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The U.S. economy showed further strength during the third quarter of 1983, continuing the upward trend discussed in the last two issues of Minerals and Materials. The National Association of Purchasing Management composite index increased to a 10-year high of 67. 1 in July. (A value of 50 or greater indicates expanding industrial activity.) The index, a weighted composite of new orders, production, employment, vendor performance, and inventories, is derived from a survey of purchasing agents for about 250 industrial firms. Investment and Other National Economic Indicators The strong consumer surge of second quarter 1983 was reinforced during the third quarter by the performance of private investment. Because of this, many analysts became more optimistic about the strength of the recovery and its potential for being sustained. Capital investment growth, negative since 1980, was positive for every investment component in the third quarter of 1983. Preliminary estimates indicate a real increase of $1.4 billion (at an annual rate) in private investment expenditures on nonresidential structures, an increase of $4.3 billion (at an annual rate) for producers' durable equipment, and an increase of $4.8 billion (at an annual rate) in real inventory levels. The second quarter 1983 increase in expenditures on producers' durable equipment was the first indicator that investment recovery would occur during the rest of the year (table 1). Corporate profits in total manufacturing increased $6.5 billion from first quarter to second quarter 1983 (table 2).

Jan 1, 1983

U.S. demand for building and construction materials, such as construction aggregate, gypsum, and cement, remained strong in 1989. Cement imports declined slightly, representing about 17% of apparent consumption compared with 19% in 1988. Mexico, supplying 29% of the total, was the primary source of imports, followed by Canada with 21 %, Japan with 14%, and Spain and Greece with 10% each. Mexico was also the target of an antidumping petition, filed by producers in Arizona, Florida, New Mexico, and Texas, alleging that Mexican cement was being sold in these areas at less than fair value. This was the second petition filed against Mexico in the last 3 years. The International Trade Commission made a preliminary determination that the cement industry in these regions was materially injured by Mexican imports. U.S. demand improved for construction aggregate for the fourth consecutive year and was at a near-record level. The U.S. gypsum industry performed well, even though new housing starts decreased for the third consecutive year. Increased U.S. exports of gypsum wallboard and strength in the remodeling markets offset the impact of declining housing starts.

Jan 1, 1990

In 1970, the U. S. Bureau of Mines contracted with Theodore Barry and Associates, a management consulting firm, to perform a one-year industrial engineering study of working-face hazards in underground bituminous coal mines. The field data was accumulated from industrial engineering observations in fifty underground mines. Supporting data for the analysis was derived primarily from the Bureau's fatal accident reports for the years 1966 through 1970. This report, Industrial Engineering Study of Hazards Associated with Underground Coal Mine Production, consists of three main parts: 1) The Fatal Accident Reports Analysis, 2) The Industrial Engineering Analysis, and 3) Multiflow Process Charts and Standard Time Data. The Fatal Accident Reports Analysis (Volume I, Section II) is based upon individual USBM fatal accident reports for 1966-1970. These were read, coded and computerized in terms of 84 significant variables. Cross-tabulations of these variables have been used to identify major underground hazards and to quantify significant causal factors. A very strong relationship was found to exist between fatal accident occurrences and low task experience. This led to a recommendation for formalized training, certification and supervision programs for miners. Victim compliance with federal regulations, mine regulations and supervisor instructions was analyzed, indicating that supervisors provide the most crucial communication link to workers. Thus, every attempt should be made to ensure the competence of immediate supervisors in the industry. Analysis of roof fall variables revealed a fatal propensity on the part of the miners to work under unsupported roof or under support conditions that are marginal. The technical approach to the problem is to make it physically impossible for a miner to work under these conditions; the behavioral approach is to ensure adequate training and develop proper safety attitudes among the miners. The Fatal Accident Reports Analysis revealed a need for normalizing data to interpret the results more accurately.

Jan 1, 1971

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

New Copper Deposit in Chile. - The recent copper discovery in Chile, made jointly by U.S.-owned Empresa Minera Utah de Chile, Inc., and Getty Mining Chile), Inc., awaits the passage of Chilean legislation which is expected to govern the terms of new foreign investment in the country's mining sector. Named La Escondida, the discovery is reported to have the potential for producing 100,000 tons of refined copper per year. This compares with Chile's total refined primary copper production in 1980 of 811,000 metric tons, and to U.S. refined primary production in 1980 of 1,122,000 metric tons derived from domestic material, and 89,000 metric tons from foreign material. U.S. Firms Buy Chilean Properties. - A bid of $18.1 million, made jointly by Chevron and St. Joe Minerals Corp., won over competing bids for the purchase of the Libra and Mena gold-silver-copper deposits in northern Chile. Chevron is the lead partner and owns 70% of the venture. The two properties purchased have not been developed to any significant extent. They are located near St. Joe's El Indio gold-silver-copper mine. The venture is also looking at the possible purchase of two other mines in the area.

Jan 1, 1981

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

Applications of helium in aerostatics, cryogenics, space, and undersea work are described in papers from the Helium Applications Symposium. Specific subjects include investigations of X-ray sources by means of balloon-borne instruments, meteorological soundings by balloons, powered lighter-than-air flight, tethered balloons, refrigeration techniques, large superconductive magnets, electronic devices, superconducting transmission lines, high-precision thermal conductivity analysis, He3-He4 dilution refrigerators, uses of helium in the atomic energy program, helium-cooled nuclear reactors, power- plant applications for high-temperature gas-cooled reactors, helium welding of stainless steel tubing and pipe, development of helium-shielded arc welding, helium as a diluent in spacecraft atmospheres, helium utilization in the Saturn-Apollo program, and helium utilization in diving environments. Papers from the Helium Centennial Symposium at the national meeting of the American Chemical Society cover the history of the discovery of helium, the history of its development by the Bureau of Mines from a laboratory curiosity to an important item of commerce, the source of helium in natural gases, the world of liquid helium, and liquid helium-3.

Jan 1, 1969

Throughout October, U.S. producers priced unalloyed 99.5 percent aluminum ingot at 53¢ per pound. Dealers, in last month's domestic market, were quoting unalloyed ingot at a range of 45.5¢-46.3¢ per pound. Costa Rica recently issued a proposal to Japanese aluminum smelters to participate in an integrated aluminum-refining project which would include bauxite development. The project reportedly would include a 600,000-kilowatt hydroelectric power station, a 600,000-metric-ton-per-year alumina plant, and a 300,000-ton-per-year primary aluminum smelter. Two U.S. firms--Aluminum Co. of Amerjca (Alcoa) and Martin Marietta Co.--and several European aluminum smelters are also said to be interested in taking part in this project. Alcoa conducted a feasibility study for the Costa Rican Government in 1970 and estimated the bauxite reserves to contain 150 million metric tons.

Jan 1, 1977

Domestic Production and Use: In 1976, 12 companies operated 31 primary aluminum reduction plants, with 3 firms accounting for 63% of production capacity. Washington, Oregon, and Montana accounted for 36% of the total production; Gulf Coast States 19%, Northern States 29%, and other Southern States 16%. Based on published producer prices output of primary metal in 1976 was valued at $3.8 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Of aluminum consuming industries in 1976 building accounted for about 25%; packaging 22%; transportation 19%; electrical 13%; , consumer durables 8%; and other uses, 13%.

Jan 1, 1977

1. Domestic Production and Use: In 1977, 12 companies operated 31 primary aluminum reduction plants, with 3 firms accounting for 65% of production capacity. Washington, Oregon, and Montana accounted for 31% of the total capacity; Gulf Coast States 23%, Northern States 26%, and other Southern States 20%. Based on estimated producer prices output of primary metal in 1977 Has valued at $4.6 billion. Aluminum consumption by 25,000 firms was centered 'in the East Central United States. Of aluminum consuming industries in 1977, building accounted for about 25%; packaging 22%; transportation 21%; electrical 11%; consumer durables 9%; and other uses, 12%.

Jan 1, 1978

Workers at the Consolidated Aluminum Corp. primary aluminum smelter at Lake Charles, LA walked out at midnight March 31 when their contract expired. Management personnel operated the smelter and prebaked carbon anode facilities until an agreement for a new 3-year contract was reached April 18. The Aluminum Company of America (Alcoa) began operations at its can recycling facility at Taylor, MS. The facility can process 3 million pounds per month of aluminum and steel cans. Alcoa announced plans to increase the capacity of its aluminum paste and flake production plant at Logan's Ferry, PA by 50 percent. Completion was scheduled for mid-1980.

Jan 1, 1979

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 Kenneth Wardell

Those flat lying, bedded or replacement, non-fossil fuel deposits which exist within the U.S.A., and which are amenable to longwall mining, are identified by reference to three principal factors associated with their physical/geological environments. These are their depth, extent and structural continuity. Technical feasibility is assessed in relation to the likely cutting speeds which can be achieved in the identified minerals with existing longwall shearer machines. Economic comparisons are made between traditional mining operations in those deposits for which technical feasibility is demonstrable. Continents are made concerning those technical deficiencies which appear to preclude the application of existing longwall equipment to the identified deposits and suggestions are made regarding the lines of research aimed at improving longwall technology.

Jan 1, 1978

By J. W. Allen

This report reviews the work performed on Task M of Bu-Mines Contract H0220073 to develop an engineering model of a surface and subsurface communications system for normal mine operations and for post disaster rescue operations. The system concept provides for one-way transmission of digital information between a number of identifiable subsurface terminals or subcenters and a single surface station. It also provides 2-way voice communications between the subcenters and the surface station. The basic communications link is electromagnetic signaling through-the-earth, but the system is also capable of using mine phone lines as an alternate link. Engineering models of three subcenters and one surface terminal (see Figure 1-1) have been fabricated in order to demonstrate the system's performance. The system concept, however, permits up to 20 subcenters to be incorporated if desired. Additional subcenters are also feasible for large mines if they can be deployed in the mine to operate on a noninterfering basis.

Jan 1, 1973

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 Earl T. Hayes

THIS BIBLIOGRAPHY has been assembled to aid research by the Bureau of Mines, and others on high-purity tungsten. It appears approximately 50 years after the development of ductile tungsten-one of the first metals to be produced in a high-purity form. Requirements of the missile age are ever more demanding that engines rout hotter and space vehicles fly higher and faster. Thus, it has become necessary to reexamine all conventional materials of construction as well as to investigate new combinations. At this stage of our technology we have alloys capable of operation at 1,800° F. and several possibilities of developing some. that will be satisfactory up to 2,500° F. Strength-weight comparisons, detrimental to tungsten at, lower temperatures, disappear at this point, mid tungsten or its alloys appear to be the only metal capable of operation at truly high temperatures. The aim of this bibliography has been to include only references that concern improving the purity of tungsten-from processing the ore to treating the finished metal. In this sense it is a selected and not a critical bibliography. The period front January 1911 through February 1959 has been covered. Because repent literature has the greatest, value, most of the selected items refer to publications issued within the pest 5 years.

Jan 1, 1960

By James R. Wait

An attempt is made here to collect together various reports and publications that are based on research supported all or in part by Contract No. H0155008 for the past two years. The subject matter deals primarily with the excitation, transmission, and reception of electromagnetic waves in mine environments. This contract from the U.S. Bureau of Mines with the Office of Telecommunications supports the efforts of James R. Wait (Principal Investigator and Consultant to OT), David A. Hill (Co-Investigator), and various associates within the Boulder scientific community. The contributions of Samir F. Mahmoud were supported, in part, by the contract while he was a Visiting Fellow with the Cooperative Institute for Research in Environmental Sciences at the University of Colorado. Administrative assistance in CIRES has been provided by Mrs. Lana R. Hope.

Jan 1, 1976

By Warren E. Morrison

The first major evaluation of the nation's raw materials prospects after World War II was completed by the President's Materials Policy Commission (Paley Commission) in 1952 and submitted to the President in June of that year, as a five-volume study entitled Resources for Freedom. The bulk of the report was devoted to an analysis of the past, present, and probable future of the Nation's mineral supply industries. The Commission's evaluation of the future situation regarding minerals was derived from its forecasts of the probable domestic demand for the major minerals in the 1970's. This demand analysis was made in the context of probable worldwide demand. Several crucial assumptions were made by the Commission's fore-casters. It was assumed in 1950 that the next 20 to 30 years would see no major wars and be a period of sustained economic growth. Another assumption was that the anticipated demand for raw materials must be supplied at essentially no increase in real cost in order to avoid crucial supply problems. The Commission's forecasts were derived within the context of the country's expected future rate of economic activity. The gross national product (GNP) growth to 1975 was derived from projections of the number of people in the labor force, hours of work, and an index of probable production measured per unit of labor input. It was believed labor hours would decrease and labor productivity would increase. The result was a forecast GNP growth rate of 3 percent.

Jan 1, 1970

As shown in Table 9, consumption has risen steadily for the period November through April, reaching its highest level since June of 1974. Imports remained at a relatively high level in spite of decreased imports from Zaire and Belgium-Luxembourg. Award prices for cobalt sold by the General Services Administration on June 17, 1976 ranged from $5.058 to $5.41211 per pound of contained cobalt. The high bid was about $1 per pound above the current market price set by the major sales agent in the U.S. for cobalt on April 15, 1976. COPPER: Eight domestic producers on July 1 hiked refined copper prices by 4¢ to 74¢ per pound for cathode and to 74.625¢ for electrolytic wirebar. New York Commodity Exchange (COMEX) June pricing of prompt contracted copper averaged 70.6¢, with daily quotes registering between 67¢ and 72.5¢ per pound. In June, London Metal Exchange (LME) cash wirebar prices averaged 70.3¢, trading between a low of 65.5¢ and a high of 73.6¢. End of the month copper stocks totaled 108,758 short tons for the COMEX and 539,350 metric tons for the LME.

Jan 1, 1976

By Joseph L. Jordan

Coal is essential to America?s future energy needs. To meet these needs mining methods must be safe, economical, and environmentally acceptable. Belt conveyor systems for coal haulage from surface mines offer great potential in this situation. The advantages over conventional truck haulage are particularly promising for area strip mines in western coal fields such as the Powder River Basin where relatively thick, flat-lying coal seams occur. The current demand for low-sulfur coal specifically emphasizes the need for better mining methods in these areas. Underspoil haulage is the term applied to transportation of coal from the pit to the surfate in area strip coal mines by belt conveyors in tunnels under the spoil. The advantages over trucks include lower manpower requirements, greater pit safety and efficiency, and improved reclamation procedure. This evaluation includes a comparison of total mining costs for truck haulage versus six variations of the underspoil haulage concept. The more efficient of these underspoil haulage systems have economic advantages over truck haulage which become more pronounced with deeper overburden, thicker coal, and higher annual production.

Jan 1, 1977