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During 1990-1999, a total of 458 fires occurred in all coal mining categories; 157 of those fires caused 164 injuries and 2 fatalities. The greatest number of fues and fire injuries occurred at surface mines, whch also had the highest risk rate values. A total of 66 fuefighting interventions were required. Of these, there were 25 mine rescue team interventions in underground mines, including 5 mobile equipment firefighting interventions, and 41 fire brigade and fire department interventions at all surface operations, including 19 mobile equipment interventions. In all, 50 fires destroyed or heavily damaged equipment (including 16 pieces of mobile equipment) because of failure of other firefighting methods, late fire detection, undetected fires, or fire size. A total of 1 14 fires were detected late by smoke, and 42 fires were not detected.

By F. W. Wessel

Manganiferous carbonate slates of the Cuyuna range, which are part of the unoxidized thin-budded iron formation, represent a large potential source of manganese. This report details recent bench-scale research by the Federal Bureau of Mines in applying mineral-dressing techniques to these materials in order to investigate their potential uses. Work outlined in the report was directed toward the production of concentrates usable as iron-blast furnace feed, but an equally important objective might have been to furnish an enriched feed for extractive processes for recovering manganese. Flotation concentrates were prepared that contained 11.1 percent manganese, 27.8 percent iron, and 12.2 percent silica, with recoveries of 73 percent of the manganese and 48 percent of the iron. Calculated analysis for a simulated sinter suggests a product containing 16.0 percent manganese, 40.2 percent iron, and 17.6 percent silica, with 31 percent recovery of the dry weight of the ore. The silica in the flotation concentrates was due to quartz and iron silicates. Substantial quantities of the iron silicates (stilpnomelane and smaller amounts of minnesotaite) were present in the slate, and the need to reject these minerals limited the recovery of iron. The sintered flotation concentrate would be usable as ferruginous manganese ore for iron blast-furnace feed because of its favorable manganese silica ratio. The unsintered flotation concentrates, representing 45 percent of the feed weight and containing manganese enriched in the ratio of 1.6 : 1, also could be used as feed to processes for extracting manganese.

Jan 1, 1961

By V. M. Benson

A simplified, routine method for determining lithium in lithium-bearing rock is presented. The sample is decomposed by repeated treatments with nitric, hydrofluoric, and perchloric acids. Since this procedure does not appreciably dissolve beryl, interference by beryllium (the principal interfering cation) is minimized for most samples. The salts are brought into solution with water and enough citric acid-ammonium citrate buffer is added to make the final volumetric dilution 0.20 M with respect to citrate. The addition of citrate greatly reduces anion interference in the hydrogen-oxygen flame, slightly increases the intensity of the lithium 671 millimicron emission line, and reduces the effect of most of the interfering cations to the extent that analytical separations are not necessary. The accuracy of results of single determinations of lithium in a pegmatite containing spodumene, lithium-bearing mica, and beryl are approximately equal to that obtained by other flame methods, INTRODUCTION This investigation was undertaken in Bureau of Mines laboratories to develop a reliable, rapid, routine analytical method for determining lithium in lithium-bearing minerals. The requirements of the procedure were that the method should be applicable to the analysis of a variety of lithium-bearing ores and test products, and the results would be reasonably accurate for materials containing 0.05 to 8 percent Li20.

Jan 1, 1961

By J. L. Reuss

The Bureau of Mines investigated the technical feasibility of smelting copper concentrates containing chalcocite (Cu2S) and native copper using nonpyritic sulfur-bearing materials to aid matte formation. The procedure consisted of combining various proportions of commercial chalcocite concentrate, smelter slag, fluxes, and matte-forming constituents to produce charges of comparable compositions. The mixtures were charged in fire-clay crucibles and smelted in an induction furnace at 1,300° C. The research proved that either sulfur or gypsum can replace pyrite as a matte-forming material, and that gypsum produces an exceptionally high-grade copper matte. The addition of small quantities of metallic iron to the nonpyritic smelting charge furthers the removal of sulfur, improves the recovery of copper, and makes it possible to utilize gypsum as the exclusive flux and matte-forming ingredient, thereby eliminating the necessity of adding limestone.

Jan 1, 1968

By John W. Cole

Ore deposits in the? vicinity of Philipsburg, Mont., have been mined continuously since discovery of the Hope mine in 1865. Although originally famed chiefly for its silver production, since about 1917 the district has been the only important producer of battery-grade manganese ore in the United States. Also, it has produced substantial quantities of zinc ore and during World War I and World War II contributed notable amounts of manganese for metallurgical consumption. Nearly the entire production of base metal ores has been mined from the outcrop area of? a dolomitic limestone bed that plunges beneath overlying beds of limestone and shale northward from the outcrop area. The Hope silver mine, with a production record of over $4,000,000, was in one of the overlying limestone beds about 3,000 feet north of the base-metal producing area and about 1,000 feet vertically above the projected downward position of the dolomitic bed that has produced the base-metal ores. Furthermore, the Hope ore bodies were controlled, in part at least by east-west fractures similar to those that controlled the deposition of the base-metal ores.

Jan 1, 1949

By H. H. Schrenk

One phase of Bureau of Mines work in health and safety, is promotion of the use of safe, satisfactory, and reliable respiratory protective devices. To insure that such devices will be available, the Bureau has established schedules of minimum requirements for self-contained breathing apparatus,3/ gas masks, supplied-air respirators (hose masks, air-line respirators, and abrasive blasting helmets, hoods, or masks),2 dispersoid (dust, fume, and mist) respirators, and nonemergency gas respirators (chemical cartridge respirators). Approval tests of self-contained breathing apparatus are conducted by the Safety Branch, approval tests of other types of respira- tory protective equipment are conducted by the Health Branch, These branches are in the Health and Safety Division.

Mar 1, 1948

By W. H. Kerns

The Critchfield manganese deposit, Huntingdon County, Pa., was investigated by the Bureau of Mines in October 1942. Iron ore was mined from an open cut just southeast of the manganese deposit about 80 years ago. The Critchfield Sand & Feldspar Co. was operating (1942) a clay-mining and beneficiation plant northeast of the manganese deposit. The Bureau completed six rotary bucket-drill holes and three hand-auger holes, aggregating 370 feet on the deposit. This report describes the work performed and presents the results obtained.

Jan 1, 1948

By W. W. Odell

The results of the 1921 cooperative experiments conducted by the U. S. Bureau of Mines and the University of North Dakota at the University mining substation plent at Hebron , North Dakota , pointed clearly to certain definite dep ficiencies in the schemes hitherto developed for benefiting and utilizing lignite . First The apparatus used in the carbonizing process or used to produce carbonized lignite suitable for briquetting is too costly , that is , the cost per ton day of residue made is too high . Second - The depreciation of the carbonizing appara tus is too high . Third The carbonizing apparatus can not be operated intermittently without seriously damaging it and impairing its efficiency of performance . Fourth Too little attention has been given to the possibility of using at least a certain percentage of the carbonized lignite directly in suitable stoves and furnaces without briquetting or other treatment . Accordingly , consideration was given to the design of an oven that could be built at a mine without the importation of highly skilled and specially trained construction men , erected at a low first cost , readily kept in a state of repair , operated at a rela tively high capacity and put into operation or shut down at will without seriously damaging the brickwork . The need of such an oven was appreciated also by the University of North Dakota and a cooperative agreement was made to build and operate such an oven during the summer of 1921.

Feb 1, 1923

By Ulrich Neumann

Mining coal by employing a method called longwall mining is gaining more and more popularity in the United states since it offers many advantages over the conventional deep mining methods. Those advantages are a higher productivity, an almost total extraction of the mineral since no pillars must be left behind for support, and an increase in safety since the personnel are protected by the shield supports and rarely have to work near unsupported, exposed root. However, on some longwalls, the dust levels liberated by various equipment such as belt conveyors, chain conveyors, crushers, longwall shearers, and moving shield supports can exceed the maximum permissible limits and therefore have an adverse effect on productivity. Many attempts have been made over the past years to reduce the dust liberation by changing designs, installing various types of sprays or scrubbers, treating the mine water with wetting agents, or even using foam to catch dust before it becomes airborne. In the year 1984, the Bureau of Mines awarded Eickhoff Corporation a contract to demonstrate a water-jet-assisted cutting system for the multiple purposes of reducing dust levels, improving bit consumption, and increasing material size. During the previous phases of this contract, various trials were conducted aimed to design, build, and test d shearer loader to meet the objective of the contract. In the early stages of the research program, it was expected to see a reduction in the overall power consumption of the machine due to the fact that the high-pressure water jet would pre-cut the mineral in front of the bit. This, in turn, would then reduce the bit wear. Since there is less cutting action performed by the bit, a reduction of the dust liberation and a reduction of product fines was sought.

Jan 1, 1991

By W. H. Ode

An investigation of standard methods for determining ash in low-rank* coals showed that generally 60 to 95 percent of the total sulfur in the coal is retained in the ash as SO3. This large sulfur retention causes a positive error in the determined mount of ash of as much as 6 percentage points for the coals examined, although it usually is 2 to 3 percentage points for lignites and about 1 for subbituminous coals. Unless the sulfur content is low or unless a correction is made for the SO3 retained, the fixed carbon and oxygen have an equivalent negative error when determined by difference; also other inaccurate analytical values occur when the data are calculated on an ash- free bas is. No simple modification of the ashing procedure was found that would reduce the sulfur retention to a point where its effect on the ash determination would not be significant, Therefore, for accurate analytical work on law-rank coals, the SO3 should be deducted from the determined ash to obtain a "corrected" ash value.

Jan 1, 1962

By R. J. Leary

Significant improvements in surface conditions or mechanical properties of steels have been attributed by several investigators to ladle additions of small quantities of rare-earth metals or their oxides. To investigate systematically these effects in wrought and in cast plain carbon and alloy mechanical steels containing approximately 0.35 percent carbon, heats of four representative compositions were melted by the Bureau of Mines in a 4-ton open-hearth furnace. Each heat was cast into three sets of ingots to exemplify respectively, treatments with (1) rare-earth metals, (2) rare-earth metal oxides, and (3) an untreated set as a control. The development of melting, casting and rolling practices is described and discussed. Lance injection of oxygen shortly after melt raised the temperature of the metal immediately as much as 500° F., principally because mechanical agitation exposed the high-carbon metal to the flame and furnace root. An exceptional degree of superheat in the metal at the termination of the refining period was attributed to oxygen injection during the refining period. Bath temperatures higher than industrial practice were permitted by the all-basic furnace lining. Rates of carbon elimination as high as 0.036 percent carbon per minute were achieved by oxygen injections.

Jan 1, 1961

By D. J. MacDonald

This U.S. Bureau of Mines report reviews published information on synthetic berlinite (AlP04) and suggests experimental conditions requisite for its production. Berlinite is a piezoelectric material with potential use as a substitute for quartz in the crystal oscillators, which are components of electronic and electroacoustic equipment. Information gathered here (mostly from published sources) includes historical background, physical properties, end-use applications, criteria of quality, and physio-chemical factors involved in berlinite crystal growth. It is concluded that growing large high-quality berlinite crystal would require high-purity starting materials in an autoclave equipped with a noncorrodible liner and operated with temperature control of ±O.OO5 ac over a range of 250 to 350 ac.

Jan 1, 1995

By F. S. LOTT, I. S. CULVER

The number of petroleum refineries in the United States decreased during 1948 from 390 to 375, continuing the trend to fewer units of larger individual capacity that has persisted since the peak in number of plants was recorded on January 1 , 1936. Large - scale construction of new processing facilities continued through 1948 with a resultant gain in daily crude-oil throughput capacity of installed equipment from 6,034,252 barrels on January 1 , 1948 to 6,438,995 barrels on January 1 , 1949. The capacity of the average refinery to process crude oil therefore increased during 1948 from 15,472 barrels daily to 17,171 . The principal areas of expansion of facilities were the strategic seaboard districts of the Texas and Louisiana Gulf Coast and the East Coast , and the important Indiana , Illinois , Kentucky, etc. , district that supplies markets in the upper Middle West region . These four districts accounted for 79 percent of the total new capacity added in the United States in 1948. The relatively small petroleum- refining industry of the Other Rocky Mountain district experienced a vigorous expansion in 1948 that will continue during 1949 . Capacity building on January 1, 1949 , amounting to 341,500 barrels daily, was 25,750 barrels lower than the comparable total on January 1 , 1948, but was the second highest on record . New construction was heavily concentrated in the Texas Gulf, East Coast , and Indiana -Illinois

Sep 1, 1949

By Michael J. Friedel

As part of an investigation aimed at improving the health and safety and competitiveness of the mining industry, the U.S. Bureau of Mines evaluated the application of common offset radar profiling, using a 250-MHz ground-penetrating radar (GPR) system, for the detection of fractures in igneous rock. A series of radar reflection surveys were conducted to detect and delineate the extent of fracturing at various granodiorite and gabbro quarries and outcrops located in Minnesota. The application of radar profiling for detecting joints, sheeting fractures, shear zones, and depth to water table was demonstrated to be feasible with minimal processing. Radar reflection interpretations were verified by visual inspection of the rock mass and field mapping of local structure. The radar reflection section provides a simple, rapid, and cost-effective means for mapping of shallow (less than 10 m) small-scale fractures (greater than 0.25 cm) in igneous rock masses (characteristic of velocities between 0.061 m/ns for gabbro and 0.125 m/ns for granodiorite). Depth or distance estimates to fractures are within 10 pct of the actual, and time-shift compensation is necessary only when topographic irregularities exceed 30 cm.

Jan 1, 2010

By Gary E. Sherman

To aid the U.S. Army Corps of Engineers in their Resource Development Navigation Study of ten existing or proposed port sites in Alaska, the Bureau of Mines examined the potential for mineral development around three Alaska port sites: Iliamna Bay, Kotzebue, and Nome. The mineral deposits near Iliamna Bay include gold, copper, and iron. Development of minerals in this area will require the discovery of new deposits or the definition of additional are reserves at known deposits. The mineral deposits near Kotzebue are primarily gold, copper, coal, lead, and uranium. Based on the character of these deposits, it appears that development of a small-scale mine supplying coal for regional use is the most likely scenario in the near-term. The mineral deposits near Nome are primarily gold and copper. Development of small underground gold mines is possible, however it appears that expanded offshore gold dredging will have the greatest impact on the flow of freight and goods through the Nome port in the near term.

Jan 1, 2011

By S. Stephen Uslan

The purpose of the study was to demonstrate the effect of positive reinforcement, specifically, social reinforcement (SR), on the frequency of eye, hand, and back injuries at four experimental salt mines. Injury data was collected from January, 1976, for the prePOMOST period and from the onset of training to September, 1978, for the post-POMOST period. All data was collected on a month-by-month basis. For the training period approximately 100 managers and supervisors from five plants were trained in the use of positive reinforcement for occurrences of "safe behavior." Each supervisor was also provided manuals and other supportive materials. Additionally, following training, all supervisors were provided some coaching experience to keep the knowledge and capabilities gained during training from being extinguished. The analysis showed significant injury reductions in two sites and no injury reductions in the other two. When the injury data was corrected for the additional man hours expended in the postPOMOST period, a third site showed reduction in injuries. Similar findings were shown when the experimental sites were compared to other sites in the industry. The results were interpreted to support the hypothesis that the application of social reinforcement is related to a reduction in injuries.

Jan 1, 1978

By M. Orchin

THIS PAPER is concerned with two aspects of the behavior of coal: (1) Dispersion by solvents atmospheric pressure and high temperature and (2) the destruction and regeneration of the coking properties of coal. Several pure polycyclic compounds and a coal-tar fraction were found to extract 95 percent of the organic material of a bituminous coal. About 20 percent of the extract was soluble in benzene, and this fraction contained the ?coking principle? of the coal. From an extensive chemical spectroscopic, and x-ray study of the benzene-soluble material, some conclusions could be drawn concerning the composition and structure of this fraction of coal. A possible commercial application of the extraction technique is in the preparation of low-ash carbonaceous material for the manufacture of electrode carbon.

Jan 1, 1951

By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldwell Counties in western Kentucky. According to the latest available statistics, this district supplied 1/5,960 short tons of fluorspar in 1937, compared with the total domestic production of 181,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds. The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldrell Counties in western Kentucky. According to the latest available statistics, this district supplied 165,960 short tons of fluorspar in 1937, compared with the total domestic production of 151,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By Will H. Coghill, C. O. Anderson

In July 1921 , we were assigned by the U. S. Bureau of Mines to an investigation of milling methods in the Tri - State zinc district ( Missouri -Kaneas- Oklahoma district ) . The work has progressed without interruption , and about onehalf of the funds allotted for it has been expended . This preliminary statement abcut the nature of the work and the results so far obtained , has been prepared for the information of the operators , and through their assistance to insure the greatest possible progress during the remainder of the work . A general survey of the district was made , and many of the mining companies cordially offered the facilities of their plants for the investigation . The work was finally centralized at the plant of the 0. M. Bilharz Mining Co. Its manager , F. H. Gartung, and his successor , O. W. Bilharz , have been especially helpful , also the millmen at this plant and elsewhere have rendered assistance without which the work could not have advanced . The Missouri School of Mines and Metallurgy , Rolla, Mo. , and the Miami School of Mines , Miami , Okla . , have given hearty cooperation . The Webb City Iron Works and the Joplin Supply Co. donated some necessary apparatus .

Jan 1, 1922