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By Paul W. Johnson, Ralph C. Kirby, Frank A. Peters

Alumina can be recovered from clay , using 30 percent nitric acid for digestion . Calcined clay is crushed and then digested at 325 ° F and 85 psig pressure with less than stoichiometric nitric acid required to form normal aluminum nitrate . In this way , a solution containing both normal aluminum nitrate , Al ( NO3 ) 3 , and basic aluminum nitrate , assumed to be Al ( OH ) ( NO3 ) 2 , is formed , and in which iron is virtually insoluble . The solution is filtered and then concentrated in vacuum evaporators to crystallize normal aluminum nonahydrate . The crystals are washed with 50 percent nitric acid and then decomposed to alumina and nitrogen oxides . The design that has been developed for this process is based on published work . For a plant producing 1,000 tons of alumina a day , the estimated operating cost is $60.69 per ton of alumina , and the estimated fixed capital cost is $ 76 million using a Marshall and Stevens chemical equipment index basis of 240.0 . This process is not competitive under current economic conditions with the production of alumina from bauxite via the Bayer process . For lowering costs , future research should include study of leaching at lower temperatures under atmospheric pressure and alternate aluminum nitrate decomposition methods .

Jan 1, 1964

By John P. Savage

This paper is one of a series being prepared by the United States Bureau of Mines on tunneling methods. The tunneling methods described are those used at the Ojuela unit of the Compania Minera de Penoles, S. A., the Mexican subsidiary of the American Metal Co., Ltd., of New York. The Ojuela unit is situated some 4 miles southeast of Mapimi, Durango. Mexico, the latter place being connected by a 15-mile narrow-gage railway with the standard gage railroad at Bermejillo, some 40 miles to the north of Torreon, the location of one of the company's smelters.

Jan 1, 1931

By Alfred L. Ransome

The plan to develop a standard system of names and definitions of regions and districts in Alaska was borne of the need for a tool to use in statistical and economic studies of the mineral industry of the Territory. The purpose of this report is to present to the mineral industry, and to those individuals interested in the mineral or allied industries in Alaska, the system used by the Bureau of Mines in connection with its legal function of collecting and disseminating mineral statistics. It is hoped that the specific descriptions given will result in a more complete understanding of what is meant by the regional and district names that appear in publications of the Bureau of Mines relative to the mineral industry of the Territory. Problem of Standardization of Names and Definitions The question might be asked, does the naming and defining of regions and districts in Alaska present a problem relative to the establishment of a standard? Is it necessary to establish a standard?

Jan 1, 1954

By D. O. Hamiltion

The ISMS program provided for the development and demonstration of equipment modifications in both conventional and continuous coal mining systems. This report describes activities during the demonstration of the conventional equipment and includes machine performance, results of data gathering, system evaluation, and recommendations for implementing improvements.

Jan 1, 1976

By J. M. Mutmansky

"The objective of this study was to produce coal dusts for laboratory research that are similar to mine airborne dusts in chemical, mineral, and physical characteristics. In this investigation, dusts produced in laboratory comminution equipment were compared with continuous miner- generated dust for similarity in physical characteristics. Mining-generated dust (MGD) and bulk coal samples were first collected from an underground mining operation. The bulk samples were then processed in the laboratory for size reduction in various comminution devices. These laboratory- generated dust (LGD) samples were subjected to size and microscopic analyses. Physical properties of the dust particles were studied on a scanning electron microscope (SEM ). A numerical shape coordinate system (SCS) was also developed and applied to 300 particles from each sample. Statistical analysis was then performed on the collected data and characteristics of the MGD and LGD samples were compared. IntroductionIn many biomedical studies, researchers routinely introduce a dust mass into an experimental environment to assess the response of a biological entity, usually lung macrophages in vitro or a live laboratory animal, to the dust mass. To provide data of maximum usefulness, it is highly desirable to use dust with characteristics of actual mine airborne dust. The primary objective of this research was to produce dusts in the laboratory similar in chemical, mineralogical, and physical characteristics to mine airborne dusts. This paper outlines the evaluation of the physical characteristics of the lab-generated dusts.Particle shape analysis is perhaps the least-developed area in mineral-related particle science and technology. There are still no standard methods or instruments to scientifically quantify particle shapes. To date, many attempts have been made to characterize particle shapes. These procedures can be roughly classified into three categories:"

Dec 1, 1995

In September 1985, the Chairman of the Transportation, Aviation and Materials Subcommittee of the House of Representatives requested that the Director of the Bureau of Mines address the issue of South Africa and critical materials dependency in testimony before the Subcommittee. Subsequent to the testimony, the Bureau has prepared a technical report focusing on the importance of South Africa and, in some cases, its neighboring countries as suppliers of six key materials. The report includes a qualitative analysis which examines the supply shortfall resulting from a potential disruption, options that are available for mitigating the impact, and their likely effectiveness, and quantitative analyses which estimate the economic impacts in the chromium and manganese markets resulting from peacetime disruption scenarios specified by the Subcommittee Chairman. The concluding section treats the role and capabilities of the Bureau of Mines in dealing with mineral supply disruptions.

Jan 1, 1986

By G. R. Hopkins

Although many small refineries were dismantled in 1934 the total number of plants, including a few under construction, increased from 604 at the beginning of the year to a new high of 638 on January 1, 1935. The capacity also reached a new record, the total of 4,072,400 barrels of crude oil daily being about 45,000 barrels higher than the previous high of January 1, 1932. The number of refineries increased materially in 1933, following construction in east Texas and the building of many small plants in the Rocky Mountain district and elsewhere. Most of the new plants of 1933 were built to provide an outlet for crude or because the ratio between crude oil and gasoline prices appeared conducive to profits However, low gasoline prices and increased costs in 1934 dispelled the hopes for profits; many plants were shut down, and some were dismantled. The number of operating plants declined from 454 on January 1, 1934, to 435 on January 1, 1935, but the number of inactive plants increased from 137 to a new high of 196 during the same period. As indicated above, new construction was at a minimum in 1934, and on January 1, 1935, only 7 plants were being built.

Jan 1, 1935

By Kenneth M. Earl

This report describes the results of a field study conducted by the Bureau of Mines during 1956 and 1957 on manganese-and iron-bearing mineral deposits in the southern district of Aroostook County, Maine. The work was undertaken to determine the extent of deposits largely concealed under glacial drift and to obtain subsurface samples for manganese mineral identification and research in ore dressing and extractive metallurgy. The investigation was confined to the Westford Hill-Daggett Hill area in Hodgdon Township and to the Stewart prospects and vicinity in Linneus Township. Over 50 magnetic anomalies were mapped by magnetometric surveys in the Westford Hill-Daggett Hill area, Hodgdon Township. The largest anomaly, as outlined by the 1,000-gamma contour, indicates a deposit 3,200 feet long with a maximum width of 350 feet. The smallest anomaly measures about 10 feet wide by 25 feet long.

Jan 1, 1962

By Raymond M. Stateham

Climatic conditions are compared with roof fall occurrence from April 1, 1972, to December 31, 1975, by the Bureau of Mines. These comparisons indicate that humidity has a strong influence on roof fall occurrence rates. Cubic regression techniques are used to develop best fit curves. Statistical analysis of these curves indicate that both are sinusoidal and exhibit positive correlation with each other. The sine waves have a period of 1 year with maximum and minimum inflection points in August and February.

Jan 1, 1978

By J. Koster

During the past several years, alunite from the Marysvale (Utah) region has been the subject of investigation by the Electrometallurgical Section of the Bureau of Mines. The nature and occurrence of this mineral, with considerable data on the Utah deposits, together with a number of results of preliminary experiments, have been given in a previous report.6/ The geology of the Marysvale region has been reviewed recently.7/ The present paper reports the results obtained by a method involving the sintering of alunite with boric acid and subsequent treatment of the sinter to produce alumina and potassium sulphate.

Jan 1, 1939

By Jack I. Paige

In this Bureau of Mines study, two fluidized-bed reactors were designed, built, and operated, one as a sorber for S02 and the other as a contactor for the regeneration of the sulfur-laden alkalized alumina. The target of 90 percent removal of S02 from a flue gas stream containing 0.3 percent S02 was attained by using a sorbent feed of 10-15 grams per minute into a 5-inch bed depth of alkalized alumina. The sorption unit was operated at about 330° C. Complete regeneration of the laden alkalized alumina containing 5 to 10 percent sulfur was accomplished in approximately 1/2 hour. An excess of reformed propane at about 730° C was the regenerating gas. Attrition losses, a major problem with this sorbent, ranged from 0.9 to 7.9 percent of the inventory. Data from these tests demonstrate, within experimental error, the validity of equations developed from short-term, thin-bed tests related to sorption and regeneration rates.

Jan 1, 1970

By Kenneth L. Kreamalmyer

"The demand for open-hearth iron ore and the existence of suitable smelting facilities in the St. Louis area seemed to warrant investigation of several Missouri iron-ore deposits of the filled-sink type. Preliminary examinations were made in the autumn of 1944 by an engineer3/ of the Bureau of Nines, and in December of the same year funds were allotted for the exploration of these properties by churn drilling. Three properties, the Silver Hollow Bank and the Newbauer and Coleman properties, were drilled. Work was completed May 8, 1945.The Federal Geological Survey and the Missouri Geological Survey and Water Resources assisted in the project by determining the stratigraphy from drill cuttings and by mapping the drilled areas.The properties explored are in the hilly section of east-central Missouri and are connected by all-weather graveled roads with various shipping points of the St. Louis-San Francisco Railway system within 3 to 6 miles of each property.The Silver Hollow Bank, in sec., 8, T, 40 N., R. l W. Franklin County, Missouri, is in the Meramec State Game Reserve. The nearest town and shipping point is Sullivan, Mo„ which is 6 miles distant. The Newbauer property, in sec. 28, T. 41 N., R, 2 W., Franklin County, Missouri, is approximately 3 miles west of Stanton; The Coleman property, in sec. 14, T. 38 N., R. 3 W., Crawford. County, Missouri, is within a short hauling distance of the railway at Elayer, Mb. These are shown on figure 1.The region surrounding the explored areas contains a series of low-lying hills or ridges and narrow winding valleys drained by the Meramec River system. These hills seldom rise more than 200 feet above the valley floors, most of which are approximately 700 feet above sea level. Except for numerous small farms and a few small towns, the entire region is covered by a dense growth of timber and small brush. The St. Louis-San Francisco Railway system, U. S. Highway 66, and numerous all-weather State and county roads traverse the area."

Oct 1, 1945

By Joe B. Rosenbaum

New applications and concepts of solvent extraction as a unit operation in extractive metallurgy have been developed in the last decade. Wider use is being made of established solvent extraction techniques in processing spent nuclear fuel elements and in winning columbium-tantalum, hafnium-zirconium, thorium, tungsten, uranium, and vanadium. Commercial application has been extended to recovery of beryllium, boron, bromine, copper, molybdenum, phosphorus, rare-earth metals, and rhenium. Systems in use and proposed typically extract metals or salts as anion, cation, or neutral species from aqueous media by reaction with a recycleable organic reagent.

Jan 1, 1971

By Alan D. Hartman

Standard metering of electric arc furnaces usually uses root mean square (RMS) or true root mean square (TRMS) measurements for determining power. Only sinusoidal signals are accurately described by RMS meters, and dc or high-frequency components normally are lost in standard TRMS metering. This can lead to inaccuracies when electrical signals are not sinusoidal, contain dc components, or include fast risetime perturbations, as is the case with the electric signals from an electric arc furnace. Electric arc furnace electrical waveforms, observed in research carried out by the U.S. Bureau of Mines, show high-frequency components and significant deviations from sinusoids. These perturbations and distortions make metering difficult for standard power meters. The inaccuracies in metering can cause further problems if those sensors are used in control systems. For control strategies requiring rapid response, any averaging scheme loses information that can be used in control decisions. In order to obtain better signals for both monitoring and control, a study of instantaneous, RMS, and TRMS power monitoring devices was conducted. From this study it was concluded that precision integrated circuits should be used to obtain instantaneous power with a bandwidth of at least 25 kHz. The information from these devices is more representative than that of standard meters and can be used in predictive control.

Jan 1, 2010

By J. Fletcher Smoak

Consumption of abrasive materials in the United States decreased 23% in value from that of 1981 to $262 million, of which 53% was manufactured abrasive, 39% was industrial diamond (natural and synthetic), and 8% was natural abrasive. Production of natural abrasives, excluding industrial diamond, appeared to be stable when compared with that of 1981. Production of tripoli, a porous siliceous rock, increased slightly after decreasing steadily over the three previous years. The production increase of garnet, an abundant iron-aluminum silicate, was attributed to increased output from one plant that had completed an expansion program in late

Jan 1, 1983

By James F. Neill, O&apos

Investigation of the Gilley fluorite deposit was based upon examinations made by several of the Bureau's mining engineers. Fluorspar was found in the dump talus of sloughed and water-filled trenches and shafts, and there were indications that faulting or other dynamic distortions favorable to deposition of this mineral in minable quality and quantity might exist. The inference was based upon a field study of the area and its comparison with fluorspar deposits in Kentucky. The proximity of this deposit to the iron furnaces at Gadsden and Birmingham was a factor that influenced its investigation, as the demand for metallurgical grades of this critical mineral is acute. The present supply for the district is obtained from out-of-State sources, and the value of any local deposit would be enhanced by the saving in freight charges. The Gilley fluorspar deposit is 17 miles east of Gadsden and 50 miles northeast of Birmingham, Ala. Mineral deposits occur as thin veinlets and small bunches of fluorite in upturned bode of siliceous limestone. The ore-bearing structure is a reverse fold, and the mineral deposit appears as a replacement along crumbled zone fractures of the contorted limestone.

Jan 1, 1950

By Jon K. Ahlness

The Bureau of Mines conducted laboratory and field experiments to determine tne amount of permeability reduction in uranium sandstone after its exposure to different drilling fluids. Seven polymer and two bentonite fluids were laboratory-tested in their clean condition, and six polymer fluids were tested with simulated drill cuttings added. Sandstone cores cut from samples collected at an open pit uranium mine were the test medium. The clean fluid that resulted in the least permeability reduction was an hydroxyethyl cellulose polymer fluid. The greatest permeability reduction of the clean polymers came from a shale-inhibiting synthetic polymer. Six polymer fluids were tested with simu-lated drill cuttings added to represent field use. The least permeability reduction was obtained from a multipolymer blend fluid. A field experiment was performed to compare how two polymer fluids affect formation permeability when used for drilling in situ uranium leaching wells. For this test, the polymer fluid with the best laboratory results (multipolymer blend) was compared with a commonly used polymer fluid (guar gum) that gave poorer laboratory results. When fluid injection rates for the four wells drilled with the guar gum were compared with those for the four drilled with the multipolymer blend, no statistically significant difference was found.

Jan 1, 1984

By J. Robert Wells

The Bureau of Mines has developed a spectrochemical procedure for determining 19 impurity elements in high-purity titanium metal, titanium oxides, and titanium halides in which all samples are converted to titanium dioxide. Determination of these impurities was studied in the general concentration range of 0 to 1,000 p.p.m., but different determination limits were found for the various elements. The procedure is quantitative for 18 elements but semi-quantitative3 for beryllium and has an overall relative standard deviation of 15.8 percent. Two mixtures were used, one composed of graphite and lithium carbonate plus gallium oxide and the other of graphite and lithium carbonate plus germanium dioxide. Each mixture was blended mechanically with an equal weight of titanium dioxide. Lithium carbonate served as buffer-diluent. Gallium was the internal standard for 1 impurity element, germanium for 7, and titanium for the remaining 11.

Jan 1, 1962

By C. M. Keenan

During the 7-1/2 years (January 1945-June 1952), immediately preceding enactment of the Federal Coal Mine Safety Act, 26 major disasters3/ in the coal mines of the United States caused the deaths of 491 persons. In the next 7-1/2 years under the act (July 1952-December 1959), only 12 major disasters occurred. The total killed was 148. This improvement is commendable. However, the continuing frequency of minor fires and gas and/or dust ignitions in the Nation's coal mines, many of which could have been of major consequence, are cause for serious concern to the coal-mining industry and those affiliated agencies engaged in promoting safety in the industry. The data presented in this report have been prepared to make available to the coal-mining industry and related groups an overall perspective of the disaster potential from mine fires and gas and/or dust ignitions in coal mines after 7-1/2 years under the Federal Coal Mine Safety Act. This act, effective July 16, 1952, which amended the original Federal coal-mine investigative act of May 1941, provides under Title II certain enforcible mine-safety provisions designed to prevent major disasters caused by explosions, fires, inundations, and man-trip and man-hoist accidents in coal mines that employ 15 or more individuals underground.

Jan 1, 1960

By Catharine T. Fogg

The U.S. Bureau of Mines investigated the availability of platinum, palladium, and rhodium from 16 deposits in four market economy countries (MEC's). Major recoverable products include 164 Moz of platinum, 80 Moz of palladium, 13 Moz of rhodium, 24 Moz of ruthenium, 4 Moz of Iridium, 2 Moz of Osmium, and 10 Moz of gold. The 12 deposits in the Republic of South Africa are estimated to account for 96.7 pct of total recoverable platinum. The base-case scenario estimates the long-term cost of production including recovery of capital, but provides no return on the investment or O-pct discounted cash-flow rate of return (DCFROR). The total production costs in January 1990 U.S. dollars ranged from $325/oz to $1,288/oz of platinum compared to an average January 1990 price of $492/oz. Approximately 83 pct of total recoverable platinum was economic at a cost level of $4S0/oz or less. At the IS-pct DCFROR, only 26 pct of total recoverable platinum was economic. For platinum-group metals (PGM), attention has been focused on the ratios of the three primary metals: platinum, palladium, and rhodium. Sensitivity analyses were performed to determine the impact long-term rhodium price increases could have on the total cost of production for platinum and palladium.

Jan 1, 1993