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By Donald W. Ross

"INTRODUCTION Sponge iron has been made commercially since 1912 at a Swedish ceramic plant; and the product, known as Swedish disk—type sagger sponge iron, has an excellent reputation as a superior furnace feed wherever high—grade steels are made. The general procedure for making brickyard sponge iron was described frequently in Swedish technical journals prior to 1932 and at that time consisted in filling clay refractory containers, called saggers, with a super-concentrate of Gellivare magnetite plus the necessary amount of solid reducing agent and desulfurizer and then firing in a Hoffmann ring furnace, as used in the ceramic industry.The early Swedish publications describe two types of brickyard sponge iron: (1) An inferior high-sulfur product obtained by mixing the ore and reducing agent, and (2) a high-grade low-sulfur product in the form of coherent disks 7 to 9 inches in diameter and 1 to 1-1/2 inches thick made by the saggers with alternate layers of solid-fuel reducr and of uniaxed ore."

Sep 1, 1945

In October, the Aluminum Company of America restarted the fourth of seven pot-lines at its Point Comfort, Tex. primary aluminum smelter. The price of primary aluminum ingot, as quoted by American Metal Market, was increased from a range of 60.5 to 63.0 cents per pound at the end of September to a range of 66.0 to 66.5 cents per pound at the end of October. BERYLLIUM On October 15, Brush Wellman, Inc., of Cleveland, one of two U.S. producers of primary beryllium products, announced a planned $6 million expansion of its extraction plant at Delta, Utah, increasing the plant?s capacity to extract beryllium from bertrandite ore by 25%. Another $5 million will be spent on two mine expansion programs in Jaub and Millard Counties, Utah. Other mineral claims and 1 eases he 1 d by The Anaconda Company will be taken over by Brush Wellman through lease or purchase. This expansion, when completed in 1981, will decrease U.S. dependence on imported beryl ore.

Jan 1, 1979

By Ronald D. Rothchild

This report describes the results of a study of longwall ignition hazards and specific suppression systems to minimize each of the major hazards. The major ignition hazards were identified by conducting a literature search and conversing with knowledgeable individuals in the United States mining industry. Three classes of potential ignition suppression systems are discussed: triggered suppression systems for face ignition, passive suppression systems, and control of ignition hazard in the gob. The triggered suppression systems included protection for the shearer, head and tail gates, welding equipment, and the shearer power cable. Passive systems include improved ventilation and water sprays, and charges in the shearer head. Gob protection can be improved by isolating the gob from working areas and by introducting inerting agents into the gob.

Jan 1, 1976

By Kenneth G. Skinner

The rapid growth of the metallurgical, chemical, and allied industries on the Pacific coast just prior to and during the war caused a sudden increase in the demand for refractories, which was the immediate cause of a revival in interest in refractory clays available on the Pacific coast, particularly in the Pacific Northwest. Population increases and shortage of shipping facilities caused an increase in the amount of various ceramic materials and products used and produced on the Pacific coast, with accompanying demand for information regarding sources of clay. In an effort to supply part of this information, the Bureau of Mines, in cooperation with the College of Mines, University of Washington, started a program in 1944 to test the refractory and other properties of clays from seven Pacific Northwest deposits that had been drilled and sampled as part of the Bureau of Mines alumina from clay investigation. Figure 1 shows the location of these deposits.

Jan 1, 1949

By C. K. Eilerts

Knowledge of the phase relations of the fluids that exist in the porous spaces of rocks constituting natural petroleum reservoirs and of the behavior of these fluids under various field conditions of operation is essential to the conservation of petroleum and natural gas and to their efficient recovery. The problem of determining whether these fluids are in the liquid or gaseous state and of recognizing the transitions that may take place as the material in the reservoir is subjected to different conditions of pressure and temperature confronts many producers today, especially in certain fields. The subject has grown rapidly in importance since the discovery of and production from deeper reservoirs that have correspondingly higher pressures and temperatures as compared with shallower

Jan 1, 1938

By C. E. Baltzer

This is the fourth in a series of coal technology reviews being prepared. in accordance with a recommendation voted by the Coal Division C.I.M. in session at the Jubilee Meeting, Vancouver, 1948, that the Department of Mines and Resources be requested to arrange for publication by the proper Government authority of a Quarterly Review of Coal Technology for distribution among those concerned in the production and use of coal in Canada. Copies of the first review, which appeared in the November, 1948, BULLETIN, pp. 612-614, of the second review in the June, 1949, BULLETIN, pp. 272-275, and of the third review in April, 1950, BUL-LETIN, pp. 1,9?3-196 (also, respectively, in Transactions, Vol. LI, 1948, pp. 262-264 Vol. LU, 1949, pp. 117-120, and Vol: LIU, 1950, pp. 133-136), were distributed by the Dominion Coal Board and are still available on request. In this review, the first in the series in the field of combustion, development and trends during the period approximately from World War II to the present time are described and therefore the presentation is general. Later reviews will particularize developments in relation to the range of coals available in Canada.-ED. INTRODUCTION THE utilization of coal in heat and power producing equipment has become of paramount importance to the coal industry in maintaining stable and profitable markets. In the past, the chief concern was with mining, transportation, and overall supply problems, but modern conditions demand interest in and knowledge of all phases of the product, from coal in situ to its ultimate disappearance in the form of products of combustion. Even the last mentoined factor has caused complications, as is shown by current widespread activity in the field of smoke abatement

Jan 1, 1951

By John D. Rockaway

Failure of the mine floor supporting coal pillars frequently occurs when the subcoal strata include "underclays" or other low strength strata. The failure process has been studied to define the response of these materials to applied coal pillar loads and to determine the applicability of bearing capacity analysis to evaluate unsafe conditions. The study has been accomplished through an investigation of both the intact and insitu geotechnical properties of the subcoal strata and through the installation of floor movement monitoring instrumentation. The results of these studies have indicated that both the shear strength of the underclay and the stratigraphy of the subcoal strata must be considered in the analysis. The shear strength was the major controlling factor determining the ultimate load carrying ability of the materials, but the thickness and stratigraphic position of the weak layers influenced the mechanism of the failure process. The methods of bearing capacity analysis were used to define pillar stability that included provisions for taking into consideration a two-layer system. Conditions assumed for a coal mine where a weak underclay overlies firmer strata. The results of the analysis compared very well with observed mine conditions, indicating marginal conditions in areas of the mine which later experienced pillar support failure. In addition, a "heave factor" was derived to predict potentially unstable floor conditions in the mines studied in detail.

Jan 1, 1979

1. Domestic Production and Use: In 1974 twelve companies operated 31 primary aluminum reduction plants, three firms accounting for 64% of production. Washington, Oregon, and Montana accounted for 32% of the total production; Gulf Coast States, 24%; Northern States, 33%, and other Southern States 11%. Output of primary metal in 1974 was valued at $3.4 billion. About 80% of the secondary recovery was from new aluminum base scrap and 20% was from old scrap. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1974, building accounted for about 27%; transportation 19%; electrical, 13%; packaging, 15%; and consumer durab1es, 9%.

Jan 1, 1975

By R. S. Nutter

The results of designing, constructing, and laboratory testing of a modular, distributed, microprocessor-based mine monitoring and control system are presented. A standard computer communications protocol (DDCMP) was utilized throughout the system. Tests were performed on the utilization of a high-level language for programming mine monitoring and control systems. Laboratory tests were run on a combined air velocity/methane sensor.

Jan 1, 1980

By Hans Korfmacher

Product take-back regulations implemented in Europe have presented significant challenges to the consumer electronic product and battery industries. Initially companies established single compliance organizations within individual Member States. These programs met business needs but were inefficient and costly. They were protected from pressures of marketplace competition and could not leverage economies of scale. In order to address these problems P&G, Hewlett Packard, Sony and Electrolux conceived a pan-European compliance organization to collect waste electronic equipment Europe-wide. This organization, called the European Recycling Platform (ERP), operates in competition with existing national compliance systems. Since 2005 ERP has collected 800,000+ tons of waste electronic products and delivered millions of dollars in cost savings. This presentation reviews the steps needed to establish successful competitive collection organizations that provide sustainable recycling at the lowest cost.

Jan 1, 2010

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 J. H. East, D. Harrington

"INTRODUCTION Considerable interest has been shown in the prospective use of Diesel-powered haulage equipment in both coal and non-coal mines. Foreign technical magazines have devoted considerable space to discussions of the use of Diesel locomotives in European mines and some mention of it has been made in technical papers in the United States. The Bureau of Mines has extensively tested the gases produced in the exhaust of the Diesel engine under various atmospheres and conditions of use; it has established a schedule of tests for permissibility of Diesel engines for use in underground coal mines, including, gassy or dusty mines.This publication provides information as to the successful use of Diesel-powered equipment underground workings in the United States and Europe, briefly discusses the characteristics of some of the toxic gases found in the exhaust of Diesel engines, and points out that Diesel-powered equipment can be used with reasonable safety in underground minus if necessary and entirely feasible precautions are taken."

Apr 1, 1947

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 Charles Janin

The recovery of gold from sands and gravels is one of the oldest forms of mining; it antedates history and has been practiced by savage peoples. In North America the search for placer gold has been a powerful agency in the exploration and development of unknown regions and has profoundly influenced the course of our civilization. With the progress of invention, the improvements in machinery, and the availability of large capital for the conduct of great operations, the tendency in placer, as in many other branches of mining, has been toward the working of extensive but comparatively low-grade deposits. The early miner washed the rich spots in stream beds or terraces with his pan, his long tom, and his primitive sluice. Then followed the growth of hydraulic mining and the use of giants supplied with water under pressures of hundreds of pounds to the square inch that could work at a profit gravels whose gold tenor was less than 3 cents to the cubic yard. Finally came the dredge that could handle deposits lying so far below water level as to be beyond attack by other methods. Although the gold dredge was first successful on a commercial scale in New Zealand, it has reached its present strength and efficiency in this country and its development is a monument to the daring, per- severance and technical skill of the many men, mine owners and engineers who have each contributed something to the final result. The Bureau of Mines, authorized to conduct investigations for the purpose of increasing efficiency in the mineral industries, had its attention called some years ago to the need of a comprehensive report on gold dredging in the United States. The director of the bureau recognized that such a report should summarize the development of the gold dredge, should describe in detail the essential features of present-day dredges, should discuss the facts that determine whether a placer deposit can be profitably dredged, and should point out the approved methods of prospecting placer ground and of operating dredges. At the request of the director, the author undertook the preparation of such a report and has been intermittently engaged on the task for several years. This bulletin is the outcome of his labors. He hopes that it will prove of interest to designers and builders of dredges, to mining engineers, and to persons who may contemplate investing capital in placer-mining ventures.

Jan 1, 1918

By Henry S. Washington

I. INTRODUCTION. DURING the last twenty years or so the chemical investigation of rocks has made great advances, and it is now generally recognized that a knowledge of the chemical composition is as essential as that of the texture or mineral composition-if not more so-for the proper classification of rocks and study of their origin and relationships. Rock-analyses have vastly increased in numbers and, what is of greater importance, in quality. New and improved methods permit of greater accuracy than was possible in the early days, and the list of chemical constituents frequently determined has risen from the seven or eight of the greater part of the nineteenth century to twenty or more. Indeed, rock-analyses with determinations of so many constituents are now commonly made by the chemists of the United States and Australia, while in Germany, Great Britain, France, and Italy the rarer constituents are determined more frequently than formerly. As a consequence of this modern, accurate work, it has been discovered that some elements which were formerly supposed to be rare are of wide-spread occurrence and are often present in considerable amount. The fact is further being developed that the elements tend to show certain relations of occurrence or abundance in connection with each other. This is a fact which is applicable to the rarer elements, and which also finds a broad geological and petrological expression in the recognition of petrographic provinces. We are beginning to obtain some definite, though as yet rudimentary, knowledge of the distribution of the elements among igneous rocks. Some of the results along these lines obtained by study of the vast accumulation of analytical data now available are well known to petrologists, while others do not seem to be so gener-

Sep 1, 1908

Jan 1, 2002

By Agne Rustan

This paper is intended to give a summary of the first ten Symposia on Rock Fragmentation by Blasting where the symposia activities were governed by a Steering Committee replaced at Fragblast 2 by an International Organizing Committee (IOC). At Fragblast 9 the name was changed to Fragblast International Organizing Committee (FIOC). Eighty four pages of statistical data about Fragblast 1-10 is documented on the Fragblast Website (ISEE.org).

Jan 1, 2014

By G. H. Bennett

A field experiment was performed in a production unit of an operating copper room and pillar mine to compare the support capabilities provided by resin and mechanical roof bolts. Resin and mechanical roof bolts were alternately installed in eight intersections in a single entry. Rock mechanics instrumentation was installed to measure roof sag, bed separation, convergence, bolt pullout, torque, and strain. Bolt cost and installation time are included. Two analyses of the test were made. The analysis of the rock mechanics data showed there was no definite difference between the two bolting systems. From a broader analysis on a mine-wide basis it was concluded that resin bolts gave better support. A critical view of the experiment is given in the appendix.

Jan 1, 1974

By P. Rambalee

A multiple coal fired boiler house provides steam for utility usage in various production plants. Maintaining stable header pressure and boiler availability is of critical importance for downstream consumers. Advanced Process Control comprising of a G2 based expert system and Model Predictive Control was implemented to improve the boiler house performance. The results yielded improvements in the main header pressure stability, reduction in boiler saturation and significant saving in coal consumption. All information used for this document is from a published whitepaper written and led by Prevlen Rambalee (Anglo Platinum) and Gustaf Gous (BluESP) titled, ?Control and Stabilization of a Multiple Boiler Plant: An APC Approach?.

Jan 1, 2012

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