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By Walter Renton, Ingalls

SEVERAL years ago I became interested in computing the historic lead production of the United States, and the mines, or mining districts whence derived. This led me subsequently to an examination of the recent records- of some of the American zinc-mining districts and of the great lead and zinc-mining districts in foreign countries. My present article thus will be to a large extent an addendum to my book, "World Survey of the Zinc Industry," which was published by the Mining and Metallurgical Society of America in 1931, and to which I shall refer hereinafter as Ingalls, op. cit. Throughout this article all expressions of tons mean the ton of 2000 lb. Where original data have been given in metric tons I have converted in many instances simply by multiplying by 1.1, and long tons by 1.12. I have not been fussy about digits and have rounded off many figures. These may explain differences between data herein and other data.

Jan 1, 1946

Jan 1, 1882

The contribution of minerals to the growth and development of the United States is best demonstrated by the uses which have evolved during the past two centures. During pre-Revolutionary days the colonies were essentially agricultural in character, producing cotton, tobacco, rice, indigo, grains and flour, fish, livestock, dairy products, and timber. Shipbuilding was the major manufacturing industry. In 1763, the total value of exports for Virginia, Maryland, New York, Pennsylvania, and Massachusetts was £2,722,000, of which £55,000, or 2 percent, was for "copper ore, and iron in pigs" (3)1 and £49,000 was for 21,000 barrels or hogsheads of "pot-ash." The value of 75 ships built for sale in 1763 by the colonies was £61,500.

Jan 1, 1976

By Sandra K. Zacharias

Brass, a deliberate alloy of copper and zinc, has been known since before Roman times. There are two main methods of making brass: (1) Cementation or calamine process - crushed zinc ore (calamine, ZnC03 , or calcined calamine, ZnO), is mixed with charcoal and small pieces of metallic copper and heated to about 900°C in a closed crucible, (2) Alloying - metallic copper and zinc are melted together in a reverberatory furnace. According to most modern authorities (e.g. Smith and Forbes 1955), the calamine process was the only one used in western Europe prior to the 18th century. At that time, the alloying technique began to take over, because metallic zinc was successfully produced on a large scale for the first time. Previously, this had been a problem because zinc vapourizes at 906°C or about the same temperature at which it can be reduced from its ore. Thus, some means had to be devised to collect and condense the zinc vapour (Tylecote 1976). Metallic zinc was known, however, earlier than the 18th century A.O. Several early finds have been made, including a rolled sheet of metallic zinc found in excavations at the Athens Agora dating to the 3rd to 2nd century B. C. (Farnsworth et al. 1949). The Chinese were producing zinc by at least the 10th century A. D. and, by the 17th century, Chinese zinc ingots were being imported into Europe by the Dutch East India Company (Needham 1974). Metallic zinc is also mentioned in several European documentary sources from the 16th century (e.g. Paracelsus, Agricola). This study traces the changes in Western brass making methods from Classical to Renaissance times by examining documentary and archaeological evidence.

Jan 1, 1999

LOCAL COMMITTEE OF ARRANGEMENTS. Major J. W. Powell, Chairman; F. P. Dewey. Secretary; S. F. Emmons, A. S. Hewitt, J. P- Hilgard, Charles Knap, and F. W. Taylor. THE opening session was held in the hall of the new National Museum, on Tuesday evening, February 21st. President Metcalf introduced General W. T. Sherman, one of the Regents of the Smithsonian Institution, who read the following address: ADDRESS OF GENERAL SHERMAN. MR. PRESIDENT AND GENTLEMEN : I have been invited to meet you here this evening to extend to you the cordial greeting of the regents of the Smithsonian Institution, and to assure you that they are most happy to have it in their power to place at your disposal this beautiful hall, dedicated to science and art. This National Museum is the property of the United States, of which the regents of the Smithsonian are simply the custodians, and the board has delegated to its secretary, Professor Baird, the right to extend its use to the National Academy of Sciences and like kindred societies, among which we are glad to class the Institute of Mining Engineers. It is eminently fit that you should meet here at this, the nation's capital, under a roof partly your own, devoted to natural sciences, and in the shadow of the Smithsonian, founded for the exclusive purpose of collecting and diffusing knowledge among men. Of all the workers employed on earth no single class seem to me more worthy the respect of their fellows than those who seek beneath the surface for the useful minerals and metals which contribute so largely to the wealth and comfort of mankind. In no branch of human industry does intelligence come so immediately in contact with labor. To the mining engineer chemistry, mineralogy, and geology are as reading, writing, and arithmetic to the merchant;

Jan 1, 1882

By Gregg Davidson, Lonnie Jacobs, Brett Zernich, Alan Howard, Robert Pintabona

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. If such services are required, the assistance of an appropriate professional should be sought. 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 the authors and are not necessarily those of SME. The mention of trade names for commercial products does not imply the approval or endorsement of SME.

Dec 1, 2014

By Alastair Torrance, Mitchell Nipperess, Andrew Olsson, Italo Onederra, Gary Cavanough

Components of bulk explosive products include ammonium nitrate, water, fuel, stabilizers, and calcium nitrate. The physical attributes include prill/emulsion ratio, density, and viscosity and in the case of prilled ammonium nitrate, hardness, size distribution and fuel oil absorption. These components and attributes in conjunction with ground conditions determine all aspects of explosive performance including the risk of fume. This paper presents a fume risk assessment matrix of explosives components and physical attributes as a function of a simple description of ground conditions. Instrumentation to provide a measure of the quality of the explosive product are also described and these include both “on bench” physical measurements and laboratory analysis. “On bench” methods include “in hole “density, velocity of detonation (VOD), detonation pressure and detonation temperature. Part of the quality control process involves a mobile laboratory unit which at this stage can provide measurements of water content, ammonium nitrate content, calcium nitrate content, fuel content, prill characteristics and prill/emulsion ratio. This unit can be taken to sites to enable the testing of bulk and sensitized products at site rather than after transportation.

Jan 1, 2015

By S. J. Hussey

This Bureau of Mines report presents a discussion of the statistical approach to the design of experiments and indicates, by concrete examples, how and when statistical design is essential for obtaining meaningful data with a minimum number of experiments. Every research worker plans his work and designs his experiments in a manner which, based on his experience, seems most rational to him and which he believes will produce the information essential for resolving the problems. If the results obtained are open to multiple interpretations and are not of definitive reliability, the failure of the experiment design to produce the desired information may be due to several causes, These include faulty judgment in selecting the factors to be tested, ignoring the importance of interaction between factors, failure to adequately control test variables, and assuming that meaningful trends in the results can be identified without comparison to a predetermined experimental error. An experienced researcher probably will deduce from the nature of the data obtained that the design is faulty and may by trial and error ultimately arrive at the correct solution to the problem. Statistical methods of planning research minimize the chance of faulty experiment design, embody concrete procedures for testing the validity and reliability of the test data and for indicating mandatory changes in the design, and enable the researcher to obtain meaningful information with the least number of tests.

Jan 1, 1963

By Robert M. Becker

This report (the second in a series of five) presents the mathematical development in extending the theory of sample reliability from a sample consisting of a fixed number of items to a sample consisting of a fixed amount of items. Examples of a fixed amount of items per sample are samples consisting of a fixed weight or a fixed volume of unequal size particles. The probability distribution functions (those here called the compound binomial and compound multinomial functions) are developed from fundamentals. Their distributions are generalized to include some measured characteristic of the items. Infinite population moments are derived from moment-generating functions, while finite population moments are developed from corresponding infinite population moments using the finite probability operator defined in part 1 of this series.

Jan 1, 1964

By D. Harrington

This circular presents Part III-A of a series reviewing the literature on effects of breathing dusts with special reference to silicosis; it deals with the economic and legal aspects of dust diseases in industry; Part III-B will contain data on the status and cost of compensation for silicosis, Parts I and II of the series have been issued as Information Circulars 6835, 6840, and 6848; Part I defines and classifies dusts, indicates sources of exposure, and describes the physiological effects of breaching dusts; Part II-A discusses the principal dust factors producing pulmonary pathology and methods of determination of dust in air; and Part II-B presents data on the engineering and medical control in the prevention of dust diseases and general recommendations for their control in industry. A summary and general conclusions will complete the series.

Jan 1, 1935

By S. Garcia, J. Gebhardt, D. McBride, A. Hernandez, A. Esplín, M. Cross

The Minera Yanacocha operation consists of several heaps interconnected with ponds and gold recovery plants and presents various operating challenges. A comprehensive process model has been developed in order to better understand the effects of certain operating parameters and inventory issues. An integral component of the process water/mass balance is a model of each heap that describes heap behavior based on the individual characteristics of the heap. The heap models are linked to a mass balancing program in order to track flows and concentrations throughout the circuit. A case study of the process heap model is presented for the La Quinua heap, including results for the normal base line operation and several operational problems such as loss of solution flow to the heap (i.e., pump failure), increased flow to a section of the heap (i.e., pond volume control), effect of significant rain events, and impact of a change in material properties (i.e., change in ore type). The impact on heap operating efficiency is discussed with regard to effects on recovery and gold solution grades.

Jan 1, 2007

By Russell R. McLellan

The Tertiary channel gravel deposits in northern California were selected Or detailed investigation by the U. S. Bureau of Mines as part of a national program to locate potential sources of gold that might be developed rapidly by large-scale mining operations. Five bureau research centers representing mining and metallurgy subsystems coordinated their efforts in a team operation to identify and investigate possible solutions to the problem area, that long have discouraged the resumption of large-scale mining in the deposits. This report summarizes the individual investigations, conclusions and recommendations conducted and prepared by all mining subsystems research groups after the completion of two years of field work at the deposits on San Juan Ridge in Nevada County, California. The studies indicate that modern mining technology can cope with the environmental problems that closed the immense hydraulic mines in 1,884. however, they also indicate that mining can be conducted with only marginal profits its unless the price of gold remains substantially above $70 per ounce or unless sufficient by-products can be recovered and sold to place the average value per cubic yard of gravel into a positive commercial range. The by-product potential of the Tertiary gravels remains to be investigated in more detail.

Jan 1, 2012

By Keith L. Harris

Surprisingly, real gross national product (GNP) surged at a seasonally adjusted annual rate of 4.3% for the first quarter of 1987 according to preliminary estimates made by the Department of Commerce, the highest rate in 3 yr and significantly above the revised fourth quarter 1986 rate of 1.1% (table 1). The spurt, however, was caused by an unusual $59.5 billion rise in inventories, mostly cars and trucks, and there was little support from other sectors of the economy. Motor vehicle inventories rose as consumers continued to tighten their purse strings--consumer spending declined 0.4% for the second quarter in a row. Nonresidential and residential fixed investment and government purchases of goods and services were also down from the previous quarter. The increasing cost of energy was the major factor in the jump to 3.696 in the rate of inflation, as measured by the fixed-weighted price index for GNP, and rising inflation also helped put a damper on consumer spending. The underlying good news was that the trade deficit shrank for the second quarter in a row as imports declined at an annual rate of 11.1%. Also, profits in the manufacturing sector rose strongly in the fourth quarter, and for the first time in 9 quarters, the primary metal industries became profitable (table 1). If one discounts the anomalous inventory growth, the bottom line is that the economy continues to grow at close to the expected 2.5% level experienced over the past 2 yr. Of concern over the next several quarters, though, is the impact of the large over- hang of motor vehicles inventories on the economy. EMPLOYMENT The civilian unemployment rate declined to 6.636 in March after remaining at 6.7% for the previous 3 months. Employment continued to expand in February and March, although growth was significantly slower in March than in previous months. The manufacturing sector, however, lost 24,000 jobs in March after gaining 46,000 in February. Three-quarters of that gain came when striking workers at USX Corp. and Deere & CO. returned to their jobs. Employment in the manufacturing sectors of direct interest to the mineral industries has generally been increasing for at least the last quarter, while worker hours for these sectors have been on the upswing since April 1986 (figures 1 and 2).

Jan 1, 1987

By C. W. Van Law

WE have just heard a very able presentation, by Mr. J. C. Cameron, on the subject of Recent Trends in Labour Relations, as they exist today in Canada (l). With minor changes, what he said applies equally to the situation in the United States. Direct negotiation between employer and employee on a man-to-man basis, wherein good faith and mutual esteem was at least sometimes a factor, has almost entirely given way to a mass struggle in which each side is represented by highly trained specialists in a new jurisprudence, built up on vote-getting labour laws, decisions in analogous cases by Boards whose members may have had very little personal acquaintance with the specific case, etc., etc. Membership in a labour union has become almost an essential requisite to a job; once in, the individual workman loses his identity and dares not act on his own initiative or even express any idea not handed him by his Union head. An honest workman cannot turn in an honest day's work, because his Union will not allow him. Leadership in the Unions has become so powerful an instrument, both politically and monetarily, that Union policies are drafted primarily to build up that power, and may have little relation to the equities of the individual case. ?While both sides still render lip-service to the doctrine that Capital and Labour can advance best by co-operation to mutual benefit, that doctrine has in effect given way to as bitter and as legalistic a struggle as any in our civil courts. There are many reasons to believe that we are, industrially, in a situation much like the European situation from 1935 to 1939; an impending war to the death with 'appeasement' as the only, unavailing, policy

Jan 1, 1945

Real economic growth for the year will most likely exceed the Administration's estimate of 3.2%, up from 2.9% in 1986, unless consumers change their spending patterns more than expected as a result of the October stock market decline. The economy grew at a real annual rate of 3.7% in the first three quarters of the year, Analysts agree that the stock market decline will slow economic growth-- most have lowered their growth expectations for 1988 by about 1%; but few would argue that the economy will slow significantly in the fourth quarter of 1987. [ ] During this economic recovery, personal consumption expenditures provided the main impetus for growth and a deeping trade deficit, the main hindrance to growth. In 1987, however, personal consumption expenditures grew at a lower rate than the overall economy. Mush of the economic growth resulted from a reduced trade deficit and growing investment by business in equipment to improve productivity and to meet the domestic and foreign demand for products. The declining value of the dollar resulted in a better competitive position for U.S. goods but also contributed to a rising rate of inflation as imports rose in price. Inflation, as measured by the fixed-weighted index for gross national product, was still far below the rates in the early 1980k, however. More than 2 million jobs were created during the year, predominantly in the service sectors of the economy, and the monthly unemployment rate in September fell to the lowest level in a decade. Then, after 13 months of decline, the unemployment rate edged up 0.1 percentage point to 5.9% in October.

Jan 1, 1987

The value of processed materials of mineral origin was estimated to have exceeded $297 billion in 1991. U.S. raw non fuel minerals production in 1991 was estimated at $30.8 billion, a 5.8% decline from that in 1990. This estimate was based on data for the first quarter of 1991 (in some cases two quarters) for most of the 21 minerals that for many years have accounted for more than 95% of the industry's production value. The value of minerals production has increased in all but 4 of the last 30 years. The metals component of production value has fluctuated much more than the industrial minerals component, reflecting the greater volatility of metal prices. Employment in metal mining rose slightly in 1991, but this gain was more than offset by a decline in employment in industrial mineral mining, resulting in an overall decline of 3.0% to 164,600 workers in 1991. Prices of several major metals declined during 1991, reflecting weakness in the economy, causing some metal mines to shut down or reduce operations.

Jan 1, 1992

By Otto L. Schumacher

The Overthrust Belt in portions of Montana, Idaho, Utah, and Wyoming, an area that has contributed generously to the Nation's mineral supply, is one of the few remaining oil and gas frontiers on the North American continent. Determination of the oil and gas potential and development of mineral resources of the area have been affected by a variety of land withdrawals and other restrictions, The purpose of this study is to determine the extent of these withdrawals and restrictions and to discuss the mineral resource potential within the study area. Statistics in this report refer to land status on January 1, 1979. At that time, of the 27.3 million acres of Federal mineral lands within the study area, applications tor Federal oil and gas leases for more than 4,4 million acres (about 16 percent) were pending; the average length of time was 2 years. Federal oil and gas leases covering 8.8 million acres were also on record. Although drilling has occurred on some of these leases, others are subject to restrictions that discourage or prevent development. Some in fact contain stipulations disallowing any development.

Jan 1, 1981

By William H. Pomroy

The potential for large-scale fires in underground fuel storage and fuel transfer areas prompted the Bureau of Mines to study fire hazards in these areas and devise improved fire safety technology for use in these areas. This report describes the Bureau's research to characterize and quantify fire hazards in fuel storage and fuel transfer areas, develop guidelines for safe and efficient fueling system design, prepare specifications for automatic fire sensing and suppression systems for these areas, test prototype systems in the laboratory and in underground mines, and perform cost-effectiveness evaluations of the devised technology.

Jan 1, 1985

By R. W. Bee

This project, sponsored by the U.S. Bureau of Mines, Division of Environment, addresses two major subjects: refuse removal and subsidence monitoring. The refuse removal task consisted of developing a methodology for selecting the most economical combinations of coal mine breaker refuse and rock banks, disposal sites and material moving systems (trucks, trains, belt conveyers and pipelines). To prepare plans for moving refuse in the Lackawanna Valley of Northeastern Pennsylvania, refuse banks were inventoried, underground disposal sites identified and unit cost data prepared for the various material moving systems. The subsidence monitoring task consisted of defining the phenomenon of coal mine induced surface subsidence, establishing operational requirements, cataloging sensors and techniques to detect and measure subsidence and testing of the most promising techniques (photoelastic patch, tiltmeter, strain gage, microseismic and precise surveying). A preliminary system for a 700 acre area in Scranton utilizing 267 grid sensors, seven microseismic sensors and precise surveying techniques was designed with initial and annual operating costs determined. Two minor tasks supported both main subjects: zoning in the Northern Anthracite Field of Pennsylvania and Technology Transfer of subsidence vulnerability prediction techniques.

Jan 1, 1972

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