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By T. F. Mitchell, B. K. Shibler, J. V. Batty, W. G. Sandell, G. M. Potter

"INTRODUCTION The Park City district, situated 30 miles east of Salt Lake City, Utah, in the Wasatch Mountains, Is a well-known producer of lead, zinc, and precious metals. Nearly continuous production has been maintained from the dis¬trict since its early discovery about 1870. For approximately 50 years, gravity milling methods were employed to beneficiate Park City ore, and during that time tailings from the mills were sluiced down Silver Creek and deposited on lands below the camp for 7 miles.Owing to the large tonnage of tailings deposited along Silver Creek, considerable work was done in the past in the attempt to develop a low-cost concentration method for re-treating this material, but no-method was found that was economically feasible. The Bureau of Mines was asked to conduct beneficiation tests on Park City tailings in November 1944, and metallurgical studies were initiated at that time. This report summarizes the results of laboratory ore-dressing studies made on samples from the Grasselli deposit."

Dec 1, 1947

By Hiland G. Batcheller

HISTORY shows that the nation which makes the most steel is the most likely to win wars. Today the course of war shows that the nations which get there first with the most steel of the right kind will be the ones to win. Not only the most steel, mind you, but the right kind. Adequate production, which was enough for victory before the days of totally mechanized warfare of 1943, must now be accompanied by still better quality as well as more effective distribution. Further, both production and distribution must be flexible enough to permit rapid shifts from one weapon to another for use in varying elements in varying geographical areas. Thus the problem of making enough steel of the right kind at the right time in the face of changing requirements dictated by experience has been and will remain highly complex. This does riot permit us to ease our restrictions on nonessential use. War is a complex business, like the job of making steel for war. Each time we solve one problem, another pops its head up. Yet we are making some progress.

Jan 1, 1943

By Dale Preece, Joergen Pilz, Zavis Zavodni

An overland conveyor was constructed at a surface coal mine to reduce the truck haul distance and make the operation more efficient. An important element in this system is a truck dump facility to transfer coal from truck to conveyor. Mechanically stabilized earth retaining walls were employed to accommodate the coal processing equipment, including the crusher, in this facility. These retaining walls are close enough to the pits being mined that blasting induced vibrations must be considered in analyses of the wall structural stability.

Jan 1, 2010

By O. C. Blade

This report on the properties of motor fuels sold through service stations in the United States was made in accordance with a cooperative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior. This paper is a continuation of a series made in cooperation with the Coordinating Fuel Research (CPR) Committee of the Coordinating Research Council (CRC), Inc. The first of this series of reports presented data on motor gasolines sold during the winter of 1935-36, and succeeding reports described motor gasolines sold during the summers and winters to and including the summer of 1941. No reports were made on motor gasolines sold during the winter of 1941-42 and during the summer of 1942. However, starting with the winter of 1942-43, the semiannual reports were resumed.

Jan 1, 1949

By W. R. Hardwick

This Information Circular describes the development of block-caving methods and practices by the Miami Copper Co. at the Miami mine in Gila County, Arizona. It is one of a series published by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. This report gives a history of the district and outlines early prospecting and exploration including methods of sampling and estimation of ore tonnage and value at the Miami mine. Early mining methods are described, particularly those that influenced developments in the caving method. Mine exploration, development, and operating methods for block caving are described with particular attention to those factors, physical, economic, engineering, and managerial that have improved efficiency in the mining operations over a long productive period. Extraction, ventilation, wage system, safety, water supply, power plant, and shop facilities are discussed. The last section gives a brief summary of such costs as are available for publication.

Jan 1, 1965

By C. E. T. White

Although trace amounts of Indium are found in many ores, commercial production of the metal has come almost exclusively from residues, flue dusts and slags generated by Zinc recovery operations. Our paper attempts to summarize the various approaches used to recover Indium from these by-products. Some comments on production and price trends are included as well as our views on future availability.

Jan 1, 1982

By Juan Kobashicawa, Bernardo Falcón

En este trabajo se describe el sistema de controles automáticos desarrollados (in house) e implementados en el circuito de molienda de Compañía Minera Antamina, el mismo que abarca molinos SAG, de bolas y los hidrociclones respectivos. Los mecanismos implementados están basados en el control por lógica Fuzzy y las bandas de Bollinger. En el artículo, se indican los criterios empleados para el diseño de los controladores y las variables del proceso, en el caso de indicadores de distancia del centro de masa de la carga respecto al centro del molino de bolas. Finalmente, se informa el impacto positivo logrado con la estabilización del circuito.

Jan 31, 2019

By C. W. Davis

THE name fuller's earth, which was derived from its early use in "fulling" or removing grease from woolen goods, is a term that is generally considered to designate mineral matter, containing hydrous aluminum silicates of the clay group, which has a high capacity for removing colors from oils, whether of animal, vegetable, or mineral origin. Fuller's earths are usually dried and may be "tempered" by heating or may be treated with water or reagents to improve their efficiency. For our purpose the term "acid-treated earths" will include those products from the partial decomposition of mineral water -by acid which are equal to or more efficient than an untreated fuller's earth from Quincy, Fla., when used in bleaching mineral oil by the "contact" process. In general, the contact process for treating oils consists of heating and agitating a mixture of oil and finely divided adsorbent, the latter being subsequently removed by filtration. The term "adsorbent" is used because, although there has been a great deal of controversy over the mechanism of removal of impurities from oils by mineral matter, there is no doubt that adsorption, which involves the surface of the solid, plays a major part.1 The properties that make fuller's earth useful in the treatment of petroleum products by "percolation" and in the purification of edible oils by the contact process have long been studied, but the comparatively recent adaptation of the contact process to the bleaching of petroleum products has made desirable the further investigation of fuller's earth and other, adsorbent earths.

Jan 1, 1929

By J. C. Underwood

"The wear performance of grinding balls under conditions of impact and abrasion is affected by their chemical composition and structure. The selection of appropriate analyses and heat treatments that will provide both abrasion and impact resistance takes into account the effects of certain elements on structure and harden-ability, as well as the over-all effect of composition and hardness penetration on the residual stress pattern developed through heat treatment. Direct quenching from forging temperatures substantially increases hardenability over that obtained in reheat-quench practices, and can be done without undue risk of damage to the ball provided that the harden-ability bears the correct relationship to ball diameter.Average volumetric hardness and percent hardened volume are convenient parameters for quantitatively expressing the response to heat treatment and indicating anticipated wear properties. A number of factors which can lead to reduced wear life as a result of material or processing problems are reviewed and illustrated."

Jan 1, 1959

By Gerald W. Elger

To determine the feasibility of removing nonferrous metal impurities from automobile scrap by thermal treatment in a rotary kiln, the Bureau of Mines conducted four series of tests with synthetic scrap mixtures heated at various temperatures under oxidizing and reducing conditions. The treated scrap mixtures were melted in an electric-arc furnace and cast into small ingots for impurity evaluation. Analyses showed that the ingots were essentially free of residual metal impurities except for copper. Test data indicated that in an oxidizing atmosphere the percentage of copper removed increased with treatment temperature. Percent of copper removed in a reducing atmosphere was found not to be temperature dependent. A significant finding was that copper was embrittled under some of the operating conditions and was mechanically removed by fragmentation.

Jan 1, 1968

By Herbert D. Drechsler

The objective of this paper is to identify the components of income above that necessary to keep a mine in production and relate those components to the profits of a mining firm. This is a discussion of "Economic Rent". Economic rent is the payment to the factors of production -- capital, labour, entreprenuer and the owner of the mineral deposit -- above the minimum necessary to keep all of these factors cooperating in the production of minerals from a particular deposit. THE SOURCE OF ECONOMIC RENT IN THE MINING INDUSTRY In the mining business each mine has a unique cost of production unrelated to any other mine. The cost of production is developed from many factors such as the technical characteristics of the deposit: depth of deposit, depth of overburden, areal extent, and type of deposit. Furthermore, there are locational factors which also alter cost of production. For example, identical mineral deposits located in Zambia or in the southwest U.S.A. would have different capital and operating costs. These differences occur because of different qualities of labour, ease of acquisition of operating supplies or investment capital and other similar factors. To explain the source of rent, we shall use ideas developed by Alfred Marshall and Kenneth Boulding. Suppose a meteorite with special qualities exploded over earth and sent showers of small meteorites to the ground in various places. At some point in time, people learned of the special qualities of these meteorites and a demand arose and one mine was started. Suppose further that the cost of production to produce these meteorites was different for each deposit. Probably the lowest unit cost mine would commence production because if a higher unit cost mine started-up, eventually someone would discover a deposit that had a lower unit cost of production. The lower unit cost mine would take over the market and the high unit cost mine would cease production. The cost curve for the first mine would look like the following Figure 1. [ ] The output for the first mine is on the horizontal axis with the cost per ton on the vertical axis. The curve labelled AC I is the average total cost of production over the range of possible production that could occur at the property. The total costs are composed of variable costs, which are dependent on output and fixed costs, which are dependent on time. For example, the cost of operating supplies would be a variable cost and normal profit would be a fixed cost.1 The opportunity cost of the investment would also be part of the fixed costs. In our example, all factors of production, are receiving the minimum necessary payment that will keep the mine operating. The average total cost curve is U-shaped because at zero output, the meteorite mine has no variable costs, only fixed costs which, on a unit basis, obviously are very high. To produce a small output of meteorites, the mining firm adds

Jan 1, 1985

By Iván Espinoza

El yacimiento de Horizonte es un sistema de vetas auríferas de qz ± sulfuros del tipo mesotermal, que está emplazado en el Batolito de Pataz, un intrusivo Mississipiano localizado en el margen occidental de la cordillera Oriental de la parte norte de los Andes Peruanos. En ese sentido, el presente trabajo describe la exploración geofísica realizada en el primer trimestre del año 2008 en Parcoy, con la finalidad de encontrar nuevas zonas de mineralizaciones potenciales y completar el modelo estructural en la zona. Para ello, se elaboró el proyecto de exploración PD para Parcoy, a través del método IP, el cual es usado en la búsqueda de mineralización de oro, así como el uso de sondajes diamantinos a las nuevas zonas detectadas por la geofísica. Como resultado de ello, se determinó 6 zona anómalas de interés prospectivo para ser analizado por el departamento de exploraciones.

Sep 14, 2009

By Colin G. ink

OUTSTANDI'NG in progress among the less familiar 'metals during 1936 is the electrolytic production of 99.9 per cent manganese meta1 readily and many quantity. Strictly speaking, manganese should not' be classed as 'a rare metal, since there is 800 times as much manganese in the earth's crust as there is zinc or lead. But manganese' as a metal is rare, just as titanium metal is rare though titanium is five times as abundant in the earth's crust as manganese.

Jan 1, 1937

By O. A. Bascur

Ores are becoming extremely variable with mineralogy and hardness disturbing the grinding and flotation circuits. The current grinding and flotation sensors provide large amounts of data for process optimisation. Adding the right context and operational events augments operational knowledge for proactive actions to improve the performance of the grinding and flotation circuits. A data-driven strategy is needed to enable operations, maintenance, and business personnel to quickly and easily take corrective action when abnormal conditions occur. A digital plant template transforms data into operational insights in real-time. It uncovers the hidden, idle and downtime losses. By measuring and managing these unproductive times, people find new ways of avoiding them, improving the profitability of the plant. The information created by the real time analytics enables the calculation of recovery in real time and develops predictive analytics models to find the best operating condition based on the type of ore currently mined. The creation of new workflows and collaboration between mining and concentrator plant and the enterprise, including services providers, are enabled. A grade recovery model is used to identify the best operating conditions in real-time. An optimal Gaudin size distribution shape is used to find the grinding operating conditions that optimise the metal recovery in the rougher sections of the mineral processing plant. Sensors in the flotation circuits enable estimation of metal recovery and determine the optimal froth depth and aeration profiles, using an industrial air holdup flotation model. The implementation of a recovery/grind strategy with industrial examples in non-ferrous metal concentrator is presented in the paper. Keywords: Digital transformation, soft sensors, predictive analytics, grinding flotation optimisation, flotation bubbles, particle size, particle size distribution shape, froth aeration profiles, flotation air hold up model, recovery predictive analytics

Jan 1, 2020

By Elmer Pabel Huayna Peraltilla

El proceso de lixiviación es un método para el tratamiento de minerales sulfuros y sulfuros mixtos que consiste en la utilización de un consorcio microbiano acidófilo y una solución rica en cloruro de sodio. En ese sentido, el presente texto destaca el método de la biolixiviación como la alternativa adecuada -en tanto solución ácida (cobre) que contiene el metal en su forma soluble. Dicho proceso se desarrolla en dos etapas: En la primera se usa una solución de cloruro de sodio, el compuesto protector, más un inóculo del consorcio microbiano. La mezcla permite obtener una recuperación de cobre de hasta un 80% basados en pruebas preeliminares. En la segunda etapa, se le agrega un agente oxidante, que no daña a las bacterias, con el fin de disminuir la pasivación del mineral y un inóculo fresco del consorcio y así prolongar la recuperación.

Sep 1, 2013

By Arno C. Fieldner

From July 1, 1949, to July 1, 1950, the Bureau of Mines conducted the research and technologic work on coal and coal products that is summarized in this report. The research, described in this fifteenth of a series of resumes, is presented in more detail in publications (see footnote references) that appeared during the fiscal year, though in some cases research data are given that have not been published elsewhere. Results of research in the experimental coal mine, on explosives, and on gas and dust explosions will be found in Bureau of Mines Report of Investigations 4228, Annual Report of Research and Technologic Work on Explosives, Explosions, and Flames, Fiscal Year 1950. An over-all view of our coal, oil, end natural-gas reserves was presented, and the future possibilities for the, production of synthetic liquid fuels from coal were delineated.3/

Jan 1, 1951

By J. C. Dumbrille

The following account of wining practices of the Kirkland Late Gold twining Co., (Ltd.), at Kirkland Lake, Ontario, is one of 4 series of papers being prepared by the United States Bureau of Mines on mining practices, methods, sad costs in various districts. The author has prepared this paper with the help and permission of J. B. Tyrrell and W. M. Sixt, the managing director and the mine manager, respectively. This mine is operating at a daily rate of about 150 tons.

Jan 1, 1931

By Lynn L. Rethi

This U.S. Bureau of Mines report summarizes common obstacles found when attempting to implement health and safety strategies in small mines and small businesses in general industry. Recently, the U.S. Mine Safety and Health Administration focused much of its attention on addressing health and safety issues at small mines. Some of the more innovative interventions practiced by small businesses in general industry are discussed for consideration of their applicability to the mining industry. The most effective intervention strategy that was developed for small businesses is the Occupational Safety and Health Administration Consultative Program. The details of this program and other intervention strategies used by small mines and small businesses are presented.

Jan 1, 1995

By T. F. Curry, L. B. Berger, H. A. Watson, S. J. Pearce

The conduct of work at elevated air pressures , such as in caissons and in tunnel - driving in subaqueous strata , poses safety problems not encountered in mining and tunneling operations at ordinary atmospheric pressure . This publication discusses some of the problems involved and presents information on the following subjects : ( 1 ) Physiological effects of gases at elevated pressure . ( 2 ) Use of respiratory protective equipment in rescue or recovery operations in event of fire or other emergency in pressurized tunnels . ( 3 ) Effect of elevated pressure on performance of some gasdetecting instruments ; interpretation of the results . Various types of respiratory protective devices are discussed in relation to their possible use at elevated pressures , especially the 2 - hour , selfcontained , recirculating - oxygen - breathing apparatus , which has had wide use in the United States during rescue and recovery work in the mining industry . A modified procedure that eliminates the hazard of oxygen poisoning enabling the safe use of this apparatus at elevated pressures , up to 45 pounds per square inch , gage , and tests to verify its practicability are described . procedure involves control of the partial pressure of oxygen in the breathing

Jan 1, 1964

By W. L. Dare

This paper is one of a series being prepared by the Bureau of Mines on the methods and costs of mining uranium on the Colorado Plateau. The Continental No. l mine is at the south end of the Big Indian mining district, San Juan County, Utah. The mine is on a school section owned by the State of Utah and leased by Continental Uranium, Inc. A 70,000-ton uranium-vanadium ore deposit was discovered as a result of an exploratory drilling program completed in 1954.

Jan 1, 1957