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By R. R. Hornor

Due mainly to conditions brought about by the war , the metal mining industry in this country is now passing through one of the most critical stages in its history , and is confronted by new problems upon the solution and adjustment of which depends , in a large measure , its future welfare and prosperity . The chief factors contributing to the cost of production are the cost of labor and supplies . It is conceded by our leading mine operators , managers , and engineers that any material reduction in the cost of labor or supplies , within possibly the next two or three years , cannot be anticipated , anl it is not thought likely that pre - war prices will ever again prevail . This being true , the mine operator must look in some cther direction to effect economies that will lower production costs . If this cannot be accomplished it will mean , in many instances , that mines and metallurgical works will have to be closed and abandoned , which will tend to disorganize the entire industry . How to lower production costs and still maintain the present high standard of wage , is the problem that is engaging the serious attention of mine operators and managers over the entire country . In As a solution to this problem it is thought that the most promising field of investigation lies in the direction of systematizing and standardizing mining practice , so as to effect economies in the use of both labor and materials . other words , to eliminate , in so far as possible , unproductive effort and waste and thereby secure a maximum of productive results , It is not the idea to speed up work or to demand a greater effort on the part of the workman , but rather so to systematize and standardize the various under ground operations that his energy will be directed into more useful and productive channels ,

Dec 1, 1919

By C. Froger

Since its creation in 1950, the Centre d'Etudes et Recherches des Charbonnages de France at Verneuil-en-Halatte (Oise) has been conducting many investigations concerned with airborne dust measurements, particularly in underground mines. The work has resulted in the development, a few years ago, of a new process of dust sampling, whereby the airborne dust particles are collected by a rotary filter of polyurethane foam rotating at high speed within 8 housing.

Jan 1, 1973

By R. Barany

This report contains the results of experimental work conducted by the Bureau of Mines to obtain the heats of formation at 298.15° K. of analcite, dehydrated analcite, lawsonite, anorthite, hexagonal anorthite, and leonhardite. Thermodynamic data for these minerals have applications in ceramics, extractive metallurgy, and particularly in geochemistry. Except for data on anorthite, no previous similar data existed. The present results will be a substantial aid in deriving the temperature-pressure-equilibrium relationships among these minerals. The heats of formation were determined by solution calorimetry, with hydrofluoric acid as the reaction medium. The results were expressed both in terms of the constituent oxides and in terms of the constituent elements. The heat of formation data were combined with related entropy values to obtain the free energies of formation at 298.15° K.

Jan 1, 1962

By D. R. Mathews

The solubility of carbon in electrorefined vanadium was determined to be approximately 0.27 wt pct at the eutectic temperature 1,650° C and 0.03 wt pct at 700° C. The tensile strength and hardness of vanadium increased with car-bon content to the solubility limit, but this effect was small, probably because of the narrow solubility range. Between the solubility limit and 0.3 weight-percent carbon, the second phase had essentially no strengthening effect in vanadium. The second phase, observed metallographically at the grain boundaries and within the grains, was shown by autoradiography to contain high-carbon concentrations. This second phase was identified as VgC by X-ray analysis. The VgC in the grain boundaries contributed largely to the poor cold-and-hot workability of vanadium-carbon alloys. Increased concentrations of V2C occurred at the grain boundaries of the high-carbon alloy ingots as a result of homogenization at 1,600° C for 1 hour. Alloy ingots containing more than 0.36 wt pet carbon (a calculated 2.9 wt pct VaC) following homogenization, cracked severely and failed by intergranular fracture upon swaging at 900° C.

Jan 1, 1965

By G. V. Sullivan, G. F. Workentine

Beneficiation studies were conducted by the Bureau of Mines on three samples of low- grade chromite - bearing material from the Stillwater complex of Montana . The objective of the study was to develop methods for recovering chromite from low- grade materials to improve the domestic reserve situation . Samples were obtained from the three largest deposits in the district , Mouat , Benbow , and Gish . The chromic oxide ( Cr₂ 0 ) content of the ore and of the chromite was about the same in each of the samples . The major gangue constituents ranged from clean olivine in the Mouat sample to such altered minerals as serpentine and talc in the Benbow and Gish samples . Tabling , flotation , high- tension electrostatic separation , and combinations of processes were applied to each ore . Treatment of the Mouat sample ( 9.95 percent Cr₂ 0 ) by high- tension electrostatic separation , a combination of tabling and high- tension electrostatic separation , and tabling with middling retreatment resulted in concentrates that graded 42.8 , 42.0 , and 40.7 percent Cr₂03 at chromium recoveries of 85 , 86 , and 84 percent , respectively . Other techniques were less selective . 2 The Benbow sample ( 7.75 percent Cr₂0 ) responded most selectively to tabling with middling retreatment and a combination of tabling and hightension electrostatic separation to produce concentrates of 40.1 and 39.5 percent Cr₂g with each process having a chromium 2 recovery of 69 percent . Response of the Gish sample ( 8.04 percent Cr₂03 ) to the various concentration techniques was about the same as that of the Benbow sample , but in general , somewhat less selective . A combination of tabling and high- tension electrostatic separation resulted in a concentrate that contained 71 percent The Mouat mine was reopened in 1953 when the American Chrome Co. contracted with the Federal Government to produce 900,000 tons of chromite concentrate . The ore , averaging 20.2 percent Cr₂03 , was treated by tabling to produce a 38.5 - percent Cr₂ O concentrate.

Jan 1, 1964

By Lewis C. Karrick, Martin J. Gavin

"Introduction.The theory of fractional ""education"" of oil from oil shale has been used by several inventors as the basis for the design of retorts for the production of oil from the oil shales of the United States. The term fractional ""education"" gives expression to the rather common belief that when an oil shales is heated it produces light, low-boiling oils as low temperatures, and increasingly heavier, higher-boiling oils as the temperature of retort¬ing rises. The theory evidently had its origin in the fact that crude petroleum may be fractionally distilled, yielding light oils at low distillation temperatures, and heavier oils as the distillation temperature increases is as, gasoline is produced from petroleum at relatively low temperatures, kerosene at higher temperature, and heavier products such as gas-oil and lubricating distillation at still higher temperatures.The writers have examined several oil-shale retorts designed to take advantage of the belief that crude, and in some cases refined, gasoline can be recovered from the shale at low temperatures; kerosene at higher temperat.res, and so on. Such retorts are usually designed to operate continuously and have several vapor-pipes lending from them at differing intervals and passing to separate condensers. Designers of such retorts repeat that the distillate from the low-temperature parts of the retort will be gasoline, and that as the shale passes to zones of increasingly higher temperatures, the vapor lines lending from these zones rill remove increasingly heavier products such as kerosene, gas-oil etc."

Mar 1, 1924

By S. Raghavan

An investigation of the possibility of improving the grinding characteristics of a gabbro ore containing copper and nickel sulfides via a thermal shock treatment technique has been carried out. The results obtained indicate that the breakage characteristics of the gabbro are particles can be significantly improved by preheating the are particles to a temperature around 400°C followed by rapid water quenching. For a given power input and feed size, the thermally treated material produces a product of much finer distribution than the untreated material. An assessment of the improvement in grindability has been made by calculating feed size selection functions for untreated and heat-treated materials.

Jan 1, 1981

By Len Blackman

The Absaroka-Beartooth Study Area is a tract of approximately 1.4 million acres of National forest land in southern Montana, part of the Greater Yellowstone Area. This study evaluated the mineral potential of four mineral terranes containing undiscovered resources in the area. The geological data is probabilistic, with estimates of the possible number: of deposits and their grades and tonnages. Possible future development scenarios range from no development to many mines, including some very large. As two thirds of the study area is within the Absaroka-Beartooth Wilderness, the future development scenarios reflect the area's mineral potential, not what we expect to see in the foreseeable future. Based on the analysis performed on these four terranes, the most likely future scenario for the study area would include the potential for two medium sized, (predominately) gold, mines, each employing a few hundred workers. There is a small chance, less than 5%, that a large Porphyry Copper or Superior Iron deposit would be discovered and be economically feasible to develop.

Jan 1, 1994

By Ann G. Kim

Acid drainage from underground coal mines and coal refuse piles is one of the most persistent industrial pollution problems in the United States: This Bureau of Mines report reviews the acid mine drainage problem generally and describes research currently underway to combat it.

Jan 1, 1982

By J. G. Donaldson

Nickel containing less than 0.01 percent of total metallic impurities was produced at the Rolla Metallurgy Research Center of the Bureau of Mines by electrodeposition from purified electrolytes. The first report on this research4 described purification of electrolytes by selective precipitation and by liquid-liquid extraction. This second report describes a procedure: or electrodepositing high-purity nickel from electrolytes purified by passing a nickel ammine solution through a column of an ion exchange resin. The nickel electroplated directly from the ammine solution without further treatment; a titanium cathode and two platinum anodes were used. The nickel deposit was dense, smooth, and adherent, and contained less than 0.001 percent each of cobalt, copper, and iron, and spectrographically detectable traces of aluminum, magnesium, and silicon. Nonmetallic impurities in the nickel metal were carbon and sulfur, each present in concentrations of less than 0.01 percent. The results of several experiments planned to purify solid nickel salts by zone refining are also reported. These salts, after purification, were intended for use in preparing electrolytes for deposition of high-purity nickel. Results were not encouraging so that the more promising ion exchange procedure was emphasized chiefly.

Jan 1, 1962

By C. H. Herty

[Ferromanganese continues to be in indispensable requirement in steel manufacture. Approximately 470,000 tons of the 80 per cent ferro-alloy was consumed in 1929 and increasing amounts will be required annually by the steel industry unless some satisfactory substitute is found. An average of 14 pounds of metallic manganese is for each ton or steel produced, The principal use of manganese is for deoxidation of the metal in the steel refining processes, although a considerable amount r s also used for the production of special manganese steels. Unfortunately, domestic production of manganese ore is inadequate to meet normal peace-time requirements, not to mention increased abnormal war-time demands.]

Jan 1, 1930

As part of a continuing program of evaluating the Nation's crude-oil resource, this report presents information pertaining to resource, primary reserve, and potential waterflood reserve for 3,209 selected reservoirs contained in 24 oil-producing States, as of January 1, 1968. To that date the selected reservoirs had not been subjected to pressure-maintenance or secondary-recovery operations. These reservoirs also met the following parameters: (1) a minimum of five oil-producing wells on January 1, 1968, (2) a minimum of 50 acres areal extent, (3) a minimum of 50,000 bbl of oil ultimate primary recovery, and (4) the principal reservoir energy was other than active water encroachment. The selected 3,209 reservoirs produced 527 million bbl of oil in 1967, about 17 pct of U.S, total production. Primary oil reserve was 4,983 million stb; in addition, there was 6,043 million stb of potential water- flood oil reserve. Oil resource in the selected reservoirs was 59,547 million stb. A brief history and outlook of waterflooding are presented for each State. Depth and producing rate statistics and geologic distributions of production, resource, reserve, and potential waterflood reserve for the selected reservoirs are presented by States in the appendix. Also included in the appendix are description, history, and technique modifications of waterflooding, and a preliminary cost estimate of a closed-system water-injection project.

Jan 1, 1970

By H. J. Coleman

Knowledge of the types of naturally occurring sulfur compounds in petroleum is of both theoretical and practical interest to petroleum chemists and geologists. This knowledge has been extended by the identification of 77 sulfur compounds, including 36 thiols, 23 chain sulfides, and 18 cyclic sulfides in a 111° to 150° C boiling range distillate of Wasson, Texas, crude oil. The characterization procedure used in separating and identifying these compounds included isothermal distillation, vacuum fractionation, liquid-solid chromatography (alumina adsorption), chemical treatment, gas-liquid chromatography, microdesulfurization, and infrared analysis. The procedural steps described represent a systematic method of sulfur compound analysis considered applicable for determining the nature and concentration of the sulfur constituents present in any straight-run petroleum distillate of the above-boiling range.

Jan 1, 1966

By J. H. Field

Capital and operating costs have been estimated for removing sulfur dioxide from flue gases of a powerplant of 12,000-kw. capacity by liquid-purification processes, using limestone, ammonia, or sodium sulfite as the reactant. The annnonia and sodium sulfite processes yield end products that may be marketable. Coals containing about 1.5 and 5.0 percent sulfure have been considered. The sulfur dioxide content of the gases to be treated is 0.083 and 0.30 percent, respectively. Estimates have been made for 90-percent removal of the sulfur dioxide from both gases. A third instance has been considered in which 70 percent of the sulfur dioxide is removed from the flue gas of 0.30-percent concentration. The scrubbed gas would contain 0.09 percent sulfur dioxide, which might be within the permissible limit for discharge to the atmosphere in most areas. Although it is unlikely that flue gases with sulfur dioxide concentrations of less than 0.10 percent would require purification, a cost estimate for such a gas is included because an estimate is available for a British plant employing the limestone process at these conditions. Capital investment and operating costs, with no credit for products, are lowest for the limestone process for gases of both concentrations. Crediting the ammonium sulfate and sulfur produced in the ammonia process at their market prices at the end of 1956 of $32 and $28 per ton, respectively, the operating costs of the ammonia process become the lowest for purification of the gas containing 0.30 percent sulfur dioxide. The operating costs of the sodium sulfite process for purifying gas of high sulfur dioxide content approach those of the limestone process when the byproduct sulfur dioxide is credited at $14 per ton. Even if credit for products is allowed for the ammonia and sodium sulfite processes, the operating costs are higher than those of the limestone process for the gas of low sulfur dioxide content. Because of the large quantity of materials that would be produced by removing sulfur dioxide from a relatively small number of plants, credit for products should be allowed with extreme caution.

Jan 1, 1959

By Philip E. Niebuhr

A procedure, which can be performed in the field by nonanalytical personnel, is given for sensitive spot tests for detecting tellurium or selenium. The expressed need of a field test for detecting small amounts of tellurium, which may be accompanied by relatively large amounts of selenium, has led to the development of this method. Tellurium search has been impeded by the lack of a satisfactory test from the standpoint of sensitivity and specificity. A quantitative laboratory method exists, but it is expensive and relatively laborious. Several other qualitative tests are known, but they require unstable solutions, which must be freshly prepared for use, and a greater variety of laboratory equipment. The particular advantages of the test described are its simplicity and the stability of the reagents required, there-fore is is well adapted for field use. Also, this test was found to be of practical use in the analytical laboratory when screening samples, thereby reducing analytical costs. The roughly quantitative interpretation of the results can save time by indicating the approximate size of the sample taken for a quantitative determination.

Jan 1, 1962

By L. C. IlsLey

One of the details which the engineers observe closely in conducting tests on explosion-proof type equipment at the Pittsburgh experiment Station of the Bureau of Mines is the construction of covers and their means of fastening. These covers are of particular concern from a safety standpoint, because they are very liable to be frequently disturbed for the purpose of making inspection or repairs to internal parts of motors, controllers, etc. When depended upon to permit frequent inspections it is desirable from a practical operating standpoint that the cover be easily and quickly removed and replaced. The position that been taken by the Bureau of Mines is that the questio of ease with which covers will permit inspection should be determined by the mamu- facturer and the user. If the scheme used requires considerable effort, as in the removal of several bolts, it has been assumed that the one going to all this trouble to get the covers off could be trusted to put the cover back in place properly, especially as the approval plate generally calls specific attention to this point. Where a cover is simply screwed in place, fastened by a single bolt, or secured by a hing in or other similar arrangement, the bureau has not been willing to assume that the, cover would in all cases be properly fastened and has required further security by means of a lock or seal. In the course of its investigations the bureau has had occasion to inspect and test five types of covers as follows: (1) Covers having two plane surfaces bolted together. (2) Covers having two plane surfaces held together by lugs, clamps, or other means besides bolts. (3) Covers which have screw thread and fit a similar thread in the compartment. (4). Covers having plane surfaces with the addition of a tongue-and-groove joint at about the center of the plane surface and in general secured by hinge pins or similar means of fastening. (5) Covers in the form of an annular ring accurately fitted to a motor shell which can be rotated around the shell, and thus make easy access to inspection openings in the shell and rotated back again to effectively seal these openings. Tests. have also been made of large bolted covers having a smaller and more accessible cover within the large one, which could be opened for inspection purposes.

May 1, 1930

By James S. Browning

The Bureau of Mines conducted laboratory batch and small-scale continuous selective flotation tests of barite-fluorspar ores from two deposits near Marion, Ky., to determine the technical feasibility of recovering commercial grade fluorspar and barite concentrates. The lignin sulfonate-sodium fluoride method of floating the fluorspar successfully produced acid-grade fluorspar concentrates. Flotation of the barite from the fluorspar tailing using petroleum sulfonate collector yielded concentrates suitable for use in compounding oil-well drilling mud. The fluorspar and barite recoveries were about 82 and 85 percent, respectively.

Jan 1, 1963

By John P. Hansen

Batches of red or brown iron ore concentrates, weighing 100 or 200 grams, were reduced with gaseous reductants in a laboratory-sized fluidized-bed reactor. Using a loss of weight technique, the rates of reduction were measured and the effects of temperature, gas consumption, and gas flow rates were determined. Below about 725° C the rate of reduction was controlled by the chemical reaction at the reduction interface having an activation energy of about 10 kcal/g mole. Above about 725° C the rate of reduction appeared to be controlled by the flow of the gaseous reductant and therefore to be directly proportional to the flow rate. Above 725° C, hydrogen reduced the iron ore much faster than carbon monoxide. In gas mixtures, carbon monoxide or nitrogen reduced the hydrogen partial pressure and lowered the reaction rate proportionally. When present in large concentrations, carbon monoxide had a serious inhibiting effect on the reduction rate, probably owing to carburization and sintering of the reduced iron.

Jan 1, 1970

By Fred D. DeVanery

"INTRODUCTION Although galena is the most common lead-bearing mineral, is easily concentrated by gravity methods, and is readily susceptible to flotation, nevertheless some galena-bearing orebodies have within them small deposits of lead ore that fail to give a high recovery when treated by the customary milling methods.The secondary minerals, cerussite and anglesite, which result from natural oxidation of galena, cause losses when the customary method of lead-ore concentration is practiced. The identification of oxidized lead-ore minerals and the efficient concentration of a lead ore taken from the oxidized portion of an orebody which has previously yielded poor recoveries mere the objects of a recent investigation. Thus the ore examined was selected from a large orebody. The work was undertaken at the Mississippi Valley Experiment Station of the United States Bureau of Mines in cooperation with the Missouri School of Mines and Metallurgy, Rolla, Mo.DESCRIPTION OF OREThe ore was of a brownish color owing to oxidation of some of the iron minerals to limonite. The lead content was 6.80 percent, and a cursory examination showed that most of the lead was present as galena. Small amounts of sphalerite, siderite, and pyrite were readily identified. The chief gangue mineral was dolomite, accompanied by smaller amounts of calcite and glauconite."

Jun 1, 1933

By Thomas C. Denton

In 1965 Africa maintained its position as a region of the world essential to advanced non-Communist nations for supply of vital metals and minerals. The position stemmed from the fact that Africa produced in large quantity a number of key minerals of which either or both resources and production capacity elsewhere did not approach the needs of the free world. The Republic of South Africa alone contributed more than three quarters of the gold mined in the entire non-Communist world besides an estimated 60 percent of metals of the platinum group and the entire new supply of amosite asbestos, and Africa as a whole was nearly the non-Communist world's only source of gem and industrial diamond. Africa also accounted for 83 percent of non-Communist world cobalt production. Besides these massive contributions, Africa in 1965 provided 50 percent or more of the new supply from non-Communist countries of the following mineral commodities: Lithium minerals, corundum, manganese ore: and chromite, and over 20 percent of new supply from non-Communist countries of columbium-tantalum concentrates, antimony, beryl, vanadium, phosphate rock, and copper. Africa also accounted for 18 percent of the non-Communist world's output of uranium, 14 percent of its tin, 11 percent of its lead, 9 percent of its zinc, and 8.9 percent of its crude oil output. With respect to chromite, at yearend Africa's reserves of the mineral were far larger than those of all other non-Communist regions combined. This probably also held true for manganese ore. In the case of crude oil, the fact that Africa's share of non-Communist world output was 1.6 percentage points greater than in 1964 was significant, particularly inasmuch as the output rate was continuing to increase at yearend.

Jan 1, 1967