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By Albert W. Deurbrouck

The performance of four sand cones was evaluated by the Bureau of Mines in three preparation plants that utilized cones in various flow schemes. The cone at plant A was a simple two-product one that provided clean coal and refuse. Plant B had two cones; one cone made a primary separation and the other a secondary separation. The primary cone separated salable coal from heavy rejects. The secondary cone separated a low-ash metallurgical coal and an intermediate-ash product suitable for plant fuel or steam markets. In plant C the sand cone was equipped with a middlings draw Which continually removed an intermediate specific-gravity product below the surface of the cone. The three primary separations of raw coal effected between floats and sinks were excellent. The recovery efficiencies for the plus 1/4-inch material ranged from 99.8 to 97.6 percent, the error areas ranged from 19 to 23 square centimeters, and the probable errors in specific gravity ranged from 0.033 to 0.024. The performance data of the two secondary separations varied from excellent in plant B, where the separation was on a par with the primary separations, to somewhat inferior in plant C, where the secondary separation was effected at the middlings draw.

Jan 1, 1965

By Green R. E.

The removal of silica from commercial iron oxide concentrates by dissolution with sodium hydroxide was investigated by the Bureau of Mines as a means for producing supergrade concentrates. The effects of strength of solution, temperature, and digestion time on the extraction of silica were evaluated using eight iron oxide concentrates. Silica extraction from the eight concentrates was enhanced by autoclave leaching in the temperature range of 150° to 250° C and varied from 70 to 95 pct depending on the concentrate used. Superconcentrates containing less than 2 pct Si02 and more than 69 pct Fe were made only when magnetite concentrates were leached in the autoclave. The investigation showed that it is not difficult to obtain a supergrade product if the gangue is mainly quartz.

Jan 1, 1973

By R. M. Santmeyers

This paper presents one of a series of digests of foreign mining legislation and curt decisions that is being prepared in advance of a. general report relative to the rights of American citizens to explore for minerals and own and operate mines in various foreign countries. This interpretation of the mining legislation of Madagascar was prepared from the best information (in French) available in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers, to whom it dill be referred through the courtesy of the Department of State. INTRODUCTION The basic mining law of Madagascar is the decree of 1923, signed at Rambouillet by the President of France on July 19, and published in the Journal Official de Madagascar et Dependances. It has been modified by a number of subsequent laves and regulations, generally of minor importance.

Jan 1, 1933

By John Paul Gries

During World. War II, when the curtailment of imports led to an unprecedented demand for domestic mica, beryl, spodumene, and other pegmatite minerals, the Bureau of Mines and the Geological Survey entered upon a program designed to expedite mining of these minerals from the Black Hills area of South Dakota. The program involved napping, sampling, and drilling of many pegmatite dikes in the southern portion of the Black Hills and beneficiation conducted in the field and in the Bureau of Mines laboratories at Rapid City, S. Dak., Rolla, Mo., Salt Lake City, Utah, and College Park, Md. This report describes the occurrence and sampling of the Beecher No. 2 pegmatite, which was investigated as part of the general pegmatite study in South Dakota. Investigation of the Beecher No. 2 pegmatite was started on November 20, 1943, and terminated in the spring of 1944. During this period, the Bureau of Mines took a series of trench samples across the pegmatite at the surface for grain-count studies and chemical analyses. The Geological Survey mapped the geology of the deposit after it was exposed by trenching and stripping.

Jan 1, 1950

By L. H. Johnson

"INTRODUCTION The Pennsylvania anthracite industry produced 53 million net tons of anthracite during 1945. Fifty-one million tons was prepared for the commercial market (3), 3/ and 2 million tons (consisting of fine sizes) was used for colliery power consumption. Of the number of tons prepared for market, 17 million tons (33 1/3 percent) was prepared by the use of acid mine water treated with lime.Mine water from underground workings is pumped, drained, and stored in huge quantities. The mine-drainage systems in the anthracite region handle over 200 billion gallons of water annually, of which 150 billion gallons is pumped to the surface. More than 69 billion gallons of water is impounded in underground pools (1). Much of this water is employed for breaker use, dust-control installations; hydraulic backfilling, combatting mine fires; and aiding in the transportation of anthracite in gently dipping places where sheet iron is used Roos(4) estimates that 1,100 gallons of mine water is utilized in the preparation of anthracite mined."

Nov 1, 1946

By Fred N. Kissell

Air recirculation caused by dust scrubbers at coal mine working faces was examined by the Federal Bureau of Mines with regard to the potential hazards caused by a possible buildup of methane gas. A theoretical analysis indicated that there was no apriori way to predict the effect of scrubber recirculation on methane concentration levels. Experiments conducted in a full-scale model of a working face area indicated that methane levels were dependent to a great extent on the location of the scrubber exhaust, but that the scrubber recirculation did not substantially increase the methane concentration above those levels that would have prevailed were the scrubber not in operation. An analysis of two underground scrubber trials showed that the scrubbers had no significant effect on methane levels, and a review of explosions attributed to recirculation showed that these were characterized by a lack of fresh air as well as recirculation. It was concluded that high methane levels are due more to a lack of fresh air than to recirculation.

Jan 1, 1975

By C. Watson Owings

"The mining Industry in the United States is becoming fully cognizant of the hazards of dust in underground mining as well as in surface plants. The dust problem in metal mines has been brought to focus through knowledge of the harmful effects of dust, especially silica, and through adoption of more or less stringent legislation classifying certain types of pneumoconiosis as occupational diseases. The coal-mining industry is aroused principally by the apparently great increase in the dust-explosion hazard resulting from the rapid growth of mechanized mining. The United States Department of the Interior, through the Safety. Division of the Bureau of Mines, has been requested repeatedly to recommend methods of allaying dust in both coal and metal mines. Methods adequate under hand-mining conditions fail to effect satisfactory reduction of dust in more rapid extraction with modern equipment. Studies of methods and equipment for allaying dust are being conducted in both metal and coal mines. Results of these studies are discussed, and indications of possible means of reducing dust concentrations are presented in the hope that the health and 'safety of men employed in the mining industry may be increasingly safeguarded.DUSTThe term ""dust"" is a common one, and yet the meaning is applied to widely different particle sizes. The general term means ""earth or other matter reduced to fine, dry, and powdery particles."" The root from which the word is derived means ""something that can be blown about by the wind."" As a result of tests on the explosibility of coal, the Federal Bureau of Mines has arbitrarily defined dust as being. ""that which will pass through a 20-mesh screen,"" based upon the fact that particles coarser than 20-mesh have little influence on the development of an explosion of Pittsburgh coal-bed dust. The study of dust, from a health standpoint, has given rise to still another definition of dust, namely,- according to Drinker3/, ""solid particles ranging in size from less than 1 micron to about 150 microns."" A micron is 1/25,400 inch, and 150 microns are approximately 1/1,700 inch. Atmospheric dust usually is considered as 10 microns or less, larger particles not being counted under the microscope in determination of dust concentrations."

Apr 1, 1942

By Paul W. Jeran, Michael A. Trevits, William P. Diamond

In this U.S. Bureau of Mines study, production trends have been analyzed for 82 gob gas ventholes on 7 longwall panels in the Lower Kittanning Coalbed, Pennsylvania. Cumulative production from individual holes was found to vary considerably, ranging from 0.03 x 106 to 10.1 x 106 m3. Peak production rates were generally about 0.03 x 106 to 0.06 x 106 m3/d, but rates over 0.10 x 1@ m3/d were observed. The variability of gas production from individual holes can be attributed to several factors, including completion practices and problems, the extent of fracture development in the strata above the extracted panel, water production, and location on the panel. Of particular significance is hole location. Holes on the ends of the panels, where overburden strata are in tension because of the support of the surrounding pillars, were generally the highest and longest producers. This observation led to the experimental placement of gob gas ventholes in the zone of tension along the margin of a panel, instead of in the traditional centerline location, which is in compression. Analysis of 7 months of gas production data indicates that the experimental near-margin holes produced 77 pct more gas than did centerline holes on the same panel.

Jan 1, 1994

By S. H. Denny

"As the result of the work of an efficient safety organization, the Midwest Refining Co. at its various operations and particularly in the Salt Creek field has been able to show a definite accident reduction. Lost-time accidents during the past year have been reduced to a small number as compared with previous years, and infection cases have been almost eliminated.The accident-prevention work of the Midwest Refining Co. is in charge of the department of industrial relations, with a director as the administrative head; two safety men handle the work directly at Midwest, Wyo. A competent medical staff with a well-equipped hospital at Midwest is also an important factor in the prompt and proper treatment of injured persons when an employee is injured, he is given first-aid and then taken to the hospital with minimum delay.About 1,450 persons are employed in the 4 departments (production, gas, pipe lines, and electrical) and in the 34 districts of the Midwest Refining Co. The work at Midwest spreads over a considerable area, and new drilling operations, pipe work, and similar activities require the services of many small gangs of workers. Complete supervision, of each job, whether shall or large, is possible through the large number of superintendents, foremen, and gang pushers employed; thus, there are 20 superintendents, 78 foremen, and 115 gang pushers. The largest number of men under any one toss is approximately 15, and it is probable that much of the good safety record is due to this intensive supervision. These company officials, including the gang pushers, have been impressed with the idea that it is their duty to see that the men under them do not get hurt; the responsibility of instructing new employees in safety practices is placed directly upon them. Monthly meetings of the field officials, including superintendents, foremen, and gang pushers, and as far as possible the men, of each district are held with the safety engineer. Both officials and men are encouraged to bring up for discussion any practice or proposals looking to the changing of any conditions that will"

Apr 1, 1928

By Fred L. Bishop

This paper describing the methods employed in the purchasing and supply departments of the Miami Copper Co., Miami, Ariz., is one of a series being prepared for and published by the United States Bureau of Mines on office practice in mining operations. GENERAL DESCRIPTION The Miami Copper Co.'s plant is located about 1 mile from the town of Miami, in the Globe-Miami Mining District, Gila County, Ariz. The property consists of a complete mining plant, concentrator, high-pressure steam power plant, and many other attendant structures. In normal times the company employs about 1,500 men, and mines and mills about 6,000,000 tons of ore annually.

Jan 1, 1932

By H. C. Ko

Calorimetric determinations of low-temperature heat capacities and the standard enthalpy of formation were made by the Bureau of Mines for aluminum sulfide, A12S3. The standard entropy (S°), enthalpy of formation (?Hf°), and calculated Gibbs energy of formation (?Gf°) at 298.15 K are 27.93±0.05 call deg-mole, -155.6±0.9 kcal/mole, and -153.0±1.0 kcal/mole, respectively.

Jan 1, 1976

By M. R. Geer

The use of the cyclone as a dense-medium cleaning device was first described by Driessen6/ in 1945, after development of the process in the Netherlands during the German occupation of World War II. A pilot plant was built in the Netherlands soon thereafter, and the first commercial plant was built in 1948. By 1958, 18 plants were operating or under construction.7/ Thus, economic factors in Europe, where the high cost of coal places a premium on efficient cleaning, dictated rapid adoption of the cyclone. American reception of the process differed. The Bureau of Mines presented the results of its own small-scale cyclone experiments in 1946;8/ showing a sharp separation between coal and impurity; adoption by industry now is taking place. There is now much greater emphasis on the efficient cleaning of fine coal, and the first American cyclone plant has begun operating; others are planned or under construction. With the present interest in improved treatment of fine coal, the Bureau of Mines felt that additional performance data on the cyclone would be helpful to industry. Therefore, a complete, open-circuit pilot plant was built to make cleaning trials on American coals covering a wide range of washability characteristics. Five raw coals and one middling product were included in the investigation, and each was cleaned at several densities; 17 cleaning trials are reported.

Jan 1, 1961

By Victor E. Kral

"SUMMARYFollowing a magnetometer survey on the McCoy iron deposit, a trenching and drilling program was carried out by the Bureau of Mines in August 1944.This deposit is 32.3 miles southwest of Battle Mountain in the McCoy Mining District, Lander County, Nevada, and lies on the east flank of the Fish Creek Mountains at an altitude of 5,400 feet, about 1 1/2 miles south of the gold camp of McCoy.Total production from the deposit has been 400 tons of magnetite, mined by hand and shipped to the west coast for ship's ballast.Bureau drilled two holes to a total depth of 92 feet and excavated 12 feet of trenches. Both holes were drilled in the same ore body and engineered magnetite ore 14 and 11 feet thick. Trenching was used successfully to show the lateral limits of the ore.Magnetite ore bodies were found to occur as replacements of a limestone bed in quartzite. They outcrop near and parallel to the exposure of a diorite entrusting that forms a long westward-trending ridge. Although magnetic outcrops can be traced for 5,000 feet trenching definitely proved the ore bodies to be disconnected to have little or no lateral extent beyond their outcrops. Only two ore bodies more than 10 feet thick were found; one of these is the inaccessible to and the other was drilled by the Bureau."

Jan 1, 1947

By C. N. Rosenecker

The power required to circulate a gas-solids suspension was determined using a centrifugal compressor and a closed system. The suspension consisted of 18- to 40-micron glass beads in a mixture of 89 percent N2 and 11 percent CO2 at 20 psig. Solids-to-gas (S/G) ratios w re O to 2.2 lb/lb; gas flow rates were l.2 to 2.5 lb/min. Power requirement was found to follow the relationship hp t = hp(. + l), where hp t = the total power, and hpg = the power required for pure gas.

Jan 1, 1967

By R. V. Higgins

This report presents the results of a study of water injection in the HX sub-pool fault block V-B, in the Upper Terminal zone, Wilmington field, California, and is based on data obtained to May 1957. An earlier report3/ describes the results of gas injection in part of the field. The principal purpose of the pilot flood was to determine whether a sand having a permeability of 1,200 millidarcys and containing oil having a viscosity of 17 centipoises could be waterflooded effectively. The results of a preliminary study by engineers of the Long Beach Harbor Department of oil recoveries from areas where encroaching edgewater was active and the results of an independent study by a consultant retained by the Long Beach Harbor Department were favorable to a trial waterflood. After these preliminary studies, a detailed petroleum-engineering exam-ination was made of the technical details. As a result, a peripheral flood was started in June 1953. The peripheral flood was deemed desirable because the producing wells are bottomed a short distance from the edgewater. The HX subpool was selected for the pilot test because it is an isolated section of the Upper Terminal zone and is separated from the adjoining pools by faults on the east and west and by edgewater on the north, south, and west. Several petroleum-engineering methods were applied to evaluate the performance of the waterflood, and all showed that injecting water stimulated oil production.

Jan 1, 1958

By Boyd Guthrie

The current use of Mid - Continent crude oil for the manufacture of war products , such as aviation gasoline and lubricating cil , has caused an acute shortage of available supply from established sources . Therefore , refiners who heretofore have had no reason to use West Texas crude oils now are considering them as charging stock and need more information concerning their characteristics . The Bureau of Mines has published several reports3/ giving analyses of the most important of these crude oils . However, to make the applicable data in these publications readily available to refiners , the present compilation of analyses of West Texas crude oils has been prepared . Data showing the effect of catalytic desulfurization of naphthas from West Texas crude oils have been presented in a restricted Bureau of Mines Report of Investigations . These analyses were made under the general supervision of R. A. Cattell , chief, Petroleum and Natural Gas Division, Bureau of Mines , Washington, D. C. , and N. A. C. Smith, supervising engineer , Fetroleum Experiment Station, Bureau of Mines , Bartlesville, Okla . , and under the direct supervision of Harold M. Smith, senior petroleum chemist, Bartlesville , Okla .

Jan 1, 1944

By Stephen Krickovic, J. E. Carpetta, T. D. Moore

Air quantity-pressure and methane concentration surveys were conducted by the Bureau of Mines in accessible portions of an area being pillared in a Pittsburgh coalbed mine in West Virginia. These included two mined-out and three active butt headings and a bleeder system. The particular mine workings were started in virgin coal directly from a set of main headings; the main reason for the study was the difficulty usually encountered in adequately bleeding the gobs under such conditions. Although the two separate return airways in each active butt heading and the North and 1 Left bleeders contained acceptable methane concentrations (0.01 to 0.78 percent in the butts and 0.73 to 1.0 percent in the bleeders) with significant total methane removal (109 cfm in butts and 631 cfm in bleeders), there were relatively large areas in the gobs with possible minimal airflows. This condition appears to have developed from lack of systematic regulation of the airflow across the gobs and appears to indicate the existence of considerably more methane in the probably low flow areas in the gob.

Jan 1, 1973

By S. A. Matthes

This Bureau of Mines report describes analysis of a copper slag for 13 elements from a single sample solution by flame atomic absorption spectroscopy. Samples are dissolved with 7 ml of an HC1-HF-HN03 (3:1.5:2) mixture in heated plastic pressure vessels. A 1.5-pct boric acid solution is added to dissolve precipitated fluorides and to reduce matrix effects that interfere with atomic absorption analysis. Preparation time is less than 1 hour per batch of 10 samples. Total analysis time is less than 6 person-hours for 130 determinations with an average relative standard deviation of 1.83 pct for the 13 elements. Simple acid standards were used for all determinations. Values obtained by this method are in excellent agreement with values obtained by slower, more costly procedures.

Jan 1, 1980

By Frank J. Wiebelt

In its efforts to maintain production of tungsten during the recent war period, the Bureau of Mines explored certain parts of the properties of the Atolia Mining Co. in San Bernardino County, Calif., by diamond drilling. Owing to past production record and other available data, the area was considered attractive for possible development of new ore bodies. Scheelite occurs in narrow veins ranging in width from a fraction of an inch to several feet. The veins are in quartz monzonite in a zone 2 miles long and 500 feet wide. Production from the district was reported to have been over 1,000,000 units of W03. Twelve diamond-drill holes, totaling 5,056 feet, were drilled by the Bureau of Mines in the vicinity of the Papoose, Papoose No. 5, Amity, and Union mines, the tailings pond, and the "Old Spud Patch." The work began in August 1943 and was completed in June 1944. This publication briefly describes the history and deposits of the district and gives full details of the work performed by the Bureau.

Jan 1, 1950

By Glenn C. Reed

"Preliminary examination of the Glass Buttes mercury deposits, Lake County, Oregon, was made in August 1945 at the request of W. S. Lazier, present lessee of the deposit.Most of the prospect openings in the area were inspected. The more significant workings were sampled and napped in detail. This report presents the data obtained from the investigation to date.In its program of exploration of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch, Lowell B. noon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples and performs beneficiation tests. Both these branches are under the supervision of Dr. P. S. Dean, assistant director.Special acknowledgment is due to S. H. Lorain, chief, Albany Division, Mining Branch and to S. R. Zimmerley, chief, Salt Lake City, Utah, Metallurgical Division, for analyses of the ores.The presence of quicksilver in the Glass Buttes district has been known since about 1930. The area immediately north of Middle Butte has been superficially prospected by numerous test pits, trenches, shafts, and short adits, which revealed a number of opalized zones. Many of these opalized zones contain weak to strong concentrations of cinnabar. The area has not boon explored thoroughly; no mercury has been produced from any of its deposits.A block of 48 full-size claims has been located to cover a large part of the area in sections 34 and 3, Tps. 23 and 24 S.,R. 23 E.,W.M. These claims, held by, location are owned by H. S. Miller, lumberman of Bend, Ore. W. S. Lazier, 10N. W. 20th Avenue, Portland, Ore., currently controls the property under,a nominal leasing agreement. J. W. McDaniel, 44 Lake Place, Bend, Ore., has done much of the underground and surface exploration on the property.The Glass Buttes district is an area of low relief in the Deschutes River drainage system near the northeast corner of Lake County, Ore. (See fig. 1.) The arid climate is marked by extremes of winter and summer temperature. Water for cane use is not available in the immediate area. Well water, however, can be obtained in limited supply on ranch property 5 miles to the south."

Aug 1, 1946