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By John R. Bitler

The Bureau of Mines conducted this study to provide information concerning the availability of and the demand for construction-mineral aggregates in the Baltimore, Md., Standard Metropolitan Statistical Area (SMSA). The demand is discussed with reference to the area's current consumption and estimates of the area's demand for aggregates through 1990. Estimates of aggregate supply are presented in conjunction with an examination of the geology of the area, the availability of substitutes, and the effect of transportation costs. A discussion of the constraints affecting aggregate availability precedes the conclusions and recommendations. The availability of aggregates is subject to geologic, economic, and political constraints. As of January 1974, an estimated 20,100 million tons of stone was available to meet the demand projected through 1990 (188.7 million tons). An estimated 139 million tons of sand and gravel was available to meet the demand projected through 1990 (84.3 million tons). Several alternative actions are available within the area to insure the adequacy of the stone supply and to increase the supply of sand and gravel: (1) The establishment of special mineral resource zones; (2) the application of sequential land use techniques; and (3) the exploration of previously undeveloped regions.

Jan 1, 1975

By W. J. Wuest

This U.S. Bureau of Mines report presents an overview of ground control considerations associated with cutter roof failure. Many of the relevant U.S. and international research studies since the late 1940's are reviewed, and summaries of recent design guides are included. Factors affecting cutter roof, such as underground stress field and rock structure around the entry, are described. Strata control techniques are also outlined. These techniques are divided into three sections: artificial support, mine structure design, and multiple-seam extraction. Other subjects covered in the report include monitoring and prediction, effect of geologic features, and mapping of adverse mining conditions. The emphasis of this report is on practical considerations; theoretical discussions are minimal.

Jan 1, 1994

By W. K. Tolley

The Bureau of Mines is testing super critical fluids as solvents to selectively extract valuable components from complex matrices. Materials recovered during supercritical fluid extraction are often highly purified. Using laboratory apparatus designed specifically for supercritical fluid research, Bureau re-searchers have measured the solubility of titanium tetrachloride (TiCI4) in supercritical, liquid, and gaseous carbon dioxide (C02), CO2, a commonly used supercritical fluid, is inert, inexpensive, and nontoxic. Supercritical CO2 formed a single phase with TiCl4 at 45° C and 1,500 psig. When the solution was heated at constant pressure beyond 55° C, TiCl4 precipitated from the fluid. Results showed that TiCl4 solubility in supercritical CO2 is not controlled by the vapor pressure of the solute.

Jan 1, 1989

By R. O. Kneisley

This U.S. Bureau of Mines report summarizes a study of large-scale strata response to longwall mining at a western U.S. coal mine. This study utilized surface and subsurface measurements, geologic mapping, in situ stress measurements, and pressure cell readings to characterize strata behavior. Preliminary analysis of surface subsidence and time-domain reflectometry (TDR) was used to determine a suggested main roof caving sequence. Coal ejected from the face apparently resulted from brittle failures that occurred because of lack of significant yield zone development. The combination of a strong coal with pronounced directional behavior, low overburden pressures, a good caving roof, and a high-production environment that minimized time-dependent loading apparently reduced yielding of the longwall face. The panel 1 headgate-entry design appears adequate; however, the abutment pillar and adjacent panel tailgate rib are highly stressed and may contribute to problems during second panel mining. The small chain pillar yielded after passage of the face, but the pillar width may be near maximum since evidence of a stressed core exists.

Jan 1, 2010

By R. V. Holmes

The properties of the Colorado Copper Co. in Sinbad Valley, Mesa and Montrose Counties, Colo., were rehabilitated and sampled by the Bureau of Mines in October, November, and December 1942. The several deposits were reexamined in March and April 1945 to obtain information disclosed by company work after December 1942. The development program included surface trenching, rehabilitation of several edits, and channel sampling of the exposures. Assay determinations wore made on 204 samples from the surface and underground workings. The results are given in the appendix. Several copper deposits in the Sinbad Valley area are similar in origin. The host rocks are sedimentary and mice in age from Pennsylvanian to Cretaceous. The Colorado No. 3 deposit occurs in the Cutler formation, which consists of many small lenses of conglomerate, sandstone, and shale. Mineralization is closely associated with faulting. On the Pyramid group the enrichment occurs in a zone of fracturing and jointing end also spreads into the adjoining sandstone. The ore deposition on the Copper Rivet claim is associated with a fault zone and is confined to en area above the contact of the Dolores-Wingate formations. Mineral deposits on the Sinbad claims occur at intersections of faults with blue-gray Pennsylvania limestone. Copper enrichment occurs along faults and as replacement of the surrounding limestone. Metallurgical tests indicate that ores from the Colorado No. 3 and Pyramid claims can be treated successfully by leaching with sulfuric acid. This method cannot be applied to ores from the Copper Rivet or Sinbad deposits because of high calcite content. Flotation tests at Boulder City, Nev., showed a recovery of less than 60 percent with a 14.24 percent copper concentrate.

Jan 1, 1952

By Michael E. Henderson

Presented in this report are the experimental results of coarse coal slurry degradation data obtained from the Hydraulic Transport Research Facility (HTRF) at the Pittsburgh Research Center (PRC), Bruceton, PA. The facility is operated by Boeing Services International, under Bureau of Mines Contract No. J0333956. Presented in this report are the experimental results of coarse coal slurry degradation data obtained from the Hydraulic Transport Research Facility (HTRF) at the Pittsburgh Research Center (PRC), Bruceton, PA. The facility is operated by Boeing Services International, under Bureau of Mines Contract No. J0333956. This particle degradation report is a summary of the particle distribution data obtained at the HTRF for the period 26 November 1982 to 1 October 1983. The testing covered herein is for coarse Pittsburgh Seam coal in the 6-in (150 mm) and 12-in (300 mm) pipelines, at velocities ranging from 5 to 18 ft/s (1.5 to 5.5 m/s), and at concentrations by weight ranging from 15 to 55 pet. Particle size distribution samples were taken systematically throughout the testing.

Jan 1, 1985

Prevention of coal-mine explosions depends largely upon thorough knowledge of the causes that initiate explosions. A review of coal-mine explosions in one geographical area when supplemented by nationwide data of similar nature, should serve as a guide for the adoption of measures for explosion prevention. Explosions in bituminous-coal mines of the United States during the 10 years ended December 31, 1932, ranked third in the causes of fatal accidents and constituted 16.1 percent of all fatal accidents in bituminous mines. Kentucky now ranks fourth in coal output in the coal-producing States of this country; a study of the coal-mine explosions in this state will be of definite interest locally among coal-mining people, as well as to those in the coal-mining industry who are concerned in preventing coal-mine explosions. This circular reviews gas and dust explosions in Kentucky coal mines to show their hazards, to point out the influence of certain factors in causing explosions, and to indicate the effectiveness of preventive measures.

Jan 1, 1934

By E. C. Lane

[The motor gasoline that s being marketed in the United States this summer slightly more volatile then that sold a year ago. This increase in volatility is shown by a general lowering ref the average distillation rang, of about 2°F. During the post 10 years the Bureau of Mines has made semiannual surveys of the gasoline marketed in the United States, the survey just completed being the twentieth in the series. The 12 cities in which samples were collected have beer chosen as representative of the more important marketing territories, as it is obviously impracticable to obtain a sample of every gasoline sold in the entire country.]

Jan 1, 1929

By Stephen M. Jasinski

The development and industry adaptation of advanced technologies have led to many important uses for bismuth and its compounds. Bismuth-base alloys are essential for manufacturing jet engine turbine blades, lenses, and various safety devices, such as fire-protection sprinklers. The addition of bismuth to iron, steel, and aluminum imparts properties to these metals that makes them useful in diversified applications. Bismuth is also used widely in medicine, pigments, and electronics. The United States relies heavily upon imports from South America and Europe to meet its demand for bismuth, which is recovered chiefly as a byproduct of lead processing.

Jan 1, 1992

By R. Van A. Mills

Crude oils are capable of dissolving quantities of gas under pressure. This fact has been known for some time, but questions have arisen as to the effects of gas in solution upon the characteristics of the oil. Previous investigations4 show that gas in solution in an oil affects the viscosity and surface tension of the oil, but the effect's on the volume and A. P. I. gravity of the oil have not been known. The results given in this report show that there is a decided change both in volume and in the A. P. I. gravity of the oil due to the solution of the gas in the oil under pressure. As gas is dissolved, the volume of the oil and the A. P. I. gravity increase. The converse of this phenomenon is also true: if the gas is released from a saturated oil, there is a shrinkage in volume and a decrease in A.P.I. gravity due to the release of gas from solution. However, various oils show marked tendencies to retain a portion of the dissolved gas upon releasing the pressure to that of the atmosphere. This retained gas has an appreciable effect on the volume and A. P. I. gravity of the oil because the oil does not resume its initial volume or gravity while it retains dissolved gas. In a sense the oil has been "Freshened" and will not return to its original or weathered volume until it loses some of the lighter fractions. Wiggins5 has shown that a fresh oil decreases both in volume and in gravity because of the weathering of the lighter fractions while the oil is standing in storage tanks.

Jan 1, 1928

By D. R. Tesarik

Displacement and stress changes in cemented backfill and ore pillars at the Buick Mine, near Boss, MO, were monitored by engineers from the U.S. Bureau of Mines and The Doe Run Co., St Louis, MO. A test area in this room-and-pillar mine was backfilled to provide support when remnant ore pillars were mined. Objectives of this research were to evaluate the effect of backfill on mine stability, observe backfill conditions during pillar removal, and calibrate a numeric model to be used to design other areas of the mine. Relative vertical displacements in the backfill were measured with embedment strain gauges and vertical extensometers. Other types of instruments used were earth pressure cells (to identify loading trends in the backfill), borehole extensometers (to measure relative displacement changes in the mine roof and support pillars), and biaxial stressmeters (to measure stress changes in several support pillars and abutments). Two-and three-dimensional numeric codes were used to model the study area. With information from these codes and the installed instruments, two failed pillars were identified and rock mass properties were estimated.

Jan 1, 2010

By C. R. McCann

The Bureau of Mines conducted an experimental study of conditions needed to produce flames of pulverized coal when the heat needed for ignition is sup-plied only from the flame and hot furnace refractory. An electrically heated furnace which burned about 1 pound of coal per hour was designed and fabricated. A sheath of air, surrounding the primary coal and air stream, was used to prevent entry of hot gases from recirculating combustion products. Furnace temperatures needed for ignition ranged from about 1,8300 F for an Illinois coal to 2,250° F for a Beckley seam coal. Apparent flame velocities were about 2 to 5 feet per second, increasing with volatile content of the coal and with distance from the burner mouth to the flame. The time required for ignition, approximately 0.02 to 0.07 sec, was a better measure of flame behavior than was velocity.

Jan 1, 1969

By Thomas Fraser

IN a Nation-wide appraisal of coking-coal reserves and of the feasibility of expanding them by upgrading marginal coals, it is natural that the Pittsburgh region of Pennsylvania should be considered first. Here, where the American iron and steel industry started, the Pittsburgh coal bed is of paramount importance. The use of coke in iron blast furnaces is said to have begun with the discovery that good blast-furnace fuel could readily be made by a simple method of coking Pittsburgh coal. To the present time, the prosperity of the steel industry has depended largely on utilization of this great coal reserve and the cheap transportation afforded by the Monongahela River system. OBJECT AND SCOPE OF INVESTIGATION The initial project in the study of upgrading marginal coking coals was laid out in this area, which contains large reserves of Pittsburgh coal contiguous to the Monongahela and its navigable tributaries. Much of the Pittsburgh coal remaining here is known to have a high sulfur content. The problem of reducing the sulfur to meet metallurgical requirements already has received much attention, and it is considered to be one of the most difficult technologic problems in the field of coal washing.

Jan 1, 1950

By Gilbert M. Farrior

Tests of resistance to molten metals , to oxidation at elevated temperatures , and to various chemical reagents were made for a series of compositions in the TiB₂ - CrB₂ subsystem . In reaction with molten metals , there was no noticeable difference in reaction of the various compositions in the ( Ti , Cr ) B₂ series . The oxidation tests were ( 1 ) a rising - temperature test in which the specimen temperature was increased 4° per minute to 1,200 ° C and ( 2 ) a constanttemperature test in which the specimen temperature was held constant at 1,000 ° C. Compositions near Tio.6 Cro.4 B2 had the best oxidation resistance . Ti。.6 The chromium- rich alloys showed marked superiority to the titanium- rich alloys in resistance to corrosion by the chemical agents investigated . The chemical reagents used were sulfuric , nitric , and hydrochloric acids and sodium hydroxide of different concentrations .

Jan 1, 1964

By Robert J. Hundhausen, Robert M. Gammell

"INTRODUCTION Several mining properties in the Pine Creek area of the Coeur d'Alene mining region of Idaho were examined by engineers 3/ of the Bureau of Mines in 1942. As a result, a broad program of exploration was recommended for the area, particularly in the eastern end, where chances for the discovery of new ore shoots seemed favorable. This report describes the work done and the factual information obtained by the Bureau of lanes.ACKNOWLEDGMENTSIn 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 Be Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch,. C. C. Ralston, chief, analyzes samples and performs beneficiation tests.The exploratory work at the Sidney mine was part of the activities of the Albany Division of the Mining Branch, S. H. Lorain, chief. Field work was under the direction of R. M. Gammell.Chemical analyses included in this report were performed at Reno, Nov., under the direction of A. C. Rice, acting engineer in charge, Rare and Precious Metals Experiment Station, Bureau of Mines. The ore-dressing tests were made under the direction of S. R. Zimmerley at the Bureau of Mines laboratory in Salt Lake City, Utah.The cooperation and assistance given by the owners of the Sidney Mining Co. is gratefully acknowledged."

Feb 1, 1948

By Joseph B. Cummings

"Occurrences of fluorite on the Packard property were first examined by an engineer3/ of the Bureau of Mines in July 1943 as the result of receipt of an application for an access road. In August of the same year the showings were examined by a geologist4/ of the Federal Geological Survey. The property was again examined by an engineer5/ of the Bureau of Mines in March 1944. This last examination resulted in a proposal that access be gained by construction of a truck trail and that the Bureau of Mines undertake to explore the fluorite showings.The truck trail was constructed by the Public Roads Administration, which began the work on February 17, 1945, and completed it 8 days later.The Bureau of Mines exploratory program was completed on May 16, 1945. It consisted of stripping overburden, trenching, test pitting, tunneling, sampling, and topographic mapping.In addition to being described in some detail, the extent of the work as well as results are shown in accompanying tables and figures.Mrs. Rhoda A. Packard, Mrs. Nora 1. Cline, and C. B. Pettingill, all of Tonto Basin, Ariz., own the property, which comprises four contiguous, unpatented lode mining claims recorded at Globe, Ariz., as the Walnut and the Bluebird 2, 3, and 4. The claims are situated in T. 6 N., R. 11 E., Gila County. David L. Roscoe of Tombstone, Ariz., holds a lease and option to purchase.Access to the property is by Highway 88 from Globe, 34 miles to Roosevelt, thence 24 miles by a graded county road along the west side of Roosevelt Lake to Tonto Basin. Here the Greenback Ranch road, constructed by the Forest Service and maintained by the county, crosses Tonto Creek and continues easterly to the foothills. The truck trail leaves the road 8.5 miles east of Tonto Basin and runs 2.5 miles in a southerly direction to the property. (Fig. 1.)The fluorite deposits lie in and along a small canyon in a rough, rocky area at an altitude of about 3,400 feet, Vegetation is scant and of the usual desert variety. The summer climate is dry and hot and the winter climate moderate. Rainfall at the Forest Service Station in Tonto Basin was 11.4 inches from May 1944 through March 1945."

May 1, 1946

By A. C. Johnson, es Hol, E. O. Binyon

"INTRODUCTION AND SUMMARYThe tungsten properties of Lincoln Mines, Inc., and North Tem Flute Mining and Development Co. were first explored by the Bureau of Mines in 1942. Work on the project comprised trenching, sampling, a small amount of road and trail construction, and a small amount of core drilling. From April 13 to December 10, 1944, additional diamond drilling was done by the Bureau of Mines to test the lateral and downward extensions of the various tactite zones along the contact south of the Lincoln mine, including the property of the North Tem Piute Mining & Development Co.Claims leased by the Lincoln Mines, Inc., are in secs. 25 and 36, T. 3 S., R. 56 E.; secs. 30 and 31, T. 3 S., R. 57 E.: and sec. 1, T. 4 S., R 56 E., M. D. B. & M., in the Tem Piute Mining District, near the north end of the Timpahute Range in west central Lincoln County, Nev. D. B. Fegles is president of Lincoln Mines, Inc. and general offices are in the Wesley Temple Building, Minneapolis, Minn.In June 1945, the Atolia Mining Co. leased the property and purchased the mill and mining equipment from Lincoln Mines, Inc. P. R. Bradley is president of the Atolia Mining Co., whose offices are in the Crocker Building, San Francisco, Calif. This company surrendered the lease on the property on September 30, 1948. The property owners are continuing operations and are now engaged in building a 20-ton mill.The claims of the North Tern Flute Mining & Development Cc. are in sec. 1, T. 4 S., R. 56 E., M. D. B. & M. Merle F. Schofield is president of the company and maintains an office at Hike, Nev. These claims were leased by H. P. Laslett, of the Utah Nevada Mining Co., in 1945 and by the Atolia Mining Co. in 1946. The owners are now doing some exploratory work."

Jan 1, 1950

By R. B. Ladoo

"Present Situation:At the beginning of 1920 a general feeling of optimism was noted in many talc-producing districts. The industry seems to have recovered from the temporary depression of the first half of 1919 and many mills are running at capacity production with their entire output for 1920 contracted for. The imports of talc for 1919 were only slightly larger than in 1918 by weight and probably no more by value. Thus foreign competition has not begun to be seriously felt. Several new companies in this country have been organized, some to operate new deposits and others to continue the work done by others.An interesting phase of the present situation is the possibility of increased use of talc in paint. There is a shortage of barium sulfate used as a paint filler. Since, for some uses, talc is considered second only to BaSo4 as a filler for paint, it is possible that part of the shortage could be relieved by an increased use of talc.A series of physical tests upon all pigment materials used in the manufacture of paints is being conducted for the Paint Manufacturers Association of the United States. It is important that all types of talc be represented in these tests. Producers of finely ground talc, 200 mesh and finer, are urged to submit samples of at least two pounds each of these grades that are available to paint makers with trade name and quality data, to the Institute of Industrial Research, 19th & B Streets, N. W., Washington, D. C., where the tests are being conducted."

Jan 1, 1920

By Wesley T. Holmes

In this final stage of a three-part investigation of the smelting of titania-bearing iron materials, the Bureau of Mines conducted semicontinuous smelting tests in a laboratory electric arc furnace on four concentrates and one are. The objective was to substantiate the significance of liquidus temperature measurements in predicting satisfactory slag compositions in electric furnace smelting of titaniferous magnetites to produce pig iron. Previously obtained liquidus temperature data were used in determining flux requirements. Self-fluxing pellets of either ore or concentrate plus fluxes and reductants were made to produce pig iron and slags containing 0.2 to 0.6 percent titanium. Individual constituents of the slags generally agreed within 5 percent with the value of the corresponding constituent of target composition. Liquidus temperature of furnace slags generally agreed within 50° C of the value obtained from corresponding nominal synthetic slag. The results of the three phases of the investigation may serve as guide-lines for determining flux requirements in smelting a wide variety of titaniferous magnetites and other titania and iron-bearing materials.

Jan 1, 1969

By L. E. Green

For shortwall mining to be profitable, the additional capital investment of about $1 million for shortwall roof supports must be offset by decreased total operating costs and/or increased coal production. The Bureau of Mines therefore conducted a demonstration project to compare shortwall and room-and-pillar mining. Daily two-shift production from the bureau of Mines-Beth-Elkhorn Corp. shortwall demonstration n project averaged 975 tons of raw coal, compared with 905 tons from a room-and-pillar unit operating undo r similar conditions. The estimated direct operating costs for the shortwall and room-and-pillar unite were $4.21 and $4.03 pier ton, respectively. The profitability of the shortwall system was found to depend not only on the increased depreciation cost of the powered roof supports and the decreased cost of supplies and materials but also on such factors as the fixed and variable indirect costs and the selling price of the coal. Shortwall mining was demonstrated to be a viable alternative to room-and-pillar mining.

Jan 1, 1977