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By K. H. Brandt

A standard planning system for the development of roadways was adopted for German coal mines based on the results of geotechnical and rockmechanical investigations. Its goal is to provide for sufficient support systems under conditions of multiple seam mining at great depth. The report points out the required determination of geotechnical parameters and the basis for achieving a high level of planning reliability and resulting high performance in roadway development and longwall mining. The instrumentation and the planning procedure for selecting the support design most appropriate for the geotechnical conditions are described and demonstrated by examples.

Jan 1, 2004

By L. A. Haas

The Bureau of Mines, in cooperation with three Minnesota agencies (Department of Natural Resources, Geological Survey, and the Iron Range Resources and Rehabilitation Board), investigated the potential of using glacial lake clay from Minnesota, as well as other areas, as a binder for iron ore pellets. The best clay-characterizing procedures for predicting binder effectiveness were the cation exchange capacity (CEC) using the methylene blue method and the plate water absorption test (PWAT). The best clay binder was found in the Red River Valley. However, compared to a typical western bentonite at the 0.5-pct-addition level, addition of about 2 pct Minnesota clay was required to obtain comparable unfired (green) pellet strengths. Soda ash addition only slightly improved the binding properties of Minnesota clay, but considerable improvement was obtained by the addition of a small quantity of water absorbing organic compounds. For example, with a mixture of 0.5 pct Minnesota clay or paint rock and 0.1 pct pregelatinized starch, the unfired and fired physical pellet properties were about the same as with 0.5 pct of typical western bentonite. The reduction rate at the 40-pct reduction level and the percentage of plus 6.3-mm particles from the reduction disintegration index test were also about the same.

Jan 1, 1987

By G. J. Perrott, H. W. Clark

During the course of the cooperative smoke abatement investigation carried on by the Bureau of Mines , the city of Salt Lake and the University of Utah during 1919-1920 , a study was made as to the suitability of Utah coals for by-product coking with particular reference to low temperature coking . was done because it was realized that a smokeless fuel for domestic consumers was the best remedy for this class of smoke producer . A report of the technical side of the work was included in the final report of the cooperative investiga- Since this report was written (June 1 , 1920) further work has been done by other investigators .

Apr 1, 1922

By G M. Evans, C M. Phan

This paper presents an analysis on the dynamic adsorption of frothers and collectors onto air bubbles in flotation. The analysis was carried out using the theory on the surfactant transfer by diffusion and adsorption. The bubble size was considered when solving the diffusion equation for the dynamic surface excess. The adsorption kinetics was modelled employing the Langmuir adsorption isotherm and its extension with the inclusion of the lateral interaction of the adsorbed molecules (the Frumkin adsorption isotherm). The numerical computation was applied to solve the governing equations. The dynamic adsorption of the surfactants was measured in terms of the dynamic surface tension for sodium dodecylbenzene sulfonate (SDBS) and Dowfroth 250, using pendant bubble tensiometry. The results show that for air bubbles with diameter of the order of 1 mm, the bubble size effect on the dynamic surface tension is small and the solution of the diffusion equation for a planar gas-liquid surface can be used to describe the dynamic adsorption onto the air bubbles. The experimental data obtained with SDBS were well described by the Frumkin adsorption isotherm and the molecular diffusion. The model description for the experimental data obtained with Dowfroth 250 required the kinetic equations. The paper is relevant for further analysis of the role of the adsorbed surfactants in the particle collection.

Jan 1, 2005

By R Lastra, J. A. Finch

An artificial standard material has been developed and used to examine the robustness of some of the procedures for correcting stereological bias. Different mineral liberation distributions were constructed from the standard material. The particles were mounted, sectioned and the sectioning data measured with an electron microscope interfaced to an image analyser. Four correction procedures were used and the corrected and true liberation distributions compared. It was found that the large-sections correction provided a simple, uncorrupted correction. Hill's fast approximation performed well except in cases of narrow liberation distributions; the sectioning data appeared to support the assumption that the locked section and locked particle distributions are identical. Barbery's correction performed well in most cases, having difficulty only with the very irregular liberation distribution. The PARGEN correction was able to provide a good estimate of the true amount of free material, but had difficulty in predicting the locked particle distribution

Jun 21, 1905

By R. S. Douglas

Introduction During the past few years, a number of changes in the mine operations at Copper Mountain have taken place. The modernization and mechanization were necessitated and given impetus by wartime and other conditions, which were: (1) The urgent need for copper for wartime purposes. (2) The scarcity of skilled labour for underground work. (3) The increase in labour and supplies cost. (4) The necessity of finding ways and means of increasing the output per man-shift, because of the scarcity of skilled labour and the rising cost of labour. (5) The desire to increase safety measures, reduce the silicosis hazard, and aid mine ventilation. (6) The desire to improve the general working conditions in the mine for all workmen. (7) The desire to reduce the amount of dilution in the ore stream by a more selective yet highly productive method of mining. To this end, mining with diamond drills, and transferring broken ore with slusher hoists, appeared to be the answer to the problem. After considerable discussion and estimation of costs for comparison with those of the operation as carried on at that time, the proposed methods were tried out and, in practice, gave very gratifying results. Reference at this point is made to the paper written by C. H. Brehaut, W. N. Taylor, H. A. Shannon, and R. S. Douglas, which was published in the September, 1945, issue of Mining Technology, by the American Institute of Mining and Metallurgical Engineers, Inc., and subsequently in commercial mining journals. Since that time some improvements have been made in undercutting an orebody - the first through experiment and practice, the second through making use of the earth's barodynamic or gravitational forces. It is the purpose of this paper to describe and discuss these later developments.

Jan 1, 1947

Low-cost housing, like automobiles, should be appraised in the light not merely of first cost but of upkeep as well. Even more important than the number of miles the family car will go on a gallon of gasoline is the number of days the family home can be kept comfortable on a ton of fuel. A furnace tender who tossed every third shovelful of coal into the ashcan would lose his job promptly, but the effect is the same when homes continue year after year to pour out precious heat through uninsulated roofs and walls, Greater economy in household heating means even more to the national economy than to the individual, especially now that we are preparing for defense. Our fuel resources, although large, should be conserved. If less fuel is used for civilian needs, augmented requirements for defense can be met without unduly increasing the number of men needed at the coal mines and oil ells or adding new producing units that might complicate ultimate readjustment to peacetime conditions when the emergency is past and over-expansion of many industries brings new problems if unnecessary demands for transportation facilities are reduced, public carriers will be able to haul more munitions, and manpower needed for national defense will be released; and by protecting workers from health hazards in their homes additional man-hours of productive effort will be gained. Moreover, reducing the running expenses of houses by proper heat insulation helps home owners to maintain payments on property, and by minimizing foreclosures helps to stabilize the financial structure of the country. In short, here is a situation where the interests of the individual and the Nation are identical and the greatest good for the greatest number is obtained without sacrifice to anyone.

Jan 1, 1941

By Charles A. Lindberg

Mobile cranes on tires are perhaps the most important accessory in truck-haulage pits. They usually are of 20-ton capacity at short radius and with outriggers but have considerable overload capacity. Standard booms are 30 ft but have 10-ft extensions with which they are usually operated. Cranes have two engines, both originally gasoline, but 150-hp Diesel engines have been found more reliable for the propulsion motor, the 100-hp gasoline motors being retained for hoisting. Pro- visions are made for dropping the ballast counter- weight to reduce axle weights to legal limits for highway travel. The weights are carried on a regular truck or are transported on an extra trailer axle behind the crane. Tractors-Probably equalling the cranes in usefulness are the track-laying tractors which are used to prepare roads and other surfaces, to clean up at the shovel, and for dozing on stripping dumps. A new type of tractor mounted on rubber tires has been tried out on the Mesabi Range for the past year and a half. The advantage of this design is its mobility which makes it capable of taking care of the spill at the shovel and then running to the dump to clean up. Alternating between these two jobs, it relieves heavy tractors that can be used to better advantage on heavier work that does not require so much traveling. This tractor can travel at speeds of 12 to 13 mph and is designed to facilitate repair of the expendable parts. Weaknesses have developed in the internal construction which have seriously marred the performance record of this unit, but when used within its capacity it is quite successful.

Jan 1, 1949

By H. LIVINGSTONE LMAN

A GOOD DEAL of information concerning flotation has come out during the patent litigation of recent years, and the legal situation has cleared considerably, to the satisfaction of Minerals Separation, Limited. Hence, Mr. H. Livingstone Sulman, one of the originators of the successful process of that company, felt at liberty to explain, on Thursday, Nov. 20, his experience and his views in a "Contribution to the Study of Flotation," before the Institution of Mining and Metallurgy. He did not give technical details. He dealt with the physical problems, so simple, as he remarked, that he had wanted 96 pages to express his views. He presented much data, partly new and based on observations of his own, bearing upon the very complex flotation phenomena in an instructive wav and made frequent references to the valuable researches especially of Prof. Edwin Edser and Mr. Emil Hatschek.

Jan 1, 1920

By J. W. Thompson

The term "minerals" when employed in a conveyance in the State of West Virginia is understood to include every inorganic substance which can be extracted from the earth for profit, whether it be solid, as rock, fire clay, the various metals and coal, or liquid, such as salt, and other mineral waters and petroleum oil and gas. Horse Creek Land & Mining Co. v. Midkiff (West Virginia), 95 Southeastern 26, p. 27. TERM INCLUDES OIL AND OAS. The term "minerals" used to describe the interest in land granted or reserved bona fide includes petroleum oil and natural gas. Horse Creek Land & Mining Co. v. Midkiff (West Virginia), 95 Southeastern 26, p. 27. INJUNCTION TO PREVENT RElllOVAL. The removal of ore from the premises of another without his consent will be enjoined. Barnes v. Esch (Oregon), 169 Pacific, 512, p. 518. TITLE TO MEXICAN BULLION-JURISDICTION OF FEDERAL COURTS TO DETERMINE. Where bullion within the jurisdiction of the Mexican Government was seized, condemned, and sold for war supplies by the Constitutionalist forces in the revolution acting under authority from Gen. Carranza, claiming to be the provisional President of the Republic of Mexico, a United States district court of Texas, into which State the bullion has been imported from Mexico, has jurisdiction to try and adjudge as to the validity of the title acquired by and through the seizure, appropriation, and sale by the Carranza forces as against an American citizen claiming ownership of such bullion prior to its seizure.

Jan 1, 1919

Arsenic.--Inorganic arsenic has been added to the Environmental Protection Agency's list of hazardous air pollutants because of a high probability it can cause cancer. EPA estimates that inorganic arsenic emissions into ambient air total more than 6,000 tons per year, with about 65;L of this coming from the operations of copper, lead, and zinc smelters. Asbestos Detection.--In June 14, the President signed S. 1658 providing $172.5 million to detect and remove asbestos hazards in schools. Asbestos Use Must be Reported.--All firms using asbestos in the manufacture of some 30 categories of products must describe in detail how they use the mineral to the Consumer Product Safety Commission, for all manufactures since January 1, 1977.

Jan 1, 1980

By G. Anger, J. Enser, H. Antrekowitsch, S. Koch

Homogeneous chemical composition and microstructure are always necessary, but not always attained in practice. As-cast aluminium alloys tend to have a segregation microstructure. Features of the cast structure, which affect subsequent processing or properties, can be altered by the homogenization. The main task of the Department of Nonferrous Metallurgy was to investigate the effect of homogenization treatment on precipitation hardening of aluminium alloys 6061 and 6082. The effect of the solution heat treatment (SHT) temperature on the mechanical properties was also analyzed. The homogenized and non-homogenized rolling slabs were produced according to the usual conditions and methods. The metallographic investigations were carried out on the as-cast samples, after homogenization, after the hot and the cold rolling mill, and after natural and artificial ageing. Then, Brinell hardness measurements and tensile tests were conducted on both alloys in order to examine the influence of the homogenization.

Jan 1, 2006

By Bruce F. Grant

This report discusses research being done by the Petroleum and Natural Gas Branch und the Applied Physics Branch of the Bureau of Mines to deter-mine the most effective uses of explosives in shooting oil and gas wells, as measured in terms of rates of production from the wells. An experimental investigation of the effects of detonating explosives in shallow holes drilled in rocks, chosen to be similar to those forming oil and gas reservoirs, forms the basis of this study. Records obtained from strain gages placed in the rock around the experimental shots permit determination of the generation and propagation characteristics of the strain wave. Water-injection tests made on the test holes before and after shooting allow the increase in fluid conductivity resulting from the shot to be determined. By rotating these data to the physical properties of the rock, and by conducting shooting experiments over the range of rock types common to oil and gas reservoirs, it is expected that relationships between the fluid conductivity and the properties of the explosive and rock can be developed and used for designing efficient shots for oil and gas wells. Four series of experiment.al tests were completed during the summer of 1949 and are described herein. The results of these tests confirmed the feasibility of the experimental approach and permitted outlining the plans for future research discussed in this report. This report is presented to acquaint industry with this research program and the progress to date, so that the Bureau may have the benefit of suggestions from interested readers.

Jan 1, 1950

The Iron and Steel Committee of the American Institute, of mining and Metallurgical Engineers held a joint session with the American Foundrymen's Association during the Annual Meeting of the Institute in February, 1928, for the purpose of discussing blast-furnace operations and the character of pig iron and castings. Dr. Richard Moldenke presided. H.. H. Sweetser, who was named on the program as the presiding officer of the session, was unable to be present, but sent a letter in which he said: " The meeting we had here last year and the meeting held in Chicago last June showed a desire on the part of blast-furnace men and users of pig iron to get the facts regarding the influence on castings made from pig iron produced in blast furnaces under varying conditions of temperature, mixture and local furnace operations. It has been my hope that at this Round Table we might he able to formulate a series of tests that, would give us the desired information. "Several independent blast-furnace investigations have. been, and still are being, carried on in different sections of the country. The furnaces investigated include a southern furnace, a middle-west furnace, a western furnace and a Chicago district furnace. The results so far show distinct characteristics for each of the four furnaces. It is possible that a furnace in the eastern part of the United States would be different from all the others. "It is hoped that a plan of action can be worked out at your meeting today whereby the IT. S. Bureau of Mines will be able, to carry on more extensive work in connection with the research departments of the different iron and steel companies and the big consumers of pig iron. "No one group can get all of the, information but if the different investigations can be coordinated it will he possible for us to (Iran. conclusions regarding the effects of varying conditions in blast-furnace practice on the pig iron produced and the castings made there from." DISCUSSION R. Moldenke, Watehung, N. J.—I was across the -water this summer and saw some of those interested in an investigation of this kind. 'I'hey told me that in Germany, where they had a joint committee of blast-furnace operators and foundry-

By C. Larsen, R. A. Walker, A. Voth, C. Daoust

"The 3000 t/d mill at Hernia Gold Mines Inc. was commissioned in March, 1985. By Canadian standards the concentrator is highly automated, however, unlike the retrofit systems in many other plants, the Hernia process control system was installed during plant construction. This paper describes the Hernia control system beginning with system development (justification, architecture, start up, etc.), proceeding to current applications (crushing, grinding, leaching, etc.) and finally discusses some of the short term objectives for system improvement.INTRODUCTIONThe Hernia Gold Mines Inc. operation is located in the Marathon area of Northwestern Ontario. Controlled by Noranda Minerals Inc. (50.1 %), the cost of bringing the mine into production was nearly $300 million. A unique feature of the mine development was the extraordinarily short elapsed time of three years from Noranda's initial involvement to the start of milling operations. Additional background information on this project can be found in the trade literature (e.g. Tinter (1986). Scales (1987).)The Hernia concentrator is designed to process 3000 tpd of ore and commenced operation in March, 1985. Figure 1 provides a general plant flowsheet indicating the major circuits. Typical annual production statistics are included on the figure and these have been extrapolated from the available 1987 year-to-date data. Larsen and Tessier (1986) have previously described the operational aspects of the mill.In a metaphorical sense, the Hernia concentrator is like the traditional bride, ""wearing something old (e.g. the cyanide leach process), something new (e.g. a plant wide digital control system installed during construction), something borrowed (e.g. crushers from Gaspe) and something blue (e.g. the cladding on the surface buildings). While the prospect of fully undressing this bride is of considerable interest, here we choose to focus on something new. In particular, we choose to examine the process control system in some detail since Hernia is one of Canada's more highly autcmated gold mills. The control system is of interest because it has received suostantial credit for maximizing metal production and minimizing operating costs. With reference to the latter, it is worthy of note that Hem lo reports recent operating costs of less than $100 U.S./oz."

Jan 1, 1988

By Richard S. Kunter

Artech Recovery Systems, Inc has developed a low pressure and temperature? leach process called the "Cashman Process" to extract metals from arsenical flue dusts and residues and fix the arsenic in an environmentally stable form as ferric arsenate (scorodite). The process was pilot tested at Hazen Research in an integrated plant including continuous recycle from August 1989 to October 1989 during which several tons of flue dust were processed. Based on this pilot program, the process was deemed technically feasible and produced commercially salable products. Residues from this pilot program were subjected to a long-term stability test jointly designed by PTI environmental services and the USEPA. The process, its versatility, and the nature of the products is discussed in some detail.

Jan 1, 1992

By Lynn B. Hales

Unfortunately, the term "control" has a negative connotation in the minds of many of our operating plant personnel. Whereas the opposite is true of those associated with research and technical centers in our industry. The magnitude of this difference in opinion and actual experience has often proved to be a major factor influencing the success or failure of process control applications. Through the years, many plant people have endured a number of unsuccessful attempts by "outside" people to "optimize" their plants; and these experiences have proved to have had quite a callousing effect on them. On the other hand, in many plants, successful process control efforts have made firm allies of the operating personnel, and have increased the number of metallurgical people who are well qualified and experienced in process control. The instrumentation industry, computer industry, and the mining industry's ability to quantify what is really happening in our processes have grown and developed rapidly since the first control efforts were made in the 1930's (1). Because of this-,: new control opportunities are becoming increasingly more feasible and older well established ones are becoming even more practical and necessary with regard to the economic s of our industry.

Jan 1, 1979

By S. D. F. Rocha1, L. Katsarou, G. P. Demopoulos

"Crystalline scorodite (FeAsO4·2H2O) has been pointed out as the most stable compound to immobilize arsenic for disposal due to its good stability performance according to EPA’s TCLP test. However, in anaerobic conditions, arsenic releasing is increased to undesired levels due to scorodite reductive break down, in eh <100 mV at 5.5< pH <7 which causes contamination of groundwater. In this work, the concept of encapsulation by controlled deposition of mineral coatings immune to pH or redox potential variations is presented. Aluminum and calcium phosphates were evaluated as coatings and the release of arsenic from scorodite previously coated with phosphates was substantially decreased when compared to the VALUES (obtained from crude scorodite, both in oxic and anoxic conditions. INTRODUCTIONThe widely acknowledged hazardous properties of arsenic as a soil and natural water contaminant and its adverse health effects when present in drinking water have led to very strict environmental regulations (Mandal & Suzuki, 2002) aiming at the drastic reduction of the presence of arsenic in the effluents of the mining and metallurgical industries.In Canada, the Metal Mining Effluent Regulations (Government of Canada, 2002) dictate that the maximum monthly mean concentration in tailings for arsenic must be lower than 0.5 mg/L. At the same time the new Environmental Protection Agency’s (EPA) standard for drinking water foresees concentrations of arsenic less than 0.01 mg/L, which means that the leachability limit for the industrial waste is set at 1 mg/L arsenic (EPA, 1994; Le Berre et. al, 2007). One of the preoccupations of the mining and metallurgical industries is directed to the elimination of arsenic presence in all its effluents, especially since arsenic is commonly found in many ores mainly in the form of oxides and sulphides. After processing of arsenic-containing ores and concentrates, arsenic can be present either in solid residues and tailings, liquid effluents or in flue dusts. Several of these forms of arsenic waste materials are soluble and therefore may cause the contamination of ground water, if disposed of without further treatment."

Jan 1, 2012

The mineral Industry, following the economy as a whole, experienced little growth in 1992. However, with modernized plants, efficient workforces, and lower operating costs, the industry is well positioned to take advantage of possible improvement in the national economy during 1993. In addition to the significant 1992 events highlighted below, important events, trends, and issues within individual mineral industries are addressed in the commodity sections that follow. The value of processed materials of mineral origin is estimated to have been about $310 billion in 1992. The value of U.S. raw nonfuel minerals production in 1992 is estimated at approximately $32 billion, a 3% increase over 1991. The value of domestic minerals production has increased in all but 4 of the last 32 years.

Jan 1, 1993

By R. H. Schutz

TO ASSIST users in the selection of reliable and satisfactory respiratory protective devices, the Bureau of Mines bas established five schedules of minimum performance requirements for the approval of respirators. The current revisions of these schedules3 include 13D for self-contained breathing apparatus, 141F for gas masks, 19B and the amendments to 19B for supplied- air respirators, 21B for dust, fume, and mist respirators, and 23B for chemical cartridge respirators. Copies of these schedules may be obtained from the Bureau of Mines, Publications Distribution Section, 4800 Forbes Avenue, Pittsburgh, Pa., 15213. Approval tests on respirators are performed only at the request of the manufacturer4 of the respirator and at his expense. If the device meets the approval requirements, a certificate of approval is granted on the complete respirator. This certificate states that as long as the respirator is manufactured as originally approved, or in accordance with any changes covered by an extension of the original approval, the manufacturer may advertise and sell his respirator as being approved by the Bureau of Mines. Many industries and regulatory agencies require that respirators approved by the Bureau of Mines he used where respiratory protection is needed. The Bureau of Mines, however, has no regulatory power over the use of the respirators that it approves. It acts as an impartial testing agency to insure the availability of suitable and safe respirators.

Jan 1, 1966