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By M. F. Werneke, J. A. Jones

Abstract- The use of a unique class of sulfhydryl collectors, the monoalkyldithiocarbamate salts ([RNHCS]) as direct collectors for malachite and azurite is presented. Microflotation and laboratory scale flotation tests were performed to define the collector properties of these reagents under a variety of flotation conditions. On the basis of the results, it is proposed that some property of the amine-hydrogen atom in the reagent has a significant influence on the unusual activity of these collectors for oxide copper minerals.

Jan 1, 1978

By J. M. Silliman

Isometrical drawing and clinographic projection are generally preferred to perspective drawings for representation of small objects or complicated mechanisms, as they present to the eye a sufficiently accurate picture of the object, while they possess great advantages over perspective in the simplicity and rapidity of execution, and the facility they give for taking measurements directly from the drawings.

Jan 1, 1882

By Dennis V. D’Andrea, Robert C. Steckley, William C. Larson, Richard A. Dick

A fragmentation experiment was performed in cooperation with Duval Corporation in a porphyry copper molybdenum deposit near the Sierrita pit south of Tucson, Ariz. A 10-hole test blast was detonated to establish relationships between blasthole spacing and the resulting fragmentation. Blastholes were 9 in. in diameter and 110 ft deep. The 10 blastholes contained a total of 17,400 lb of aluminized slurry blasting agent in 50-ft columns with 60 ft of stemming. Blasthole spacings of 25, 20, and 15 ft were tested. Diamond drill core examination was the primary method used to determine the condition of the rock before and after blasting. Topographic surveys were used to measure the rock swell produced by the blast and a fragment size distribution was obtained for the rubblized material on the surface. The rubble zone at the surface was ideal for in situ leaching. Fragmentation to depths of 110 ft was excellent from the 15- to 20-ft blasthole spacing patterns. Good breakage was also produced by the 25-ft pattern although the effects of the blast were not as obvious. In situ leaching tests were not conducted. However, based on size consideration only, all three blasting patterns produced adequate breakage for successful leaching.

Jan 1, 1974

Gentlemen:-I herewith present a report on some of the more important activities of the Institute for the year 1921. The present incumbent took. over the active management of the Secretary's office on the first of July and his, work was facilitated, while becoming acquainted with the routine of the office, by the constant and., kindly assistance of the former, Secretary, Mr. Stoughton, during the following three months, and that no interruption occurred inn its regular and smooth operation is due to him and to the Assistant Secretary, who has always been ready to give the benefit of his experience and assistance. MINING AND METALLURGY Through the efforts of President Ludlow and the generous assistance of one of our members, coupled with the excellent work of Major Barbour, MINING AND METALLURGY has, during recent months, shown constant improvement, which could not have taken place, however, had it not been, for the support given by a number of our contributing members. We have every reason to feel encouraged with respect to the quality of the publication and its cost of production. For the year 1921, the net cost of MINING AND METALLURGY was about fifty cents per member, per annum. Occasional letters are received criticizing the Board for producing this publication, but they are more than offset by letters of approval. When the, full purpose of the publication is appreciated, criticism ceases. The elimination of MINING AND METALLURGY and reversion to free distribution of all papers to all members, whether desired or not, would mean such a heavy additional expense that the number of papers would have to be much curtailed. The generous cooperation of members in sending for only such papers as they particularly desired has saved, the Institute thousands of dollars. A plan is being worked out that will materially assist in securing a prompt distribution to members of all pamphlets dealing with subjects in which they are especially interested.

Jan 2, 1922

By Maurice E. Peloubet

This discussion of accounting will describe the statements and the information that the accounting system produces, from the point of view of those who use such systems rather than of those who prepare them and who do the detail and technical accounting work. In any well organized mine, quarry, or other enterprise exploiting a mineral deposit, no matter how small, some clerical and accounting work must be done. Miners and other employes must be paid, supplies must be purchased and issued, and various tax and information returns, which even the smallest enterprise must file, have to be prepared. In this chapter it is assumed that the enterprise has employes of this type and that they understand the fundamentals of record keeping and accounting. It would be impossible here to give sufficiently full explanations to enable a man with no previous clerical and accounting training to set up and operate an accounting and cost system for even the simplest extractive operation. Rather, we shall hope first, to tell the investor and the operator, from the chief engineer or president down to a subforeman, what to expect from the accounting statements and records and how to use this information in his daily work; and second, that it will enable the man with some knowledge of accounting or bookkeeping, but with little or no experience in any extractive industry, to set up and operate a satisfactory system for a mine or other extractive enterprise. For readers who wish to go further, the bibliography at the end of this chapter contains many references. The emphasis has, therefore, been placed on the statements to be produced and the purposes for which they are to be used rather than the underlying books and records. These are, with a few exceptions which will be described later, essentially what might be found in any industrial enterprise and would probably, in the extremely small enterprise, consist of handwritten journals, ledgers, analysis books, payroll books, and stores ledgers. In the larger enterprise, various types of mechanical accounting would be introduced in proportion to the complexity of the operation.

Jan 1, 1959

By William D. Schwab

In the technical literature of 1965 and 1966, there were several papers about future power for mining and construction equipment. Most of these papers made the same predictions: •More power •Better reliability and durability •Ease of service and maintenance •Operating economy •The possibility of future environmental concern •The entrance of the gas turbine In the five years that have since passed, some of the 1965-66 predictions have at least partially come true, while others have not been fully realized. Actually the list still appears sound today. Priorities may have changed and details may be different, but the main points cover the requirements for future prime movers quite well.

Jan 1, 1971

By R. Hogg

The mathematical description of solids transport in mills is an important aspect of the development of comprehensive models for the analysis, simulation and control of grinding systems. The basic mechanisms of particle transport and mixing, including gravity flow, carrier fluid transport, and "diffusion", are reviewed and their relative importance in wet and dry ball mills is discussed. Specific models for transport and mixing in dry, grate-discharge and wet, overflow ball mills are described. The limitations of the models, parameter estimation problems, scale-up criteria etc. are discussed and the conditions which lead to particle size dependent transport, and hence to internal classification in the mill, are described in detail.

Jan 1, 1984

By Walter H. Ortel, George B. Wallace

INTRODUCTION A greater understanding is required about the factors which control tunneling operations if we are to meet the expected demand for tunnels. Much of the needed information can best be achieved by the proper use of instrumentation and advanced engineering concepts. Tunnel measurements and their analysis may prove to be the key which will give the insight necessary to understand the relationship of rock, tunnel supports, and linings. There are three main areas which can be improved through the use of tunnel instrumentation. First, and of prime importance, is safety for men and the project. When unstable conditions occur, sets become distorted. Even without measurements, it is sometimes possible to tell when trouble is approaching. In effect, the set acts as a load cell. Distortions in the set indicate reinforcements may be required to maintain stability. Additional sets or rock bolts, if they are placed soon enough, may provide this stability. However, when large rock displacements occur in short periods of time, it could be too late. Figure 1 is an example of the difficulties encountered in stopping moving rock. To stop the movement and possible failure, large props were placed above the spring line and the massive concrete gravity buttress was constructed along the legs. Rock bolts from the buttress deep into the rock were also used in an attempt to stabilize the rock mass. However, this work is for a highway tunnel and eventually these props and buttresses must be removed.

Jan 1, 1971

By E. J. Wasp, T. C. Aude, F. B. Raymer

Abstract-The following paper deals with technical aspects of terminal facilities for western coal pipelines. The information is taken from the Ohio and Black Mesa pipelines and the proposed one in Wyoming. This paper first discusses the feed terminal, the product that it must produce, and the reasons for coal cleaning. Then, in the delivery terminal section, the various methods of dewatering the coal and some recent innovative ideas on bunkering the dewatered product and storing the dewatered coal in large outdoor piles are discussed.

Jan 2, 1978

By Paul K. Krueger

SUMMARY Since 1970 the Federal Preparedness Agency has been using computer models to help establish the amounts of strategic and critical materials to be held in the National Stockpile. Fifty-three of these materials are metals or minerals. The following diagram shows the linkage of models used to estimate material requirements. [ ] The starting point for the models are estimates of the major components of GNP for some future period. These may be estimates purchased from a forecasting service or may be produced in-house. The projections are translated into industrial final demands using DITT (Demand Impact Transformation Tables), a system developed at FPA. Then using a version of the current Bureau of Economic Analysis input-output model, estimates are made of the gross output of each industry necessary to support the level and composition of GNP as specified by the macro-economic model.

Jan 1, 1977

By H. M. Chance

WITHIN the last 10 years the subject of mine taxation in its relation to coal-mining interests has come to have growing importance, not only to those engaged in the mining of coal, but also to the owners of land underlain by coal. A disposition has developed among legislators to accept the principle, which has been laid down y many judicial decisions, that coal underlying the surface must be regarded as a part of the real value of all properties so underlain, and as such is chargeable with such burdens of taxation as the necessities of the government may impose. These necessities arise from the normal expense of maintaining State and local governments, and in the past have been met principally by, taxes based upon assessments of real estate values, which values in many cases have been confined principally or wholly to the value of the surface, without taking into consideration the value of minerals underlying the surface. It is not proposed here to deal with the question of Federal taxation, whether levied on production, or on products transported from one State to another, or exported from the country, or upon thegross or net earnings of corporations engaged in interstate commerce, or upon the production of materials which may be transported from one State to another, or levied. upon the profits or upon the obligations of corporations. The present discussion will be confined to the appraisal of coal lands as assessed for State, county, township, or borough taxation. The methods heretofore and at present in use in the different States vary widely and have resulted in more or less litigation. Discussions appearing from time to time in the technical and trade journals and in the proceedings of mining and engineering associations frequently direct attention to the need for the adoption of fixed principle in levying taxes, and of uniform methods for applying such principles, but there does not seem to be a general demand from the public for the adoption of such methods.

Jan 7, 1914

By L. Adler

A fairly complex analysis is required to select or evaluate a piece of excavating and bulk handling equipment for its performance. At present, there is little agreement as to what points should be considered, and even less on what procedure to follow. This paper provides both of these in a consistent and direct form. The analysis applies to all types and sizes of equipment. The importance of the equipment characteristics, job activities, and work conditions are stressed. Separate analytical stems are established in a flow chart for these. They are combined using suitability tests in: problem statement; natural conditions; suitability guidelines; appropriate equipment types; operational activities; encumbered space; geometric design; equipment sizing; failure and limits; performance and consumption; public policy checks; and costs and profitability. Public policy and economics receive emphasis towards the end. The procedure is iterative, containing distinct feedback loops. Specifying the steps and sequence provides a necessary structure which has long been overdue.

Jan 1, 1985

By R. P. Killmeyer, B. S. Gottfried, J. T. Wizzard

The US Department of Energy's Coal Preparation Branch has developed a computer program to calculate the performance characteristics of coal washing devices. This program uses specific gravity analyses of the clean coal and refuse streams as input, and generates dependent and independent performance criteria for the washer. Partition curves are internally represented in a functional form by a Weibull function. Comparisons are made between performance criteria calculated by hand and the performance criteria calculated by the program for 120 different dense medium cyclone tests. Results show that the computer program gives results in close agreement with hand-calculated values while greatly reducing the amount of time involved in performing the analyses.

Jan 1, 1984

By W. J. Whiten

Current developments in one type of crushing and screening model is reviewed and general design techniques and policies are proposed for the control of crushing plants.

Jan 1, 1984

By E. H. Crabtree, T. C. King

THE ferrosilicon grinding unit at the Central Mill of the Eagle-Picher Mining & Smelting Co. near Picher, Okla., was completed in March 1947. The object of the plant was to grind pigs of ferrosilicon, having a size of approximately 1 ½ by 4 by 12 in. and an analysis of 85 pct Fe and 15 pct Si, to approximately 100 mesh by crushing and wet grinding in a ball-mill classifier circuit. The minus-loo mesh ferrosilicon had formerly been purchased, and was used as medium in the heavy media process for treatment of lead-zinc ores. From the standpoint of dollars and cents, the cost of minus-100 mesh ferrosilicon was roughly $40.00 per ton more than pigs of the corresponding alloy delivered to the mill. Estimated wet grinding costs were considerably below this figure. The possible saving in cost of make-up medium for the cone plant was particularly attractive since, at that time, the plant losses averaged over four tons of minus-100 mesh ferrosilicon per day. Aside from the probable saving on the grinding charge, the need for such a unit was twofold. First, periodic fluctuations in the differential between the top and bottom densities of the cone were thought to be detrimental to metallurgy. There was little doubt that an intermediate differential existed at which the heavy media separation was most efficient, representing a compromise between concentrate grade and tailing loss. Furthermore, if a finer, but considerably cleaner, medium could be obtained, there was the possibility that the differential could be decreased without increasing the viscosity, or conversely, the viscosity of the medium decreased without increasing the differential. Preliminary to experimental work aimed at pegging the cone differential and circulating medium viscosity at whatever values were found to be most efficient, it was essential to have control over both the non-magnetic content of the medium and the particle size of the contained ferrosilicon. The latter was possible by means of a grinding unit at the mill. Second, whereas the ferrosilicon alloys are made by a number of manufacturers, only two, to our knowledge, grind it in any quantity for use in heavy media plants. For all practical purposes, the Central Mill was limited to one source of supply, a particularly vulnerable position. In case the supply was cut off, it was thought that pigs of the 85 pct Fe, 15 pct Si alloy could be obtained elsewhere, providing means of grinding them was available. There was no published information available covering wet grinding of ferrosilicon. Dry grinding in batch mills and in continuous mills with air classification was being practiced, but the cost of grinding was excessive and the dust condition objectionable. It appeared that primary and secondary crushing was no particular problem, providing heavy duty equipment was used;

Jan 1, 1947

By William G. Pariseau

There are important phenomena in rock and soil mechanics that cannot be explained in terms of theories of homogeneous, isotropic materials. Subsidence of strata about mine openings is an example. In-situ stress measurements in nonisotropic sedimentary and metamorphic rocks is another. Patterns of joints, faults, fractures, and similar geologic features impart directional mechanical properties to rock masses that are locally isotropic or anisotropic. On the geologic scale, the nonhomogeneity of composite rock masses may, in certain instances, be dealt with as homogeneous anisotropy. The mechanics of large rock masses can, therefore, be expected to involve considerations of anisotropy. The source of the anisotropy is not relevant. Once the scale of observation is selected and the material is defined accordingly, the analysis of stress and deformation proceeds without regard to the numerical values of the material constants. There are also important phenomena in rock and soil mechanics that cannot be explained in terms of linear elasticity, theory. For the mechanical description of anisotropic geologic materials capable of deforming beyond the limit of purely elastic strains, a plasticity theory is required. The purpose of this chapter is to present a plasticity theory for anisotropic rocks and soils. The proposed theory is based on the work of Hill in anisotropic metal plasticity and represents an extension of his work so as to include anisotropic geologic materials. The point of departure from metal plasticity theory begins with the inclusion of the normal stresses as linear terms in the yield condition, which plays a central role in plasticity. Once the yield condition is established, the plastic strain increments are obtained immediately through the principle of normality. For practical applications, some simplification of the three-dimensional theory is re-

Jan 1, 1972

Until the end of 1960, the small primary aluminum industry in Australia was run by the government. The entire operation was at Bell Bay on the north coast of Tasmania. It consisted of an alumina plant and smelter, owned jointly by the Commonwealth and the State of Tasmania. Apparent domestic demand that year was about 48,000 long tons; 11% thousand came from Bell Bay; the rest was imported. By March 1964, Australia had two fully integrated aluminum companies. The government has stepped out of the picture and the key word of the industry from bauxite to metal is "growth." Present annual capacity of the two companies for making aluminum metal totals 92,000 long tons a year. Australian demand is about 60,000 tons. By 1968 Australian consumption should be 90,000 tons and by 1970 it is expected to reach 107,000 long tons per year. Export markets for bauxite, alumina and metal are developing.

Jan 10, 1964

By Alexander Gakner

Since the end of World War II the Soviet Union has made great strides toward economic development of the country. Today it is firmly established as the world's second largest industrial power after the United States and it has committed itself before the people on both sides of the Iron Curtain to catch up with and to overtake us within a few decades. No nation could achieve such a degree of industrialization or aspire to become the world's industrial leader without a large supply of many basic mineral raw materials or at least easy access to such resources. In addition, it requires technical competence, a large skilled labor force, and a high rate of capital investment. Why should we concern ourselves with these Soviet aspirations? The Free World's yardstick of measuring a nation's well-being is the standard of living of the people in that country. Presumably even Communist governments are committed to some, however gradual, improvement in the standard of living of their people. The population of the USSR is 20 pct greater than that of the United States. Hence, if they ever achieve a standard of living equal to ours, they must by all logic reach a greater overall industrial output. However, in the U.S.S.R. the standard of living of the masses has not kept pace with the expanding industrial production and is still far behind that of the United States. Our concern, therefore, is with what the USSR intends to accomplish with its expanding industrial power: Will they produce large mineral raw-material surpluses and manufacture products to compete with us for world markets and attempt to put us out of business if not use it directly to wage war; or will they use their resources merely to produce more consumer goods for the Soviet people; or will they, along with other Communist nations in the not-too-distant future, compete with us for the world's sources of mineral raw-materials to maintain a high level of mass consumption?

Jan 6, 1960

By William Daly

THE application of artificial refrigeration, or air-conditioning, to the ventilation of deep, hot mines has long been a subject of interest to the operators of such properties. Artificial cooling of the air in theaters, railroad coaches, and various industrial plants has been so successful within recent years that it has been natural to assume that the adoption of similar methods would afford a ready solution to the difficult problem of mine ventilation. It should however, be obvious, that although there may be nothing technically impossible in the application of this process to mine ventilation there is a great economic distinction between the maintenance of a high standard of comfort for a large number of people in a relatively small space such as a theater and the cooling of air to improve working conditions for miners scattered throughout the extensive workings of a large mine. Many methods of air-conditioning have been considered by the management of the Anaconda Copper Mining Co. at various times, but until the development of the process to be described in this paper none has seemed economically practicable.

Jan 1, 1934

The Commissioner of Education has issued a call for a public conference on business training for engineers and engineering training for students of business. This conference, national in scope and character fully representative of all interests, will be held in Washington, D. C. on June 23 and 24. Educational institutions, commercial organizations, and educational and engineering societies will be given an opportunity to state their views. Engineers, educators and business men will be invited to discuss the following major topics: Business Training for the Engineer; Engineering Training for Commercial Enterprises; Significance of the. War Experience for Engineering Education; Training of the Engineer for Foreign Projects. This conference has been called on behalf of the Conference Committee on Commercial Engineering. This Committee is composed of administrative professors in engineering and commerce from several of the large educational institutions and representatives from the American Institute of Mining and Metallurgical Engineers, Society for the Promotion of Engineering Education, The American Society of Civil Engineers, American Institute of Electrical Engineers, American Society .of Mechanical Engineers, and a committee f fifteen on Educational Preparation for Foreign Service.

Jan 6, 1919