that the former mountains are rounded and massive, while the serrated peaks of the latter, fingering into the sky, bring an entirely different. picture. These two mountain ranges, with the comparatively level valley between, serve splendidly to introduce the subject for discussion. It is rather strange that, despite the fact that wear is undoubredly the greatest force with which human ingenuity bas to contend, it has come in for very little study from the stand point of pure science. Empiricism has been the sole ally in the fight for improvement! That we may have a clear understanding as to what we mean by wear, I would include in the term the breaking dawn of ail solid matter, from the natural wearing dawn of the mountains previously mentioned, to the hale in the mill pipe-line, which forces one to shut-down-usually at some un-earthly hour-to carry out a repair. It seems a far cry from mountains to mill launders or pipe-lines, but, magnified sufficiently, most of the materials with which we have to deal would show surfaces not unlike those we see around us. The progressive steps of wear, or ?erosion' as our geological friends would prefer to term it, are exemplified in the two ranges of mountains and the valley between. True, the wearing dawn by natural forces is a slow process. The aeons which have passed since first these mountains were formed seem endless. The natural forces pitted against them seem puny in the light of the interminable rime that has been needed to effect the changes. But here, as in the case of the materials with which we are dealing day by day, the combination of many forces ultimately brings about that condition which we describe as 'worn out'. In the case of the mountains, it is when they are finally levelled into plains, and in the case of equipment which we use, it is when that equipment will no longer serve its purpose.

Jan 1, 1943

By NA UMC

Abstract Booklet

Dec 1, 2022

By John H. Soule

Although known since 1902 , the Capitan iron deposits have not been mined mainly because of the low grade of the ore . A small amount of exploratory work carried on at an early date was reported . C. E. Johnson , district engineer of the Bureau of lines for New, Mexico , visited this propert , and as a result of preliminary sampling and mapping by the Bureau3/ and the Federal Géological Survey , an exploratory project was conducted during March , April , and liay 1944. Further mapping and logging of the vagon -drill samples was done by V. C. Kelly , geologist , of the Survey .

Mar 1, 1947

As has been the case since the early Phoenician traders, the minerals used by modern man come from deposits scattered around the globe. The price received is more and more being set by worldwide supply and demand. Thus the price component in the profit equation:Profits = Material sold (units)x(Price/unit û Cost/unit) is largely determined by others. The recent price history for two of the major metals, copper and iron, are given in Figures 1 and 2, respectively. As can be seen there has been a steady decline in the prices (when expressed in constant dollars) over the 20 years which have lapsed since the first of the International Conferences on Mass Mining, æDesign and Operation of Caving and Sublevel Stoping MinesÆ was held. If one would look back over the entire 20th century this would also be the trend. Cost containment/reduction through efficient, safe and environmentally responsive mining practices is serious business today and will be even more important in the future with increasing mining depths and more stringent regulations. A failure to keep up is expressed very simply as: Profit This, needless to say, is unfavourable for all concerned (the employees, the company, and the country or nation). The mining companies have had to look at ways of reducing the expense part of the profit equation while maintaining safe, environmentally conscious operations. Table 1 summarises the rules for working in todayÆs economy.

Jan 1, 2000

By B. P. Watson

The first crush pillars on the Bushveld platinum mines were introduced at Union Section in 1978. Before the introduction of crush pillars, serious problems were experienced when stoping advanced to a point 30 m to 40 m on both sides of the centre gully. At least three to four stopes were collapsing per month. The introduction of the pillars stopped the stope collapses in the mining area where they were introduced. The residual stresses of these pillars were never measured; however, the successful elimination of the ?back-break? problem suggests that the original pillars had a residual strength of at least 8 MPa. Apart from back analyses, very little work has been done to determine the residual strength of crush pillars and only very recently have any measurements been made. The lack of knowledge in this field has resulted in pillars being designed based on experience. Concerns about stope collapses, similar to the Coalbrook disaster, have led to larger pillars being cut in more recent times. If such pillars were cut in brittle quartzites they would always fail violently but the ductile nature of the Merensky Reef generally allows large pillars to fail without bursting. Occasionally, however, one would burst in a working area. Increased incidence of bursting has been reported on some mines at deeper levels but most of these bursts occur in the back areas. Nevertheless, the incidence of bursting increases the risk of falls of ground in already dangerous areas, and the larger pillars decrease the extraction ratio. This paper describes the evaluation of stress measurements conducted in two boreholes over a crush pillar with dimensions 2.5 m x4.0 m, and a height of 1.2 m. Boussinesq equations for vertical and shear stress were used to analyse the original measurements and provide a stress profile across the pillar as well as the residual strength of the pillar. The results showed an unexpectedly high peak stress of 280 MPa at the centre of the pillar and a residual strength of 48 MPa. The reason for the high residual strength is suspected to be the result of the stiff environment under which the pillar failed and the small height of the siding on the up-dip edge of the pillar. More measurements should be conducted on several mines to establish a range of residual strengths for narrow crush pillars.

Jan 1, 2008

By Dave Bulled

"This paper describes the design of a molybdenite flotation circuit using FLEET technology applied to kinetics data produced from laboratory flotation testing and distributed across the blocks of a mine plan using a geostatistical approach. The geostatistics assigned the statistical error that arises from having a limited amount of sample testing data to the kinetics estimates of each block of ore in the mine plan. The final design then included a quantification of risk based on the accuracy of the block flotation kinetics and model fitting. The design made reference to the extensive technical reports describing earlier metallurgical test work including some pilot plant work over thirty years ago.The testing involved conducting MinnovEX Flotation Tests (MFT) to determine the rougher flotation kinetics at the specified reagent conditions and rougher-cleaner tests to determine the change in kinetics resulting from regrind. These flotation kinetics were used within FLEET simulations to create a full-scale flowsheet and plant design including recommended equipment sizes and the forecast of operating results. Measurement of detailed flotation kinetics for a wide range of samples allowed the effect of size of grind and efficiency of classification (i.e. width of size distribution) to be predicted for the whole ore body.INTRODUCTIONAdanac Moly Corp. proposed to develop a 20,000 ton per day mill to produce high quality molybdenite concentrate from its Ruby Creek resource in north-western British Columbia. It is a relatively clean low grade porphyry-monzonite occurrence containing minimal quantities of other sulphides such as chalcopyrite, pyrite, sphalerite and galena. Molybdenite occurs mainly as coarse flakes with lesser amounts of finer sized values. An optimum plant design was required to can achieve the predicted operating results, at a known level of risk, while treating the variability inherent in the ore body."

Jan 1, 2007

By J. P. BONARDI, J. C. Williams

Until the end of 1918 Boulder County ranked as one of the foremost tungsten-producing districts of the world, but in August, 1919, there was practically no production in the district. The operators there could not compete with tungsten ores from foreign sources, particularly China, Burma, and South America. As a. result there · has been a strong movement for placing a protective tariff on all imported tungsten ores and products; and it seems to be the general belief of tungsten producers that some form of protection is necessary to the maintenance of the industry in this country. The stimulus, due to the great demand for · tungsten alloys in the manufacture of munitions during the war, was felt in all the productive localities of the world. The ores of Boulder County were especially in demand on account of their comparative. freedom from • harmful impurities, and this demand greatly extended mining operations in the district and increased the efficiency of the gen~ral milling practice there.

Jan 1, 1921

By S. Zekovic

"The paper gives an overview of the economics condition and strategic business challanges of the mining&metallurgy sector and their possible impact on the future development of the Bor basin of copper in Serbian part of Danube Region. Economics and strategic challanges in the mining& metallurgy complex are emphasized by world economic and financial crisis. An analysis of strategic challanges is undertaken by application of a comprehensive development framework approach. Paper indicates that an economics and evaluation of possible impacts of constraints and challenges for the development of Bor basin shows that it must be included in corporative decision, local and regional plans.INTRODUCTIONRisks are characteristic of every strategic development and business decision-making, so their successful management should be a part of the development strategy of the corporation, especially longterm. Due to the growing uncertainty in the general socio-economic environment, “risk management”, risk insurance, risk control, risk culture, risk optimization are frequently talked about. Among the key risks at a corporate level are the financial risks and risks of the regulative framework, especially in the field of environment and land use. In both cases, it is a question of external risks, which the companies need to relativize and successfully manage. Some companies pay more attention to production risks and search for better solutions in that domain which is not enough (Ernst&Young, 2008). Strategic business risks appear mostly on the macro-economic level, from where they should be” transferred” onto the level of sector economics and action level in corporations. Risk management include transferring the risk to other parts, avoiding the risk, preventing hazard, reducing the negative effect or probability of the risk, accepting some or all of the consequences of a particular risk.The research has included perspective and the general market trend and market positioning of the production and copper processing complex in the world; the impact of the requirements and strategic goals of the EU Directive and Kyoto Protocol on the institutional and other adjustments important for business in this sector; the impact assessment of the regulations important for business in the mining and metals sector, and case study of economics and challenges for the development of mining and metallurgy sector in the Bor basin of copper in Serbian part of Danube region. The analysis has included the identification and assessment of the global challenges on the future development of the copper complex in the miningsmelting basin Bor. Presented results in the paper are part of the research project “Sustainable spatial development of the Danube area in Serbia"" (No. 036036), financed by Ministry of Education and science of Republic Serbia."

Jan 1, 2012

By R. E. McIvor, Brian Cornish, J. A. Finch, Yue Tan, Claude Gagnon

Fred C. Bond is recognized throughout the mineral processing world as the father of comminution equipment applied science and engineering. The Bond Work Index became a universal standard, and is the most widely used measurement tool for comminution energy consumption. This biography is the story of his lifetime of study, work experiences, experimentation, analyses and findings. His numerous published writings are reviewed. His legacy is one of comminution process engineering that will be used in perpetuity.

Feb 1, 2024

By Hamid Maleki

A comprehensive study consisting of stress determinations, core logging, laboratory testing, and numerical analyses was conducted to investigate the cause and potential alternatives to the coal bump conditions that developed in the Second North Panel of the Little Dove mine near Buntington, Utah. Roof rock characteristics were such that a cave did not develop above this 420 ft wide panel. After 700 ft of pillar retreat, severe coal bump conditions developed during pillar mining. The coal bump conditions resulted from excessive pillar stress which was caused by load transfer from the extracted, noncaving, portion of the panel. Site specific data and numerical modeling techniques were used to back-analyze the bump prone condition. This back- analysis lead to the identification of critical stress, closure, and energy release levels. These critical levels were then used to evaluate alternative pillar mining sequences in the hope that the potential for coal bumps could be reduced. It was found that while alternative sequences offered some potential improvement over the pillar mining sequence used in the mine, alternative pillar mining sequences would not significantly reduce the potential for bumps. For the roof characteristics at this mine, coal bumps are best avoided by developing narrow panels or significantly wider panels, which incorporate properly sized barrier pillars. Narrow panels, on the order of 300 ft, would not cave, but panel pillar stresses and the potential for umps would be moderated by the reduced r' panel width. Wider panels, of approximately 650 ft, would allow a cave to develop, also reducing panel pillar stresses and coal bump potential.

Jan 1, 1987

By E. W. Dean, H. H. Hill

Gasoline has become of such commercial and military importance that it is now practically indispensable. This product is of special interest because, in addition to realizing its value, the Nation is learn- ing that the raw materials from which gasoline is obtained are not unlimited. ACTIVITIES OF THE BUREAU OF MINES IN PROMOTING EFFICIENCY IN THE PRODUCTION AND UTILIZATION OF GASOLINE. The Bureau of Mines has directly and indirectly worked for the conservation and efficient utilization of this important product. Some of the bureau's activities have been along lines widely different from those reported in this bulletin. The work of the bureau toward the increase in efficiency of processes for the production and refining of crude oil is too well known to need mention here. Another line of activity in which the bureau has engaged is the collection and publi- cation of statistics on refinery operations. Finally, as immediate preparation for the present bulletin, two surveys of the gasoline mar- keting situation have been made. The primary object of this bul- letin is to make available to the public information obtained in con- nection with these surveys. PURPOSE OF THE GASOLINE SURVEYS OF 1917 AND 1919. Shortly after the United States declared war on Germany the bureau collected gasoline samples in the retail market throughout various parts of the country. Information regarding the sources of these gasolines and the details of marketing them was obtained, and they were subjected to analytical tests which furnished conclusive informa- tion regarding their properties. The information obtained through this survey proved of inestimable value both to the bureau and the United States Fuel Administration, particularly in drawing up speci- fications and in ascertaining the best means of obtaining supplies of particular types of gasoline that were needed. A similar and more extensive survey was made in the months of April and May, 1919, in order to obtain data needed for the revision of the Federal motor gasoline specification. The specification adopted during the war had been the subject of numerous complaints, and it seemed desirable to determine whether or not these objections were valid before attempting revision.

Jan 1, 1920

By H. Harzer

Statistics Canada record s indicate that in recent years 70 to 80% of the entire Canadian coal production originated from Western Canadian mines, in which about 55 to 65% of the coals are bituminous. Until recently, less than 20% of the latter were extracted by underground methods , the remainder being surface-mined. However, it is estimated that within the foreseeable future up to 80 or 90% will have to be gained by underground techniques. Although Western Canadian coal resources are considerable, they are unfortunately locked in severely distorted, steeply pitching and faulted seams of variable thickness. Consequently, their economic extraction poses serious engineering problems. One possible solution to the problems is to apply hydromechanical methods to underground mining. This is a well-proven method shown to be economically viable under Western Canadian conditions. This paper endeavours to widen the scope of published data on hydraulic coal mining and is based on practical engineering and cost data gathered through contacts with West German designers and operators of hydraulic mines.

Jan 1, 1978

By William T. Reid

Low-temperature carbonization of coal in Japan served as an important source of liquid fuels during the war. Six plants operating in Japan Proper produced 203,069 KL (53.7 million gallons) of liquid fuel from 1940 until the end of the war in August 1945, while four additional plants in Karafuto and Korea produced 211,943 KL (56.0 million gallons) for a total of 415,012 KL (109.7 million gallons) of liquid products. Semicoke produced in these plants was used for domestic fuel, for gasi- fication in portable gas producers on automotive vehicles, and to replace imported low-volatile bituminous coal in the manufacture of metallurgical coke. Since 1936 one plant had produced more than 300,000 metric tons of semicoke for blending with bituminous coal to form coke, while the total production of semicoke since the beginning of the industry in 1923 is approxi- mately 2,000,000 metric tons. Despite an apparent annual carbonizing capacity of about 2,000,000 metric tons of coal for the entire country, the maximum amount of scmicoke produced during the peak year, 1943, was 468,446 metric tons. The equipment used is primarily of Gorman design. Just before the end of the war, 6 plants using 20 Lurgi carbonizers were operating with a total rated capacity of more than 1,500,000 metric tons of coal per year, while 2 Koppors units had a combined annual rated capacity of 400,000 metric tons of coal. One plant using the Japanese-designed Mimura system was in service but with so much mechanical trouble that its output was small, while in another plant 4 Wanisht carbonizers of Japanese design but based on an early German development were running satisfactorily, and carbonizing about 100,000 metric tons of coal per year. A single installation of 15 American-designed Knowles ovens was operating near Tokyo but was carbonizing pitch for electrode carbon. ..! No true low-temperature process used in Japan could carbonize strongly. caking coals satisfactorily. The Mimura process designed for this purpose was unsuccessful, as was the Shimomura process before it, while the Lurgi, Koppers, and Wanishi systems operated only with noncaking or very weakly caking coals. The Knowles ovens, really a medium-temperature process, could carbonize-caking coal without difficulty...

Feb 1, 1948

By S. Gallagher, C. A. Hamrick, A. G. Mayton, R Sonier, R. L. Unger

Introduction Industrial safety professionals recognize that adequate illumination is essential to a safe and productive work environment. The need for effective, lighting in underground coal mines is even greater.1 Designing appropriate lighting systems for these mines is no easy [ ] task because of the unique environment and work procedures encountered in underground coal-mining operations. Miners must depend totally on artificial lighting systems to see. Moreover, the working face is a low-reflectivity and low-contrast environment and is continually advancing or retreating.2 Laboratory mock-ups have been a major part of the process lighting equipment manufacturers must under- go to design an underground machine-mounted lighting system. The mock-ups often have taken considerable time. Furthermore, modifications to a lighting system (using different luminaires with an existing configuration or changing a luminaire's location, orientation, etc.) could require more time with additional mock-ups and laboratory measurements. Understanding the need to improve this situation, the US Bureau of Mines has developed an alternate method for facilitating lighting system mock-ups. A PC-Program (CAP),* with the latest software technology enables users to design, alter, and evaluate under- ground machine-mounted illumination systems. Lux levels and distance are measured as the luminaire is moved incrementally through angular traverses about horizontal and vertical axes. The measurements and angles subsequently are entered into the model. From this input data, three-dimensional isolux or isofootcandle profiles are constructed for luminaires that can be placed at various locations and orientations on a mining machine. As an example, Figure 1 shows a computer display of 21.5 Ix or 2.00 fc profiles for luminaires mounted on a simulated mine-shuttle car. Using this information, the model allows the user to determine the lux level at different locations in space about the shuttle car. How the model calculates illumination During initial development of the CAP model, the isolux profile of the luminaire was determined using the inverse square law (ISL) .3 The method of gathering data comprised recording a single measurement of distance at 21.5 ± 1.21x (2.00 ±11 fc) for angular traverses following 0.09 rad (5 degree) increments. This data was then used to find the illumination in space for any other distance at a given azimuth and elevation using the ISL. Limitations, however, exist with this method.4 The main one is that the ISL assumes a luminaire is a single point source of light, so long as the distance is greater than five times the 1al;gest dimension of the luminous area of the luminaire.5 Also, by using a single measurement to calculate the illumination for a given luminaire in the CAP model a large error could result from an inaccurate measurement.

By Chung Yu, Wang

CHINA can he roughly divided into three metallogenetic province: North China, the Yangtze Valley, and South China. In North China the old Pre-Cambrian schists and gneisses are represented by the abundance of quartz mines in which sporadic occurrences of copper, lead, zinc, gold, and silver are sometimes found in subordinate quantities. Along the Yangtze Valley and in Central China, extending eastward as far as Shantung, are found here and there intrusions of dioritic rocks, in which occur the famous contact deposits of iron ore, besides which minor quantities of copper. lead, and zinc are also found. In South China the igneous intrunsions are of granitoid type in which, or in the vicinity of which, occur in certain regions immense deposits of antimony, tungsten, tin, and mercury. Broadly speaking. most of the famous coal mines are now situated in regions north of the Yangtze River, in which occur also the sedimentary deposits of iron in contradistinction to the contact deposits of iron along the Yangtze Valley.

Jan 1, 1943