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By R. R. Sayers

Radioactivity, the property of radium that led to its isolation more than 30 years ago, is the characteristic that makes it of value in the treatment of disease. Tyler3 gives the following brief history of the investigation: The way to the discovery of radium was opened in 1895 by Rontgen, who found that the glow from a Crooke's tube contained penetrating rays, which .he called X rays. Prof. Henri Bequerel, while investigating the effect of various phosphor¬ escent substances, found that uranium salts produced photographic impressions even when enveloped with opaque substances. To Marie Sklovouski, a young Polish student, who later became Madame Curie, Professor Bacquerel delegated the task of learning how and why uranium possessed power to emit these peculiar rays, which he had proved to be electrical in character. Madam Curie, examining by electri¬ cal methods the radioactivity of a large number of minerals containing uranium and thorium, discovered that some specimens of pitchblende had about four times the activity of the metal uranium; that chalcolite, the crystallized phosphate of copper and uranium, was twice as active as uranium; that autunite, a phosphate of calcium and uranium, was quite as active as the same weight of pure uranium. In order to check these discoveries, she prepared chalcolite artificially, starting with pure products, but found that this artificial chalcolite had only the acti¬ vity represented by its composition, or, roughly, 40 per cent of the activity of uranium. This led to the conclusion that there was some element or substance in the residue from uranium minerals that possesses a high degree of activity. After an exhaustive chemical investigation of pitchblende from Joachimsthal, she found that this mineral contained not only uranium but also another radioactive sub¬ stance, to which she gave the name of polonium, in honor of her native land. Later in 1898, Monsieur and Madame Curie found still another element, which, when brought to a state of concentration, was several million times as active as uranium, and to this was given the name of radium. Debierne afterwards found a fifth radio¬ active substance, actinium; and in 1906 Boltwood isolated the metal ionium. Strict¬ ly pure radium chloride was first produced in 1902. The first radium was produced commercially from the uranium residues obtained from the mines of Joachimsthal, Bohemia. Tyler calls to attention that, as the ores were a government monopoly, search was begun at once for sources in other parts of the world. As a result, radium-containing ores have been found in about 10 countries.

Oct 1, 1932

By R. E. Green

The Bureau of Mines undertook a bench-scale study of three different types of oxidized taconites3 from the Lake Superior district to improve the dispersion-selective flocculation-desliming process for beneficiating these materials. The response-surface contours of the effects of dissolved ionic species in the water and of three dispersion systems on the selective flocculation process were studied. Results of metallurgical data and chemical analyses of the aqueous phase showed that the water quality affects the performance of the selective flocculation process.

Jan 1, 1984

By D. W. Bridges, R. O. Dannenberg, Laird Crocker

Preliminary solvent extraction studies , reported by the Bureau of Mines (5) , have been continued and expanded to improve on the previous estimate of process requirements . The solvent extraction portion of the process was examined at a scale large enough to enable meaningful extrapolation of the results to geometrically similar equipment of plant size . About 82 pct of the beryllium was recovered from approximately 0.5 pct beryllium oxide (Be0) Spor Mountain , Utah , ore by a process involving ( 1 ) sulfuric acid leaching , ( 2 ) counter current decantation (CCD ) washing , (3 ) iron ( III) reduction by sodium hydrosulfide ( NaHS ) , ( 4 ) beryllium solvent extraction by di - 2- ethylhexyl phosphoric acid ( EHPA) , ( 5 ) caustic stripping of beryllium- bearing EHPA, (6 ) hydrolysis of sodium beryllate - caustic strip liquor , and (7 ) calcination of beryllium hydroxide (Be ( OH ) 2 ) formed in step (6 ) . The resulting beryllia assayed 98 to 99 pct Be0 and was suitable for most nonnuclear uses . Best overall results were obtained by using pH 2 , 1.6 grams of BeO per liter of leach liquor as feed and 0.25 N EHPA in kerosine containing 2 wt vol pct (grams per 100 ml of solution ) isodecanol ( IDA ) as solvent . Analysis of the data indicated that a commercial plant would achieve 95- pct overall extraction operating at 45 ° C with 20 hp per 1,000 gal of dispersion in each of seven mixer- settlers , having 290 gal per ton of ore hourly mixer capacity and 90 gal per ton of ore hourly settler capacity . At least 79 lb H2SO4 , 13 lb sodium hydroxide (NaOH ) , 3 lb NaHS , 0.25 lb kerosine , 0.07 lb polyacrylic flocculant , 0.03 lb EHPA , and 0.007 lb IDA would be required in H2SO4 leaching and subsequent processing to recover 1 lb BeO .

Jan 1, 1964

By A. U. Miller

Protection against fire is a greater problem at a coal mine, than at an ordinary industrial plant. Generally mines are located in isolated districts and do not have the protection of city fire departments; consequently fire fighting aquipment must be installed by the mining company. Fire protection around a mine is just as essential as it is in the city.. and undoubtedly is more important if the fire should be underground where many lives would be endangered and all means of escape cut off. A surface fire can generally be attacked from any angle, but an underground fire can be attacked only as conditions will permit.. U. S. Bureau of Mines engineers have investigated many serious mine fires that undoubtedly could have been extinguished in incipiency if a fire extinguisher or fire hose and water had been readily available. In past years very little attention was given..to fire fighting equipment and organization around mines, but in recent years three gen a derde hange of opinion among many of those engaged in mining, and nearly all up-to-date mining companies now have some kind of fire protection about their mine Probably the first company in Illinois to install regular fire fighting equipment and effect a fire fighting organization at its mines, was the Madison Coal Corporation, which operates several mines in Illinois. The main office of this company is in Chicago and the general field office is at Glen Carbon, Ill.

Jul 1, 1930

By Yael Miron

Two recent unplanned detonations occurred during blasting operations in sulfide-bearing ores in a Nevada gold mine. Other premature detonations have also reportedly occurred at other Nevada, California, and Arizona operations within the past few years, with increasing frequency. Unplanned or premature detonations can be extremely hazardous to life and can cause extensive property damage. A miner was injured in one of these occurrences. This report, by the U.S. Bureau of Mines, is intended to acquaint personnel involved in such mining activities with the basic causes for these accidents. These causes include the exothermic oxidation of pyrite (FeS2) and formation of ferrous sulfate (FeS04), the exothermic and energetic reaction of the ferrous sulfate with ammonium nitrate-fuel oil (ANFO)-based explosives, and the associated elevated temperatures that can set off detonators and explosives in the boreholes. Recommendations for safe operation by the Mine Safety and Health Administration, the Bureau, and the mine involved with the recent incidents include monitoring temperatures in the blast holes, analyzing for sulfate and ferrous ions, and limiting the time between loading and firing in accordance with conditions in the blast holes. Other procedures for safe operations should fit specific conditions in, the mines.

Jan 1, 1992

By Richard L. Sayrs

The Eve Mills deposit is in Monroe County, Tenn., near the southeastern corner of the State. The deposit was examined in February 1943 by a Bureau of Mines engineer, and drilling the property was recommended to increase the on: reserves enough to justify mining should war needs require it. The deposits were explored, by 32 diamond-drill holes totaling 11,649 feet during the periods from July 1943 to November 7, 1945, and from April 1944 to August 17, 1944. The drilling campaign disclosed a large area of mineralization. The ore, however, is apparently confined to long, narrow sheets. The indicated grade of the ore bodies blocked cut by the Bureau of Mines is 4.o8 percent zinc and 2.10 percent iron.

Jan 1, 1949

By Donald J. Barnes

The Glacier View RARE Ii further planning area contains no identified mineral deposits, other than stone, which cannot compete favorably with similar deposits closer to major markets. Pierce County mining claim records show six coal claims were located in the study area between 190b and 1907; however, no coal was found at the described locations. Two coal prospects, the H.O. Lamming and Floyd Rice, are within 0.5 mi (0.8 km) of the area's west boundary (fig. 1). At these prospects, impure bituminous coal beds strike approximately north and dip east toward the study area. Analyses of samples 1/ indicated an average heating value of 2,767 BTU 2/ per pound (6,436 joules per kg). Because of the low heat value, this coal is subeconomic. Intense folding and faulting which disrupted the beds would limit the use of conventional coal mining equipment, making future economic development even less likely. Trinity Resources of Houston, Texas has leased approximately 1,404 acres (568 ha) inside the study area and an additional 1,020 acres (413 ha) adjacent to the study area for oil and gas exploration. However, no oil or gas wells are known to have been drilled in or around the study area.

Jan 1, 1983

By E. F. Foerster

The Bureau of Mines used a diphenyl ether calorimeter to determine the heat contents of natural and synthetic blast-furnace slags. For solid slags, enthalpy (HT-H298) at 1,448° to 1,680° K ranged from 282.1 to 348.5 cal/g (±3 percent); liquid slag values were 400.1 to 514 cal/g (±3 percent) in the temperature range between 1,626° and 1,890° K. Experimental results for liquid slags were 14.3 to 16.2 percent higher than the enthalpies calculated from thermodynamic tables; values for solid slags ranged from 5.3 percent lower to 3.9 percent higher than calculated values. Experimental results for liquid synthetic slags ranged from 14.9 to 24.3 percent higher than the calculated enthalpies; values for solid synthetic slags were from 1.0 to 3.4 percent higher.

Jan 1, 1967

By David M. Gullikson

Since publication of the paper on the composition of California oilfield waters by Jensen (6)3/ in 1934 the only other information on the subject was published recently by Chave (4). To supply needed information on the composition of California waters in areas of current drilling activity, the Federal Bureau of Mines collected formation water samples for analysis. Thirty-eight samples from oil-and gas-producing formations in 12 fields located in Ventura, Kern, Glenn, and Colusa counties were analysed by the Bureau's San Francisco Petroleum Research Laboratory. The samples were selected particularly from fields where the water composition was not well known or where interpretation of electrical logs has been difficult and the interpretation may be affected by unusual composition of the water. These samples were obtained from rocks ranging in geologic age from Cretaceous to Upper Pliocene. Fifteen constituents of these waters were determined including sodium, potassium, calcium, magnesium, strontium, barium, lithium, chloride, iodide, bromide, carbonate, bicarbonate, sulfate, borate, and residual acidity. These analyses are the first to be published on California oilfield waters in which determinations for potassium, strontium, bromide, iodide, boron) and naphthenates were made on a significant number of samples. The electrical resistivities of tae samples were determined at 75° F. and 175° F.

Jan 1, 1961

By Ralph V. Higgins

The present methods of appraising the long-range performance of oil reservoirs are based upon physical properties of the crude oil and the permeability of the reservoir rock. By means of these methods the performance of a reservoir may be estimated throughout its entire life. Before these methods were used, the future performance was estimated mostly by extrapolating pressure-decline curves -a method that is satisfactory for extrapolating only for a short period into the future. One factor that affects satisfactory long-range prediction of reservoir performance is the extent to which small changes in the physical properties of the oil and differences in the choices of relative permeability influence the calculated oil recovery. Selection of the physical properties of the samples to represent those of the oil and rock for the entire reservoir is difficult. This report is concerned with the error in calculated recoveries that may result from these inherent difficulties.

Jan 1, 1956

By Steven R. Davis

Voyageurs National Park in northern Minnesota, and a 30-mile radius area of influence on the United States side of the International Border, was examined for hardrock (nonferrous metallic minerals and diamonds) mineral potential and environmental sensitivity by the U.S. Bureau of Mines. The investigation also included an analysis of current Metallic Minerals Leasing Rules of the State of Minnesota, and the probable effects of changes proposed to the current rules by the State of Minnesota in order to "encourage mineral exploration and development." The study has determined that the proposed changes to the Minnesota State Leasing rules will have minimal, if any, impact on the likely, foreseeable levels of mineral-related activities in the State as a whole, and particularly, in the area of influence to the Park. Voyageurs National Park management was advised on the extent and character of the proposed rules changes, and on those items of concern meriting a specific and timely response by the National Park Service.

Jan 1, 1994

By D. Harrington

Along with other phases of mining , the ventilation of metal mines has been affected by the business depression of 1930. As might be expected , some of the results are favorable , and some are distinctly disadvantageous to progress . Probably the worst effect of the recession of mining activity is that , as usual , one of the first departments of almost any industrial establishment ( and this is especially true of mining ) to be curtailed is that which concerns what might be called welfare work , such as safety , health , etc. , and ventilation : in consequence , a number of men who were employed mainly on ventilation work in metal mines are now out of employment and their former duties either are being handled by others as only part of a crowded routine or are being allowed to lapse . On the bright side of the picture is the following paragraph from a letter by the ventilation and sarety engineer of the United Verde Copper Co. , Jerome , Ariz . , indicating that money and effort expended on ventilation during " flush " times give results which aid in money savings when depression comes : The desirability of absolute control over the ventilation system has again been demonstrated at this mine . Under full operation we have been using approximately 500 hp . to drive our big fan . Under curtailed operations we naturally do not require as much air , so by sending the air only where needed and airing out all other places periodically to keep timber , etc. , in good condition we have been able to economize in the quantity of air required . The fan speed has been reduced and the power dropped to 300 hp . , thus effecting a material saving in the power bill , and still maintaining an efficient ventilating system . "

Jul 1, 1931

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 H. S. Caldwell

The objective of this investigation by the Bureau of Mines was to develop and test for laboratory use a retort embodying many features required for practical commercial-scale applications of vacuum distillation of metals. A gas-fired vacuum retort was developed comprising a hollow, cylindrical graphite liner encased in a thin shell of stainless steel. The liner prevents the shell from collapsing under vacuum and protects it from corrosion by metal vapors and the molten metal charge. The vacuum-tight shell protects the liner from oxidation and flame erosion. The retort was used to distill zinc from dross and die-casting scrap. More than 99 percent of the zinc was recovered as a condensate containing 99.8 to 99.9 percent zinc. (Atmospheric distillation recovers 95 to 98 percent at a purity of 99.5 percent zinc.) Distillation rates of 50 pounds of zinc per hour were attained at a temperature of 65° C. with pressures ranging between 50 and 100 microns. Distillation at this low temperature is not practicable at atmospheric pressure. Also, the retort is suitable for distilling other volatile metals such as cadmium and magnesium.

Jan 1, 1961

By E. F. Ferrell

Electrowon molybdenum powders and a commercial hydrogen-reduced powder, all with different minor impurities, were investigated by the Bureau of Mines with respect to inherent properties, to fabrication techniques, and to proper-ties of the fabricated sheet. Compared with the commercial hydrogen-reduced powder, the electrowon powders had a larger particle size, a greater flow rate, a higher apparent density, and a lower oxygen content. Sheet materials prepared from the two types of powders showed similar mechanical properties, under the same conditions of heat treatments, except for low-temperature ductility. Yield strengths varied with carbon content, heat treatment, and test temperature.

Jan 1, 1970

By A. F. Colombo, R. T. Sorensen, D. W. Frommer

The Bureau of Mines developed a flotation method for concentrating spiral tailing produced from pilot plant tests on the Champion mine ore fines . The feed material contained about 49 percent Fe and 15 percent SiO2 and was posed mostly of specular hematite , muscovite , and chlorite . Bench- scale , batch flotation research developed a reagent suite composed of tall oil - fatty acid , fuel oil , sulfuric acid , sodium fluoride , and sodium silicate for recovery of iron minerals in the froth product . Concentrate made with the reagent suite contained 87.3 percent of the iron and analyzed 65.6 percent Fe and 1.9 percent SiO2 . Continuous flotation tests were made with a nominal feed rate of 400 lb /hr , but without middling recirculation . Using nearly the same amount and complement of reagents as in the batch tests , three similar continuous tests gave concentrates averaging 63.9 percent Fe and 3.1 percent Sio while recovering about 86 percent of the iron .

Jan 1, 1964

By Robert H. Peters

This report presents findings from a Bureau of Mines study on barriers that may prevent miners from correcting and avoiding groundfall hazards. Such barriers stem from four basic types of problems: (1) inability to recognize groundfall hazards, (2) inability to correct groundfall hazards, (3) lack of motivation to search for groundfall hazards, and (4) lack of motivation to correct groundfall hazards. Data are presented that summarize the views of miners, section supervisors, and mine inspectors about the contribution of these barriers to groundfall accidents and what they think should be done to reduce the frequency of injuries sustained by falls of roof and rib. The report also includes a summary of miners' responses concerning their recent experiences with groundfall accidents, along with industrywide statistics on accidents and injuries caused by ground falls in underground coal mines.

Jan 1, 1987

By E. D. Gardner

"Introduction Ore from stopes in metal mines is generally dumped or drawn into chutes or raises through which it passes by gravity to the haulage levels. Occasionally, and under some conditions quite frequently, the ore in a chute will wedge or hang and refuse to run. This hanging of the ore may be due to the packing of damp or clayey material, to boulders forming an arch, or to loose lagging or other timber becoming lodged in the chute.In drawing material from a loading chute it is drawn out a car at a time, and the intermittent flow of the material .increases its tendency to hang. When the obstruction in the chute is near or at the loading gate, the chute pullers start the ore by punching it with iron bars inserted through openings in the chute gate. When the obstruction is beyond reach of the bars, other means of starting the ore must be used.In some systems of mining, chutes or ore raises are built with timber as the stope extends upward. Generally, a manway is left alongside of the chutes, and when the ore hangs in a chute usually it can be started by a miner from the manway ladder by pounding on the timbers of the chute or by punching the ore with a bar inserted through small holes in the chute lining. Special methods of starting clogged ore, such as shaking a chain left hanging in the chute, are used at some places.In other systems of mining, ore passes or chutes are run through solid rock and when the ore hangs in one of these passes, either it must be blasted or else started from the top. Sometimes the ore can be started by running water into the top of the chute, but if the water does not start the ore moving, it must be blasted from underneath. This is done by detonating a bundle of cartridges under the obstruction in the chute or raise."

Jan 1, 1927

By James S. Browning

The Bureau of Mines conducted laboratory and small--scale continuous tests of weathered mica pegmatite ores from Hart County, Ga., to determine the technical feasibility of recovering commercial-grade mica concentrates by flotation. Two modifications of the Bureau-developed anionic-cationic method were used. In one method, sodium carbonate and calcium lignin sulfonate were used for pH control and quartz depression; this method yielded mica concentrates containing 98.5 percent mica with a recovery of 91.4 percent. In the other modification, lime and sodium silicate were used with the calcium lignin sulfonate; concentrates containing 98.9 percent mica with a recovery of 86 percent were obtained.

Jan 1, 1966

By E. S. Shedd

Misch metal was electrowon from a treated bastnasite concentrate in a REF3-LiF-BaF2 electrolyte at 950° C. The metal was prepared and tapped from a 1,000-ampere cell, and nearly 100-percent utilization of the rare-earth oxide was achieved. Prolonged operation in a smaller cell (40 amperes) indicated that the composition of the misch metal product was reasonably constant, and no significant increase of impurities, with the exception of carbon, was noted.

Jan 1, 1970