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By E. J. Matson

Under the investigation for critical and strategic minerals the Kaiser mine, formerly the Baxter fluorspar property, in northeastern Mineral County, Nev., was explored. The work comprised excavating 32 trenches averaging 90 feet in length, 8 feet in width, and 1 1/2 feet in depth. The trenches were excavated across the strike of the ore body to enable the engineer to spot the diamond-drill holes; 7 such holes were drilled, aggregating 3,276 linear feet. A total of 20 core samples and 107 sludge samples was taken. The work under this program indicated that the fluorspar southwest of the deposit extended laterally and also at depth at least 250 feet below the 400-foot level. INTRODUCTION The Kaiser fluorspar deposit is in the northeastern portion of Mineral County, Nev. Mining was begun about 1928, and the property has been a consistent producer of both Acid- and Metallurgical-grade fluorspar. The mineralized zone has been developed along a strike length of about 2,000 feet and to a depth of over 700 feet along the dip.

Jan 1, 1957

By P. S. Haury

"INTRODUCTION Preliminary examinations of the Mohawk zinc prospect were made by John 14. Price and the author in July, August, and September 1943. Considerable quantities of oxidized lead and zinc minerals were found in old shallow work¬ings along two faults - one an over thrust fault with Paleozoic limestone in the hanging wall overlying Cretaceous shale and arkose in the footwall of the fault, and the other a bedding fault in the Paleozoic limestone.The chances appeared good for finding important lead-zinc sulfide ore bodies at 200 to 300 feet beneath the surface, so exploration in three steps by the Bureau was recommended:Surveying, mapping, and character sampling of the outcrops with topographic and geologic mapping of the immediately surrounding area.Preliminary drilling of four test holes, aggregating about 1,500 feet, to locate the top of a possible sulfide ore zone and determine the thickness and intensity of the sulfide mineralization.Contingent upon favorable results of the second step, diamond drilling of about 6,300 feet of additional hole to explore the sulfide ore bodies.The outcrops were surveyed and sampled, a topographic map was made of the area, and the geology was mapped. A project was set up for preliminary drilling of step 2 in the fiscal year 1944-45. An access road to the drill sites was built in April 1945. Diamond drilling was started on April 28 and completed on September 25, 1945, under the supervision or the Bureau of Mines. The exploratory work is covered in this report."

Oct 1, 1946

By Herman W. Sheffer

This report describes and discusses present-day leaching technology employed to recover copper from low-grade mine and dump materials derived from the exploitation of copper ore deposits in the Western United States. Illustrations of the integral parts of the leaching, precipitation, and recovery operations at several copper-producing companies are presented. Schematic drawings are included to present typical flowsheets of leaching and precipitation operations. Operational problems common to most copper leaching and precipitation plants are discussed. Areas of present and future research to improve leaching techniques are cited.

Jan 1, 1968

By W. W. Adams

Because of insufficient funds for printing, the Bureau of Mines was unable to publish its annual bulletin covering accidents at metal mines in the United States for the year 1933. A brief mimeographed summary of the principal statistical data for that year was released to the public late in 1934. Since then reports for 1934 have been received from the mining companies, and in order to avoid further delay in releasing this information to the mining industry and others interested in the prevention of accidents in mining, statistics for both years are presented in this publication with a minimum of interpretation and comment. The fatal-accident rate for the metal and nonmetallic mines (excluding coal mines) of the United States was more favorable in 1933 than in any previous year since 1911, the first year for which the Bureau of Mines obtained reports from the operators. Further progress was made in 1934, when the fatality rate was even lower than that of 1933. On the other hand, the nonfatal-accident rate, which had reached its lowest level in 1932, increased in 1933 and increased further in 1934, although not to such an extent as to prevent the rate for either of those 2 years from being better than that for any year previous to r1931.

Jan 1, 1936

By L. O. Bacon, H. R. Joesting, J. H. Getz

"INTRODUCTION For a number of years manganiferous iron ore has been mined on a small scale at Boston Hill, in Grant County, N. Mex. Total production up to 1943 is estimated to be over 793,000 long tons, containing 8 to 35 percent manganese and 26 to 46 percent iron. 4/ During 1941 to 1943 production was estimated to be 206,000 long tons, containing about 13 percent manganese and 37 percent iron. During 1944 daily production was several hundred tons, mostly from a single open pit. Several moderately large deposits have been mined: and many smaller ones have been found.From February to April 1945 geophysical surveys were carried out on Boston Hill by the Division of Geophysical Exploration, in cooperation with District 5, Central Region, Bureau of Mines, to determine if hitherto undiscovered manganiferous iron deposits exist. Field work was interrupted for a total of about 1 month during this period by work on other projects in nearby areas. Previous to the geophysical surveys, a preliminary examination was made by H. R. Joesting to determine if geophysical methods could be utilized in exploring the area. 5/Field measurements were made by L. O. Bacon and J. H. Getz, project geo¬physicists of the Bureau of Mines, under the general supervision of H. R. Joesting. A grid survey of the area, to locate geophysical stations, was made by Paul Russell, Bureau of Mines engineer, who also collected specimens for laboratory tests. Most of the computations and the preliminary magnetic and resistivity maps were made by L. 0. Bacon."

Feb 1, 1948

By D. N. Tallman

The electrokinetic properties of MgO have been utilized to simultaneously filter suspended solids and remove trace amounts of dissolved heavy metals from synthetic mine water. Greater than 95 pct removal of metals from influent at neutral pH containing 1 to 6 mg/L of dissolved Cd, Cu, Mn, Ni, and Zn can be routinely achieved by filtering through a granular bed of MgO at flow rates typical of rapid sand filtration (0.3 cm/s). Filtrate concentrations of most metals can be maintained below 0.1 mg/L for 160 bed volumes or more loading. The more mobile metals (those with larger solubility products) are more difficult to remove, and are strongly bonded to the MgO granules so that chemical stripping with chelating agent is required to clean the bed. Less mobile ions are easily removed by the filter and are effectively stripped by conventional filter backwashing. The fraction of metals recovered by chemically stripping the loaded MgO filters correlates to the zero points of charge of the metals. This process may be applicable to removal and recovery of trace amounts of heavy metals in mine drainage that is partly neutralized by liming. Also, since many of these metals are critical and strategic, the technique can be adapted not only to recycle process water from mineral and milling waste streams, but also to reclaim their metal values.

Jan 1, 1986

By Haskiel R. Shell

Methods of chemical analysis of clays for the following constituents are presented: moisture, ignition loss Fe2O3, TiO2, P2O5, CaO, MgO, Na2O, K2O, total. carbon, carbonate carbon total sulfur, soluble salts, and soluble sulfate. In these procedures the attainment of accuracy has been the primary consideration sample was taken to insure accuracy, with ordinary precautions. The procedures may therefore be somewhat somewhat and will not be suited for routine work on samples for which the approximate analysis is already known and in which the need for accuracy is not very exacting. However, the method shod be as a set of detailed directions, that have been tested and shown to yield accurate results with clays and other aluminum silicate minerals. Among these minerals are clays of all types, bentonite bauxite, shale, brick; soil, calcined refractory, and sand. Although some of the methods are Unusual, no particular claim is laid to originality. The material was drawn frail many sources, put together and tested.

Jan 1, 1949

By P. S. Jacobsen

In 1960 over 93 percent of the coal cleaned mechanically in the United States was cleaned in processes that utilized water or dense-medium suspensions of fine solids in water. Thus, in the process of removing deleterious ash-forming and sulfur-bearing minerals, another deleterious substance--water-- is added to the coal. The subsequent removal of the water from the coal, and the concomitant recovery of the coal from the water, is not troublesome in the sizes coarser than 1/4-inch. In the finer sizes, however, it is a difficult procedure that often costs more than the original washing operation. Because of the importance of liquid-solids separation in coal preparation, the Bureau of Mines has a continuing program of research in this field. The objective is to make available information on the performance characteristics of various types of equipment available for liquid-solids separations, thus promoting the wise selection of equipment for specific applications, and, thereby, more effective processing of coal. Results of work on flocculation as an aid to filtration5 and the sieve bend screen6 have been published. The present investigation of the screw-type classifier operating in combination with the cyclone was undertaken primarily because such classifiers are comparatively new to coal preparation and information on their performance is not available. The cyclone has become well-known since its introduction in this country by the Bureau of Mines in 1948.7 Use of the cyclone in conjunction with the screw-type classifier represents an attempt to provide the maximum recovery of solids at minimum moisture content.

Jan 1, 1962

By Thomas C. Ruhe

The Bureau of Mines conducted research to determine the safe operating conditions for using recycled (used) lubricating oil from mining equipment as a partial replacement for diesel fuel to make ANFO-type blasting agents. The use of recycled oil (RO) saves energy, reduces oil imports, and reduces mining costs. Low ambient temperatures may cause these recycled oils to become too viscous for proper absorption by ammonium nitrate (AN) prills and result in poor blast performance, safety hazards, and environmental problems. To help quantify and resolve these issues, viscosity, mixing, and performance tests were conducted at various temperatures. Diesel fuels No. 1 and No. 2 were studied separately and in blends with 25,50, and 75% RO. Good quality ANFO mixes (94-6) were produced with dry absorbent prills and blended fuel (No. 1 diesel plus RO) at temperatures as low as -40°F (-40°C) with 75% No. 1/25% RO, and at -20°F (-29°C) with 50/50. Diesel fuel No. 2 also made good mixes as low as -30" F (-34°C) with 75% No. 2/25% RO, and at 0°F (-18°C) with 50/50.

Jan 1, 2008

By J. M. Riley

The Bureau of Mines investigated a promising new technology for recovering A1203 from alunite to support the Bureau's alumina miniplant project. Results are presented for a study of the technical feasibility of treating alunite crushing and grinding reject fines for recovery of A1203. Alunite pellets having sufficient strength and resistance to degradation were produced by combining fines and coarse alunite with a KOH binder. The best pellets were prepared, in a laboratory pelletizer, by adding 1 pct KOH as a 5-pct solution to a mixture of 40 pct alunite dust (98 pct minus 65 mesh) and 60 pct coarse alunite (minus 20 plus 65 mesh). Calcines suitable for K2SO4 and A1203 recovery were produced by reducing dehydrated alunite pellets with sulfur in a laboratory shaft furnace for 4 h at 600° C, followed by air oxidation of the reduced calcine for 1 h at 600° C. This report presents design calculations, schematic diagrams, and discussions of the essential features of a proposed process research unit (PRU)--a continuous, 6-lb/h alunite shaft furnace--for studying the process.

Jan 1, 1983

By Donald P. Blasko

The Bureau of Mines investigated two areas of oil and gas seeps in the north-central Gulf of Alaska--Katalla River to Bering River and Cape Yakataga to Yakutat Bay to determine (1) whether previously reported seeps are still active, (2) the characteristics of the seeping hydrocarbons, and (3) the amount of bitumen contained in the drainage leaving the seeps and entering the Gulf of Alaska. Thirteen separate oil seeps, six bitumen deposits, and eight gas seeps were located, sampled, and analyzed. The oils ranged from 35.2° to 14.1° API gravity and had sulfur contents from 0.53 to 1.31 wt-pct. Bitumen samples had API gravities from 2.4° to 14.6° and sulfur contents from 0.28 to 0.88 wt-pct. Gas samples had specific gravities ranging from 0.577 to 0.883 and caloric values from 724 to 1,427 Btu/cu ft. A total of 63 water samples obtained from seep locations and seep drainages were analyzed by atomic absorption spectrophotometry for ionic content and by solvent extraction for hydrocarbon content. Although some of the water at the oil seeps had a bitumen content as high as 246,000 mg/1, the amount of hydrocarbons actually reaching the Gulf of Alaska averaged <0.2 mg/1.

Jan 1, 1976

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 John W. Cole

As part of a general preliminary investigation of lead-zinc deposits in Stevens County, Wash., the Electric Point and Gladstone mines on Gladstone Mountain, in the Northport Mining District, were examined by R. M. Gammell, an engineer of the Bureau of Mines, in June 1946. A trenching and sampling program was executed later the same year under&apos; the supervision of Miro Mihelich and the author. This report presents the factual data obtained from the trenching and sampling operations.

Jan 1, 1949

By Chas. F. Jackson

During the past 5 years the Bureau of Mines has published information circulars dealing with mining methods and costs at 78 ore mines; 7 circulars, each of which is devoted to a discussion of one of the principal mining, methods; and 23 circulars dealing with special phases of mining, such as ventilation, shaft sinking, tunnel driving, the cost of equipping and developing prospects and small mines, underground transportation, diamond drilling, and ground support. These circulars were written by many different authors, and in order that the method of presentation and the basis for compilation of data might be the same in all the papers the Bureau drafted an outline to be followed in their preparation. To clarify the data in these circulars, which are in the libraries of many engineers and mining companies, and the summarized data presented in this paper, that portion of the outline dealing with cost and labor-performance data is reproduced below.

Jan 1, 1934

By J. W. Thompson

"The recent discovery and exploitation of petroleum territory have resulted in the enactment of new petroleum laws in most of the South American Republics. The activities in the discovery of these new fields were engendered by the knowledge of the fact that present producing fields must within well defined periods be exhausted. Oil operators were willing to take the initial steps in exploitation in the absence of legislation that applied strictly to petroleum operations. The enactment of modern legislation in many of these Republics encouraging and protect¬ing exploitations may cause tremendous oil activities in these countries, and the results may be comparable with the magnitude of the undertakings and the prestige of the companies now entering this territory.These, oil fields are admirably located for convenient distribution of petroleum by water to all the Nations using oil as fuel for shipping and industrial concerns. The oil markets of the western coast of South America will derive immense benefits from the Panama Canal. This navigation route brings these markets into direct ocean shipment with the Atlantic coasts of the Western and Eastern Hemispheres.One deterrent to oil production in the Republics of South America is the want of inland. transportation facilities, but the recent laws of these Republics without exception provide for acquiring rights of way for pipe lines and other modes of transportation; and doubtless the great interests and. syndicates already operating in these regions will, as production increases, provide ample pipe line transportation sufficient to convey to the coast the oil produced. It way be assumed, from the legal guarantees afforded, and from operating equipment and machinery that are now being concentrated that refineries will be erected at shipping points for the purpose of making these petroleum products accessible to the world."

May 1, 1921

By J. M. Stuve

Low-temperature heat capacities and the enthalpy of formation were deter-mined calorimetrically by the Bureau of Mines for CuO?CuS04. The derived standard entropy (S°298.15) was 40.36±0.04 cal/deg-mole, and the enthalpy of formation (?H°f) was -219.l±0.3 kcal/g-mole. A large thermal anomaly was observed in the heat capacity of CuO?CuS04 at 20±0.1 K. Gibbs energy of formation data are tabulated up to 1,200 K. Construction details of a precision low-temperature adiabatic calorimeter capable of determining heat capacities of solids in the temperature range 5 to 320 K are given. A calibrated miniature germanium resistance thermometer was incorporated into the calorimeter to extend the range of accurate measurements below 15 K. High-resistance dc heater windings were used throughout the cryostat to reduce heat conduction of inner connecting wires.

Jan 1, 1975

By Gary L. Hundley

The Bureau of Mines has devised and demonstrated an ammoniacal sulfate leach process for recovering nickel and cobalt from low-grade domestic laterites. Solvent extraction of cobalt, one of the process steps, requires the reduction of hexammine complexes of C03+ to C02+ in an ammo-niacal leach solution. Previously, reduction was accomplished using cobalt metal shot in a column. This report presents experimental results and an economic evaluation comparing two alternate techniques with the shot column: (1) an electrolytic reduction cell with an extended surface area cathode and (2) direct electrowinning from purified leach solution using a cell with a fluid bed cathode. The second alternative eliminates the conventional solvent extraction-electrowinning steps. The costs of the three methods, based on the requirements of a pro-posed commercial-sized plant, including all unit operations, were deter-mined by the Bureau&apos;s process evaluation group. The operating costs for the shot column, $1.19/kg Co, and for electrolytic reduction, $1.20/kg, are essentially the same, but the cost of direct electrowinning, $3.77/ kg Co, would eliminate this method as a practical alternative. The cap-ital cost of approximately $14.4 million for reduction in a shot column is much higher than the approximately $4.4 million for electroreduction.

Jan 1, 1985

By H. E. Heide

The serious shortage of domestically produced asbestos during the war prompted the Bureau of Mines to investigate reported asbestos deposits in Alaska. The most promising&apos; appeared to be these in the Cosmos Hills and Jade Hills areas along the Kobuk River in northwestern Alaska. The deposits along the west side of Shungnak River, a tributary of the Kobuk River, were the first to be investigated by the Bureau, in the summer of 1944. Four bulldozer trenches were excavated, from Which a 2-ton sample was taken. This sample was shipped to Rolla, Mo., for testing in the Bureau of Mines laboratory. In the summer of 1945 an investigation of asbestos deposits on Cosmos Creek, also a tributary of the Kobuk River, was begun; the work was completed during the field season of 1946.

Jan 1, 1949

By J. B. Vander Sande, L. C. Rainey, P. Bolsaitis, B. Dirsa

"The structure and composition of silica-rich particles recovered by lavage from the lungs of three active miners with different medical histories were studied using high-resolution electron microscopy and chemical microanalysis. The results arc compared to the similarly determined structure and composition of respirable-size mineral particles obtained from roof-bolter dust-box samples from two coal mines of widely different bulk quartz concentrations. The results show that the lungs of the miners contain silica-based particles with structures not found in the mine samples. Also, the particle structures and compositions found in the macrophages were different in each of the miners. The rau.lu suggest the possibility that intracellular processes may affect the susceptibility of individuals to silica-induced pneumoconiosis. The cytotoxic and fibrogenic potentials of mine dusts result from the activity of their individual components. Whether this effect is additive or even mass (i.e., dose) related is questionable and has been the subject of many investigations. Particle size and size distribution of various constituent minerals, the surface structure and properties of individual particles, and the self-cleaning capability of the lung (i.e., the capacity of the macrophage system) may, among other variables, affect the pathogenic changes induced by dusts lodged inside lungs. Extensive epidemiological investigations conducted on miners from different coalmining districts, where equivalent dust exposures have been shown to result in vastly different frequencies of lung disease incidence, also confirm this hypothesis (1) In a recent study, Ferrer et al. (2) used energy-dispersive X-ray analysis (EDXA) to investigate the inorganic element content in pleura and lung in reference, silica exposed non-pneumoconiosis, and silicotic populations. Constant depositions of silicon and calcium were detected in visceral pleura, parietal pleura, and lung of the refence group and in visceral pleura and lung of the exposed non-pneumoconiosis and silicotic groups. Comparison of the silicon content in pleura between silicotic and exposed non-pneumoconiosis subjects showed a nonsignificant probability of difference, whereas there were no differences with respect to the silicon content in lungs."

Dec 1, 1995

By M. W. Pullen

It is recognized that the determination of electrical resistivity of the earth within a given area may furnish information concerning the location of certain mineralized strata of economic importance. Present knowledge of the electrical resistivity of the various rock formations is almost nil, and the geophysicist who is detailed to make a survey of an area without any data as to the relative resistivity of the underlying rocks is greatly handicapped. Such surveys are usually made within areas known to contain mineral deposits to aid in locating desirable points for drilling. Usually these areas have been prospected by diamond drilling, and drill cores of the various rocks and ores are usually obtainable. Were it possible to make resistivity tests in a laboratory of the drill cores or from pieces of the rocks and ore within an area before attempting a field survey, this would indicate not only the advisability for such a survey but would aid considerably in the interpretation of the results of such a survey. To be of most value a definite method should be used for all such tests, and as yet such a method has not been established.

Jan 1, 1929