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By Kung-Lee Wang

This Bureau of Mines study illustrates the economic significance of the Florida phosphate industry to the State and to the Nation. Environmental considerations related to phosphate industry activity are discussed briefly. Based on forecasts of Florida phosphate production in 1975, and using 1972 dollars, regional and national output value, income, and employment created by the phosphate industry were estimated for 1975. State and Federal government tax revenues generated by the phosphate industry, are also measured. Further, the concentrated impact of the phosphate industry on certain Florida areas and on regional industries is examined. Finally, the phosphate industry's importance to the U.S. balance of payments, U.S. agricultural production, and the Frasch sulfur industry is considered, in addition to byproduct fluorine, and potential byproduct uranium from fertilizer manufacturing.

Jan 1, 1974

By Jeffrey H. Welsh

The Bureau of Mines studied the use of computerized, continuous, remote monitoring systems for safety from power system faults in underground coal mines. In this report the need to improve protection against power system faults is documented, and types of faults are identified. The relationship between mine safety regulations and computerized, continuous, remote monitoring is analyzed.

Jan 1, 1983

By [F. P. ] Stambaugh

Results of research on the hydrothermal precipitation of zirconium oxide from the Bureau of Mines' zirconyl chloride-sulfate strip liquors indicate that nuclear grade material can be prepared by this process. Greater than 99% of the zirconium value can be precipitated at 250-260°C in short (5-10 minutes) reaction time without consumption of acid value of the liquor. Thus, precipitation of zirconium dioxide on a continuous basis, i.e., the zirconium dioxide is precipitated in a continuous mode of operation by pumping the strip liquor through a heated pressurized reactor and recycle of the acidic (spent) liquor to the process stage are favored. The results of accompanying studies of liquod/solid separation, product washing and dewatering, product purity, and chlorination of the product are presented and discussed.

Jan 1, 1980

By Russell R. Trengove

Bureau of Mines exploration at the property of the Tulare County Tungsten Mines was by core drilling from the surface from May 16, 1950, to July 13, 1950. The property is in the western foothills of the Sierra Nevada Range, 18 miles northeast of Lindsay, Calif. It has been in almost continuous production since 1942 and has produced 40,831 units of tungsten trioxide (W03) with a grade of approximately 67 percent. The work performed comprised a study of the geology, mapping the area, sampling the outcrops, and diamond drilling the area adjacent to the mine workings. Ten holes were drilled for a total of 1,824 feet. Ore reserves were found to be confined to tactite zones in a surface area approximately 250 by 400 feet and extending downward about 350 feet.

Jan 1, 1956

By J. S. Webb

This is one of a series of papers dealing with mining methods, practice, and costs be¬ing published by the United States Bureau of Mires. In this paper a description of the mining practice in vogue at the Braden unit of the Kennecott Copper Corporation is undertaken. PRODUCTION At present (1931) the entire production of ore is being obtained from the Teniente mine. The miring method in use is an adaptation of block undercutting which has been a development of the stoping and pillar caving experience obtained at this property. Improvements in mining practice are constantly being made.

Jan 1, 1932

By S. H. Ash

The Pennsylvania anthracite-mining region is the only one in the world of major magnitude. As the deposits of anthracite in the United States are limited virt113.lly to Pennsylvania, the difficulties of this industry have been commonly considered a State rather than a national problem. However, there is also national interest in the conservation and wise utilization of all fuel resources and in the control of interstate waterways. The anthracite industry is confronted with the very se:;-ious :problem of accumu.lation of water in many of the mines. This problem must be solved soon if progressively higr-er mi~ing costs are to be avoided. The water proble~ cannot be solved by the operating compa,nies without State or Federal aid, or both, owing to the magnitude of the work requir~d, diversity of interests of the coal ana surfa.ce ovmerships, hazard to the whole mining community, and interests affec~ed outside the mining region. The cost of abati~ the ever-increasing_surface seepage to mine workings and of handling this seepage once it }3s occurred is beyond the economic resources of most ope~ating ma.'18.gements. The data in this paper giving the high lights of the water problem and indicating what appears to be a step in the right direction are based upon observations made during the past year that the industry desires and believes it is to the npublic interesttr to keep mine workings free of flood end surface waters.

May 1, 1941

By A. L. Engel

This report is a compilation of results of preliminary concentration tests of seven manganese-ore samples. Six of the seven samples were submitted through the Mining Division, and 1 from Mexico was submitted by H. A. Doerner, formerly chief metallurgist, Region III. These investigations were made to assist development of mineral resources and particularly to aid economical exploitation of marginal or complex ores, from which strategic or critical minerals may be recovered.

Jan 1, 1953

By Donald W. Mitchell

Certification tests for urethane-foam systems and techniques for apply-ing foam safely in mines are described. Fire hazard from foam exists if flame propagates beyond the ignition source or penetrates the foam. Foam that passes the certification tests can be applied on stoppings, continuous sections of ribs of relatively wide passageways (with no foam on the roof), short sections of roof such as overcasts, roof cavities, and intersections (with no foam on the ribs), and between buntons on one wall of a shaft. Foam on the ribs and adjoining roof presents a fire hazard. Stoppings covered with foam passing the certification tests are resistant to penetration of heat, flame, and smoke than similar stopping without foam. Flame propagation can be arrested by water sprays. Spontaneous ignition of foam can be prevented.

Jan 1, 1966

By F. R. Cattoir

The Federal Bureau of Mines refined chromium from an aqueous electrolytic process in molten sodium chloride-chromium chloride electrolytes. Oxygen and nitrogen contents were reduced by a factor of 10 to 40, but most other impurities were little changed. The product usually contained a little more iron than the feed. Since iron was entering the bath from the iron pot and the graphite liner at a nearly constant rate, contamination of the chromium deposits by it was more serious at low currents and deposition rates. A few runs in an iron cell with a nickel liner yielded chromium containing one half as much iron as the feed, but up to 1.5 pct. nickel. In all cases the anode feed lay in the bottom of the container, which itself was used as the anode connection. With a 12-in. cell, variations in applied voltage from 0.05 to 1.5, in current from less than 10 to over 100 a., and in initial cathode current densities from less than 100 to over 2,000 a./sq.ft. had little or no effect upon the analysis of the metal produced) except for iron content. Changes in bath analysis from 3 to 11 pct. chromium were also without effect. These changes did bring about large differences in the physical forms of the crystals obtained. The thick heavy crystals produced at low voltage and current contained voids which made them difficult to leach free of chlorides. Easiest to leach were the thin leaf-like crystals obtained at around 1 v.

Jan 1, 1960

By Robert C. Dyni

The use of techniques and equipment designed to pneumatically place backfill into an underground mine opening through boreholes for subsidence abatement has historically met with limited success, largely due to the inability to directly monitor the placement of the backfill in the opening. The success of a backfilling project cannot be guaranteed if it is not known whether the underground opening has been completely filled with backfill material. To overcome the inability to directly monitor backfill placement, the U.S. Bureau of Mines developed a pneumatic backfilling system that allows for direct viewing of the backfill as it is placed in an underground mine opening. This system utilizes a recently developed pneumatic nozzle coupled with an instrumentation package that allows for real-time observations and measurements of backfill placed in an underground opening through a borehole. The nozzle utilizes a high-velocity airstream to redirect backfill falling through a pipe in the borehole and directly in front of the nozzle; the airstream redirects and propels the backfill horizontally into the .mine opening at over 100 ft/s. The instrumentation package, mounted directly to the nozzle, contains a video camera, high-intensity lamps, laser-rangefinder, electronic compass, and water sensor.

Jan 1, 2010

By Ben E. Lindsly

The study of "bottom-hole' samples follow,-is in natural sequence the study of samples3 obtained under high pressures at the well heads of flowing wells. The principal object of this phase of gas-solubility research, started actively in January, 1530, was to gain a more accurate knowledge of the physical and chemical characteristics of the oil-gas mixtures that exist in natural reservoirs. In possession of actual data regarding the condition of the oil; the quantity of gas liberated from solution upon dimunition of pressure; and the relative volumetric proportions of gas to oil at various pressures throughout the flow string in a well, it should be possible to predict, with a fair degree of accuracy, what physical changes these mixtures would undergo throughout the life of a pool. Such information not only is important in designing flow strings in flowing wells but is important also in solving problems relating to pumping efficiency and the power required for pumping. Although certain fundamental rata Mere obtained in the stud of samples taken at the well head, "bottom-hole" samples are more representative of subsurface mixtures of oil and gas because they are obtained at reservoir temperatures, and before the oil has had the opportunity of intermingling with extraneous gas; that is, gas which either was not in solution originally, or which was liberated from solution at some higher pressure, and later became mired with the original undissolved gas.

Jan 1, 1933

By T. H. Miller

This piper is a continuation of a series of yearly review articles started in 1925 by Thomas Varley. The development of flotation has been rapid, and better understanding of the functions o' flotation reagents has resulted in many changes in the kinds and quantities o reagents used. It is the purpose of this report to present the information in such a manner as to be of value to the milling industry as well as to the manufacturer of flotation reagents. These data have been compiled from a. survey of approximately 250 flotation plants of all classes within the United States. Many of these plants made complete reports of their operations, out others were apparently unable to supply this information in sufficient detail to meet the requirements of this investigation. Although it is realized that the data obtained in this survey are not as full as they should be to render the greatest service possible to the milling industry, it is hoped that succeeding articles will include complete information regarding milling; conditions and recoveries. As in the past, every effort has been made to conceal individual plant operations. RESULTS OF INVESTIGATION Table 1 gives the tons of ore treated by gravity and flotation methods and the concentrates produced as reported by 208 plants. The totals of 77,043,535 tons of ore and 4, 596,640 tons of concentrates from this table compare with totals of 78,973,012 tons and 4,683,972 tons respectively (furnished by the Bureau of Mines, Division of Mineral Statistics), indicating that the milling survey is about 98 per cant complete.

Jan 1, 1930

By Maria I. De Rosa

The U.S. Bureau of Mines performed experiments to determine the embedded hydrogen chloride (HCI) and smoke particle characteristics during combustion of polyvinyl chloride (PVC) and chlorinated mine materials for development of a test parameter. The experiments were conducted in an approximately 20-L furnace at set furnace temperatures of 250° and 1,000° C, for a 14-min duration, with an airflow through the furnace of 10 L/min. The variables studied, as a function of time, were hydrogen chloride embedded on smoke particles, hydrogen chloride concentrations in the gas phase, smoke particle average diameter (dg) and particle concentration (no), and product of smoke particle diameter and concentration (dgno). Other variables included carbon monoxide (CO), carbon dioxide (CO2), and oxygen (O2) concentrations; sample mass weight loss; and furnace temperatures. Results show that there is a correlation between embedded hydrogen chloride, hydrogen chloride gas concentrations, and inverse of the smoke particle diameter-concentration product (1/dgno); the higher the hydrogen chloride gas concentrations, the higher the embedded hydrogen chloride, the higher the 1/(dgno) values. These correlations will enable development of a simple test parameter to assess the toxic hazard that these materials pose during fire.

Jan 1, 2010

By Scott Turner

We are here today to witness the graduation of 63 young men as Engineers in the mineral industries . It is an important occasion and one in which the public takes a keen interest , since this school has long been famous for the educational facilities it affords young men, and for the high professional standing of its graduates . : : : It is fitting that once each year we should pause to review the path the student has traveled , and to reflect upon the perspective opening before him as an engineer . I was invited to come from Washington to take part in this ceremony and to say something to these young graduates . In searching for a theme ," it occurred to me. that perhaps my best contribution would be to duscuss certain beliefs as to college training , deal with the situation in which the young engineer finds himself on graduation , touch on the new ideas of the social and political responsibilities of the engineer , and point out what he may expect to find in practice , and , above all , what he must do to orient himself properly in the mining profession and maintain the best traditions of our brotherhood . Let us first review your college days and see what they have done for you . I am told there are still many temptations in college . I know there used to be . Rest assured the same holds true in the professional life ahead of you. The main difference is , perhaps , that your greatest temptations in college were those offered by your teachers , who tried to entice you into realms of harder work, closer application , increased concentration , clearer thinking and better understanding , by animating your curiosity and increasing your powers of reasoning and of observation . In other words , here you have carefully and systematically been decoyed toward finer and loftier things . Do not expect that similar helpful influences will greet you on every side in your professional life . Often quite the contrary is the case .

Oct 1, 1930

By E. J. Lintner

This paper is one of a series being prepared by the United States Bureau of Mines describing gypsum mining and crushing methods and costs at various operations throughout the United States. These papers are designed to disseminate technical information regarding methods used. The cost tabulations represent local operating expenditures only and not total production costs. It is recognized that publication of total production costs may in many instances cause embarrassment to individual operators as well as to the industry as a whole. On the other hand, operating costs are essential to a technical discussion and study of the methods employed. The attention of the reader is called specifically to this differentiation so that there may be no misunderstanding of the scope of the cost tabulation. This paper deals specifically with the mining and crushing methods employed by Victor Plaster, Inc., Victor, Ontario County, N. Y. The maximum annual production capacity of this company is 150,000 tons of crushed gypsum. The methods and practices employed arc typical of those followed in the gypsum mines in western New York State. The shaft is, perhaps, the deepest and the thickness of the gypsum mined is above the average for the section.

Jan 1, 1937

By D. G. Kesterkel

Low-melting thoriurnrbase binary alloys or metal solutions were prepared by two different techniques involving the electrolysis of ThO2 dissolved in fluoride melts. Experiments were performed at 950° to 1,250° C using electrolytes containing ThF4 and various alkali and alkaline earth fluorides. In the first method, electroreduction of ThO2 and deposition of thorium on a nickel or iron cathode formed a molten alloy that dripped off and collected on the bottom of the cell, or in a tungsten cup. An electrocodeposition technique was used to prepare thorium-base alloys or solutions containing nickel, iron, chromium, or manganese. Electrolytic reduction of the component metal oxides and simultaneous deposition of the two metals on a tungsten cathode yielded a liquid alloy product. Complementary experiments were performed on the fused fluoride electrowinning of dendritic thorium from Th02 at 1,075° to 1,200° C in which thorium crystals were recovered and arc-melted into buttons. Major contaminants were aluminum, carbon, copper, iron, oxygen, and silicon, totaling 0.2 percent.

Jan 1, 1966

By R. Hogg

"The problems of sampling particulate materials, and of characterizing the distributions of particle size and composition are reviewed. Requirements for sampling from comminution systems are discussed and a simple formula is presented for estimating the minimum sample size needed. The limitations and errors associated with the techniques available for particle size analysis are evaluated and guidelines are suggested for the selection of appropriate methods. The use of microscopic and macroscopic approaches to the characterization of particle composition are discussed.INTRODUCTIONComminution is a process of particle size reduction in which the goal is to produce a material with a specified particle size distribution from a coarser feed. In mineral processing applications, the product size distribution is often qf secondary importance to the extent to which individual mineral grams can be liberated from one another. However, due to poor understanding of the nature of the liberation process and the lack of reliable procedures for characterizing it, the actual specification is normally in terms of particle size.Particle size distribution can be regarded as the fundamental characteristic of a particulate system. The distributions of particle shape and composition among the various particle sizes present are often sufficient to define the bulk properties and behavior of the system. Description of the distributions of size; shape and composition of the different phases which may exist within individual particles is necessary to complete the picture and is especially important for predicting liberation etc., in comminution processes. It is quite obvious that · the complete characterization of real particulate systems is a formidable, if not .impossible task. Practical characterization procedures should involve ·evaluation of those characteristics which are deemed to be important and which can be measured. In comminution systems, this should ideally include the particle size distribution, the size-by-size distributions of particle composition, and as much information as can be acquired on the internal composition and structure of individual particles. In most cases, of course, we fall far short of even this rather limited goal."

Jan 1, 1988

By S. M. Shelton

The widespread occurrence of domestic manganese deposits and the shortage of ferromanganese-grade ore have been sources of much speculation and investigative effort for many years. The present emergency has intensified the search by the Bureau of Mines for methods of producing ferromanganese-grade concentrates4/ from low-grade ores.

Jan 1, 1941

By S. M. Shelton

[The widespread occurrence of domestic manganese deposits and the shortage of ferromanganese-grade ore have been sources of much speculation and investigative effort for many years. The present emergency has intensified the search by the Bureau of Mines for methods of producing ferromanganese-grade concentrates4/ from low-grade ores.]

Jan 1, 1941

By Lulie H. Crump

U.S. supply and demand data for dry natural gas by source, form, and major consuming sectors--within and between States and defined regions--were tabulated for the years 1960 and 1965. State-by-State quantitative data are provided for the natural gas industry that can be arranged into regional groupings and used to determine regional flow patterns. The tables show the derivation of the total supply of gas available for consumption from total marketed production. The tables also report the distribution of the supply among the major consuming sectors (household and commercial, industrial, transportation, and electricity generation, utilities). The summarized data show an increase in the absolute demand for natural gas in all regions for the period 1960-65, although the relative posit ions of the various subregions, with respect to national consumption, remained about the same. To enable comparison of data on dry natural gas with data on other energy sources, quantities in terms of million cubic feet were converted to British thermal unit (Btu) equivalents.

Jan 1, 1969