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By J. B. Umhau

During 1928 the United States consumed 73,270 long tons of virgin or primary tin, which was approximately 7.5 per cent more than the 68,198 long tons con¬sumed in 1927 and equaled 41 per cent of the world's production in 1928 (approximately 178,000 long tons). Consumers' stocks amounted to 9,268 tons on January 1, 1928, and 8,587 long tons on December 31, 1928, a net reduction of 681 tons. In addition to the virgin tin accounted for above, 12,106 long tons of secondary metallic tin were used by manufacturers of tin products in 1928. These figures are the result of an inquiry addressed by the Bureau of Mines to manufacturers to determine the amount of metallic tin used by them; in reply, 1,307 establishments reported consumption in 1928. The distribution of the amount consumed by various uses, as shown in the allowing tabulation based on Bureau of Mines canvasses for 1927 and 1928 in comparison with consumption by uses reported by the War Industries Board for 1917, emphasizes the fact that new uses for tin have been developed in only minor or insignificant amounts. Furthermore, although the studies for recent years show that some older uses have been discontinued, the amounts involved were all small and insignificant. Variation in consumption from year to year parallels the fluctuations in demand for the already well-established tin products. For example, the manufacture of bearing metals and solders for motor cars and trucks required 19,000 tons in 1928 compared to 16,000 tons in 1927; the canning industry continues to require the greater portion of the tin plate and also much solder. Growth in the electrical and the more recently developed industries (aeroplane, refrigerators, radio, etc.), while affecting total consumption of bearing metals, solders, etc., has made little change in the proportions required for these basic methods of using tin.

Jan 1, 1929

By Abdurrahman Cetinbas

The periphery of longwall panels in the Pocahontas No.3 coalbed is characterized by a zone of reduced permeability that inhibits the natural drainage of methane. A residual gas pressure of 105 psig was measured after 1 year in an isolated block of coal measuring 340 by 1,100 feet. The buildup of gas pressure within such large blocks causes methane problems during plowing operations. However, natural drainage holes drilled during development have been found to reduce the gas content of the coal in this coalbed by over 90 percent. The effect of water infusion on dust during plowing operations was investigated using existing methane drainage holes. These holes were cleaned of debris and a pipe was grouted into the hole for water infusion of the panel. Both total and respirable dust levels were reduced by 40 to 79 percent. Water infusion of the panel proved more effective than did the use of a plow-mounted spray system.

Jan 1, 1974

By R. L. Balmer

This information circular, which describes the methods and costs of sinking a small underground shaft with steel supports at the Keystone mine of American Smelting and Refining Co., near Crested Butte, Colo., is one of a series being prepared by the Bureau of Mines on current shaft-sinking practices in various mining districts of the United States. Preparations for sinking a combined exploration, development, and production shaft from the lowest level of the Keystone mine began early in 1957. This vertical, three-compartment, 6-1/4-by 16-foot rectangular shaft was to be sunk in separate stages or lifts so as to correspond with the progress of an associated lateral exploration and development program. The first section of the shaft was collared and sunk to a depth of 209 feet between September 1957 and April 1958. Because of the depressed base-metal market, the mine was shut down as soon as the initial phase of the exploration and development program had been completed and before any deeper sinking could be attempted.

Jan 1, 1962

By George S. Rice

In response to numerous requests for information as to the status of internal-combustion mine locomotives of the Diesel type that use heavy or non- volatile oil for fuel, with special reference to their safe use in coal mines, the United States Bureau of Mines is issuing this report. Data mere obtained, on application of such locomotives to cod mining only in Belgium, France, Germany, and Great Britain. The locomotives are used in coal mining in other countries, as well as in potash, iron, and other kinds of mining, but their chief development has been in coal mining in Germany, France, and Belgium. Recently popular interest in the Diesel type of engine for motive purposes was aroused in this country by the successful application of Diesel engines to railroad locomotives hauling fast transcontinental trains, and, according to published statements, at a low cost of fuel per mile of run.

Jan 1, 1936

By T. A. Henrie

A technique was devised for measuring the rate of chemical reactions between reactive metals and molten-salt mixtures at high temperatures. The rate of the heterogeneous reaction between high-purity titanium metal and titanium trichloride in molten sodium chloride was determined. The reaction is surface-controlled, and the heat of activation is 8.29 kilocalories per mole TiC13. An active site or reaction nuclei is created by adsorbing a TiC13 molecule at the metal surface. Reaction of the second TiC13 species forms an activated complex that decomposes into three TiC12 molecules.

Jan 1, 1963

By David A. Andrews

Coal occurs at many scattered localities in Arizona, California, Idaho, Nevada, and Oregon, but in most of the known occurrences thick coal beds are of small extent and the coal generally contains a high percentage of impurities. The coal beds occur at many different horizons in strata of Cretaceous and Tertiary age. Bituminous coal has been found in several areas, the most extensive of which is the Eden Ridge field of Oregon. Lignite also occurs in many places, but the only extensive deposit is in the Goose Creek field of Idaho, Nevada, and "Utah. The coal reserves of the region are largely of subbituminous rank; most of the subbituminous coal is in the Black Mesa field of northeastern Arizona and the Coos Bay field of Oregon. The Black Mesa field contains more than 80 percent of the coal reserves of all ranks but is remote from both transportation facilities and centers of consumption. Substantial reserves ill the Coos Bay field are favorably situated with respect to transportation and markets. ARIZONA Subbituminous coal occurs in the Black Mesa, Pinedale, and Gallup coal fields in Apache, Navajo, and Coconino Counties, Ariz. (fig. 1). Bituminous coal occurs in the Deer Creek field in Pinal and Graham Counties and in a small area in Apache County at the north-east corner of the State. All the coal beds are in strata of Cretaceous age. The coal in the Gallup field and at the northeast corner of the State lies in the Western edge of the San Juan structural basin. "Vest and south of this basin the coal-bearing strata have been removed by erosion except in high mesas.

Jan 1, 1947

By Eldon C. Pattee

Reconnaisance samples of reported beryllium occurrences in Idaho, Washington, Montana, and Oregon were chemically and spectroscopically tested in a mobile laboratory. The two predominant types of occurrences were green beryl associated with Cretaceous intrusions and disseminated aquamarine associated with Tertiary intrusions. Although the beryllium content of known deposits in the Northwest is too low for economic development at present, total submarginal-grade beryllium resources in pegmatites are estimated to be 570,000 to 1,870,000 tons containing 0.024 to 0.167 BeO. A potential source of 500,000 to 700,000 tons of beryllium-bearing tactite in Idaho and Montana averages 0.033 to 0.080 percent BeO.

Jan 1, 1968

By Roy E. Peterson

The Bureau of Mines conducted bench-scale research to evaluate materials which showed potential as low-cost reductants for use in the ironmaking industry. These materials were lignite, subbituminous coal, coal char, tree trimmings, refuse--derived paperboard, used crankcase oil, and peat. To compare their effectiveness, the materials were tested in the reduction roasting of nonmagnetic taconite and, except for oil and peat, in the reduction of iron oxide pellets to metallized pellets. Reduction was conducted in a 18-cm-diameter, rotary drum, which was externally heated in an electric furnace. Over 92 pct of the iron was magnetically recovered from a nonmagnetic taconite after roasting with any of the reductants, but greater quantities of reductant were required to achieve this when the waste materials were used. The fossil fuels were also more effective for metallizing pellets, although metallizations above 90 pct were also obtained with tree trimmings and refuse paperboard. However, refuse paperboard had to be frequently recharged to the furnace because it depleted rapidly.

Jan 1, 1983

By Charles M. Mason

The Bureau of Mines evaluated equipment and procedures for drop-weight testing of explosive liquids as prescribed by Test 4) a widely used method. It was demonstrated that partial ignitions, originally designated as negative results, should be designated positives; it was also shown that wear or erosion of the sample cups and the type of mount used for the apparatus had important effects on the results. Relative sensitivity as measured by Test 4 was found to vary slightly with temperature. The Bureau also designed a fixed 2-kg weight and associated electromagnetic release, which subsequently were incorporated as standard in a revision of Test 4. The original concept that the test involves only adiabatic compression was found to be an oversimplification; an alternate mechanism for the initiation process is proposed in which due consideration is given to the effects of cavitation and microjets.

Jan 1, 1966

By K. Y. Haramy, 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, 1992

By T. O. Llewellyn

The Bureau of Mines conducted batch-?scale tests on a sample of parphyry copper mill tailings as part of a study to determine the feasibility of rutile recovery from this source. The tailings that were tested contained 0.75 percent titanium dioxide (Ti02), with about two-thirds of the Ti02 values occurring as rutile. Mineralogical studies indicated that about one-half of the Ti02 content could be considered recoverable. Beneficiation studies of the tailings showed that best flotation results were obtained when sulfides and carbonates were removed by bulk flotation prior to rutile flotation. Rutile flotation was most effective when a petroleum sulfonate collector was used in an acid circuit. From this basic method of flotation, two alternative procedures were developed. The first procedure was to size and grind the tailings to minus 200 mesh; deslime the total pulp; and then float the sulfides, carbonates, and rutile. The second procedure was the same, except that it did not include sizing and grinding. Flotation of the sized and ground tailings yielded rutile concentrates containing 43.1 percent Ti02 and 75.7 percent of the recoverable Ti02. Rutile concentrates floated from the tailings that were deslimed but not ground contained only 34.7 percent Ti02 and 69.4 percent of the recoverable Ti02.

Jan 1, 1980

By Bruce I. Thomas

[THIS PAPER, tine of a series on placer ml n in iii Alaska, describes mining methods and gives unit costs at operations where hydraulic and mechanical excavation equipment is used with nonfloating washing plants. The mining methods described were developed during the last 30 years to copy with conditions peculiar to arctic and subarctic regions arid are now used by a large segment of the placer mining industry in Alaska. The operations described have been classified if m ii into three main categories: Those having sluices at a bedrock level, those having sluices above bedrock and those having mobile nonfloating washing plants (dryland dredges). Diesel-powered bulldozers and draglines convey or clevate gold-bearing gravel to the sluices, remove tailings, and strip waste gravel and other overburden. Diesel-powered centrifugal pumps supply water foe sluicing and hydraulic stripping. Detailed descriptions and unit cost arc presented for 14 operations to illustrate the numerous arrangements udder the first 2 categories.]

Jan 1, 1959

By W. H. Goghill

Numerous investigators have studied grinding. Each has contributed his bit to a literature that is difficult to correlate. Too many of the results have been transformed into curves with so many "inflection points" and "counterflexures" that they obscure the issue. Some of the investigators have neglected the very essence of the problem, namely the power and the amount of material to which a known amount of work was applied. The purpose of this paper is to show the ease with which results can be interpreted when these quantities are duly recognized. Some grinding tests will be given for illustration. Grinding studies are of two kinds: (1) Study of the character of the ore and (2) study of the performance of the machines. Several ores may be crushed by a given machine, or several machines may be used on a given ore. The illustrations given in this report cover both objectives.

Jan 1, 1934

By R. F. Abernethy

Recent investigations in the United States and in other countries have produced considerable information on the nature and occurrence of minor elements in coal. The possibility of recovering certain elements, particularly germanium and uranium, from coal ash and other coal products has received considerable attention. Some flue dusts are potential sources of germanium, and certain lignite deposits are potential sources of uranium, but industrial recovery of these elements has been limited to small quantities for technical and economic reasons. Considering the large amount of coal mined annually, a small percentage of a rare element may have industrial significance if an economical method of recovery can be developed. In 1944 information on the occurrence of rare elements in coal was reviewed in Bureau of Mines Technical Paper 669 (46).3 This report is a revision of that paper with the view of summarizing published information available for United States coals, and pertinent information concerning coals of other countries. Selected references from the original paper are retained. New references do not include all preliminary reports when more permanent literature describing complete projects is available. Consequently, the list of references should not be considered complete.

Jan 1, 1963

By D. Harrington

This circular presents part I of a series of papers of a review of the literature on air conditioning in mines, with particular reference to the health, safety, and efficiency of miners. It deals with the physiological aspects of exposure to air contaminated by organic matter, noxious and toxic gases, and dusts that emanate from various sources in underground workings; part II will discuss the relation of abnormal mine temperatures and humidities to the health and efficiency of minors; and part III will describe theoretical and practical methods of air conditioning mines to correct or alleviate the conditions mentioned and will discuss the results attained by some of the systems now in use in various parts or the world.

Jan 1, 1938

By E. R. Maize

[In %-port of Invcstiptionn 7452 ,g dcniing with roof ~wet,ent in the Cmcibla r~ine, rof&apos;erence .,as m.da to the f~ct tiwt timker decny war, bsing studied at tho tine of writing. Thic napor, written a3er completion of that ~tudy, describ~s t1l.e ~mrl&apos;: and sunlharizea the fiats obtained. Ifhen tlle stu* oi roof novement bras be,- at Cxcible tw igeas \%.ere a6-r;incsd. on decay of tiriber Q: scne of :he olficialr;: (I.) 9:la.t timber decay v:as unustmlly rapid in ,tho Ciuoiblc mins, ,m?. ((2) that timber coated with rock ri..~st deixiyad morrl mpirlly thnn those %hat vsrc not so coated. Thsx ::ore no records by which tkeso &apos;iaeas could &apos;L;e tertcc?, ard it cnpsarefi vise to make a limite6 in- vo3tiption, p~.rticu!.ai.ly of +.he effect of roc!< dusting on decny, as rock ductirg is nn importnnt mer-ns of ~rc-,rcnt?;~g cad-dust eql-osions. ]

Jan 1, 1941

By J. D. Dixon

This Bureau of Mines report describes a technique for determining the confining pressures that must be provided for stabilizing underground openings in incompetent rock. The technique is adapted for use with a nonlinear finite-element computer code, NONSAP, to obtain stabilization pressures for linear or nonlinear stress distributions in the rock media around the excavation. This analysis permits a point-wise calculation of active rock pressures that depend on the values of shear stress and strength along the excavation surface. The approach is applied to the solution of several sample problems. The results show that both the magnitude and the distribution of stabilizing confining pressures are significantly influenced by rock and joint strengths, joint orientation, and biaxial nature of the load field.

Jan 1, 1976

By Frank C. Townsend

Waste disposal schemes using spent shale in embankments require a thorough knowledge of its geotechnical engineering properties for environ-mentally safe disposal. In this context, the objective of this laboratory investigation was to determine the physical properties, geotechnical properties, and composition of spent oil shale retorted by the PARAHO and TOSCO processes. Physical properties consisted of mechanical analyses, Atterberg limits, and specific gravity determinations. Geotechnical engineering properties were determined by compaction, maximum-minimum density, unconfined compression, triaxial compression, permeability, direct shear, Ko, cyclic tri-axial, resonant column, and Los Angeles Abrasion tests. Petrographic, chemical, and scanning electron microscopy analyses were used to determine compositional features. Unprocessed shale is hard and durable and more properly described as a carbonate rock instead of shale. PARAHO is classified as a GP, while TOSCO classifies as an SM. PARAHO requires no moisture for compaction to maximum densities; however, TOSCO does. Retorting causes a loss in durability but creates self-cementing characteristics, which for PARAHO a 3-to 8-fold strength increase was observed, while for TOSCO the increase was 1.5 to 3 folds. The shear strength, compressibility, and dynamic properties of compacted PARAHO are comparable to those for sandy gravels. Compacted PARAHO is semipervious, while compacted TOSCO can be semipervious to impermeable.

Jan 1, 1979

By Michael L. Clar

This volume is an annotated bibliography of published literature pertaining to the occurrence and control of surface and groundwater in underground coal mines. This literature was used to develop Volume 1 of this report, which assesses the feasibility of water diversion and overburden dewatering for underground coal mines in the Appalachian Region. Each abstract is followed by subject descriptors. the abstracts are listed alphabetically by title and are numbered consecutively. These numbers are used in the subject index to help the reader locate the appropriate articles.

Jan 1, 1981

By G. E. McElroy

This report discusses the construction and use of an all-pressure psychrometric chart in which the requirements of simplicity of appearance and absolute accuracy have been waived, to a certain extent, to provide for the rapid determination of psychrometric data and for the rapid solution of air-conditioning problems of major interest to the mining industry. Many mines in which air-conditioning problems are important are situated at elevations far above sea level and embrace great differences in elevation - in excess of 8,000 feet in certain mines - throughout their airflow circuits. Under these conditions, the effects of variations in the pressure of the atmosphere upon the physical properties of the mixture of air and water vapor of which it is composed are considerable and should be taken into account in the solution of problems. The simple types of psychrometric charts in common use, such as the Carrier, Bulkeley, Hill, and Goff (American Society of Heating and Ventilating Engineers Guide), are not generally suitable, in that they are drawn for a single barometric pressure - 29.92 inches mercury.

Dec 1, 1947