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By Keith L. Harris

Recent data indicate a marginal decline in overall growth in world economic output from 3.1% in 1985 to 2.9% in 1986 (table 1),2, 3 Many nations experienced slower economic growth because of the huge trade imbalances existing between the United [ ] States and Japan and the Federal Republic of Germany, the U.S. budget deficit, and the growing Third World debt. Some developing nations, however, experienced booming growth. Declining prices for energy and nonenergy commodities and the fall of the dollar against the currencies of major industrial countries benefited several developing countries--energy importers and exporters of manufactured goods with currencies tied to the U.S. dollar, which were able to expand markets in the industrialized nations. The drop in commodity prices increased demand in industrial countries and depressed it in developing countries. Lower demand in the developing countries contributed to a decline in the real net exports from industrial countries. As a result, output growth in industrial countries declined from 3.0% in 1985 to 2.4% in 1986, despite growing internal demand, Average output growth of developing countries increased from 3.296 to 3.596 during the same period, however, primarily because of the low prices of their products and the strength of demand in industrial countries for those products. Developed country output growth was extremely uneven, however. For example, the economic output of nonfuel exporters grew 5.4% in 1986, while that of fuel exporters dropped 0.7%.

Jan 1, 1987

By Shelby Z. Palya

"The Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mining-substances; to promote health and safety, in the mineral industries; to conserve Material resources , and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other Mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue describes reports and articles published during the period January 1, 1975, to December 31, 1979. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960; 2 the 50-year list, of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960; 3 the 5-year lists of publications and articles, from January 1, 1960, to December 31, 1964,, from January 1, .1965, to December 31, 1969,5 'and from January '1, 1970, to December 31, 1974; and the annual ,lists of Bureau publications and articles from January, 1 to December 31, 1975,7 from January 1, to December 31, 1976,8 from January 1 to December 31, 1977, and from January 1 to December 31, 1978."

Jan 1, 1981

By H. Kenworthy

Sulfide-ore concentrates containing cobalt, nickel, copper, lead, and iron from the operations of the National Lead Co. at. Fredericktown, Mo., were treated successfully on a laboratory scale to recover more than 90 percent of the cobalt, nickel, and copper. A cobalt -nickel-bearing, lead-copper matte., produced by the St. Joseph Lead Co. at Herculaneum, Mo., was treated to produce a lead-zinc fume, a copper sulfide concentrate, and a cobalt nickel-iron product, netting a recovery of over 75 percent of the cobalt and about 90 percent of the nickel and copper. National Lead Co. bulk concentrates were chlorinated with gaseous chlorine to form anhydrous metal chlorides and sulfur chlorides, sulfur chlorides were recovered by distillation, a high percentage of the ferric chloride was converted to ferric oxide, and the chlorinated residual metals were extracted with water. Metal ions were removed from leach liquors by pH-controlled fractional precipitation as hydroxides. Cobalt solutions "were prepared from cobaltic hydroxide, and procedures were developed to remove contaminating metal ions. Purified cobalt solutions were employed as electrolytes for deposition of high-purity cobalt.

Jan 1, 1953

By John I. Kasteler, John H. Hild

"INTRODUCTION The South Hecla mine, one of the principal mines of the Alta United Mines Co., is situated at Alta in thee Little Cottonwood mining district, about 30 miles southeasterly from Salt Lake City, Utah. The mine has produced copper, lead, zinc, gold, and silver, and is reported to have been one 'of the principal sources of this country's bismuth from 1912 to 1925. The tungsten mineral, scheelite, has been found but has not been recovered. The extreme need for these minerals during World War II prompted an examination of the property by the Bureau of Mines and resulted in an unpublished report entitled ""The South Hecla Mine, Salt Lake County, Utah"" (fig. 1).A Bureau of Mines project 3301 was initiated, and operations were started early in 1943. The primary purpose of the project was to increase substantially the reserves of bismuth and tungsten ores. The critical situation in regard to lead, copper, and zinc developed during the early stages of the operation, and the work was expanded to include the development of ores 'of these metals.An investigation of 'the Albion, Rustler, and Greeley workings adjoining the South Hecla mine was made, and this work is also described (fig. 2); ACKNOWLEDGEMENTSIn Its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each investigative project as soon as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual investigative work, and prepares the final report. The Metallurgical Branch, O. C. Ralston, chief, analyzes samples and performs beneficiation tests."

Jan 1, 1948

By Bernard Lewis

This report summarizes fundamental research end technical studies conducted in the Explosives and Physical Sciences Division, Region VIII, of the Bureau of Mines in the 2 years July l, 1950, to June 30, 1952. It is the fifteenth of a series of, ordinarily, annual reports whose aim has been to provide the reader with a resume of the research results that have appeared in published form during each fiscal year under the authorship of members of the staff. These are referred to throughout the report. ACKNOWLEDGMENTS Acknowledgments art, made to the following members of the Division wider whose mediate supervision the described studies were carried out. Stuart R. Brinkley, Jr., chief, Mathematical and Theoretical Physics Section, and special assistant to the chief of the division.

Jan 1, 1953

By A. D. McMahon

This survey is one of a series of Bureau of Mines publications designed to serve the needs of Government and industry for comprehensive information on mineral commodities and activities. Copper, a versatile metal, has been vital to all civilizations from pre-historic times to the present. Its essential value in antiquity and until the nineteenth century arose from its malleability and ease of working, its corrosion resistance and durability, its attractive colors in alloyed and unalloyed forms, and, of course, its availability. The principal uses were for tools, utensils, vessels, weapons, pipe, statuary and other objects of art, and for building and architectural purposes where formability, permanence, and beauty were necessary qualities. Utilization of copper based on these physical and mechanical properties has grown tremendously for commercial, structural, mechanical, architectural, and art items; and its capacity for forming numerous alloys has led to a myriad of applications from miniature copper and brass eyelets to huge bronze battleship propellers. The early nineteenth century marks the epoch of the greatest use of copper, transmitting electrical energy. This particular property of copper is fundamental to the spectacular growth of the electrical industry and all associated industries relying on electricity for power, light, and heat. More than half of all copper produced is used for transmission of electricity.

Jan 1, 1964

By S. Burks

This paper develops the themes explored by the authors at the Fourth International Platinum Conference,. Optimization techniques can be used to significantly increase the value of mining businesses by enabling better long-term planning decisions. Open pit and underground mine design, mine scheduling, cut-off grade and blending, stockpiling, and the linking of these to flexible elements of the metallurgical recovery processes are all evaluated together. Transport or sale of intermediate products and the requirements of the product metal markets can also be considered. Experience shows that net present value (NPV) can potentially be increased by 5-35 per cent or more, usually even before the expenditure of significant amounts of project capital. The case studies presented include: > An existing operation with multiple open pits and PGM concentrators linked to offsite downstream processing facilities, and with infrastructure constraints for which the scheduling of current operations and the potential for expansion were investigated > An existing operation with an integrated portfolio of mines, concentrators, smelter, and refinery, for which the various possible sources of ore for processing were prioritized to match the downstream process plant constraints and the product markets > An underground operation in Zimbabwe for which the optimum mining width was calculated and expansion plans were evaluated > An underground mine with many separate mining sections, for which a revised schedule was developed aiming to keep the shaft system and processing plant at capacity with the highest net value material available at any time throughout the life of mine. In the concluding section of the paper, a few brief notes are included suggesting how the strategic recommendations from enterprise optimization studies may be implemented by the owner's team.

Jan 1, 2013

By Almon F. Robertson

This report is one of a series based upon investigations made and being made within the Missouri River Basin in Montana by engineers of the Bureau of Mines , Albany Branch , Mining Division . These investigations are being made primarily to provide preliminary information to the Department of Interior agencies and to others concerned with planning the proposed Federal power developments within the Missouri River Basin. This report has been designed to permit public distribution of the factual data obtained . Virtually all known metallic -mineral occurrences and some nonmetallic mineral deposits within Fergus County were investigated in 1948. The investigations cannot be considered complete , however , because some long inactive mines or prospects may have been missed . Most of the old mine and prospect openings now are caved ; many are completely inaccessible . Many of the claims located years ago have been abandoned ; others have been relocated under different names and ownerships . Because of such conditions , much of the information regarding their development and operation necessarily has been obtained from available Federal and State publications , supplemented by information provided by owners and local residents .

Jan 1, 1950

By R. A. McIvor, R. Levac

"The Stobie No. 7 shaft, 14 ft diameter, double- drum skip hoist, was installed at the INCO Limited Frood Stobie Complex in 1942. Figure 1 shows the hoist layout. The hoist was originally equipped with babbitted journal bearings on the main drum shaft and pinion gears. In 1990, the hoist was modernized with a new braking system, two new 2000 hp D.C. drive motors, a thyristor armature supply and a PLC control system. The new drive motors were connected to the drive pinion gears with a gear type flexible coupling. The pinion gear journal bearings were refitted during the refit in 1990 as the existing babbitted bearings showed signs of wear. The pinion gear journal bearings had always run warm and had external cooling applied during the warm summer months. Figure 2 shows the journal bearings on the pinion shaft. The skip hoist main bull gear and two pinion gears were replaced in 1997 because of cracked bull gear spokes. New drive couplings were installed on the pinion gears and the pinion journal bearings were modified to allow some self-aligning properties to try to reduce the heating and wear on the babbitt. The modifications did not significantly reduce the heating problems and a decision was made in the spring of 1998 to convert the bearings to self-aligning, anti-friction-type bearings.The traditional roller bearings used on double helical pinion drive gears in hoist applications has always been double-row spherical roller bearings due to their high load-carrying capacity and misalignment allowances.Unlike single helical gears, double helical arrangements do not exert axial thrust on the pinion gear bearings, therefore, both bearings in the pillow blocks must float easily with any pinion displacement. Drum misalignment, thrust bearing end play and a multitude of other influences causes continuous axial displacement of the pinions when in operation. This constant displacement or “hunting” of the pinion gear to maintain its centre on bull gear often exceeds the axial clearance limits of spherical roller bearings thus resulting in a continuous sliding motion of the bearing outer rings against the housing seats. With time, the housing fit eventually wears, creating an out-of-round condition for bearing housing (maximum allowable cylindricity tolerance is IT4/2). When this happens, the pillow block housings must be replaced or re-machined to specification. Premature bearing wear and overheating will occur if a housing out-of-round condition is encountered."

Jan 1, 2001

Real economic growth for 1988 may fall short of the 3.3% projected by the Department of Commerce in August 1988 because the summer drought and intense heat in many areas curtailed output more severely than expected. The economy grew at an average annual rate of 3.0% for the first three quarters of the year, slowing in the second and third quarters. Export growth, which occurred even as the dollar edged up compared with other industrial country currencies, was an important factor in the expansion. Notable gains were posted in sales of machinery, computers, aircraft, chemicals, and telecommunications equipment. Imports increased, but not as much as exports, and the U.S. trade position was still much improved from that of 1987. Personal consumption expenditures grew slightly faster than the economy as a whole. Purchases of consumer durables showed notable strength in the first half of 1988, but slowed down in the third quarter. Despite the moderate rise in interest rates, business spending for new plant and equipment also rose and contributed to 1988 gross national product (GNP) growth. Both new business investment and export demand spurred orders for U.S.-made machine tools. Orders for machine tools for the first 8 months of 1988 were almost triple those in the corresponding period in 1987.

Jan 1, 1989

By Herbert H. Einstein

This report contains the documentation for 11 computer programs representing the entire computer documentation for the eight-volume report entitled "Risk Analysis for Rock Slopes in Open Pit Mines." A detailed summary of the programs is included.

Jan 1, 1979

By S. Akhtar

Interstitial compounds of iron, cobalt, and nickel, and their binary and ternary mixtures with silver, gold, palladium, and platinum were prepared and tested as fuel cell catalysts. The first step in the preparation of the interstitial compounds consisted of preparing finely divided metals. This was done either by the Raney method or by reduction of precipitated hydroxides of the metals. The finely divided reduced metals were then treated with carbon-and/or nitrogen-containing gases to prepare their carbides, nitrides, and nitrocarbides. The materials were tested for cathodic activity towards O2 and for anodic activity towards H2, C3H8, NH3, CO, and N2H4 in acid and alkaline electrolytes at 25° to 90° C in half-cell assemblies. Samples of carbided and nitrocarbided INi-lAg-1Au were about one fifth as active as Pt-black in the reduction of O2 in 35 percent KOH solution, whereas the activities of several interstitial preparations exceeded the activity of Pt-black in the reduction of O2 in 12M KOH containing N2H4. Nitrocarbides of x-Fe2C, 3Ni-1Au, and 1Ni-3Au were effective catalysts for oxidizing N2H4 in liquid NH3 containing NH4SCN. Corrosion of the catalysts by electrolytes was severe in many cases.

Jan 1, 1970

By Johnny Zhang, Yang Anguo, Li Weifeng, Xueyi Guo

"SKSTM oxygen bottom blowing smelting technology was developed by SKS-ENFI at SKS Smelter, Hunan in the 1990s to replace the conventional sintering process and thus to meet the high national EHS standard for lead.Since then, two major milestones have been achieved:1. Since 2002, the SKS oxygen bottom blowing smelting-blast furnace reduction has been in operation at SKS, YGL, Chizhou smelter etc. Now in China, about 50% of the lead (4.2 millions t/year) is produced using SKS process; and2. Since 2008, the blast furnace has been replaced by direct reduction of molten rich lead slag at YGJ smelter, which is more energy-efficient since no slag cooling is required. This two stage process (SKS Oxidation- Direct Reduction) is named as the YGL process.Since 2008, numerous technological innovations have been implemented in the furnace design, process control, and maintenance at YGL. The plant has been successfully demonstrated its unique excellent performances on all aspects from processing capacity, product quality, energy reduction, cost reduction and emission reduction. The purpose of this report is to update all the improvements with proven tracks.Meanwhile, a preliminary comparison on the following aspects between the YGL process and other similar technologies has been discussed:1. Plant design and operating conditions;2. Mass and heat balances, metal (Pb, Ag) recovery;3. Consumables, oxygen gun and refractory lining life;4. Energy consumption and operating costs;5. Sulfur capture and emission reduction etc.It is concluded that the modified SKSTM process is a clean SO2-free emission process. The process is characteristic of other features such as no extra fuel addition, low capital with a small foot-print design, low OPEX, high throughput, easy operation, long refractory lining life and high productivity (95%+ on line time annually). It offers an alternative cost-effective technology for lead smelting industry."

Jan 1, 2014

By M. D. Cooper

IN spite of the uncertainty in the bituminous coal industry during 1933, progress worth recording has been made. Along with other industries, coal has felt the effects of business stagnation, but even in the worst weeks of the past four years, .the total production of bituminous coal in the United States was seldom less than half the production in some of the best weeks of the more prosperous years, a record better than that of many industries. However, the competition of other fuels and sources of power, together with the increased efficiency in the use of coal, has brought anxiety to producers. This has resulted in pressure for reduction of costs, not always by the wisest means. On the other hand, the effort to survive has directed increasing interest toward research, a wholesome development in a difficult situation. Wages, limitation of hours of labor, and the NRA have occupied much time and thought. Following a period .of wage cutting paralleling price cutting, the industry found itself rather suddenly faced by the President's Agreement, followed in due course by the Code, and then in many places by the agreement with the United Mine Workers. Although there is still some uncertainty in regard to the detailed working out of the new arrangements, there seems to be an honest endeavor by the signatories to the Code and Agreement to work them out in a straightforward manner.

Jan 1, 1934

By Jeffrey M. Listak

This U.S. Bureau of Mines report describes the implications of in-mine ground control on the automated or remotely controlled operation of longwall mining equipment, Perhaps the greatest challenge to longwall automation researchers is the development of systems that will continuously function in the complex and unpredictable underground environment. The high degree of environmental variability, together with conditions brought about by the extraction process, makes complete automation of longwall mining a difficult task. The intellectual thought processes and split-second decision making required to avert disasters are lost when workers are removed from the face. As many mine operators can attest, minor problems, left unresolved, can eventually accumulate and lead to catastrophic consequences. The automation process will have to assess and manage various routine problems that are otherwise resolved through worker observation and experience.

Jan 1, 1990

By Jack E. Brockway

As tunnel boring machine technology has expanded, so has its range of application. Tunneling machines (TBM's) are tackling tasks today that fifteen years ago were considered "inappropriate". A case in point is incline/decline TBM boring. An incline or decline bore presents peculiar design considerations that differentiate it from a horizontal bore. This paper reviews those design considerations as they apply to TBM's, backup, muck handling and other tunneling subsystems. In addition, several abbreviated case studies are presented. By the review of real life tunneling techniques as well as design considerations, the "appropriateness" of TBM incline/ decline boring today becomes apparent. INCLINE Introduction In contemplating the impact of incline versus horizontal tunnel boring system design, the obvious consideration is gravity. Up-hill boring can be quite different than horizontal boring. Muck, water and machine weight all tend to slide down the incline. In addition, hydraulic and lubrication systems if unaltered, will find their fluids pooled in the lower corners contentedly ignoring such higher elevation items as gears and bearings. In order to address this inherent gravity problem, a review of

Jan 1, 1983

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 N. H. Emmons

In the United States the value of gold- and silver-ores is everywhere reckoned in ounces troy of the metal per " short ton " (2000 lbs. avoird.) of the ore. In the case of silver, which fluctuates in market value, the New York quotation on a given day must be known, in order to determine the gross value of an ore at that date. In Mexico the assay is reported 'in kilogrammes of silver or grammes of gold per metric ton. As everyone is aware, this is practically a percentage system, 1 kg. of silver per metric toll (1000 kg.) being 0.1 per cent., and 1 gramme of gold per metric ton, 0.0001 per cent. The notation is simple and convenient for both assayer and miner.* The Mexican government purchases at an unvarying price for silver, payable in silver, and at a fixed price for gold, payable in gold if the seller insists, but preferably in silver at about the rate of exchange between U. S. gold coin and Mesican silver coin. The value of silver is $40.915 per kilogramme in Mexican silver dollars. That of gold is $675.416 per kilogramme in gold coin. The mints do not, as a rule, issue gold dollars, as the government keeps them to pay the interest on the national debt. Almost all bullion containing a considerable percentage of gold is shipped to foreign countries (principally the United States) to be refined. The Mexican mint receives for refining and coining no bullion which is not at least .950 fine in gold and silver, separately or

Jan 1, 1902

By R. E. Scheffel

Most supergene copper heap leach operations today employ forced-aeration, irrespective of ore grade. Unfortunately, there is little published quantification of its benefit. There is a natural desire to strive for the ideal chemical kinetics. The reality, however, is that physical mechanisms control the commercial extraction rate. This paper presents the performance of a number of operations, their operating conditions and physical ore characteristics, which contribute to non-ideal solution distribution and variable extraction rate. Regardless whether one uses forced-aeration, commercial experience to date suggests it is prudent to design for longer leach cycle times to ensure the production target is met.

Jan 1, 2006

By George F. Becker

(San Francisco Meeting, October, 1911.) A MERE record of Emmons's professional career would very inadequately represent the man. That he was eminent we know, and our successors will realize in due time; but they must depend upon us for knowledge of a singularly wholesome, modest, unselfish personality, and of a character that did honor to a profession in which trustworthiness is indispensable: Those members of the Institute who met Emmons are his friends, and I never knew one of these who was not the better for that friendship. Emmons was born in Boston, Mar. 29, 1841, the son- of Nathaniel H. and Elizabeth (Wales) Emmons, and was named Samuel Franklin after an ancestor who was of the same family as Benjamin Franklin. He took the degree of Bachelor of Arts at Harvard in 1861, and soon afterwards went abroad to complete his education. From 1862 to 1864 he attended the courses at the École Impériale des Mines at Paris, lie e Beaumont and Daubrée being among his professors. The year 1864-1865 he spent at Freiberg under Cotta and other famous teachers; after which he spent another year in traveling through Europe. Like many other renowned geologists, he approached his ultimate profession from its economic side, and was thus from the first imbued with a sense of high responsibility in the promulgation of scientific opinions or conclusions. With hypotheses which were interesting merely because. they were ingenious or even plausible, he would have nothing to do. In 1867 he joined the Geological Exploration of the Fortieth Parallel at its organization under Clarence King, serving at first as a volunteer, but soon receiving a regular appointment. This expedition was the first one of purely geological character sent out by the United States Government. As Emmons has shown in his admirable presidential address on " The Geology of Government Explorations," its work was founded on a com-

Sep 1, 1911