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By R. H. Richards, A. E. Woodward

In Rittinger's Aufbereitungskunde of 1867 occurs (p. 195) the following table, which shows the rate of falling in water of fragments of minerals, of irregular shapes and of five different specific gravities: Diameter of particles in millimeters. 10 8 6 4 3 2 1 .5 Sp. Or. Velocity in meters per second. Auriferous silver, 16..9 .8 .7 .57 .5 .4 .29 .20 Galena,. ..7.5 .62 .55 .48 .39 54 .28 .20 .14 Pyrites,. ..5.0 .49 .43 .38 .30 .26 .22 .15 .10 Quartz,. ..2.6 -30 .27 24 .19 .17 .14 .10 .07 Coal,. ..1.3 .13 .12 .10 .08 .07 .06 .04 .03 With the purpose of extending this valuable table, to cover a larger number of minerals and sizes of each mineral, and of making it more easy of application in deciding upon a sieve-scale for any group of minerals, we have prepared the curves of velocity of fall of bodies in water shown in Plates I., XI., 111. and IV., using Rittinger's formula V= 2.44d(8 —1) where V= velocity in millimeters per second. " D = diameter of particles in meters. " 8 = specific gravity of the mineral. These curves embrace a large number of specific gravities, and for each specific gravity the relation of the diameter of the mineral particle to the velocity of its fall in water is given for all diameters and velocities used in practice. The second diagram is an enlargement of the lower left-hand corner of the first, the third bears the same relation to the second, and in like manner the fourth to the third. Plate I, therefore, covers the work of the coarsest jigging 2 inches in diameter; and under

Jan 1, 1890

By Warren E. Morrison

This study was prepared in response to the need for a series of data that reflect the basic flow pattern of energy resources in the United States. To effectively measure and analyze energy,2 it is necessary to prepare balances that reflect both production and consumption, and the various forms energy resources take at different stages of utilization. Before energy can be measured it must also be put into a common unit. In this study the common unit used is the British Thermal Unit (Btu). The ideal point to survey energy is at the stage of final ultimate use, representing the useful work derived from the interaction of energy inputs and the prime mover. Unfortunately this concept of efficient or useful work from energy output cannot readily be measured in the aggregate. With the present available official data, energy measurement can be carried to the point of calculation of net inputs of energy3 into the economy at various stages of utilization. However, preparation of energy balances, on a net basis is hampered by the fact that this can only be done for years when the censuses of Mineral Industries and Manufactures are taken, usually at 5-year interval.

Jan 1, 1964

By Warren E. Morrison

This study was prepared in response to the need for a series of data that reflect the basic flow pattern of energy resources in the United States. To effectively measure and analyze energy,2 it is necessary to prepare balances that reflect both production and consumption, and the various forms energy resources take at different stages of utilization. Before energy can be measured it must also be put into a common unit. In this study the common unit us d is the British Thermal Unit (Btu). The ideal point to survey energy is at the stage of final ultimate use, representing the useful work derived from the interaction of energy inputs and the prime mover. Unfortunately this concept of efficient or useful work from energy output cannot readily be measured in the aggregate. With the present available official data, energy measurement can be carried to the point of calculation of net inputs of energy3 into the economy at various stages of utilization. However, preparation of energy balances, on a net basis is hampered by the fact that this can only be done for years when the censuses of Mineral Industries and Manufactures are taken, usually at 5-year intervals.

Jan 1, 1964

By J. Baird

The Sappington Bridge, a steel arch span bridge constructed in 1904 over the Meramec River, was demolished due to its advanced state of deterioration. The demolition was a project to benefit Crawford County, Missouri, the U.S. Army, the Missouri Department of Transportation, and the University of Missouri – Rolla (UMR) was conducted jointly by the UMR Rock Mechanics and Explosives Research Center (RMERC) and the UMR Center for Infrastructure Engineering Studies (CIES). By arrangement with Crawford County, a 55-foot span of the old bridge was brought to the University Structures Laboratory in Rolla, while the longer, 200-foot span of the bridge was demolished using preburning and explosives. Originally, the longer span was to be blown up by C Company of the 5th Engineer Battalion (from Ft. Leonard Wood, Missouri) under the supervision of personnel from UMR. Unfortunately, permission for the operation from the Department of the Army could not be obtained in time to meet permitting requirements for the demolition. Therefore, a commercial demolition contractor was employed to perform the demolition, and to remove the scrap.

Jan 1, 2003

La presente investigación refiere los aspectos de salubridad en las minas de Cercapuquio, a partir del ambiente de actividad del trabajador y su desarrollo fisiológico corporal. El yacimiento minero situado en el distrito de Chongos Alto, provincia de Huancayo, departamento de Junín, tiene una altura máxima de 2400 m.s.n.m, que influye en la formación biológica del hombre andino, puesto que tanto la altitud, temperatura y atmósfera son características morfométricas constituyentes de su fisiología. Sin embargo, según un estudio realizado a los hombres de trabajo provenientes de los departamentos de Junín (89%), Huancayo(7%) y Lima, se estableció que aunque hubieron desviaciones fisiológicas (volumen de sangre,capacidad respiratoria, etc,), las posiblidades de vida en la altitud para el hombre aclimatado son las mismas que para el hombre de mar. Sobre el resultado de estas bases, se evaluaron otras características de la patología del trabajador y los trazos posibles de morbilidad, logrando reducir los altos índices de la enfermedad. Las medidas adoptadas por la minera para proteger al personal empleado fueron: Foto-fluorografía de ingreso para el personal nuevo, instrucciones sobre la alimentación, higiene y prevención de enfermedad, llenado de fichas, control integral de partos respecto de las familias ubicadas en el asentamiento minero, difusión sobre profilaxis de enfermedades, vacunación total, esterelización del agua, etc. Respecto de los índices de morbilidad, se consideraron las patologías desarrolladas en el niño y recién nacido del trabajador, tales como las infecciones respiratorias, digestivas, carenciales, las cuales respondieron de forma óptima al uso de los tratamientos moderno-hidrosalinos, dietéticos y anti-infecciosos.

Jul 20, 1957

By William Priestley

The author has shown, by .practical experiments, how the rate of cooling steel in the mold governs ingotism, segregation, the formation of dendrites, and the distribution of intergranular material; and the resulting effect these conditions have on the physical qualities of the steel before annealing, after annealing, and after forging. The paper also describes how the structure of steel is affected by the design of the mold and the method of pouring. It is shown that the various constituents of carbon steel segregate differently under different rates of cooling. For the classes of steel covered in this paper, it is concluded that the best physical structure and the most uniform chemical composition is obtained by pouring the steel at a low temperature and solidifying as rapidly as possible in the mold. MUCH time has been devoted, by metallurgists, to the study of steel after solidification and remarkable strides have been made in the heat treatment of steel, but less knowledge is available of the thermophysical, activity of the constituents of steel prior to solidification in the mold. It is known that certain elements added to steel produce marked changes in physical properties, also that other elements added to steel produce similar changes, but we have only meager knowledge as to how these elements combine in steel under different conditions of solidification. It is not sufficient to know, from chemical analysis, that a certain element is present in steel. We should know how this element is in combination with the other elements and whether the combination is such as will give the greatest physical properties. Certain elements go into solid solution with the iron, while others segregate to the grain boundaries and combine with the impurities collected there. Until it is known where an alloy produces the most beneficial effect and a means, is determined for controlling its physical location by altering solidification conditions, or otherwise, we will not obtain the maximum value from our alloys.

Jan 2, 1924

By Harlan A. Walker

This paper on the mines of El Potosi Mining Co. is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in the various mining districts of North America. Grateful acknowledgment is made of the helpful suggestions and criticisms offered by the management, together with the assistance of the mining staff in preparing maps and drawings and of C. L. Thornburg, mine geologist, in preparing the section on geology.

Jan 1, 1934

By G. Budge

In the extractive industry the term ‘continuous improvement’ (CI) usually means procurement of the latest state of the art equipment. This is generally perceived as the only way to add further value to the supply chain, with the driving philosophy of increased tonnage to dilute operational costs. However, not all market places can facilitate this approach. RJB lives in a fiercely competitive market and has targeted the standard efficiency drivers of rationalisation and stock management with a vengeance; and also operate CMMS (Computer Maintenance Management System), RCM (Routine Condition Monitoring)and CBM (Condition Based Maintenance) methodologies. Ultimately though, these systems are only as good as the people who operate and manage them and to add further value without procurement, people must be re-introduced back into the operation. Through TPM (Total Productive Mining), that is what RJB have set out to do.

Jan 1, 2001

By Gang Chen

This paper explores the possibility of using short-term time-dependent plate loading tests to estimate the elastic and viscoelastic parameters of the weak floor strata typically associated with coal seams in Illinois. Plate loading tests with incremental loads, similar to incremental creep experiments, were conducted until the floor failure occurred. For each increment, the load was held constant for a period ranging from 1-4 hours until a constant deformation rate was achieved. The deformation-time data were analyzed for viscoelastic parameters of weak floor strata assuming its behavior to be adequately represented by the standard Burgers model. The analysis required development of mathematical equations for the time-dependent deformation of the standard Burgers material under a three- dimensional state of stress. Time-dependent pillar settlement data at one mine were also analyzed for elastic and viscoelastic parameters of the weak floor strata using the developed equations. These parameters were compared with similar parameters estimated from plate loading tests.

Jan 1, 1990

I have spent most of the past 35 years working as an economic geologist in the area of exploration and development of base and precious metals. Most of this period has been as an employee of Trans-National-Corporations (TNC's). I presently act as a consulting geologist to a joint venture company, bringing together two such TNC's: Anglo American Corporation and affiliated companies De Beers (Diamonds) and Minorco (Metals mining outside of Southern Africa), and Normandy Mining Limited ofAustralia. Normandy is presently through its gold arm PosGold, Australia's largest gold miner and Anglo American can claim to be the world's largest gold company producing over 280 tonnes of gold a year, more than twice its nearest rival Gold Fields of South Africa. In addressing this topic, the role that Government can, and should play in mineral development, I will be drawing heavily on some examples from these and other TNC's experience in recent offshore mining investment.

Jan 1, 1995

By L. L. Chasko, D. W. Alexander

Los investigadores del National Institute for Occupational Safety and Health’s Office of Mine Safety and Health Research han evaluado los efectos que la malla de control de suelos podría tener en la distribución de polvo flotante de roca y carbón en minas de carbón. El creciente uso de mallas para controlar el desconchado o caída de material del techo y las vigas introduce superficies elevadas adicionales para recolectar el polvo de roca o de carbón. Es posible que el potencial para la propagación de explosión del polvo se incremente si el polvo flotante de carbón no es convertido en inerte de manera adecuada. Adicionalmente, la malla podría interferir con la recolección de muestras representativas de polvo cuando se usa el método de recipiente y brocha desarrollado por la U.S. Bureau of Mines y usada por la Mine Safety and Health Administration para muestreo de banda. Este estudia hace una estimación del polvo de roca o carbón adicional que pudiera acumularse en la malla y desarrolla un método para recolectar muestras de polvo representativas atrapado en las mallas.

Jan 1, 2014

By G D. Price

Scheelite mineralisation east of the main divide in' the Southern Alps of New Zealand was originally identified by Royden Thompson who is now a geologist with the NZ Geological Survey. This mineralisation was brought to the attention of CRA in 1978. Reconnaissance surveys were carried out in 1979 to delineate the extent of the mineralisation. This was undertaken using ultraviolet light examination of the sediments within the major drainages in the Southern Alps. This defined tentative zones of prospective mineralisation. As a result of this, preliminary reconnaissance, exploration licences were applied for -those areas in which indications of scheelite mineralisation were strongest. A total of 1737 km2 of ground was applied for within four exploration licences. These covered the main Southern Alps mountain chain between the Haast/Wanaka highway and the Mt Cook National Park.

Jan 1, 1983

By Héctor Benavente Revilla

El presente texto señala la ubicación y acceso, reseña histórica, geología general y operación del yacimiento aurífero San Antonio de Poto, provincia de Sandia, distrito Ananea, ubicado en el departamento de Puno.

Mar 1, 1978

By Pierre Mousset-Jones

A questionnaire was sent out to three classes of mines to determine the extent of the heat problem in U.S. and Foreign underground mines. The following list shows the replies received from this questionnaire, however not all the known hot mines in the US replied. A complete listing of the results can be seen in Appendix I. 1) US coal mines - 37 replies 2) US non coal mines - 23 replies 3) Foreign non coal mines - 36 replies. At the present time there are approximately eleven non coal and one coal mine in the US experiencing heat problems which require special efforts to maintain an acceptable working place climate. However since the survey was completed some of them have been placed on standby. The Mine Safety & Health Administration (MSHA) does not have any specific regulations relating to heat stress. Informally the American Conference of Governmental Industrial Hygienists guidelines are followed which use wet bulb globe temperature (WBGT) with values ranging from 26.7°C to 31.1°C for a moderate workload, and different rest regimes. An MSHA report (Misaqi 1976) recommended that conditions should not exceed 26.1°C WBGT for men and 24.4°C WBGT for women. However, quite recently the organizations involved with planning two of the proposed nuclear waste repositories in the United States, have opted for the criteria of an air cooling power of 300 w/m2, and a WBGT of 27'C respectively.

Jan 1, 1986

Book review Proceedings of the Symposium on Mining Methods. London, Institution of Mining and Metallurgy, 1974. 160 pp. The Symposium was held from 30th October to 1st November, 1974, and the papers include an interesting range of subjects in coal-mining operations, covering the improvements achieved to date, current practice, and required development for the future. Salamon, M.D.G., and Oravecz, K. 1. Rock Mechanics in Coal Mining. 119 pp. NIM reports Report no. 1822 Stability constants and linear free-energy relations for the platimtm-group metals. (22nd Oct., 1976). Report no. 1852 A revised method for the dissolution of platiniferous materials by the sealed-tube technique. (18th Oct., 1976). Report no. 1828 y-picoline adducts of the nickel, copper, and zinc chelates of 2-thenoyltrifluoroacetone. (26th Nov., 1976) Report no. 1847 A pilot-plant investigation of a kinetic model for flotation.(19th Nov., 1976)

Jan 2, 1977

By W. J. Witte, M. K. Witte

"The purpose of this report is to present a generalized preliminary design and cost estimates for a typical heap leach operation such as might be undertaken in Northern Ontario. This report should be of value to anyone in the mining industry planning, or contemplating, a heap leaching operation in Ontario, either on a large or small scale. While more detailed costing and design work will obviously be required for each specific project being contemplated, the data provided in this report should enable parties to make preliminary estimates of the costs of proposed projects and should identify most of the planning and design parameters that will need to be considered.Although heap leaching has been used extensively as a low cost gold recovery method in other parts of the world for many years, it has only recently become of interest to the Canadian mining industry.In order to investigate and demonstrate the feasibility of using heap leaching in Ontario, the Ontario Ministry of Natural Resources in 1982, undertook to locate a private sector proponent willing to undertake a 10,000 ton demonstration project. This project was to have been carried out at a production scale under normal northern Ontario field conditions. The Ministry was to have provided technical management and design for the designated project."

Jan 1, 1985

By Figueroa L. Aquiles

El presente trabajo plantea el uso de la pre-concentración en la etapa de chancado de las plantas metalúrgicas polimetálicas, como método de limpieza que busca eliminar el material estéril (ganga) antes de alimentar a los molinos y así reducir los altos costos de la molienda, flotación, secado y otros. Asímismo, los procesos de concentración van desde el pallaqueo hasta procesos sofisticados como la pre-concentración por análisis de dispersión de radiación gama y aquellos de separación por medios densos.

Nov 8, 1984

The addition of a thallous salt to the cyanide leach of a calcined pyritic concentrate causes a marked increase in the rate of extraction of gold. This is due probably to the activation of passive gold by the thallous ions. Lead, bismuth, and mercury salts, which should produce a similar effect, fail to do so. It is postulated that this latter result, together with the reprecipitation of silver at low cyanide levels, is due to the presence of soluble sulphide.INTRODUCTIONThe work of Fink and Putnam (1950) showed that the rate of solution of gold in cyanide can be increased by the addition of small amounts of lead, bismuth, mercury, and thallium salts. Mills (1951), during a study of the electrochemistry of gold, with particular reference to cyanidation, was able to show that gold may become passive towards cyanide solution. The addition of lead or thallium salts prevented this passivity, although the action of lead was limited to the pH range 10 to 12. In a recent paper Cathro (1963) confirmed the findings of Mills, and presented results which showed that the addition of thallium to a cyanide leach of a calcine from Lake View and Star mine, Kalgoorlie, increased the rate of extraction of gold appreciably. In, this paper the use of thallium to prevent the gold becoming passive, and hence to decrease leaching time and cyanide consumption, is examined.EXPERIMENTALA series of leaching tests was carried out on a sample of Lake View and Star calcine, comprising calcined pyrite (about 70 per cent.) and siliceous gangue (about 30 per cent.) and containing 165 p.p.m. gold, 45 p.p.m. silver, 0·1...

Jan 1, 1964

By Mokhinabonu Mardonova, Yosoon Choi

Open-source technology for supporting the Industry 4.0 has become the target of academic research in many sectors. This study reviewed the trends of open-source technology, its forms, and some industrial applications. As a case study using open-source hardware and software for the mining industry, this study proposed a low-cost environmental monitoring system for non-metallic underground mines to support mine safety and occupational health issues. The system was developed using open-source hardware, Arduino and 3D printer, to design the monitoring device. An open-source software, MIT App Inventor, was used for developing an Android application for smartphones to enable remote communication with the system. Field experiments were conducted at an underground tunnel and a non-metallic underground mining site to assess the performance of the system in both mobile and static modes, respectively. Although a few limitations related to the precision of the low-cost dust and gas sensors still exist, the findings of the experiments show that the mining industry can benefit from open-source technology deployment when considering cost factors

By Gabriela Fernández-Dávila

Los diecisiete Objetivos de Desarrollo Sostenible de las Naciones Unidas (ODS) constituyen parte importante de la agenda global orientada a erradicar la pobreza, proteger el planeta y asegurar la prosperidad para todos. En un contexto de constante expectativa social y, ya que el sector minero es tan relevante en nuestro país, por ser el que aporta la mayor cantidad de riqueza económica, cabe asumir el reto de incluir en la agenda del sector un enfoque de inversión que incluya a los ODS como marco orientador de las iniciativas que buscan contribuir a mejorar la calidad de vida de la población.

Sep 20, 2019