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By A. B. Hooker, E. J. Coggeshall

"Dry cells are modified wet primary cells in which the electrolyte is held by absorbent material so that it does not spill aid the cell jars are sealed to prevent evaporation of the absorbed electrolyte. Most dry cells in commercial use are modifications of the Leclanche wet cell. In their usual form they have a hollow cylindrical zinc negative pole that constitutes the containing vessel. An absorbent material, either as a lining in the zinc jar or a bag, separates the zinc cylinder and a rod or flat plate of carbon placed axially inside. A mixture of crushed coke, graphite, and manganese dioxide is tamped about the carbon rod, and the whole mass is saturated with salaanoniac-zinc chloride solution.Dry cells are suitable for services that require minute currents continuously or larger, though limited, amounts of current intermittently. Though limited in this way, they have a wide use, even in underground mining. This paper details some of the applications of dry cells in mines, particularly from the standpoint of greater safety through their use.APPLICATIONSThere are four fields of application of dry cells to mining: (1) Electric shot firing; (2) auxiliary lighting; (3) signaling; and (4) testing.SHOT FIRINGFiring an electric detonator requires very little electrical energy because although the current flow may be 1 to 3 amperes the duration of flow is so small (1 to 4 milliseconds) that the energy withdrawal per shot is almost negligible. Batteries for shot firing need not be large; they may be used for firing either single or multiple shots."

May 1, 1934

By William P. Stroud

Chemical alteration of the compressive strength of sandstone has been investigated by the U.S. Bureau of Mines (USBM). Successful development of this technology would offer an attractive alternative to the methods now used for stress control in mines. Sandstone cores were stressed to failure under uniaxial compression at two different strain rates. Specimens saturated with either distilled or tap water showed an average 14% reduction in stress at failure compared with those dried in vacuum. Samples saturated with dilute solutions of aluminum chloride, hydrochloric acid, and polyethylene oxide showed no statistically significant difference in failure stress compared with those saturated with water. By contrast, compressive strength of the cores was increased some 7% by saturation with the nonpolar solvent carbon tetrachloride. No correlation was found between zeta potential and compressive strength.

Jan 1, 2010

By B. Benmokrane, G. Ballivy

"RésuméLe mécanisme de transfert des charges et le processus de décohésion le long des scellements d'ancrages scelles dans des massifs rocheux sous des charges de tensionnement peut être examine par instrumentation de l'ancrage à l'aide de jauges de déformation. Dans ce contexte il est présente ici les résultats d'une étude, en vraie grandeur sur chantier, ayant porte, d'une part sur des essais d'arrachement conventionnels et d'autre part sur des essais déflagrée barres d'ancrages instrumentées et scellées à l'aide d'un coulis de ciment dans un massif rocheux sain et compètent. Les résultats décrits ici, particulièrement les profits de contraintes de cisaillement le long de l'ancrage, obtenus à partir des valeurs de déformations relevées sur les jauges, ont permis de préciser le niveau de chargement correspondant à la décohésion initiale du coulis de scellement, d 'examiner l'effet de la décohésion sur la distribution des contraintes et de caractériser le fluage du système barre d'ancrage/coulis de scellement.ABSTRACTThe load transfer mechanism and the debonding process along grouted rock anchor, subjected to tention loads, can be examined through the instrumentation of the anchor with the aid of strain gauges. In this context, the resultsof a full-scale site investigation including classical pull out tests and creep tests are presented in this paper. These tests were performed on instrumented bars which were cement grouted in a competent rock mass. Results presented in this paper concern, among others, shear stress pro/ties along the grouted anchors which were determined from strain values obtained from the strain gauges. These results have been used to: (1) predict the load level corresponding to initial debonding of the grout; (2) study the effect of debonding on shearstress distribution along the anchor; and (3) characterize the creep behavior of the bar anchor/cement grout system."

Jan 1, 1991

By J. H. Jacobs

This report records a chapter in the history of the development of an electrolytic manganese industry in the United States. Nearly all the manganese requirements of the United States have been imported. Although there are large quantities of manganese ore in the United States, most of it is low-grade and cannot be used for the production of ferromanganese. Since the electrolytic production of manganese carried out by a process developed in the laboratories of the Bureau of Mines offers a method whereby the extensive low-grade deposits may be utilized and since commercial development had proceeded slowly, the Bureau constructed a new and larger pilot plant at Boulder City, Nev., where abundant electric power was available. An authorization in November 1940 covered a plant of only several hundred pounds daily capacity. Additions to some sections author¬ized by subsequent appropriations have enabled the plant to produce over 2,000 pounds a day for extended periods.

Jan 1, 1946

By S Worden, A Lee Zhi Yi, E Sellers, G Corder, A Littleboy

The global shift towards decarbonisation is driving competition for the extraction of critical minerals such as nickel, lithium, and copper. To meet this demand, new mines are being developed while mines approaching closure are being reimagined as sites of potential resources. This reimagining challenges how mine closure is being conceptualised. In the conventional case, when a mine reaches the end of its economic life, it is closed or put into care and maintenance until it transitions to the next land use, such as agriculture, native ecosystem corridors, solar farms or integrated eco – precincts (Murphy et al, 2019; Holcombe, 2020) (the authors acknowledge that unplanned mine closures have left a devastating legacy of contamination, safety and cultural heritage impacts). Extracting minerals from closed or closing mines will extend mine life and, therefore, delay relinquishment and transition. In this context, innovative technologies are needed to make mining economically viable. In the first year of her doctoral research on improving stakeholder engagement in mine transitions, Lee Zhi Yi has coined the term ‘mine life extension technologies’ (MLETs) to describe a class of technological solutions that optimise extraction of resources after a mine reaches the end of its economic life. Examples of MLETs include agromining (van der Ent et al, 2015), in situ recovery (Robinson and Kuhar, 2018), and reprocessing or reuse of tailings (Gou, Zhou and Then, 2019). MLET extraction offers several benefits compared with conventional mining processes, such as waste remediation, value recovery of minerals, a smaller footprint and less environmental impacts (Sellers, Picorelli and Salmi, 2022). What requires further investigation is the consequences of MLET implementation to host communities or community perspectives towards the proposed technology and subsequent delays in transition.

Aug 2, 2023

By J. B. Gayle

In a modern blast furnace, production depends, to a large extent, on the rate at which the furnace gases can be forced through the charge. Since these gases must make their way through the voids between particles of coke, ore, and limestone, the size and size distribution of the stock-column materials are of considerable importance. Also, because the coke pieces support the weight of the overburden and provide the majority of the voids through which the gases pass, their ability to withstand the shattering and abrading forces to which they are subjected should be related to the maximum obtainable production for any particular furnace. Although the wide acceptance of this point of view is indicated by the ever-increasing demand for stronger and more uniform blast-furnace cokes, economic considerations demand that a quantitative evaluation of the relation between coke quality and blast-furnace performance be made available to the industry at the earliest possible date. The following studies of size-distribution patterns and breakage processes were, therefore, conducted as a part of a preliminary investigation intended as a basis for future studies of the relation between coke quality and blast-furnace performance. The major findings may be summarized as follows: 1. New evidence for the presence of two independent distributions of sizes in run-of-oven cokes has been obtained, and a method for characterizing and estimating the relative importance of the individual distributions has been demonstrated. This method has also been used to study the different types of degradation taking place during the tumbler test.

Jan 1, 1954

The hematite deposits of Quadrilßtero Ferrffero (QF) are hosted by the Proterozoic itabirites of the Itabira iron formation (Harder and Chamberlin, 1915). These deposits are widely distributed at QF and include the hard hematite ore bodies. However, considerable variations in ore structure and texture can be observed. A preserved banding and lamination in the thin bedded, compact hematite ore, apparently reflects the original layering and/or the prominent foliation of the partly or completely replaced itabirite. The structure of the hematite ore deposits varies from almond shaped, rootless, to bedded bodies, both concordant with the main foliation, and to mesoscopic veins and irregular bodies. Hematite ore textures, which depends on the structural characteristics of the deposit, may be grouped into four main types:thin bedded, laminated and banded; micaceous, foliated and schistose; brecciated; and compact/massive. Thin bedded ores occur in the western, central and subordinately eastern portions of QF, while submicaceous, micaceous and schistose ores are predominant at the eastern part. Brecciated ores exist mainly at the western part and subordinately in central QF. Structureless, compact hematite ores may be either related to the brecciated hematite or occur as isolated bodies at central QF. It is suggested that a synkinematic, acid and oxidant, metasomatism during metamorphism, under a ductile regime, was responsible for the hard hematite ores of the types 1 and 2, and a static, subsequent, hydrothermal, regional metasomatism, under brittle regime resulted in the formation of the types 3 and 4. The common texture present in the all ores is the ubiquitous magnetite porphyroclasts replacement by hematite. Quartz and other silicate minerals are also substituted by hematite. Muscovite, tourmaline, talc, chlorite, apatite and kaolinite have been recognised in the hard hematitic ores. Apparently that mineral association denotes different equilibrium conditions of formation.

Jan 1, 2002

The evident need to improve the reliability of fluid power systems in underground coal mining equipment prompted the U.S. Bureau of Mines, and later the Department of Energy, to contract with the Fluid Power Research Center at Oklahoma State University for a research project to develop methods for achieving this end. Since the work of the contract was completed at about the time DOE was relinquishing its underground coal mining projects to BOM it was decided to issue the final report under 80M cover. The contract revealed that the major causes of poor reliability were: (1) poor overall system design, (2) poor component contamination toleranace, (3) poor system filtration, and 4) poor maintenance practices stemming from a lack of defined maintenance procedures and enforcement of same. This report demonstrates the variability of the reliabilities of components of similar performance description when subjected to standard tests. Improved design procedures are recommended and the information needed to specify and select components whose reliability is predictable and optimum without sacrifice in performance or significant increase in envelope size.

Jan 1, 1983

By L. H. Harrison

In coal mines equipped with electrically driven mechanical mining equipment, the problem of protection for electrical circuits and machinery important, because the hazards of fires and explosions resulting from electrical failures is greater than in most other industries. There is need for better methods and improved protective devices for this service. Studies and tests designed to determine possible value of the short-circuiting contactor as an electrical device for coal mine service were investigated. Preliminary made to determine the operating characteristics of the device, after which tests were made under actual service in three coal mines. Ordinarily, electrical protection in coal mines is divided into three classes, as follows: 1. Overload protection that is intended to protect against damage from overheating and excessive mechanical strain due to overloading. 2. Short-circuit protection that provides a means of de-energizing the equipment instantly when an accidental short circuit occurs in the equipment or on the power system. Short cm protection tends to damage from fires and, explosions resulting in the dissipation of large amounts of electrical energy in a short circuit. 3. Ground fault protection that, in its various forms, is intended, to maintain the frames of electrical equipment at or near the same potential surfaces in contact with the earth for the purpose of safe-guarding human life.

Jan 1, 1951

By D M. Aranha, M A. Fonseca, M Echtern

The regional syndeformational metamorphism affecting the Itabira Iron Formation (IIF) at Quadrilßtero Ferrffero (QF) was formerly discussed by Dorr (1965), who proposed that quartz grain size could monitor the metamorphism, according to James (1955), and that the formation of haematite could be the result of the synchronous metasomatic process. Herz (1979) suggested the existence of three metamorphic zones, not mentioning the haematite formation. It could be observed that the primary oxide phase in the IIF is magnetite and most of the hard haematite was derived from the metamorphic replacement of magnetite, forming micaceous or schistose haematite. Differently from most iron formations in the world, the formation of haematite deposits at QF occurred under high oxygen fugacity during metamorphism. The haematite microlaths display a strong preferred orientation, which determines the alongated shapes of the fragments. The terms foliated and unfoliated haematite have been applied by Dorr to the micaceous or schistose haematite, and to the isotropic, hydrothermally derived haematite. Under the microcope, the haematite exhibits a strong crystallographic or lattice orientation encircling the magnetite and martite porphyroclasts. The strain rate determined and defined the textural variation, size and economic importance of the deposits and the ore grade. Metamorphism at QF increases eastward and resulted in the formation of a gruneritic Fe-Mg amphibole, at the western portion, followed by a cummingtonitic amphibole at the central-western part, succeeded by the actinolite zone at the central-eastern part, and finally to the tremolite-anthophyllite zone to the east. These zones, arranged in a north-south pattern, can be followed in the pelitic units, whereas appear sericite-chlorite, kyanite-chloritoid and garnet-staurolite respectively. Carbonate geothermometry in IIF also may support the metamorphic variations. At the western zone the haematite forms small lenses within the itabirite, P-contents are slightly higher than in the remaining IIF, haematite grain size is minute, resulting in a submicaceous texture and the amount and dimension of relict magnetite within haematite is greater than in the other parts of QF. Jangada and Serra Azul deposits are examples of this zone. The central-western zone is characterised by significant haematite deposits, in considerable quantity and size, haematite grain size increased, in order to produce a micaceous texture, the P-contents and the amount of magnetite decreased. Pico do Itabirito, Cappo Xavier, Capitpo do Mato and Tamanduß correspond to the deposit type of this zone. At the eastern-central portion the amount of the hard haematite deposits decreases, increasing the soft haematite ore due to higher strain rates. However, it can be perceived that the relict magnetite almost disappeared and the haematite grain size became coarser than the haematite from the western zones. At the eastern zone, the haematite deposits exhibit typical schistose texture, the magnetite porphyroclasts are absent and the lowest P-grades in the haematitic iron formation. The haematite bodies characteristic from this zone are Andrade, Morro Agudo and the deposits at the Itabira District. The hydrothermally derived compact and isotropic haematite deposits, formed subsequently to the micaceous haematite bodies, were generated after deformation ceased, but under very high fluid pressure. The metamorphic reactions magnetite + quartz + H2O = grunerite + haematite and magnetite + quartz + H2O = grunerite + O2 were decisive in the formation of the metamorphic haematite deposits.

Jan 1, 2007

By Paul M. Tyler

The literature on radium is already voluminous, but mcuh of it is too technical to be intelligible to the average reader, and there is no single publication that covers certain economic features of the radium industry. As a result of the renewed interest in the possibilities of domestic carnotite deposits a number of requests have been made to the Bureau of Mines for information, more particularly with reference to the business aspects of the industry. In order to meet this apparent need, the present paper has been prepared from material available in the files of the bureau. The technical data are compiled from various sources and are believed to be reasonably dependable, but the attempt has been not so much to achieve meticulous scientific accuracy as to brim; together facts of industrial significance and popular interest. GENERAL DESCRIPTION Radium is a brilliant white metal that melts sharply at about 700°C. and volatilizes appreciably at that temperature. With an estimated specific gravity of nearly 6.0, it is more than twice as heavy as aluminum and 25 per cent lighter than irons. Although it has been isolated in its metallic state, it is not used in that form, partly because it tarnishes rapidly even in dry air (forming a nitride), partly because of the greater expense of reducing it to metal, and partly because of the difficulty of dealing with such minute quantities of material. It is used always in the form of its compounds, the most important of which from the vie point of utilization are the bromide, chloride, and sulphate.

Jan 1, 1930

The first metal-mine accident-prevention course was prepared and published in 1942--45 as a series of seven miners' circulars (Nos. 51-57). The scope of the course has been broadened, revised, and brought up to date, and it is being published as a similar series of seven miners' Circulars (Nos. 51-57, revised) on accident prevention in metal and nonmetallic mines. These circulars are: Accident Statistics (Miners' Circular 51), dealing with general statistics on accidents and injuries at metal and nonmetallic mines, including causes, costs, and the uses of investigations and reports of all accidents.

Jan 1, 1957

By C. W., Davie

"DEFINITIONDiatomaceous earth consists almost entirely of the silicious remains of minute flowerless aquatic plants known as diatoms. The name diatomaceous earth, therefore, is to be preferred to others such as trade names, inappropriate terms, or names correctly applied to some other product. The following names should, therefore, not be used for diatomaceous earth,-- kieselguhr, infusorial earth, diatomite, celite, moler, bergnehl, English rottenstone, tripoli, tripolite, fossil earth, desmid earth, white peat, tellurine, randanite, ceyssatite, or any trade name.FORMATIONDiatoms live in practically all kinds of water, fresh or salt, hot or cold, still or running and under different conditions of depth and pressure. These minute plants assimilate inorganic salts from their environment and produce skeletons of silica much as mollusks secrete lime and form their Shalls. When the diatoms die they settle to the bottom together with anything else which may be present, such as sand, clay or volcanic ash. The organic matter gradually disappears leaving the silicious skeletons of the diatoms which, with impurities, make up the deposits of diatomaceous earth. These deposits which are still being foamed at the present time and which were produced throughout very different epochs, were more prolifically formed in the Tertiary, so that the thickest beds so far discovered are of that Age."

Nov 1, 1925

By Stanley A. Feitler

This Bureau of Mines report deals principally with the resources and economic aspects of feldspar in the United States east of the Mississippi River. Although in a strict sense, all phases of the feldspar industry affect its economic structure, emphasis in this study is on supply, demand, and marketing. Although feldspar was originally mined for use in the manufacture of pottery and other ceramics, the glass industry, which began to use feldspar in the mid-1920's, now consumes more than half of the annual output. Most mining is open cut, and the methods used are similar to those used in mining crushed b stone. Excess plant capacity has been chronic, and production is usually about 30 percent of capacity fur the industry as a whole. Since 1947, feldspar consumption has grown more slowly than the average for all U.S. industry. This has fostered intense competition, especially for the glass market. Prices have not kept pace with inflation, and profits are small. The trend of consumption through 1970 for glass feldspar is expected to be upward; less rapid in consumption of ceramic feldspar is anticipated.

Jan 1, 1967

By Victor Romero, Steve Redmond

All Rights Reserved. Printed in the United States of America. Information contained in this work has been obtained by SME, Inc. from sources believed to be reliable. However, neither SME nor its authors guarantee the accuracy or completeness of any information published herein, and neither SME nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information. This work is published with the understanding that SME and its authors are supplying information but are not attempting to render engineering or other professional services. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Any statement or views presented here are those of individual authors and are not necessarily those of the SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2011

By Stanley A. Feitler

This Bureau of Mines report deals principally with the resources and economic aspects of feldspar in the United States east of the Mississippi River. Although in a strict sense, all phases of the feldspar industry affect its economic structure, emphasis in this study is on supply, demand, and marketing. Although feldspar was originally mined for use in the manufacture of pottery and other ceramics, the glass industry, which began to use feldspar in the mid-1920's, now consumes more than half of the annual output. Most mining is open cut, and the methods used are similar to those used in mining crushed stone. Excess plant capacity has been chronic, and production is usually about 50 percent of capacity fur the industry as a whole. Since 1947, feldspar consumption has grown more slowly than the average for all U.S. industry. This has fostered intense competition, especially for the glass market. Prices have not kept pace with inflation, and profits are small. The trend of consumption through 1.970 for glass feldspar is expected to be upward; less rapid growth in consumption of ceramic feldspar is anticipated.

Jan 1, 1967

By A. E. Wraith, J. Protheroe Jones, P. J. Mackey

The world’s first copper electrorefinery started production in 1869 at Burry Port in South Wales. Built within the Pembrey Copper Works which had commenced smelting operations in 1849, the new refinery was based on principles described in the British patents issued to J.B. Elkington in 1865 and 1869. Refining principles and practices pioneered there were key to the foundation of modern electro-refining practice in what is now a dominant international industry producing over 16 Mt of electrical grade copper annually. This paper explores the background to this pioneering application of the new, early 19th century, science of “electro-metallurgy” and examines its links to the contemporary decorative electro-plating industry and to the shortcomings of 19th century fire refining. The beginnings and early years of the Pembrey electrorefinery are briefly discussed in relation to the quality, applications and pyrometallurgy of copper at the time. More than a decade would elapse before the birth of the electrical age: the Pembrey refinery may be seen as one of its vital precursors. Note: This paper was originally published as part of the Copper 2013 proceedings (A.E. Wraith, P.J. Mackey and J. (formerly R.) Protheroe Jones, “Origins of Electrorefining: Birth of the Technology and the World’s First Commercial Electro-Refinery”, paper in Electrorefining, Vol. V, Book 2, (Eds. R. Abel and C. Delgado), Cu 2013 International Conference, pp. 19-33, IIMCh, Santiago, Chile, 2013). It is reproduced here together with a new Appendix and supporting references that lists the year of commencement of the first electrolytic copper refinery by country, 1869 to 1956. It all, the year of the first electrolytic copper refinery established for 15 countries is included. These 15 countries now produce more that 70% of world refined copper (for 2018). INTRODUCTION In the 1840s, the new science of ‘electro-metallurgy’, a term coined by Smee in 1841 (Smee, 1841), was being adapted to the decorative electro-deposition of silver in a thin, bright adherent coating that was evidently equal in appearance to traditional silverware (Williams, 1976). Chief among innovative manufacturers of decorative objects who took up the new art of silver electro-plating was the acclaimed firm of G.R. Elkington and Co. of Birmingham, England. The company, which vigorously developed all aspects of electro-metallurgy for the decorative trade, entered the field of ‘electrotyping’, a technique in which the surface features of a mould are copied on an electro-deposited copper layer which, when stripped off, can be used to reproduce an imprint of the mould. In essence, it is a form of casting by electrodeposition, invented in 1837 independently by Jacobi in Russia (Pavlova, 1968) and Spencer in England (Wyatt, 1851).

Jan 1, 2019

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 E. H. Boyle

The Bureau of Mines has evaluated the potential availability of silver from 436 mines and deposits in 41 market economy countries (MEC?s) comprising five major economic categories of deposits: predominantly silver deposits and predominantly zinc, lead, copper, and gold deposits. This study evaluated the long-term cost and availability of primary silver production from 53 producing and 13 nonproducing predominantly silver properties in 11 MEC's and estimated the total recoverable silver from 370 properties as a coproduct or byproduct of zinc, lead, copper, or gold production. This study resulted in estimates of a demonstrated resource of 5.99 billion tr oz of recoverable silver as of January 1984. Of this total, 23.5 pet is in the 66 mines and deposits classified as predominantly silver properties. The largest quantity of recoverable silver, 43.9 pct, lies in the 121 properties classified as predominantly zinc, with 26.5 pct in 120 properties classified as predominantly copper, 4.1 pet in 21 predominantly lead properties, and 2.0 pct in 108 predominantly gold properties. At current silver prices, the economics of silver production favor silver that is a byproduct or coproduct of zinc, lead, copper, or gold, and much of the silver production in the United States from the predominantly silver mines is at an economic disadvantage in comparison with silver production in other countries.

Jan 1, 1986

By Courtney A. Young

Cyanide is a fast-acting, highly toxic substance but, at the same time, is deemed essential for sustaining life as well 'as our standard of living. In this manuscript, the facts about cyanide are presented beginning with a brief history and definition and ending with a discussion on cyanide alternatives. Other topics include speciation, physical characteristics, toxicity, manufacturing, cyanogenics, cyanide cycle, separation, destruction, and markets including those outside the mining industry. Emphasis, of course, is placed on gold production by leaching and how it is influenced by ore type, mineral characteristics and economics as well as its advantages and disadvantages.

Jan 1, 1998