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By Batric Pesic

Solvent extraction of nickel and cobalt from the real leach solutions was studied by using a novel extraction system. The extraction system was a mixture of 2,6-bis-[5-n-nonylpyrazol-3¬y]] pyridine (BNPP) and dinonylnaphthalene sulfonic acid (DNSSA). The BNPP represents a novel molecule, which was designed and synthesized in our laboratory. Real solutions for the study were prepared by leaching of two different cobalt-nickel bearing concentrates, cobaltite [CoAsS] concentrate from Blackbird Mine, Idaho, and siegenite [(Ni,Co)3S4] concentrate from Missouri Lead-Belt. The major strength of the system was the selectivity of extraction toward nickel and cobalt from iron containing solutions. Other metals such as Mn, Mg, Ca, Al and As were not extracted. Due to the irreversibility of copper extraction, its removal from solution was required prior to the extraction of nickel and cobalt. Zinc was not as strongly extracted (i.e. its stripping was readily achieved) as was copper . Flowsheets for the recovery of nickel and cobalt were also developed.

Jan 1, 1997

By Tim Q. Haldane

The ability to efficiently process lowgrade ores has allowed the Gold Fields Mesquite Mine in Imperial County, CA to expand from a 2.1 Mt/a (2.3 million stpy) rate in 1986 to its present 7.3 Mt/ a (8 million stpy) processing rate. Increased tonnage demands led to the 1989 construction and startup of a dump leach pad to supplement the existing heap leach operation. This resulted in an excellent opportunity to compare the two processes at the same operation. Additional operating costs associated with the crushed ore heaps are justified through enhanced recoveries, even at very low ore grades. Gold Fields' Mesquite Mine is a gold heap leach facility located about 55 km (35 miles) east of Brawley in southeastern California. Five open-pit mines will be developed over the projected life of the property, covering a total area extending to a maximum of 5.5 km (3.4 miles) to the east and west, and 2.4 kin (1.5 miles) to the north and south. Mesquite will process 7.3 Mt (8 million st) of ore and produce more than 6.2 t (200 000 oz) of gold in 1990.

Jan 1, 1990

By H. Akbari

Ordinary portland cement (OPC) is the key pozzalonic component of the concrete mix widely used as a construction material worldwide. B illions of tons of OPC are used in the construction industry each year. However, calcinations of limestone and silica that produce OPC also produce almost an equal amount of C O2 during the cement manufacturing process. Thus, OPC production accounts for nearly 7% of all anthropogenic C O2 emissions each year. The main objective of this study was to develop a geopolymer-based composite to be used as a substitute for OPC in concrete application to significantly lower the carbon footprint of the construction industry. A waste material produced during the coal combustion process was used as the main raw material for the geopolymer-based composite. It was mostly the nonmetallic content of the F-type fly ash produced from the combustion of bituminous coal. The authors envisioned extracting some of the valuable metal oxides from fly ash prior to using the major nonmetallic portion of the fly ash for geopolymer concrete application. The results obtained from this study showed that the compressive strength of geopolymer concrete compares favorably with that of conventional concrete prepared using OPC.

Dec 1, 2013

The sulphide ores of the principal lodes of the Boulder Mines are mainly composed of a schistose guess with a varying proportion of silica and lime, containing tellurides of gold, silver and mercury, associated with iron pyrites. It is a great difficultyto obtain pure and homogeneous samples of the tellurides for analysis, and from a number of tests made with excellent specimens it was found hardly possible to procure two to agree in analysis, the precious metals being found to be combinedwith tellurium in most varying proportions indeed, a close inspection of a partially crushed specimen will reveal, even to the naked eye, the various shades of colour characteristic...

Jan 1, 1901

Several primary ingot producers have introduced price changes for July. Howmet Aluminum Corp., Revere Copper and Brass, Inc. and the Anaconda Co, will increase late-July prices of 99.5 percent unalloyed aluminum ingot by 3 cents to 56 cents per pound, Prior to this, Kaiser Aluminum and Chemical Corp. had advanced June ingot values by 4 cents to 57 cents and Consolidated Aluminum Corp., 4.5 cents to 57.5 cents. Domestic merchants held June quotes at a range nearing 50-50.8 cents per pound. ANTIMONY Although NL Industries, since April of this year, stopped publishing prices for RMM and Lone Star antimony grade, values of domestically-refined antimony in alloy are being made available to industry, The current price of this material is $1.75 per pound of antimony contained in alloy, New York dealer-marketed metal was available in June at $1 -13-$1 .20 per pound. Important industrial uses of antimony are for flame retardants, storage batteries, chemicals, pigments, rubber, plastics, glass, ceramics and machinery.

Jan 1, 1978

The new legislative regime applying to the mining industry has been in force for nearly two years. However the parameters for the permits required under the Crown. Minerals Act 1991 and the resource consents required under the Resource Management Act 1991 are still being established. Mining operators will benefit from participating in the development of policies and plans currently being formulated by local authorities. The Energy Legislation Amendment Bill currently before the House contains amendments to the Crown Minerals Act to clarify points of uncertainty and to reduce transaction costs where possible.

Jan 1, 1993

This dictionary is published by the Bureau of Mines as a contribution to the mining and mineral literature in the belief that it will fill a recognized need. Several attempts have been made over the years to revise Albert Fay's Glossary of the Mining and Mineral Industry which first appeared in December of 1918. Frank L. Hess of the Bureau of Mines worked on a revision, but his untimely death prevented its completion. Subsequently, the writer was employed to compile and edit this dictionary in cooperation with the technical staff of the Bureau of Mines. Fay's glossary contained about 18,000 terms with 27,000 definitions; the present compilation contains about 55,000 terms with approximately 150,000 definitions. These terms are of both a technical and local nature, and they apply to metal mining, coal mining, quarrying, geology, metallurgy, ceramics and clays, glassmaking, minerals and mineralogy, and general terminology. Petroleum, natural gas, and legal mining terminology, unless of a general nature, has been excluded, as has been foreign terminology where there is an English equivalent. Several thousand Spanish-American mining terms that appeared in Fay's compilation have been removed to make way for the thousands of new English terms that have evolved over the years. Those Spanish-American and Mexican terms still used in the Southwestern United States have been retained.

Jan 1, 1968

By J. J. Forbes

Problems connected with the incidence, effects, determination, and control of dusts are still much before the public, although more information is available to the layman than when Bulletin 400, of which this publication is a revision,5 was issued in 1937. Bulletin 400 attempted to assemble information in convenient form on various phases of the dust problem, largely in the mining and allied industries. This revision includes data that have accumulated since 1937 and some that appeared previous thereto but were not available to the authors at that time. The literature on this subject is so voluminous that no attempt has been made to include all published material or all types of dust diseases, but only to assemble some of the more outstanding data on several aspects of the subject.

Jan 1, 1950

By Henry Kreisinger, WALTER T. RAY

In its investigation of more efficient methods for utilizing the coals and lignites in the United States, to the end that waste might be avoided, the value of low-grade coals increased, and the life of the nation's fuel resources prolonged, the technologic branch of the United States Geological Survey carried on a study of the factors involved in the manufacture and use of briquets, including the suitability of various coals for briquetting, the cheapest and most satisfactory binders, and the furnace behavior and evaporative efficiency of briquetted fuel. The investigations had their beginning in the work done at the coaltesting plant at the Louisiana Purchase Exposition, St. Louis, Mo., in 1904, and were continued at St. Louis and later at Norfolk, Va. Accounts of various tests and statements of the conclusions to be drawn from them have appeared in a number of bulletins. a In connection with the work at Norfolk, comparative steaming tests were made in stationary, marine, and locomotive boilers with run-ofmine coal and the same coal formed into briquets of two sizes. The tests in a locomotive boiler that are described in detail in this bulletin were undertaken to add cumulative evidence to work done at other places. They were made possible through the courtesy of the Seaboard Air Line Railway Company in supplying both the locomotive and the coal used. During the trials the locomotive stood on a side track in the shop yards of the railway company at Portsmonth, Va. No running tests were made.

Jan 1, 1911

By Bengt L. Stillborg

INTRODUCTION This paper summarizes the result of a two and a half year research program. The objective of the research was to develop a fundamental understanding of the Rib-in-Roc method. Through the development of a new model technology, namely three-dimensional physical models which powerfully exploit the results of dimensional analysis Stillborg, Stephansson and Swan (1), it has been possible to establish the contribution to both permanent and immediate stabilization of a large underground opening pre-reinforced by the Rib-in-Roc method. Using the results from these physical models and earlier work by Stillborg and Stephansson (2) and Åkesson (3), a conceptual synthesis is given in this paper so demonstrating the Rib-in-Roc method to be a practical working system of pre-reinforcement. DESCRIPTION OF THE RIB-IN-ROC METHOD To give the reader an idea of how this method of pre-reinforcement is performed, a short description will be given, Figure 1. Before any full-scale excavation takes place an entry is made in the host rock and rib raises are driven around the proposed opening. These raises are made at a spacing that is dependent upon rock quality; an opening in poor rock needs more ribs per length of opening. As the ribs are driven they are used as a site from which very competent rock bolting can be done. As a rib is excavated it is filled with reinforced concrete. Finally after having in this way reinforced the zone around the proposed opening, (a reinforced arch is formed) the displacements are automatically controlled as the opening is being excavated. Using this method openings with a span of 50-60 meters (160-200 ft) and a height of 60-80 meters (200-260 ft) are likely to be realised.

Jan 1, 1979

By Rosa Coronado

Este documento técnico muestra el estado de la economía circular — estrategia que fomenta el desarrollo productivo— en el sector industrial minero. Si bien la minería ya ha venido trabajando desde hace más de una década los principios en los que se basa la economía circular, puesto que así lo exige el sector y la normativa nacional ambiental; es momento de integrar acciones para alcanzar esta meta.

Aug 30, 2020

By Grey CA

Any economic evaluation of a lead-zinc mining project requires the estimation of net revenue per tonne of concentrate at the "mine gate". The value at the mine gate equals the Net Smelter Return minus all realisation costs. The paper develops a simple predictive model for Net Smelter Return based on metal prices.

Jan 1, 1990

By Juan José Retamozo Padilla

El presente texto señala los beneficios de la gestión en salud ocupacional a través de NATCLAR, empresa con estándares OIT (Organización Internacional del Trabajo) de Gestión de Salud Ocupacional y Competencias Laborales del Perú. En este sentido, el estudio de causalidad de los riesgos o accidentes de trabajo nos derivará a causas inmediatas y básicas, las cuales se dividen en factores personales y de trabajo, para así identificar peligros y evaluar los riesgos directamente relacionados a la salud de los trabajadores por grupo ocupacional. Asimismo, contribuir con la empresa para evitar problemas legales, laborales y en beneficio de la salud del trabajador a partir de una adecuada planificación de perfiles de evaluaciones médicas específicas y finalmente, contribuir a la maximización de la productividad de los trabajadores a través de un programa de recuperación física para las personas con alteraciones anatómicas.

Sep 14, 2009

By Elias Macedo de Oliveira

Este trabalho tem por objetivo realizar a avaliação das propriedades mecânicas da zona termicamente afetada (ZTA) de junta soldada de aço fundido de alta resistência, obtida pelo processo eletrodo revestido, analisando o efeito da variação do tempo de tratamento térmico pós-soldagem. Foram soldadas juntas multipasses para avaliação de propriedades mecânicas de um aço fundido de alta resistência mecânica, com preaquecimento de 200°C, corrente contínua, posição plana e aporte térmico médio de 1,5 kJ/mm. Após a soldagem, realizaram-se ensaios mecânicos e metalográficos em corpos-de-prova retirados da ZTA e metal base, tanto na condição de como soldado quanto após tratamentos térmicos pós-soldagem. Os tratamentos térmicos pós-soldagem foram realizados à 600°C, por 1, 2 e 3 horas, visando avaliar o efeito destes tratamentos nas propriedades da ZTA. Os resultados mostraram que as propriedades mecânicas não apresentaram diferenças significativas em relação ao metal base com os tratamentos térmicos realizados, propiciando resultados satisfatórios em relação aos requisitos da norma IACS W22 Grau R4.

Aug 7, 2018

By M. T. Ansari

"This article explains the ways in which investment on mining infrastructure is a geopolitical issue. It discusses the effect of installing sufficient infra structure to get the product to the world market, and argues that there is a risk involved in depending on traditional suppliers who wish to invest in the infrastructure. It explains how to make a distinction between dedicated purpose infrastructure and general use infrastructure by examining the positions of the main actors in mining projects. It argues that these positions can not be understood as analogous to projects in developed countries. To conclude, infrastructure is a crucial link in the supply chain to market but the relative size of such projects in relation to the economy means that investors decisions in developing countries have quite different implications from those in developed countries."

Jan 1, 2011

By James W. Bass

Introduction Atmospheric fluidized bed combustion (AFBC) is an improvement over coal-fired boiler design. It offers several advantages over conventional boilers. AFBC can meet sulfur and nitrogen oxide emission regulations without the need for add-on flue gas treatment equipment. The relatively low combustion temperature inhibits ash melting, thus reducing slagging and fouling that can in turn increase a boiler's fuel flexibility. AFBC process The fluidized bed boiler that operates at atmospheric pressure on the fire side (AFBC) is relatively simple and no different in purpose from those pulverized coal boilers used by utilities today. Fluidized bed boilers can generate steam at the pressure and temperature needed by modern steam turbines. Only the firing system is different. In fluidized bed combustion, the fuel can be almost any coal or waste fuel. It is burned in the presence of a bubbling bed of limestone. Air is forced through the bed at a velocity sufficient to support the weight of the bed particles. When the bed is fully fluidized, it bubbles like a boiling liquid. Although the burning coal makes up less than 1% of the fluidized bed, all the bed particles are heated quickly by the turbulence. The calcium in limestone reacts with sulfur dioxide produced in coal combustion to form calcium sulfate in a dry solid state. In this way, sulfur emissions regulations can be met without installing flue gas desulfurization equipment. Boiler tubes submerged in the bed absorb heat directly from the turbulent solids. The heat converts water in the tubes to steam or superheats the steam. Because of the intimate contact of the boiler tubes with the fluidized bed, heat transfer is highly efficient. Consequently, less boiler tubing surface is needed to generate the same amount of steam as in a comparable pulverized coal boiler. The optimum temperature for sulfur capture is relatively low, about 815°C (1500°F) as opposed to 1370°C (2500°F) for pulverized coal boilers. This results in the formation of lower levels of NON. Because operating temperatures are below those that fuse coal ash, a single design can burn a variety of coals without slagging or fouling problems. TVA's AFBC development program Tennessee Valley Authority's (TVA) involvement in AFBC development began in 1974 and has addressed the technical uncertainties through a comprehensive program of design, experimental, and analytical studies. In 1979, TVA and the Electric Power Research Institute (EPRI) developed plans for a 20-MW AFBC pilot plant, a 10-fold scale-up over the next largest test facility. Pilot plant design features TVA constructed the pilot plant at the Shawnee Steam Plant near

Jan 4, 1986

By James C. Barker

The analytical variability encountered when sampling for platinum-group metals (PGM) was statistically evaluated during a 1983 study by the Bureau of Mines and the University of Alaska. Sampling procedures were designed to systematically incorporate commonly used reconnaissance exploration techniques under actual field conditions. Analytical variability was evaluated at each procedural step. Analytical data from each sample from a single deposit grouped relatively well around the calculated mean for that deposit. Standard deviations did not exceed 43 pct of the mean for any of the deposits; more commonly, the deviation was about 25 pct. Statistical treatment of the data by analysis of variance indicated the most important source of error is selection of the sample site. Two or more replicate samples appear necessary to adequately quantify the PGM content. Secondly, significant variation occurs during preparation of a pulverized split for fire assay. The optimum sample size was in the 11-lb range; larger samples did not appreciably reduce variability. Smaller samples generally indicated a higher degree of variability. Evaluation of the sample method suggested the common grab sample, if carefully taken, is a useful indicator of the general range of PGM concentration but potentially includes a considerable margin of error.

Jan 1, 1985

By Catherine C. Kilgore

The Bureau of Mines investigated the availability of fluorspar (CaF2) from 36 U.S. and 50 foreign mires and deposits in 13 countries. Only 6 U.S. properties are considered to be economic, as 29 domestic deposits were found to have an average total cost of production that was uneconomical at a breakeven (0-pct) discounted-cash-flow rate of return (DCFROR). The 50 foreign properties evaluated represent at least 55 pot of demonstrated fluorspar resources located in market economy countries and China. Al I evaluated foreign operations were found to be economic to marginally economic in January 1984 dollars when compared against published prices for each country. Reserves for 56 properties totaled 97 million metric tons (mt) (recoverable Ca F,) from demonstrated ore resources of 344 million mt that contained 123 million mt CaF2. The average total cost needed to cover all costs over the life of each operation was determined for all recoverable fluorspar products. Comparisons of ruining, beneficiation, and transportation costs per metric ton of fluorspar concentrate illustrate advantages between countries. Of the three countries with the greatest fluorspar production, China, with its high-grade, low-cost operations had the lowest weighted-average total cost of production ($38/mt concentrate), Mexico was next, at $54/mt concentrate, and benefited in U. S. dollar terms from the devaluation of the peso. The Republic of South Africa needed an average of $90/mt of concentrate to cover all costs of production at its large low-grade deposits.

Jan 1, 1985

By E. G. Noble

The effects of hydrogen chloride (HCI) concentration and temperature on the solubility and hydration state of the alkali chlorides LiCI, NaCI, and KCI and the alkaline-earth chlorides, MgCI2, and CaCl2 were investigated by the Bureau of Mines. Saturated aqueous solutions of the chlorides were sparged with HCI gas at temperatures of 20°, 40°, and 60° C. Increased HCI concentration caused decreased salt solubility be-cause of the common ion effect. Aqueous solubilities for the chlorides of Ca, Li, Mg, K, and Na ranged from 42.6, 45.2, 35.2, 25.5, and 26.1 pct, respectively, at 20° C to 56.9, 49.4, 37.6, 31.0, and 27.0 pct, re-spectively, at 60° C. In solutions sparged to HCI saturation, solubili-ties for these chlorides ranged from 22.4, 26.5, 3.0, 1.3, and 0.05 pct, respectively, at 20° C to 53.2, 48.8, 28.3, 2.6, and 0.8 pct, respec-tively, at 60° C. The solubilities of LiCI and CaCl2 in HCI solution were high because HCI solubility is low in these solutions. The chlo-ride salts of Ca, Li, and Mg formed hydrates, which depended on tempera-ture and HCI concentration. Monohydrates for LiCI, tetrahydrates and hexahydrates for MgCI2, and dihydrates, tetrahydrates, and hexahydrates for CaCl2 were obtained.

Jan 1, 1985

The Aluminum Company of America (Alcoa) announced plans to shut down production at the remaining two potlines at its Point Comfort, Texas primary aluminum smelter due to the increased costs of natural gas. Total capacity of the facility, which had been partially closed since 1976, was 185,000 tons per year representing 3.6 percent of current capacity in the United States. There were practically no price movements in March on 99.5 percent aluminum ingot, with producers at 53¢ per pound and dealers, 48¢-48.5¢. BISMUTH The March selling position of U.S. producer metal was held at $3.50 per pound. In contrast, east coast dealers and traders adjusted their quotes from $2.55-$2.60 to a wider range of $2.40-$2.60.

Jan 1, 1978