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By I. D. Shah

The copper-nickel ore of the Duluth Gabbro Complex in northeastern Minnesota is a large potential domestic resource of cobalt and platinum-group metals. However, because of the low grade of the primary metal values (0.5 pct Cu, 0.15 pct Ni), the private sector has assigned a relatively low priority to the development of technology for processing this ore, anticipating that mining probably would not begin until the mid-1990's. Furthermore, preliminary processing flowsheets considered by the mining companies centered on the primary metal values. As part of an effort to help provide the basis for technology to recover critical and strategic minerals from domestic resources the Bureau of Mines is investigating methods to recover all of the mineral values, in the Duluth Gabbro material, with particular attention to the byproduct critical minerals. A key step in this process is the removal of a relatively large amount of iron present in the bulk sulfide flotation concentrate to permit subsequent extraction of mineral values. This report describes a direct smelting method that removes most of the iron and produces a copper-nickel-cobalt matte, an intermediate product from which the metal values subsequently are separated. Copper, nickel, and cobalt grade and recovery data are presented for the direct smelting method. Test results showed that under certain conditions some of the mineral values reported to the slag, requiring slag cleaning to recover them.

Jan 1, 1983

By David K. Denton

There are no active mines in the Mt. Eddy RARE II area. Chromite, gold, and stone prospects were examined. The RARE II area contains no identified mineral resources; however, a sample of a 260 ton occurrence contained 38.1 percent chromium oxide (Cr203) at the Ratero Prospect (fig. 1, no. 3), which has low potential for chromium resources. The Johnson Mine (fig. 1, no. 6) produced a small unrecorded amount of chromite during World War IT, but only a low potential exists for chromium resources. A low potential exists for gold resources at the Half Century Prospect (fig. 1, no. 2). At a borrow pit northwest of the study area (fig. 1, no. 1), sheared serpentinite is quarried for road metal; similar rock occurs in the RARE II area, but better material is more readily available elsewhere. Sand and gravel occurrences are too inaccessible and distant from markets to be considered resources. Mineral fuels and geothermal resources were not evaluated during this Bureau of Mines study. There currently are three unpatented lode mining claims in the study area. INTRODUCTION The Mt. Eddy RARE II area is 7 air-mi west of Mt. Shasta City, California, and straddles the Siskiyou-Trinity county line. The roadless area includes 7,200 acres of rugged, glacially carved, ridges and drainages which comprise Mt. Eddy. Elevations vary from 6,000 ft along the North Fork Sacramento River to 9,025 ft at the summit of Mt. Eddy. The area is covered with conifer forest below 8,000 ft elevation.

Jan 1, 1983

1. COAL PRODUCTION: Under Section 402 of Public Law 95-87 (SMCRA), coal operators are required to pay a fee when coal is sold, used, or transferred. These fees are deposited in the U.S. treasury as the Abandoned Mine Land Fund. Information about the type of coal (bituminous, lignite, or underground) and tonnage are tabulated on Form OSM-1 and submitted with the fee, which is paid quarterly to the Office of Surface Mining. The coal production data presented in this report was compiled from information stored in the Office of Surface Mining Fee Collection System computer data base. Collection of the fee began with the last quarter of 1977; therefore, 1978 data includes the last quarter of 1977 and the first three quarters of 1978. Information for each successive year follows the same tabulation pattern. Surface production includes both bituminous and lignite coal; underground includes tonnage reported as underground mined. In New Mexico and Montana, coal production on Indian land is listed under the Crow, Hopi, and Navajo Tribes. 2. HISTORIC COAL PRODUCTION: Federal Government agencies have published coal production data since 1807, the date of the earliest record. The source of coal production data used to compile this graph was: 1891-1895, U.S. Geological Survey, Division of Mineral Resources; 1896-1977, U.S. Bureau of Mines annual Minerals Yearbook; 1978- 1991, Office of Surface Mining data described in footnote 1 above. 3. NUMBER OF MINES: The number of mines was compiled from Office of Surface Mining Fee Collection System data described in footnote 1 above. Annual totals were calculated by adding together the number of operations with the same Mine Safety and Health Administration numbers reported each quarter and dividing by four to give an annual number in each state. 4. ENFORCEMENT ACTIONS: Enforcement action data was compiled from annual reports developed by Office of Surface Mining field offices and historical field office records. The data presented are all actions taken by both the state regulatory authority and the Office of Surface Mining. Citations issued are the sum of Notice of Violations (NOVs) and Cessation Orders (COs). Because the Hopi and Navajo jurisdictions overlap in Arizona and New Mexico, enforcement actions data for the tribes have been combined in annual reports prepared by the Albuquerque Field Office; therefore, they are combined for this report and listed under Navajo Tribe. 5. ACREAGE PERMITTED: Acreage permitted data was compiled from annual reports developed by Office of Surface Mining field offices and historical field office records. The acreage listed was permitted during the year shown and is not the total acreage under permit during that year. 6. BONDS RELEASED: Acreage of reclamation bonds released was compiled from annual reports developed by Office of Surface Mining field offices and historical field office records. The sum of final Interim Regulatory Program bonds and Phase 111 (or final release) bonds shows only the land area where reclamation is complete and has been released by the regulatory authority.

Jan 1, 1992

By M. L. Whisman

Radiotracer techniques were developed for stoichiometric studies of photochemical reactions associated with atmospheric smog formation. Stock blends of separate hydrocarbon and oxygenated compounds were prepared and calibrated. 14C-labeled reactants and products in reaction systems involving hydrocarbons and nitrogen oxides at the ppm level were analyzed for qualitative and quantitative data. Precision and accuracy of these methods developed by the Bureau were determined by replication and statistical treatment of data, and these methods are described.

Jan 1, 1969

By I. N. Beall

The present survey indicates 'that the average volatility of motor gasoline now being marketed throughout the country falls well within the limits of Federal Specifications. As would be expected, there is a slight decrease in volatility as compared with the gasoline marketed last wine:., but on the average the gasoline sold today is about the same as that sold last summer. During the past five years the Bureau of Mines has made semi-annual surveys of the gasoline marketed in the United States. To obtain a sample of each gasoline sold is obviously impracticable, but the cities in which samples have been collected have been so chosen as to be representative of the more important marketing territories. It is believed, therefore, that the samples obtained are indicative of the quality of gasoline marketed throughout the country.

Jan 1, 1925

By J. J. Shields

This is the Seventh of a series of publications that describe methods and practices used in mining bituminous coal mechanically.3/ This report deals with the operation referred to in coal mining as continuous mining, and the interest shown by mining companies in this method is the reason for this study. Only continuous mining as it applies to the room-and-pillar system of mining, or a modification thereon, is discussed in detail in this report. Although not always as continuous as the name implies, it is a system of mining in which a machine is used to cut and load coal in one continuous operation without drilling and blasting the coal. With the mining equipment in most general use today, the usual cycle of operation in mining of coal is: (1) Timber, (2) cut, (3) drill, (4) blast, and (5) load. As the phases of this type cycle cannot be performed simultaneously in the same working place, it is necessary to operate from 3 to 7 working places so that at least 1 place is available for coal loading at all times. Even if the schedule of the phases in a cycle is maintained, coal production ceases during the time required to move the loading equipment from one loading place to the next. In 1920 a continuous-type mining machine4/ was installed in an Illinois coal mine to drive entries. Several other companies used these entry drivers for short periods in the following few years. In 1927 a southern Illinois coal company installed 2 of these machines which, in the next 25 years, were reported to have driven over 200 miles of entries. The machines did not attain widespread usage.

Jan 1, 1954

By J. J. Forbes

The Coal Mine Inspection Branch of the Health and Safety Division, Bureau of Mines, was established to carry out the provisions in Public Law 49, 77th Congress, H. R. 2082, approved May 7, 1941. The series of major disasters that beset the coal-mining industry in 1940 aroused public interest in mine-safety measures, and the act 18 the direct result of this rekindled interest. Under the provisions of the act, the Secretary of the Interior, acting through the Federal Bureau of Mines, is authorized and empowered to make, or cause to be made, annual or necessary inspections and investigations in coal mines, the products of which regularly enter commerce or the operations of which substantially affect commerce. The principal functions of the Federal coal-mine inspectors are to determine the causes of accidents and occupational diseases in coal mines and then endeavor to eliminate or ameliorate them (1) by revealing, through personal conferences with mine personnel, correspondence, and published reports, the unhealthful and unsafe conditions and practices existing in the mines and (2) by recommending practical means for correcting the conditions observed. The act does not provide any enforcement powers, and therefore compliance with the inspectors' recommendations is not mandatory; it does give Federal coal-mine inspectors the right to enter coal mines for inspection purposes.

Jan 1, 1951

Until man was able to produce light, his working day was pretty much limited to daylight hours. Underground miners have a special problem because in a mine it is just as dark during daytime as it is at night. The first devices used for mine lighting were torches and open flame 011 lamps. Torches made from twisted grass and dipped in tallow or pine pitch would burn for a while, but they made a lot of smoke and probably went out when they were needed most. During the 15001s, miners lamps consisted of a small metal dish with a hook attached to hang it up. The saucer-shaped dish was filled with animal or fish oil and a wick made of twisted fibers was laid In the 011 and hung over one edge where it would burn. This lamp would burn longer than a torch, but the amount of light cast by the pale, flickering flame was probably only a little better than no light at all.

Jan 1, 1976

By T. E. Gray

This report describes the preparation characteristics of the more significant coal beds in Washington County, Pa. It is one of a series planned to determine coals suitable for producing metallurgical coke, either as mined or after beneficiation. More than 15 million tons of coal was produced in Washington County in 1956; 89.8 percent was cleaned mechanically in 10 cleaning plants. The Bureau of Mines has estimated that 2,280 million tons of recoverable coal remained in beds 28 inches thick or more as of January 1, 1954.

Jan 1, 1959

By Andrew B. Cecala

The Bureau of Mines conducted laboratory and in-mine tests on the Racal airstream helmet (Model #AR21) to evaluate its protection efficiency. Laboratory tests indicated that as ambient air velocity increased, the protection offered by the helmet decreased. In tests conducted at several coal mine long-wall sections with face velocities under 400 fpm, the helmet was 84 pct effective at reducing respirable dust in the miner's breathing zone. However, at a high-velocity section, 1,200 fpm, the efficiency of the helmet was significantly reduced, confirming our laboratory results.

Jan 1, 1981

By H. C. Miller

[California's sensational rise to supremacy as an oil-producing State in 1923 was accompanied by a loss of 62 lives. These 62 deaths were from oil-producing accidents alone and do not include fatalities at the refineries, on tankers, or on any work not directly connected with the drilling for and the production of oil. The number of facilities for 1923 was 82 per cent greater than in 1922, the next most fatal year, with a record of 34 lives lost. The data submitted in Table 1 show that for the calendar years 1917 to 1923 inclusive, an average of 4.74 million barrels of oil were produced per Vitality in the California oil fields. On this basis, the record for 1923, hough a trifle below the average, shove up slightly better than that for 1922.]

Jan 1, 1924

By T. E. Gray

This report describes the preparation characteristics of the more significant coal beds in Allegheny County, Pa. It is one of a series planned to determine coals suitable for producing metallurgical coke, either as mined or after beneficiation. More than 7 million tons of coal was produced in Allegheny County in 1957. Of this, more than 5 million tons was cleaned mechanically in nine cleaning plants. The Bureau of Mines estimated that, as of January 1, 1953, more than 384 million tons of recoverable coal remained in the county in beds 28 inches or thicker.

Jan 1, 1959

By L. W. Higley

Particulates generated in electric furnace (EF) steelmaking constitute approximately 1 to 2 pct of the charge. This flue dust is a rich source of zinc (values are substantially higher than in ore), but although there are several processes for recovering the metal, none are considered economic in the United States. This report reviews extraction technology and presents results of Bureau of Mines reduction-volatilization tests on pelletized EF dusts which achieved high recoveries of zinc. The data are sufficiently encouraging to warrant consideration of EF dusts as raw material for primary zinc smelters.

Jan 1, 1977

By D. A. Wilson

A process was developed on a laboratory scale in which a solid waste byproduct from refining of secondary lead was converted into three valuable products. Roasted lead blast furnace matte was leached with water to recover copper. This was followed by brine leaching to recover lead. Residues were finally smelted to yield pig iron. Copper was precipitated as cement copper and the lead product obtained was a mixture of pure 3PbO.PbC12.xH20 and Pb(OH)C1. Copper recovery was 89 percent and lead recovery was 96 percent.

Jan 1, 1967

By Maria I. De Rosa

For all coal mining categories, data on coal mine fires during 1990-1999 have been reported as actual numbers and calculated values. 1. For each mining category, actual numbers include the total number of fires, fire injuries, employees' working hours, lost workdays, and coal production (for underground and surface mines only) for a 1 0-year period (1 990- 1999) and for five successive 2-year periods with the 10-year period. These numbers have also been reported by state ( 10-year period). The actual number of fire fatalities has been reported by time period. Furthermore, actual numbers of fires for the five 2-year periods have been reported by ignition source, method of detection and suppression, equipment involved, location, and burning material. Actual numbers of fire injuries per number of fires causing injuries and total fires have been reported by year, ignition source, equipment involved, and location. 2. For each mining category, the calculated values include the fire and injury risk rates during the 10-year period and the five 2-year periods. The fire risk rate (Frr) values were calculated according to the USBM formula [Pornroy and Carigiet 19951. The injury risk rate (Irr) values were calculated according to the MSHA formula [MSHA 1991a, 1992, 1993, 1994a, 1995a, 1996, 1997, 1998b, 1999c, 20001. Also, risk rate values for individual states (10-year period) were calculated according to the above-mentioned formulas. Of note is that only the risk rate values for the 10-year and five 2-year periods and risk rate values for individual states with the highest number of fires and fue injuries were considered for comparison purposes. The fatality risk rate values were not calculated because of the extremely small number of fire fatalities during the 1 0-year period. 3. Calculations of risk rate values are as follows: a. Fire risk rate (Frr) value: Number of fires per million tons of coal produced [Pornroy and Carigiet 19951. b. Injury risk rate (Irr) value: Number of fire injuries multiplied by 200,000 working hours per total employees' working hours [MSHA 1991a, l992,1993,1994a, 1995a, 1996, 1997, 1998b, 1999c, 20001. The Irr value is the average risk rate value for the number of fire injuries per 200,000 working hours for a given time period.

Jan 1, 2004

By Edward L. McHugh, Charles Sabine, Louis J. Denes, Jami M. Girard, Peter Metes

The Spokane Research Laboratory, National Institute for Occupational Safety and Health, is investigating various remote sensing technologies as possible tools to detect, monitor, and mitigate hazardous situations in surface mines that could lead to catastrophic slope failure. Promising technologies include a field-portable spectro-polarimetric imager and a stationary interferometric radar device. Field tests were conducted of a prototype visible and near-infrared spectro-polarimetric imager (SPI) built at the Carnegie Mellon Research Institute. The SPI employs anacousto-optical tunable filter (AOTF) to control wavelength, a phase retarder to measure polarization signatures, and a digital camera and computer to capture data. Images obtained at the Mountain Pass and Castle Mountain mines in southeastern California showed that the instrument is capable of obtaining hyperspectral images of highwalls, outcrops, hand samples and drill core in the field. We have retrieved spectra from Mountain Pass images that closely match those of bastnaesite and have had some success in classifying images. Although radio frequency noise in the data limited spectral classification of imagery, we project that careful alignment of the AOTF should minimize the noise and greatly improve classification.

By Thomas M. Barczak, Christopher Mark

Roof supports can only be understood in conjunction with the rock structure that they support. The strength of the rock depends on geology, and the loads are applied primarily by the in situ and mining-induced stresses. Other factors, such as wider spans and retreat or multiple-seam mining, can also reduce the stability of mine openings. Roof supports are used to help stabilize these openings, but their performance characteristics must be properly matched to the loading environment and ground behavior if they are to succeed. Roof supports include both intrinsic supports, such as roof bolts, and standing supports. The key characteristics of any support include its maximum load-carrying capacity, stiffness, and residual strength. Other important factors are the timing of installation, the stability of the support as it is loaded, and the capability of the support system to provide skin control. This paper explains in practical terms how supports work and the important factors in ensuring that a good support design and application strategy are developed.

Jan 10, 2000

By Frank J. Cservenyak

Curtailment of bauxite importation by enemy activities during World War II focused attention on the necessity of developing domestic deposits of aluminous materials. Large quantities of aluminum ores such as kaolin, siliceous bauxites, high-iron bauxites, anorthosite, and diaspore clays are available but not readily amenable to Bayer processing because of excessive impurities. The Bayer process, which is the only commercial method in use in the United States for producing metallurgical-grade alumina, requires a high Al2O3 bauxite relatively low in SiO2 and Fe2O3. The Bureau of Mines was charged by Congress to investigate processes for the production of alumina from these low-grade ores. One part of the program was an investigation, in the laboratory and pilot plant, of the recovery of alumina by the lime-soda sinter process. Ores comprising kaolin, diasporic clays, anorthosite, and siliceous bauxites have been investigated and studied in the laboratory and pilot plant, and a series 'of reports covering these investigations has been prepared.

Jan 1, 1948

Provide a means of recovering precious metal values from finely ground tailing materials. Approach Determine the procedures needed for agglomerating the finely ground material for subsequent heap-leach cyanidation of the precious-metal-bearing tailings. Applying Agglomeration/Heap-Leaching to Fine Tailings Agglomeration technology was developed by the Bureau of Mines to provide cost-effective recovery of precious metal values though better heap leaching of clayey or low-grade ores. While many precious metal producers have adopted this technology to reclaim precious metals from crushed ores and wastes, other operations have experienced problems in using the heap leaching technique effectively on piles of fine tailings. In contrast to the coarser ore and waste material, most tailings piles contain more than 50 percent minus 200 mesh materials with no coarse material. Fine particles and clays present in the pile can impede 8 uniform flow of the leaching solution through the heap, thus preventing efficient and cost-effective precious metals recovery.

Jan 1, 1986

By R D. Fleming

A single-cylinder research engine was operated on pure hydrocarbons and simple (two-component) mixtures of pure hydrocarbons to study the effect of fuel composition on exhaust emissions from a spark-ignition engine. Used as fuels were three pure hydrocarbons that represented the primary hydrocarbon types present in commercial motor fuels: A paraffin (2,2,4-trimethylpentane), an olefin (2,4,4-trimethylpentene-2), and an aromatic (meta-xylene). The engine was operated at the same equivalence ratio for all of the fuels used in the experiment. Exhaust gas samples were collected and quantitatively analyzed for carbon monoxide, carbon dioxide, hydrogen, nitrogen oxides, aldehydes, and hydrocarbons. Exhaust hydrocarbons were separated and quantitatively measured with a chromatographic system employing a flame-ionization detector. Unknown hydrocarbons and oxygenated materials in the exhaust were identified with a Time-of-Flight mass spectrometer coupled to a chromatographic system. The results of the exhaust gas analyses showed that ethylbenzene, l-methyl-3-ethylbenzene, and l-methyl-3-vinylbenzene were more abundant in the exhausts from either 2,2,4-trimethylpentane--m-xylene or 2,4,4-trimethylpentene-2--m-xylene fuel mixtures than in exhaust produced from m-xylene. Also, the pure 2,4,4-trimethylpentene-2 fuel produced smaller amounts of C2 to C7 olefins in the exhaust than that produced by the pure 2,2,4-trimethylpentane fuel. The exhaust from pure m-xylene fuel contained aromatic hydrocarbons of higher molecular weight than the parent fuel. The amount of total hydrocarbon (moles of exhaust hydrocarbon per mole of fuel used) in the exhaust from the three pure fuels decreased in the following order: 2,2,4-trimethylpentane > 2,4,4-trimethylpentene-2 > m-xylene. The hydrocarbon mole-fractions of unreacted fuel in the exhausts produced from each of the pure fuels were 0.20 for 2,2,4-trimethylpentane, 0.13 for 2,4,4-trimethylpentene-2, and 0.66 for m-xylene.

Jan 1, 1970