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By Herbert R. Babitzke

The Minerals Availability System (MAS) was formally established by the Bureau of Mines in May 1975 to provide current appraisals of the engineering and economic availability of nonfuel minerals for consideration in the formulation of both domestic and foreign minerals policy, Domes- tic mineral property reports are developed by the Bureau's four Field Operations Centers, and foreign data are obtained under contract. This site-specific information is subsequently subjected to engineering verification and economic evaluation, and the results are analyzed and published as Minerals Availability System Appraisals. The deposit-specific data are also entered into the computerized MAS data base, where a subset of this information, the Mineral Industry Location System (MILS), is available to the public in the form of computer graphics and listings. Other MAS products are also described. The Bureau's MAS personnel are frequently involved in special engineering and mineral economic projects for other Federal and State agencies. MAS personnel also work closely with the private sector, both in the area of mining and processing cost estimation, and as a source of nonproprietary mineral deposit information.

Jan 1, 1982

By Donald E. Buck

In 1988, Albania's centrally planned economy continued to decline. The country's officially published yearend economic report did not contain concrete results such as the growth of national income or industrial output. 2 The shortfall for central budget earnings for 1988 amounted to 9% below the planned target. Losses in industry were attributed to poor management and organization, as well as to low technical standards and excessive consumption of fuels and raw materials. The construction, energy, and mining sectors of industry did not meet their annual production plans. As in 1987, within these sectors, the chromite and petroleum extracting and processing industries continued to lag in output. Both chromite and petroleum remained Albania's chief sources of foreign exchange; the production downturn of these commodities continued to negatively affect the country's foreign trade position, especially in view of constitutional prohibitions against using foreign credit to finance trade. The chief events in the minerals industry in 1988 included the construction startup of the first of four planned new concentrators at the Bulquize chromite mine, as well as the construction startup of new ferrochromium capacities at Elbasan. Also, the copper mining industry reported the completion of facility expansion at the Perlat mine in the Mid-rite district. Albania began new facility construction at the Dinamo heavy-equipment enterprise at Tirana to maximize self-sufficiency in mining equipment production. Upon completion, the new factory would double the out-put of mining equipment at the enterprise and would introduce new designs for electric trucks and pneumatic drills for the mining industry. The new facility would also increase the production of new machinery and equipment for the country's beneficiation plants.

Jan 1, 1990

By J. W. Paul

This circular is one of a series of reports on coal mining methods and cost s which are being prepared by the U. S. Bureau of Mines for the purpose of making available to those interested in the industry a knowledge of the mining methods employed in mines where mechanical and hand loading is practiced and the cost data on the several operations pertaining to the removal of coal from the working faces and its transportation to the tipple for loading into railroad cars. The methods employed are influenced by the natural local conditions with respect to the thickness and character of the coal beds and the overlying strata, the means employed for roof support and its control, and the disadvantages incident to the development of mines in thin coal beds.

Jan 1, 1929

By J. A. Organiscak

Enclosed cabs are a primary means of reducing the silica dust exposure of equipment operators at surface mines. The National Institute for Occupational Safety and Health (NIOSH) has investigated various factor effects on enclosed cab air filtration system performance. Factors experimen­tally investigated were intake filter efficiency, intake air leakage, intake filter loading (filter flow resistance), recirculation filter use and wind velocity effects on cab penetra­tion (inside to outside cab concentration ratio). Adding an intake pressurizer fan to the filtration system was also investigated. Results indicate that the intake filter efficiency and recirculation filter were the two most influential factors on cab penetration. Use of a recirculation filter significantly reduced cab penetration over the intake air filter by itself due to the multiplicable filtration of the cab interior air. Cab penetration was also affected to a lesser extent by intake filter loading and air leakage. Adding an intake pressurizer fan notably increased intake airflow and cab pressure while providing only minor changes to cab penetration.

Jan 1, 2008

By Clinton C. Knox

The Townsite mine, consisting of 40 acres in the town of Cardin, Okla., is in the center of a highly productive part of the Picher-Cardin district of the Tri-State zinc and lead field. Previous to the time of the work done by the Bureau of Mines, the property had been partly explored by churn drilling, and an area-of about 8 acres in the southwestern corner had been exploited by underground workings. The Bureau of Mines investigation had as its object the more intensive development of the northern part of the property where previous drilling had indicated a possible ore deposit of commercial grade. Churn drilling by the Bureau began in September 1942 and continued to February 1943. Twenty holes totaling 4,827 feet of bore were completed. Utilizing the information gained from these drill holes, the Weidman Mining Co., lessee of the tract, sank a shaft and proceeded to the exploitation of the indicated ore bodies.

Jan 1, 1949

By S. Kodama

Starting on a small scale, the equipment for processing synthesis gas to form liquid hydrocarbons was expanded to handle 100 m) 3/hr. This reactor was successfully designed and constructed, and a basis for future design methods was established. Because, however, this work was carried out on an empirical basis, it is felt that a more thorough theoretical study should be made in an effort to increase the efficiency of the process, particularly in the development of a simpler converter.

Jan 1, 1951

By Elaine T. Cullen, Thomas W. Camm

The mentor/learner model is a time-honored approach to teaching, including within the mining industry. Miners know when they see excellence and have a deep respect for experts in their field. By using expert miners as mentors to other, less-experienced miners, training programs can be developed that will have a legitimacy and credibility that resonates with those being trained. Building upon concepts in current theories of adult education, this paper highlights the unique advantages of using mentoring as a teaching method that can make the educational experience both interesting and effective. Current NIOSH safety training materials use these concepts to deliver effective adult learning experiences for workers in the mining industry.

Jan 1, 2002

By R. J. Fantel

The Bureau of Mines investigated the resources, costs, capacities, market relationships, and short- and long-run supply of phosphate rock and phosphoric acid. The 206 mines and deposits evaluated in 30 market economy countries contain an estimated 35.1 billion mt of recoverable phosphate rock (demonstrated resource level). U.S. resources are sufficient to satisfy the domestic and export markets for phosphate products well beyond the year 2000. Because of resource depletion at current producers, however, new properties (with higher cost levels) need to be developed if U.S. production levels are to be maintained. Existing worldwide capacity can satisfy expected demand through the early 1990's. Expansion at existing mines or low demand growth could mean that no new property development will be needed before the late 1990's. Worldwide, almost $8 billion could be required for development of new phosphate rock properties between now and the year 2000, given 3-pct annual growth in demand. Most properties that could develop in the 1990's would require price increases of 20 to 50 pct to break even. To earn a 15-pct rate of return on investment, prices must rise to nearly double the present level of $24 to $29 per metric ton.

Jan 1, 1988

By James N. Bayne

An examination and analysis of Landsat digital data in the monitoring of surface mines in selected counties of South Carolina.

Jan 1, 1979

By J. J. Bean

This paper, describing the milling practice at the oxide concentrator of the International Smelting Co., is one of a series on milling methods and costs being published by the United States Bureau of Mines. GENERAL DESCRIPTION The oxide concentrator is properly an integral part of the Tooele plant of the. International melting Co., located 5 miles from Tooele, Tooele County, Utah. It has a capacity of 300 tons of ore per day and uses an all-flotation process to treat custom siliceous oxidized lead ores obtained principally from the Tintic district in Utah. Ores found amenable to the process are purchased on a custom basis, the principal tonnages being obtained from the Tintic Standard and North Lily mines.

Jan 1, 1933

By Joseph A. DeCarlo, Eugene T. Sheri dan

The process of converting coal into coke is known as carbonization. Essentially, carbonization is destructive distillation in which the volatile matter of coal is released when coal is heated above its decomposition temperature and passes through a plastic stage before solidifying and forming coke. The mechanics of coke formation are complex, and the specific properties of certain coals that allow them to "cake" or form coke are still unknown. Coke is a hard, cellular, carbonaceous mass, formed by heating coal in the absence of air. It is porous, irregular in size and shape, and is similar in appearance to wood charcoal. Coke, however, is denser, more porous, and more abrasive than charcoal. Coke has been in use for several thousand years. History has recorded its use in Greece before the birth of Christ, and it is thought to have been used in China even before that time. It was not until the l6th century, however, that a method for coking was developed in Europe that subsequent ly evolved into the coking process that is known today. The coke industry in the United States began in the latter half of the 19th century when beehive-coke ovens were built to supply fuel for iron blast furnaces. Before this time, an iron industry fueled principally by charcoal had been in existence for several hundred years. With the depletion of timber resources, coke gradually replaced charcoal as blast-furnace fuel, and by 1875 more iron was made with coke than with any other fuel. Before 1893 a 11 coking was done in beehive ovens. These ovens are refractory kilns with arched roofs, sometimes joined together to form batteries.

Jul 1, 1964

By T. J. Ballard

Chromite deposits in the vicinity of Louise, Troup County, Ga., were studied y the Bureau of Mines from September 1, 1942, to March, 15, 1943. They are about three-fourths of a mile southeast of Louise and 8 miles northeast of La Grange, Troup County, Ga. The existence of chromite deposits in that area has been known for more than 75 years, but no active prospecting was done until World War I. Prospecting continued intermittently' until 1928. The Bureau became interested in the deposits in connection with its strategic minerals investigations during World War II. The chromite in these deposits occurs as grains ranging from "pin-head" size to 3/8-inch and occasionally 1 inch. Some of the material is magnetic, indicating the presence of magnetite. Of the 300 samples taken during the course of the project, 266 were analyzed. Tables showing the analyses accompany this report.

Jan 1, 1948

By Edward E. Johnson

The Bureau of Mines publishes in its ?Minerals Yearbook? a series of indexes on the domestic minerals industry. Among these are the index of physical volume of mineral production, indexes of stocks, and indexes of average unit mine value and implicit unit value, This report describes the material coverage of these indexes and the methods used in their construction. Detailed descriptions are given for several other mineral-oriented indexes regularly published by other government agencies. These descriptions give the index user a better understanding of what each index purports to measure and aids him in selecting the most appropriate index for his purpose.

Jan 1, 1965

The Appalachian Mountains divide Pennsylvania into two distinct coal regions, bituminous and anthracite. The western region of the the state, where the majority of bituminous mines are located, is characterized by mountains and gently rolling hills. Bituminous coal seams underlie about 12,000 square miles in 28 counties. The anthracite coal region, located in the northeast, covers approximately 3,300 square miles. This area contains more than 20 different coal beds that vary in thickness from a few inches to 50 or 60 feet. The anthracite region is characterized by steeply pitching seams that require highly specialized mining techniques and present unique challenges for solving problems such as the mine subsidence associated with abandoned underground anthracite mines. For more than a century, coal has played a major role in the economic and industrial development of Pennsylvania, particularly the steel industry. Estimated bituminous reserves total 23 billion tons, or 5.3 percent of U.S. reserves, and anthracite reserves total 7.1 billion tons, or 97 percent of U.S. anthracite reserves. Pennsylvania received conditional approval of its regulatory program July 31, 1982. Pennsylvania's Abandoned Mine Land Program was approved on the same date.

Jan 1, 1992

By Edward E. Johnson

The Bureau of 'Mines publishes in its ?Minerals Yearbook? a series of indexes on the domestic minerals industry. Among these are the index of physical volume of mineral production, indexes of stocks, and indexes of average unit mine value and implicit unit value, This report describes the material coverage of these indexes and the methods used in their construction. Detailed descriptions are given for several other mineral-oriented indexes regularly published by other government agencies. These descriptions give the index user a better understanding of what each index purports to measure and aids him in selecting the most appropriate index for his purpose.

Jan 1, 1965

By Raymond W. Hiteshue, Sam Friedman, Robert Madden

Experiments were made in a semicontinuous unit to provide engineering data for designing experimental continuous systems . These systems would be used to study the hydrogasification of hvab coal and char (from lowtemperature carbonization ) to high - Btu gas . In experiments at 800 ° C and with a coal residence time of several seconds , yields of hydrocarbon gases increased from about 2,000 scf / ton of maf coal at 250 psig to 7,000 scf at 1,000 psig . With 15 minutes residence time , yields increased from 8,000 scf/ton of maf coal at 250 psig to 17,500 cubic feet at 1,000 psig . In all cases , small quantities of heavy oils were produced along with the gaseous hydrocarbons . Production of oils could be minimized with a corresponding increase in gaseous hydrocarbons by increasing the retention time of the volatiles within the hot zone . Yields of gaseous hydrocarbons from char were slightly greater than from coal under similar conditions . Although the hydrogasification reaction is very pressure dependent , substantial quantities of coal (40 to 60 percent ) could be reacted to gaseous hydrocarbons at pressures as low as 50 psig provided reaction temperatures were increased to 1,200 ° C. It was also demonstrated that a hvab coal could be hydrogasified continuously without incurring agglomeration . This was achieved by dispersing coal in a relatively large reactor with concurrent flow of hydrogen . At 1,000 psig and 800 ° C , it was possible to react about 35 percent of the coal and to produce a gas containing up to 52 percent methane .

Jan 1, 1964

By G. R. Hopkins

For several years prior to about the middle of 1928 both the number and capacity of natural-gasoline plants showed a steady increase; this resulted from a material gain in the supply of casinghead has due to the discovery of a number of flush fields with relatively high gas-oil ratios. From 1928 to date some form of proration has been continually in force, with a consequent curtailment in the supply of wet gas. This decline in available gas and a severe decrease in prices, due largely to the increasing competition of light refinery products, has eliminated virtually all of the weaker units during the last 5 years, with the result that the number of plants declined from 1,155 on January 1, 1928 to 19035 on January 1, 1930, to 909 on January 1, 1932, and then to 859 on January 1, 1934, The struggle of the small high-cost producers to exist is illustrated further by the trend in the number of shut-down plants, which has increased from 36 on January 1, 1930 to 100 on January 1, 1932 and to 128 on January 1, 1934. The increase in the number of plants prior to 1929 resulted in a material gain in the total capacity, but the decline in number between 1929 and 1932 was not followed by a corresponding decrease in capacity, as gains resulting from the construction of a few very large plants overbalanced the loss due to the dismantling of a large number of small ones. However, the low prices of 1932 and 1933 supplied little incentive for new construction, and the total capacity declined in approximately the same ratio as the number. Thus the total capacity declined from 11,387,000 gallons daily on January 1, 1932 to 13,060,000 gallons daily on January 1, 1934, Of the latter 9,181,000 gallons (91 percent) represented the capacity of the operating plants and 679,000 gallons (9 percent) the capacity of the idle plants.

Jan 1, 1934

By Otto Ruhl

The Oronogo-Webb City-Duenweg district is in the northeastern part of the Tri-State zinc and, lead field. Its metal-mining history dates from the early 1850's. For some years prior to 1918 it ranked as the leading producing area of the entire Tri-State field, but by 1920 most of its mines had been abandoned and allowed to fill with water. Its mine operators had-been attracted, to the newly discovered and richer deposits around Picher, Okla. In 1943, the Orenogo Mutual Mining Co. was exploiting the Oronogo Circle deposit in the northern end of the district, and the Federal Mining & Smelting Co. was preparing to mine on its holdings in the southern part near Duenweg. The area between these two operating units ranked as the largest single block of ore reserves under water in the Tri-State field. In 1942, engineers of the Bureau of Mines, in collaboration with the William Stewart Engineering Co. of Joplin, collected all available mine maps, mine reports, and logs of old drill holes in the inundated area. From a careful study an appraisal of these data, the reserves in the block were calculated at 20,647,800 tons of ore containing 606,440 tons of 60-percent zinc concentrates and 46,970 tons of 80-percent lead concentrates. The ore was estimated to contain 1.76 percent recoverable zinc and 0.18 percent recoverable lead.

Jan 1, 1949

By T. M. Barczak

This U.S. Bureau of Mines report investigates shield mechanics and component stress development in a two-legged longwall shield for unsymmetric canopy and base contact configurations. Previous studies analyzed shield behavior for symmetric contact configurations. The goals of these efforts are to improve longwall support selection and design. This study provides vital information that will help develop improved procedures for performance testing of longwall supports and will benefit future research to improve support design through stress optimization and evaluation of failure mechanisms. Combinations of six canopy (three symmetric and three unsymmetric) and six base (four symmetric and two unsymmetric) contacts provided a total of 36 configurations for evaluation. Of these 36 configurations, 10 were eliminated because of fixture limitations or shield instability. Controlled vertical and horizontal displacements were applied by the Bureau's mine roof simulator to the remaining 26 configurations. Component responses were determined from pressure transducer and strain gage instrumentation in order to identify contact configurations and boundary displacements that produced maximum loading in each of the support components. This report describes these test results and provides conclusions relevant to critical contact configurations for performance testing of longwall supports.

Jan 1, 1990

By David A. Lipton

In the summer of 1985, at the request of the U.S. Forest Service, the U.5. Bureau of Mines examined the 109,000-acre West Big Hole study area to evaluate its identified mineral resources. The study area is in Beaverhead County, about 50 mi west of Dillon, MT. Four lode properties within or adjacent to the study area contain an estimated 452,000 tons of identified subeconomic gold-silver resources. Resources ranged from 900 to 302,000 tons, with estimated grades between 0.02 and 0.23 oz/ton gold and as much as 4.8 oz/ton silver. Gold, silver, and base-metal content in samples of poorly exposed mineralized structures indicate that exploration may identify resources on 18 additional lode properties within the study area and 5 properties adjacent to it.

Jan 1, 1988