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By W. T. Adams

The production of natural abrasives var¬ied in quantity and value compared with 1975. Output of tripoli-type materials and garnet increased in both quantity and value; special silica stone products decreased in quantity and increased in value; the production of emery decreased. The production and value of manufactured abrasive materials increased for all types. [ ]

Jan 1, 1978

Wildcat strikes in the Appalachian coal fields, primarily in West Virginia, have resulted in an estimated 4.5 million ton loss in coal production during July and through the first week in August. Since then, the strike intensified further, and on August 9, nearly all of West Virginia's 60,000 miners were off the job with another 10,000 miners on strike in eastern Kentucky. The Bureau of Mines estimates that West Virginia's coal output is currently (8/9) eight million tons below last year when the state produced 108 million tons. West Virginia, the Nation's second largest coal producer of coal behind Kentucky, has not failed to mine over 100 million tons a year since 1938. At the end of the second week in August, nearly all coal miners in West Virginia remained out. The strike is a protest against a cutback in union health and retirement benefits. An announcement June 23 about the United Mine Worker's health and retirement fund precipitated the strike, Fund directors said that because of inflation and production losses caused by earlier wildcat strikes and the severe winter, miners would have to pay the first $250 of hospital costs and 40 percent of doctor bills, up to $500 a year. Previously, the funds paid all hospital and doctor bills. According to the West Virginia Coal Association each day of the strike in West Virginia results in a loss of coal production of 500,000 tons, a loss of $3.8 million in miners wages and $1 million in contributions to the UMWA's health and retirement fund.

Jan 1, 1977

By M. G. Wallis

This report presents the results of a study to develop a detailed mining method design based on longwall mining with sublevel caving. The method is applicable to low-dipping coal seams 20 or more feet thick such as are found in the western United States. The report covers (1) the development and description of the mining method, (2) evaluation of the engineering feasibility of the design, (3) estimates of productivity and recovery, and (4) an engineering cost analysis and economic feasibility evaluation of the mining method design.

Jan 1, 1977

Electric power curtailments resulting from the coal strike, required Noranda Aluminum, Inc. to shut down its 140,000 ton-per-year (tpy) primary aluminum smelter at New Madrid, Mo., and layoff 308 workers. Other primary aluminum production facilities affected by the coal strike included the Aluminum Company of America plant at Evansville, Ind. which shut down half of one potline; the Eastalco Aluminum Co., smelter at Frederick, Md., which cut production by 7 percent; and the National-Southwire Aluminum Co. plant at Hawesville, Ky. which cut production by 6 percent. Alumax, Inc. announced that construction had started on a 91,000 tpy potline at the Eastalco primary aluminum smelter. The new potline will be owned 65 percent by Alumax and 35 percent by Mitsui & Co. Ltd. Howmet Aluminum Corp., which currently owns 50 percent of the existing 176,000 tpy facility, has the option of becoming a 50 percent owner of the third potline in 1982. Construction of the new line was scheduled to be completed in 1980.

Jan 1, 1978

The domestic mineral and material industry grew in some key sectors and declined in others during 1993; overall, the industry was poised at yearend for stronger growth in 1994. Metals production is expected to increase with anticipated growth in U.S. motor vehicle sales. There also may be increased demand for industrial minerals in 1994 based on domestic highway and building construction. Additional information on events, trends, and issues in the mineral and material industry is presented below and in the commodity sections that follow. Overall Industry Performance The value of processed materials produced from minerals in the United States during 1993 is estimated to have been about $326 billion, an increase of 5% compared with that of 1992. The estimated value of U.S. raw nonfuel minerals production in 1993 was $31.6 billion, about 1 % less than in the preceding year. The value of domestic minerals production has risen in 28 of the last 33 years.

Jan 1, 1994

By R. Farrar

The survey work on protective canopy design was conducted in a 2-month period commencing November 15, 1973. The reported re¬sults under this contract are intended to provide guidance to coal mine operators in complying with federal regulations pertaining to incorporation of protective canopies on underground coal mine electric face equipment. All coal mine electric face equipment manufacturers and 11 coal mines were visited in the course of conducting this survey. Canopy designs currently being manufactured and those now being used underground were examined and discussed with manufacturers, mine operators, machine operators, and safety committeemen. The general objective was to find out what kind of canopies are now being made and used underground, what the operational problems are, and what can be done to secure improvements. Specifically, the survey scope was as follows: a. Survey all electric face equipment manufacturers. b. Survey 10 coal mines (seam height 60 inches and greater). c. Identify current production canopy configurations and minimum mine entry dimensions for each model and type of electric face equipment. d. Assess in-mine operation of canopies developed by manufacturers and/or coal companies. e. Specify optimal canopy configuration and minimum mine entry dimensions for each type and model of electric face equipment.

Jan 1, 1974

By D. J. Parker

Because of its convenience and availability, natural gas (and to a much less extent manufactured gas) in being used more generally throughout the country for domestic and industrial purposes. With this use, specific and little-recognized hazards have arisen owing principally to the fact that the public and the consumer lack knowledge of the explosive property of this fuel. During the past 8 years gas explosions hove occurred in public and private buildings with loss of more than 300 lives and injury to many others. Such appalling catastrophes can and will be prevented if and when the necessary precautions are taken in the construction of buildings and the installation and maintenance of gas lines and gas appliances, plus adequate supervisions inspection, and education.

Jan 1, 1941

By Edward H. Williams

IN the middle of the eighteenth century John Frazier and wife, Sarah Ingraham, removed from Boston, Mass., to Philadelphia, Pa., where he was held in such esteem that we find him one of the Committee which arranged the ball at Washington's inauguration. Their son John. Nalbro Frazier, was prosperous in his mercantile career and fortunate in his wife, .Anne West; who was an important personage in the early life of Professor Frazier. This cultured lady brought into the family an atmosphere of religious enthusiasm, of thoroughness and: of unity of purpose. Her son, Benjamin West Frazier, inherited her traits and displayed them during a. short and active life. Like his father, he engaged in mercantile pursuits, and was a member of the firm of Zimmerman, Frazier & Co. In their interests he lived for a short- time in Montevideo, and on his return married Isabella Zimmerman, a daughter of the head of the firm. Their happy married life was cut short by the death of Mrs. Frazier shortly after the birth of the subject of this sketch which, occurred October 3, 1841. Mr. Frazier did not long survive her, and left his orphaned sons to, the care of his mother, from whom he had inherited a lovable and deeply religious nature, an : artistic temperament and a capacity for thorough work. Whatever of these traits fell by inheritance to these children were strengthened by the influence of their grandmother, and. the purity of mind, the delicacy of sentiment, the refinement of honor, which characterized. Professor Frazier, are due to Anne West Frazier, and are generally present in the characters of all of gentle blood who have been under the sole and immediate influence of a mature and refined woman. Professor Frazier was educated at the Episcopal Academy in Philadelphia, and passed thence through the University of

Sep 1, 1905

By Jos. R. Guiteras

This paper is one of r series published by the Bureau of Mines dealing with the mineral resources of western South Dakota. The mining of pegmatite minerals is described mainly from the standpoint of the feldspar industry, as most of the other .pegmatite minerals produced are recovered as byproducts from the mining of feldspar. Feldspar is shipped from the Black Hills by three companies, all operating in the southern Hills. Because the pegmatites of the northern Hills, represented by tae Tinton area, have been described in other papers3/ of this series, the present paper is confined to the pegmatite dikes of the southern Black Hills. Emphasis is placed upon the current activity in pegmatite mining; little attention is given to the history of many famous mines in the district, and information concerning them may be obtained by consulting resorts cited in the bibliography. The field work was carried on from July 28 to October 15, 1938. ACKNOWLEDGMENTS The geology of the Black Hills has been studied almost continuously during the last half century. A wealth of literature has attempted to explain the geology and mineralogy of the pegmatite dikes of this region. The writer acknowledges his indebtedness to all earlier investigators, as well as to the following men, whose assistance in the field was of particular value: F. C. Lincoln, professor of mining, South Dakota School of Mines; Mont Heumphreus, State mine inspector, South Dakota; Harold. H. Eyrich, superintendent, and Batemen Eilbeck, mine foreman, b. E. Schundler Feldspar Co.; J. W. Mitchell, field man, Consolidated Feldspar Corporation; John Wells, mine operator and local mineral buyer, Ouster, S. Dak.; Frank Hughes, general superintendent, and Harry Wasson, nine foreman, Hugo mine; D. W. Peterson, mine superintendent, Etta mine.; Lon Walker, Mine superintendent, Peerless

Jan 1, 1940

By Raymond B. Ladoo

Talc is a hydrous magnesium silicate having the chemical formula H2Mg3 (SiO8 ) 4 ; it is often called steatite, soapstone or potstorie, and by the trade names talc clay, agalite, asbestine, and verdolite. The term talc may be used to include all forms of the pure mineral, whereas steatite denotes particularly the massive, compact variety, and soapstone the impure, massive form that often contains only 50 per cent of talc. Merrill 1 says: The name soapstone is given to dark-gray and greenish talcose rocks, which are soft enough to be readily cut with a knife, and which have a pronounced soapy or greasy feeling; hence the name. Such rocks are commonly stated in textbooks to be compact forms .of steatite, or talc, but as the writer has elsewhere pointed out, and as shown by the analyses here given, few of them are even approximately pure forms of this mineral, but all contain varying proportions of chlorite, mica, and tremolite, together with perhaps unaltered residuals of pyroxene, granules of iron ore, iron pyrites, quartz, and, in seams and veins, calcite and magnesian carbonates. When pure, talc is soft, having a hardness of 1, but when impure or when it grades into its varieties, the hardness increases to 3 or 4. Talc ranges in color from pure white and silvery white through gray, green, apple green, gray green to dark green, nlso yellow, brown, or reddish when impure. It is rarely, if ever, found in wellformed crystals, but often occurs in foliated plates or in fibrous aggregates. It is commonly compact or massive or in fine granular aggregates. Several analyses of talc from different regions ·are given in Table 1. Talc has several varieties, the most important of which is Rensselaerite. This variety, found in a small area near Gouverneur, St. La.wrence County, N. Y., is a hard, fibrous, -waxlike mineral having the same chemical composition as talc, but lacking its softness and its peculiar greasy feel. Its hardness and its peculiar fibrous form, even when ground, have made its grinding and separation a separate problem. In addition to the varieties of talc and soapstone, the mineral pyrophyllite or agalmatolite, a hydrous silicate of alumina, with the formula H2Al2 (Si08 ), is also mined and sold as talc. It resembles talc in color, feel, luster, and structure, and may be successfully substituted for true talc for most uses. In this paper it will be considered as one of the commercial forms of talc.

Jan 1, 1923

By Wendell L. Reich

Percussion drilling dates back to the hand operated star drill and hammer. Eventually steam and compressed air were substituted for muscle power and the mechanical percussion drill was born. From the hand held jack hammers, driving a forged steel bit into the rock, there evolved the jack leg, the rubber tired and crawler mounted drill carrier with automatic feed, increasing power and reducing man?s muscle requirements. Because the reaction of a blow on one end of a piece of steel has to be transmitted to the other end there is a limit to the depth or length of drill steel that can economically be used in out of the hole percussion devices. During the late 1800?s there is evidence that designers were attempting to put the percussion tool at the bottom of the hole, directly on the bit, in order to avoid the long drill steel which absorbed much of the blow, leaving little to be applied to the bit and the rock being drilled.

Jan 1, 1972

By David J. Hoadley

This report describes the development and limited testing of a semi-automatic, raise climber, Compact Service Hoist System designed for stope access in underground metal and nonmetal mines. Demonstrated capabilities of the system include a 1,000-lb payload capacity, control from the traveling cage and from up to three remote stations, operating in vertical or inclined raises 3 ft in diameter and up to 300 ft in length and a travel speed of 50 ft/min. The system has the capability of operating in crooked raises because the conveyance climbs two stationary wire ropes suspended down the raise. The drive unit is electrically powered with power and control signals supplied to the drive unit through an umbilical 'cable also suspended down the raise. The system has been designed for portability, ease of installation and minimum raise development. The hoist has been demonstrated successfully in an above ground test tower. This report provides a detailed description of the hoist design and its demonstrated performance to date.

Jan 1, 1985

By BUREAU OF MINES

Mercury has been used by mankind since prehistoric times. It has been, and is now, widely used in industry and medicine and has unique properties which make direct substitution difficult or impossible. At present its prin- cipal uses are for electrical apparatus, control instruments, electrolytic soda preparation, mildew-proofing paints, pesticides, and medical and dental preparations. Deposits of mercury are less common than those of other base and precious metals, but some of the deposits are very large and have been ample to meet the world's past demands. The price of mercury has had many sharp fluctua- tions, but in general, the limited number of producers has resulted in a more stable price structure than that of many other commodities. The United States has been one of the main producers of mercury, and from 1850 to 1961 produced 3,247,704 flasks. Yearly production since World War II has varied from 4,535 to 38,067 flasks. An estimate of domestic resources of mercury producible at various price ranges was prepared for each mercury mine by combining specific knowledge of mercury mineralization with estimates of potential, based on geologic informa- tion and past production history. The sum of the individual estimates for each price range is shown in a table. A parallel estimate of nationwide production potential was made from a study of past price and production relationships. These were analyzed by plotting yearly production figures against the previous year's price, expressed in dollars of constant purchasing power. An equation was fitted to the data by mathematical means and was used to extend the curve into areas of higher than historic prices. Potential production rates at various price levels were taken from this graph. The estimated yearly production rates were used to make an estimate of total potential based on the premise that produc- tion rates and reserves have a proportionate relationship.

Jul 1, 1964

By COLIN A. LAWRENCE, Anthony Del Vescovo

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, 2017

By J. Venter

The history of firedamp is the same as that of coal: The initial stage was the accumulation of vegetation, which was converted into peat under certain local conditions, then lignite, bituminous coal, and finally anthracite. These deposits ceased to increase owing to inundation that deposited earthy sediment, sometimes as much as several tens of meters (several tens of yards). The vegetable matter, whether it was covered with sediment or not, began to ferment. The basic organic components of the vegetable matter are: Cellulose, lignin, and wax and resin in varying proportions, according to the different kinds of vegetable matter. There are, in addition, some impurities, generally mineral.

Jan 1, 1953

By Willard C. Lacy

A mining operation begins with prospecting and exploration-stages with long periods of investment and high risk of failure. However, success in exploration ultimately determines survival of the mining industry. Prospecting and exploration may discover evidence of a mineral occurrence and outline its size and character, but ore deposits that support mining are "made" through the collective efforts of project geologists, geophysicists, geochemists, metallurgists, engineers, chemists, lawyers, and even politicians (Joralemon, 1975). Some deposits may go through multiple cycles of rejection and recommendation, discovery and development, decline and abandonment, rediscovery and development, etc., as economic, technological, or political conditions change or geologic understanding is improved. Peters (1987, p. 233) graphically illustrates the normal life cycle of a mine and the position of exploration in the cycle (Fig. 4.0.1). During the past fifty years, mineral exploration has evolved from comparing evidence of mineralization of prospects with that of known deposits to a more quantitative science employing many facets of geochemistry, geophysics, multispectral sensing from space, computer data storage, analysis, modeling, and most importantly, a better understanding of ore genesis. This modem approach to exploration began in the late 1940s and continues to develop. Exploration efforts peaked in the 1960s with emphasis upon the search for porphyry copper deposits, Mississippi Valley lead-zinc deposits, and volcanogenic massive sulfide copper-lead-zinc deposits. It peaked again in the middle and late 1980s with emphasis upon micron-size disseminated gold and epithermal and stratiform precious metal deposits.

Jan 1, 2008

By LESTER W. STRAUSS

FOR fifteen months after the other dominions of the British Empire and the entire so-called sterling 11loc loosed the shackles that bound the111 to the gold standard, South Africa, giant among gold-producing nations, remained stubbornly attached to gold at the traditional ratio of 85 shillings in currency to one ounce of gold. But eventually even South Africa had to heed the dictates of trade and the obvious interests of its great gold-mining industry. In December, 1932, South Africa's currency severed its golden bonds. Today the South African pound is 011 a par wit11 the British pound.

Jan 1, 1935

Reynolds Metals Company announced plans to increase its rate of production of primary aluminum by 17 thousand tons per year by the end of February. Other producers were expected to increase operating rates during the first quarter of 1976 (see table 10 pg. 29). CHROMIUM -Under the Trade Act of 1974, a petition was filed July 16, 1975, with the U.S. International Trade Commission (ITC) by the Tool and Stainless Steel Industry Committee for Import Relief and the United Steelworkers of America, AFL-CIO, for import relief for certain stainless and alloy tool steel products. The Commission determined on January 16, 1976, in a report to the President, that increased quantities of imports of stainless steel sheet and strip, plate, bar, and rod and alloy tool steel except ingots, blooms, billets, slabs, and sheet bars were a substantial cause of serious injury or threat thereof. The Commission recommended import quotas for the period 1976 through 1980. The President has 2 months in which to act, with his decision subject to a Congressional override.

Jan 1, 1976

Demand for primary aluminum ingot increased during February, and several producers temporarily suspended new bookings for ingot. Alcoa announced that it would restart a potline at its Warrick, IN aluminum smelter by April 1, 1979, increasing the operations of that plant to its full capacity of 290,000 tons per year. At the end of February, it was reported that Alcoa would reactivate two of the seven units at its idle Point Comfort, TX smelter in May 1979, increasing the company's annual capacity by about 60,000 tons.

Jan 1, 1979

By Keith L. Harris

Real2 gross national product (GNP) grew at a seasonally adjusted annual rate of 1.3% in the fourth quarter and at 2.5% for all of 1986, according to the most recent Department of Commerce estimates table 1). The 1986 GNP growth was the lowest since the recession in 1982, and was slightly below the estimate published in the last issue of Minerals and Materials. Barriers to greater economic growth in 1986 included the Federal budget deficit, the trade deficit, reduced energy-sector investment because of low oil prices, and uncertainty over changes in the Federal tax code.3 Major sectors of the economy responsible for the fourth-quarter growth included real Government purchases of goods and services, up $19.9 billion from the third-quarter level; real net exports, up $12.2 billion; real residential investment, up $3.0 billion; and nonresidential fixed investment, up $1.5 billion. The increase in Government purchases of goods and services was attributed to the S25.1 billion rise in net purchases of farm products by the Commodity Credit Corp-oration. Real personal consumption expenditures and inventory investment declined, however. Personal consumption expenditures declined primarily because of reduced motor vehicle purchases. Despite only modest growth during the fourth quarter, the economy improved significantly because of the narrowing of the trade deficit and growing employment (table 2) while maintaining low unemployment and inflation rates. Business sounded an optimistic note, with planned increases in current-dollar capital spending of 0.9% for 1987 compared with a 1.7% decrease in 1986. While it is primarily the nonmanufacturing industries that expect to increase investment from 1986 levels, some manufacturing industries are increasing investment by significant percentages as well, notably the steelmaking and nonferrous metals industries (table 3).

Jan 1, 1987