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By Greaves M. C, Amos M. D

A study was made of the instrumentation and technique of atomic absorption spectroscopy developed by Walsh of the Commonwealth Scientific and Industrial Research Organisation (C.S.I.R.O.), Australia.The method was evaluated for the determination of silver in lead sulphide concentrate. The precision of the procedure developed is equal to that of the uncorrected fire assay method and the accuracy is greater.Brief mention is made of the use of this technique for the determination of silver and other elements in ores and concentrator products.INTRODUCTIONThe fire assay method, although accepted on a world-wide basis as the umpire method for the determination of silver in ores and concentrates, is freely recognized as yielding results which are lower than actual due to unavoidable losses.King (1934) investigated the influence of the cupelshape, size and material on silver losses during cupellation. Using 100 mg silver prills he recorded silver losses ranging between l. and 10 per cent under extreme conditions and averaging approximately 2 percent under conditions which might be considered normal. Guerin (1957) made a detailed study, under carefully controlled conditions in a furnace similar to that described by Esdaile (1952), of the effect of temperature on silver losses during cupellation. He concluded that if cupellation were carried out at 840°C., then the amount of lead retained by the silver prill was insignificant and that the silver losses were governed by the equation: Y = 0·055 XO.74where X = the final weight of the silver priIl (mg)and Y = the silver lost (mg)

Jan 1, 1961

By Ezequiel Pomachagua Quijada

En el Perú, el cierre de yacimientos es una etapa nueva de la vida productiva minera, pues a partir del año 2005 la norma rige y se les otorga un plazo de un año para elaborar y lograr la aprobación del plan de cierre de todas las unidades mineras. Sin embargo, en el año 2008-2009 se iniciaron las actividades de rehabilitación en unidades mineras que no habían logrado su aprobación. En ese sentido, el presente artículo señala la experiencia sostenida por la empresa C.M Centauro como ejemplo de cierre progresivo en botaderos de desmonte. La restauración se inició con el botadero suroeste a través de tres etapas: cierre progresivo, cierre final y postcierre. Así también planificó el cierre de los componentes desde el diseño mediante actividades como la estabilidad física, remoción, perfilado y conformación de banquetas, estabillidad química, extendido de caliza, batido de caliza, compactado de sustrato estabilidad hidrológica, biológica y revegetación.

Aug 1, 2015

By C. Lumley

The management of the Anglo Platinum (AP) mining technical systems (MTS) embarked upon a process of defining the strategy for the MTS department. The newly established department forms part of the greater Group Information Technology (IT). The strategic process took place within an environment that had witnessed a dramatic proliferation of IT implementations across the group within the last three years. The IT department has been structured in terms of the classical plan, build and run functions with the applications and integration streams running perpendicular across these three functions. The application stream is divided into commercial and mining technical systems with business systems integration the third stream. The mining technical systems department supports mine management to effectively gather, analyse and disseminate data relating to the ore reserve by integrating a number of strategically selected IT applications to ensure that the safety, legal and operational requirements are met. This service to business is rendered by management of a strategic outsource partner via tightly controlled service level agreements (SLAs). The framework used for creating a mining technical systems department that is empowered to add value to business was formulated using the AP value chain as both the starting point and guiding process to ensure alignment to the greater internal strategy of the business. Keywords: Platinum, Mine planning, Mining technical systems, Value chain.

Jan 1, 2003

By Edmundo Alfaro, Álvaro Ordoñez

En el Perú existen diversos yacimientos mineros con contenidos de oro, plata y de metales base tales como el cobre, zinc, plomo, hierro, presentándose tanto como especies mineralógicas sulfuradas como de óxidos. En la zona sur del Perú se encuentran yacimientos de Zn–Pb–Cu–Ag–Au con depósitos híbridos de carbonatos y sulfuros masivos polimetálicos en rocas volcánicas. El tratamiento de este tipo de minerales presenta diversas dificultades para la recuperación de todos los metales de valor. En este sentido, se ha desarrollado investigación técnica preliminar utilizando el sistema peróxido de hidrógeno / amoniaco. (H2O2 / NH3); el peróxido actúa como agente oxidante y el amoniaco como agente acomplejante, dentro de una solución alcalina.

Sep 30, 2022

By Eti Purwaningsih, Widi Astuti, Erik Prasetyo

Selective-reductive leaching of manganese from low-grade manganese ore using tannic acid as a reductant in acidic media was demonstrated by XRD, SEM-EDX characterization, and batch leaching studies at room temperature. The pH change in the liquid phase before and after leaching revealed that selectivity of manganese over iron was due to the hydrolysis of iron. The acidity in the liquid phase during leaching was dictated by two mechanisms: proton-consuming reaction (manganese oxide reduction by tannic acid) and proton-producing reaction (ferric ion reduction by tannic acid to produce ferrous ion). Based on the leaching studies, the more prevalent reaction between these two was determined by initial leaching conditions: tannic acid concentration, sulfuric acid concentration, liquid-solid ratio, temperatures, and agitation time. Kinetic studies revealed that maximum recovery was attained within 6-h agitation, which indicated a product layer diffusion process.

By Eti Purwaningsih, Widi Astuti, Erik Prasetyo

Selective-reductive leaching of manganese from low-grade manganese ore using tannic acid as a reductant in acidic media was demonstrated by XRD, SEM-EDX characterization, and batch leaching studies at room temperature. The pH change in the liquid phase before and after leaching revealed that selectivity of manganese over iron was due to the hydrolysis of iron. The acidity in the liquid phase during leaching was dictated by two mechanisms: proton-consuming reaction (manganese oxide reduction by tannic acid) and proton-producing reaction (ferric ion reduction by tannic acid to produce ferrous ion). Based on the leaching studies, the more prevalent reaction between these two was determined by initial leaching conditions: tannic acid concentration, sulfuric acid concentration, liquid-solid ratio, temperatures, and agitation time. Kinetic studies revealed that maximum recovery was attained within 6-h agitation, which indicated a product layer diffusion process.

By Harry C. Wiess

PETROLEUM has come to be one of the most important and essential of the mineral re- sources of the nation. It is the most advantageous source of mineral fuels and of lubricants, and as such it has provided in large measure for the phenomenal development in our modern means of travel and in the facilities for transportation by land, sea, and air. Without it the remark- ably rapid industrial and social progress in our country during the past thirty years could not have occurred. In view of its important place and the fact that petroleum is irreplaceable and existent in limited quantities in nature, its conservation is essential.

Jan 1, 1939

By James J. Dowd

The investigation to evaluate the reserves of coking coal in the United States suitable for the manufacture of metallurgical coke is being made by the Bureau of Mines in three parts: (1) To estimate known (measured plus indicated) recoverable reserves of all coking coal; (2) to upgrade marginal coals through effective preparation; and (3) to study the carbonizing properties of coals and coal blends not now widely used for metallurgical coke making. This is the sixth of a series of reports giving the results of studies by counties under part (1) of the investigation. (See appendix.) This report covers Fayette County, Pa., which comprises the Uniontown and parts of the Brownsville, Connellsville, Donegal, Waynesburg, Masontown, and Confluence, Pa., Morgantown and Bruceton, W. Va., and Accident, Md., quadrangles. (See fig. 1.) A short resume of the chemical and carbonizing properties of the coals ar.9 included. Data on the coal beds in this county were obtained from mining companies, land companies, individual landowners, and other sources of authentic information.

Jan 1, 1951

By Fernando Pajuelo Rincón

El presente trabajo señala el proceso de la explotación de los conjuntos de vetas en la Compañía Minera Huarón, su optimización y función en la producción de las estructuras estrechas y totales de la producción minera. Para tal proceso se utilizó los vehículos electromecánicos (LHD) de pequeñas dimensiones que se adecúen a los parámetros técnicos y explotación de las estructuras. Asimismo, para cada conjunto se aplicó el sistema de corte y relleno ascendente mecanizado a fin de obtener una mejor selectibilidad, seguridad, productividad y economía de la estructura mineralizada.

Nov 24, 1986

By Charles W. Merrill

The U .S. Treasury stocks of silver have been reduced at such a rapid rate to meet industrial and coinage requirements that they face exhaustion in 3 or 4 years. Alleviation of the silver problem will require increasing supply or reducing demand. This paper examines possible long-range resource development and research programs and improved secondary recovery. The possible reduction or elimination of silver in coinage and development and introduction of substitutes in the arts and industry are also discussed.

Jan 1, 1965

By Walter E. Vanderpool

Three drilled foundations for an elevated water-tank were instrumented, tested and monitored during construction and the first two years in service. One shaft was load tested by the Osterberg method. A void was detected in one shaft by cross-hole sonic logging, pulse-echo logging and concrete coring. The void was instrumented, hydrostatically tested and pressure grouted. The shaft was ?abandoned? and replaced by two smaller shafts with a straddle beam cap. One of the replacement shafts and the cap were instrumented. The strain that appeared in the abandoned shaft, the replacement shaft and the cap were monitored during the remainder of the construction, through the commissioning test and the first two years of service. The results demonstrate the precision and sensitivity of the vibrating wire strain gage.

Jan 1, 2004

By Vitor Luiz Sordi, Gustavo Henrique Pelissari

O AISI201LN é um aço inoxidável austenítico com teor reduzido de Ni em relação aos tradicionais da série 300 e com adições de Mn e N como estabilizadores da austenita. Os aços da série 200 se propõem a substituir outros inoxidáveis em algumas aplicações com vantagem econômica pela redução do Ni, porém há pouca informação sobre o seu comportamento em temperaturas elevadas. Este trabalho avalia a resistência à tração do AISI 201LN na temperatura ambiente e na faixa de 500ºC a 800ºC e a resistência à fluência na temperatura de 700ºC. Observou-se que, comparado a outros inoxidáveis austeníticos, o material estudado tem resistência à tração comparável em temperatura ambiente e mantem boa relação ductilidade – resistência no intervalo de 500ºC a 800ºC. O aço AISI201LN apresentou desempenho em testes de fluência na temperatura de 700oC comparável ao de outros aços inoxidáveis austeníticos largamente utilizados para aplicações em altas temperatura, incentivando assim a ampliação dos estudos em outros intervalos de tensões e temperaturas.

Oct 21, 2019

By Charles W. Merrill

The U.S. Treasury stocks of silver have been reduced at such a rapid rate to meet industrial and coinage requirements that they face exhaustion in 3 or 4 years. Alleviation of the silver problem will require increasing supply or reducing demand. This paper examines possible long-range resource development and research programs and improved secondary recovery. The possible reduction or elimination of silver in coinage and development and introduction of substitutes in the arts and industry are also discussed.

Jan 1, 1965

By Michael J. Klishis

West Virginia University researchers examined risk and exposure in the roof bolter operator's job and developed approaches for preventing accidents and for evaluating system and human performances that may be appropriate as a general application to improve safety and efficiency in the industry. Using a microanalysis of accident data and underground observations, the researchers classified bolting injuries within one of four work routines: 1) drilling bolt holes; 2) bolt installation; 3) machine tramming, (re)positioning and setting the ATRS; and 4) general face preparation. Time and motion studies were then combined with injury data analysis to develop risk and severity indices, as well as a severity-weighted index that served to determine the degree of risk and exposure by work routine. More than two dozen bolting-related problems were identified as potential situations that could lead to injuries or expose workers during their job. Approaches to avoid these situations were suggested and then applied at six mining operations to evaluate specific problems in roof bolting operations. These suggestions encompassed the three E's of Safety (Engineering, Education, and Enforcement) and emphasized the analysis of worker behaviors that lead to human error accidents.

Jan 1, 1993

By Elear Gómez

La pirometalurgia de los concentrados de plomo se inicia en el siglo XIX y desarrollada con mayor intensidad en el complejo metalúrgico de La Oroya que inició sus operaciones en el año de 1922, con el proceso pirometalúrgico de los concentrados de cobre, en el año de 1928 se inicia el proceso pirometalúrgico de los concentrados de plomo. Los procesos se desarrollan a una altitud de 3,720 m s. n. m. Nuestros conocimientos del tratamiento pirometalúrgico de los concentrados de plomo, nos permite estar en la capacidad de poder refinar todos los concentrados de plomo que se producen en nuestra patria. Esto permitirá generar fuente de trabajo que es lo que necesita nuestro país, en la primera etapa seria producir los metales y en una segunda etapa industrializar el país.

Sep 29, 2023

By F. C. Noyes

DAME Nature was in a generous mood when she distributed widely over the face of the globe numerous deposits of phosphate rock from which man can make phosphatic festiIizer to replace the phosphate re- moved from the soil by crops. The principal deposits are readily accessible to the world's greatest consuming areas and most of them are such that mining operations can be carried on at relatively low cost. The world's known reserves shown in Table 1 are sufficient to last well over 2000 gears at the present rate of consumption. Before giving a brief outline of the phosphate rock industry of foreign countries let us try to get a picture of the movement of phosphate rock throughout the world in 1938, the last full normal calendar year where it came from and where it was consumed. Table 2 shows the origin and finial destination of world shipments in 1938 by grand divisions. Table 3 (p. 499) shows shipment9 of phosphte rock to each country in Europe. Europe is seen to be by far the world's greatest market and the French North African mines the world's most important producers outside of the U. S. A.

Jan 1, 1944

By Guillermo E. Philipps Jaramillo

El objetivo del presente trabajo es optimizar la productividad en la recuperación del mineral a través del programa de planeamiento desarrollado en la mina San Vicente. El programa revisa el análisis de la operación minera actual, las ventajas del método de corte y relleno ascendente por lonjas, las ventajas del método de cámaras y pilares con corte y relleno ascendente con galería al piso, las desventajas del método de corte y relleno con galerías al piso y la supervisión como elemento primordial de optimización de productividad.

Nov 24, 1993

The STATE MINERAL SUMMARIES publication provides estimated data and summaries of mineral activities at the State level for 1993. Most of the estimates are based on nine months data. Individual State summaries are published separately as State Mineral Industry Surveys and copies can be obtained from the appropriate State mineral officer. In an effort to facilitate the rapid dissemination of information and publications produced by the U.S. Bureau of Mine, an electronic document dissemination system is now available for use. MINES FaxBack is a simple-to-operate automated fax response system that operates 24 hours a day, seven days a week. All a user needs is access to a fax machine with a touch-tone telephone. MINES FaxBack can be accessed by calling (412) 892-4088, using the touch-tone telephone attached to the user's fax machine. After calling MINES FaxBack, the requester is guided by a series of voice messages to assist in ordering the desired documents.

Jan 1, 1994

Recommendations from 44 mining industry workshops are summarized and reviewed in the context of Bureau of Mines research and development programs on-going during the period 1974-1977. Approximately 1,000 specific recommendations for research and development are summarized in a systematic and comprehensive format appropriate for review by mining research and development program managers. Relevant Bureau of Mines research programs are briefly described and some opportunities for future research and development are identified.

Jan 1, 1979

By W. T. Malone, J. R. Williams, R. L. Tiner, J. M. Tinsley

Hydraulic fracturing methods for production stimulation have become a common procedure in the oil and gas industry. Fracturing treatments are performed on wells of various potentials to help increase the production rate. In addition to the desire for increased production is the need to predict what increase might be expected. This knowledge is useful in economical treatment planning to accomplish the desired production goals for the well. Theoretical production increases due to horizontal radial fractures may be calculated using equations developed from mathematical analyses and electrical models.1,2,6 It also is possible to predict theoretical production increases due to vertical fractures using curves developed from electrical3 and mathematical models.8 However, these studies assumed that the vertical fracture height and the formation height were equal, which may not be true." In addition, the final fracture height through which fluid is produced may not be equal to the created height. The development of vertical fracture proppant transport relationships has made unrealistic the assumption that propped fracture height is equal to created fracture height. Through the use of published proppant transport equations,4'12 it is possible to calculate the height of a bed of propping agent deposited in a fracture of a given height. Assuming that the fluid flowing in the fracture moves through only the propped portion of that fracture (i.e., that the un-propped part of the fracture heals) it becomes essential to know how production increase varies with the ratio of propped fracture height to formation height. It should be recognized that future investigation may determine that the fracture does not heal completely and that a highly permeable channel exists over the deposited bed of proppant. The effect of this channel was not considered for the present study. The following analysis of experimental data allowed development of curves to determine theoretical production increases considering fracture height as a variable. Discussion In designing a fracturing stimulation treatment a number of variables must be considered. The size of the treatment, type of proppant used, proppant concentration, treatment fluid properties and well conditions are all factors affecting the dimensions and permeability of the fracture. Production increase due to a vertical fracture is affected by propped length, height, width and permeability of the fracture for a given set of formation conditions. Production increase may be defined as the ratio of production rate after fracturing to the production rate before fracturing at the same pressure differential, pe — pw. The producing rate in an

Jan 1, 1970