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By Arthur E. Wells

"The present and possible future commercial production of potash from various sources in the United Status is discussed below under the following heads:1. Potash from the saline lakes.(a) Nebraska lakes.(b) California lakes.(c) Other lakes.2. Potash as by-product from the cement kilns.3. Potash as by-product from the iron blast furnace.4. Potash from silicate rocks.(a) Feldspathic material.(b) Leucite rocks of Wyoming..(c) Sericite slates of Georgia.(d) Glauconite (greensand) of New Jersey.5. Potash from Alunite.6. Potash from organic sources other than kelp.7. Potash from kelp.In this discussion very little more than passing reference, if any, will be given to those projects which up to date have been developed only slightly, if at all, beyond the small scale laboratory stage, or for the development of which there appears to be very little financial and technical backing at the present time. Nether or not many of these proposed projects have merit can be determined only by an actual operating demonstration.Generally speaking, the potash industry of the United States has been hardly more than marking time since the armistice. This is, largely due to the fact that the consumers of potash have been expecting that heavy shipments of foreign potash to the United States would be resumed soon at somewhere near the pre-war prices, and they have not seen owing domestic potash at present prices for many months. The result has been that domestic producers have been unable to sell their product at even cost and many producers of potash have been obliged to close down. Thu Nebraska lake plants were closed down in February. The California saline plants were operating at below capacity, and the only large alunite plant is closed down. Even the cement plants have little or no inducements to recover the potash being lost in their waste gases and the production is very small at present.This condition will doubtless continue until a definite policy is decided upon as to the future importation of potash salts from Germany and. France. If unrestricted importation is allowed at prices even 50% greater than in 1913, only a very few, if any, of the domestic projects will be in position to compete with the foreign potash immediately, and the present industry will probably greatly decline with little or no prospect for a future resumption of the industry."

Aug 1, 1919

By D. J. Stoops, H. Kato, M. D. Carver

The effects of impurity elements silicon , aluminum, copper , nitrogen , and manganese , at 50 to 300 ppm, on properties of the zirconium alloy Zircaloy 2 were investigated . Variations in microstructure , mechanical properties , and corrosion behavior in some inorganic acid and salt solutions were observed with variations in level of impurity element . Corrodents were solutions of sulfuric acid , phosphoric acid , copper chloride , and iron chloride . Silicon was found to modify annealed microstructures by spheroidizing and dispersion of secondphase material throughout grains . Silicon or manganese improved ultimate and yield strength of the alloy without loss in ductility . All five elements affected corrosion rates of the alloy , the effect being generally different for each element .

Jan 1, 1964

By James H. Cobbs

The utilization of large diameter drilled holes for mine shafts seems to have had its beginning in Europe about 1850 (28) where the mining industries of Germany and The Netherlands first used drilled shafts. Recent shafts in softer formations of diameters as large as 25 feet and as deep as 1, 700 feet have been drilled in both The Netherlands and Germany. The first shaft drillers utilized cable tool or churn drilling techniques which limit both hole diameters and drilling speeds. Though some churn drilling of shafts is still performed, rotary drilling has been the dominant technique for many years.

Jan 1, 1973

By Wilson Blake

This report presents the results of a 7-year Bureau of Mines program to review, revise, and make an effective engineering tool of the microseismic method of determining the stability of rock structures. The program consisted of developing new microseismic equipment and data analysis techniques and extensive field investigations to demonstrate the effectiveness and potential of the broad-band microseismic method. The guidelines for choosing the components of a microseismic system are presented along with approximate cost figures. Different microseismic systems are discussed, including completely automated systems. Procedures for conducting microseismic investigations and analyzing microseismic data are discussed in detail. Field situations which show the full value of the microseismic technique as an engineering tool are described.

Jan 1, 1974

By M. H. Kline

Round Mountain is one of a number of locations investigated by the Bureau of Mines in its search for manganese deposits during the early phases at the strategic minerals program. The Suiter mine, on Round Mountain, had provided some 5,000 tons of manganese concentrates during the period 1917 to 1919, and early in 1941 prospecting by the Virginia Hardwood Lumber Co. in this same area had discovered manganese on what later became known as the Hall Pit. These promising indications encouraged the Bureau to begin an exploration project in search of additional reserves of manganese on Round Mountain in January 1942 (fig. 1).

Jan 1, 1948

By H. S. Kalman

A table of factors for rapid, accurate calculation of the volume of pure helium in cylindrical steel containers, at base conditions of 14.7 psia and 70° F, is presented. The table covers a pressure range from 10 to 10,000 psin in 10-psi increments and a temperature range of 0° to 120° F in 2° increments. The volume of helium is calculated from the observed pressure and temperature of the helium, expressed as a factor from the table, and the known internal volume of the container. The calculation requires a single multiplication. A discussion and evaluation of the accuracy obtainable and a derivation of the formula used (which takes into account compressibility of helium, thermal expansion of steel containers, and the stretch of steel due to internal pressure) are presented. An example showing how the table can be used is given also.

Jan 1, 1968

By B. W. Gandrud

This is the first report published by the Bureau of Mines on washability characteristics of coal from beds in Tennessee. It is based principally upon screen-sizing and float-and-sink tests of raw coal from a bed on the Cumberland Plateau. Stripping operations were undertaken recently on this bed by the Cumberland Collieries, Inc., near Chalybeate,Van Buren County, Tenn. The bed has not been definitely correlated, but it may be an extension of the Sewanee bed, which has been mined extensively in the Tracy City district to the south-vest and at points near Dunlap and Pikeville to the southeast and east. It was spoken of by officials of the Cumberland Collieries as the Sewanee bed at the time of sampling for this study. In a letter dated October 16, 1948, W. D. Hardeman, geologist of the Department of Conservation, Nashville, Tenn., states: "The stripping operations of the Cumberland Collieries near the old postoffice at Chalybeate are, I am fairly certain, in the upper part of the Whitwell shale, which carries the Sewanee coal. This coal may be a stray seam, but it probably can be correlated with the Sewanee coal, which is mined farther east. "There are no detailed geologic maps or reports covering the area, and this opinion is based on what was observed in visiting the strip mines in that general vicinity." The laboratory work upon which this report is based was done at the Southern Experiment Station of the Bureau of Mines, United States Department of the Interior, in cooperation with the University of Alabama and the Cumberland Collieries, Inc.

Jan 1, 1949

By William K. Cunningham

The investigation described in this report was begun as part of the Bureau of Mines progress to develop acid processes for the extraction of alumina from low-grade bauxite and. clays. A domestic shortage of high-grade bauxite sui table for treatment by the Bayer process became acute as a result of' World War II; an intensive search for a practical acid process using lower-grade alumina-bearing raw materials was therefore warranted. The laboratory development was described in a preceding Bureau of Mines publication wherein the basic theory for the design and erection of a pilot plant maybe found. A 2-ton-per-day continuous pilot plant was constructed and successfully operated at College Park, Md., which demonstrated conclusively the chemical and mechanical feasibility of a solvent purification process for aluminum sulfate. The estimated production cost of $38.64 indicates that under present market conditions the process would not be economically feasible.

Jan 1, 1948

By G. Richards Gwinn

In modern warfare, mica is truly indispensable. Coordination of combatant units necessitates maintenance of intricate communications equipment, in the construction of which high-grade sheet mica is essential. Scrap, ground, and the poorer qualities of block mica, which are less essential to the military program, are not considered in this paper. Furthermore, as the paper is designed primarily to assist mica miners, mica derivatives, Such as splittings and films, also are excluded from discussion. The paper therefore relates solely to block mica of strategic quality. Understanding of t e many factor involved in marketing mica is definitely advantageous to mica, miners. The nature and detrimental effects

Jan 1, 1943

By J. M. Goris

Cable bolt supports are becoming an important ground control technique in underground mines in the United States and Canada. They show great versatility and are adaptable for use with many mining techniques, they have high load-carrying capacities, they can be installed in small areas with low roots, and they are cost effective. Investigators in a number of research institutes in North America have conducted studies to assess the material and support properties of cable bolts, evaluate their support capabilities under various mining conditions, and provide design criteria for using cable bolt supports as roof control systems under varying mining conditions. While conducting these studies, personnel have collected important information on the history, application, performance, and economics of these supports. This U.S. Bureau of Mines report documents this information so that ground control personnel unfamiliar with cable bolt supports can gain an understanding and appreciation of their use. A comprehensive bibliography of technical information on cable bolt supports was selected by the authors and is also presented.

Jan 1, 1994

By John B. Goodman

This report summarizes the work done by the Koppers Company, Incorporated, in cooperation with the Bureau of Mines on the commercial evaluation of the primary low-temperature tars produced from Texas lignite in the Rockdale, Tex., plant of the Aluminum Company of America in conjunction with the Texas Power and Light Company. The interest of the Bureau of Mines in this project is twofold. First, through its cooperative agreement with the Texas Power and Light Company the Bureau has assisted in the technical design and practical operation of the prototype, externally heated, entrained-state carbonizer for producing char for electric-power production and for primary low-temperature tar. Second, the first successful operation of the prototype carbonizers employing the Bureau of Mines-Parry process on lignitic coal in 1953-54 led to the production of large quantities of primary lignitic tar, concerning which too little was known or had heretofore been published in this country.

Jan 1, 1959

By W. L. Falke

This Bureau of Mines report illustrates critical path planning and scheduling techniques as applied to typical mining operations. Detailed examples of arrow diagramming and computer oriented applications of critical path methods are given. Program Evaluation and Review Technique (PERT) is discussed briefly in comparison to the Critical Path Method (CPM).

Jan 1, 1966

Objective: Improve the dust control effectiveness of enclosed operator cabs on surface mining equipment.

Oct 1, 2007

By M. R. Geer

The Bureau of Mines examined the washability data for 25 Appalachian coals requiring low-density washing to reduce sulfur content to 1 percent, using the distribution-curve method. The purpose was to estimate how closely theoretical sulfur values could be approached, what yields of washed coal could be expected, and the recovery efficiencies that might be achieved. Assuming that the run-of-mine coal would be crushed to 3/8 inch and cleaned in dense-medium cyclones, the calculations indicate that theoretical sulfur contents could be approached closely when cleaning at a specific gravity of separation as low as 1.30. With coals that have favorable specific gravity compositions the recovery efficiency anticipated for cleaning at 1.30 specific gravity is surprisingly high. Similar calculations for cleaning with concentrating tables at intermediate specific gravities indicated that theoretical sulfur contents at 1.50 specific gravity could be approached closely with some coals but not with others. The calculations suggest that operating a table at a specific gravity of separation much lower than about 1.50 probably would be unsatisfactory with most coals.

Jan 1, 1968

By Irving Kabik

Chlorates and perchlorates, when mixed with certain reducing materials, may give a detonating explosive of considerable power. Concerning explosive chlorate mixtures, Guttman3/ states that they "have at all times fascinated inventors on account of the large amount of oxygen stored up in potassium chlorate, which can be given off so readily. When Lavoiser and Berthollet tried to make a chlorate powder in a stamp mill in 1788, they made a great show of it, and even two ladies were present. Unfortunately, after a certain amount of pounding the powder exploded and killed an official and the daughter of the Government commissary, who assisted at the experiments.***. It is interesting to observe how the same old mixtures are proposed over and over again with slight alterations only, in order to qualify for a patent. Potassium chlorate with some carbonaceous matter like charcoal, sugar, starch, glycerin, flour, or sometimes a vegetable or mineral oil and the like occurs again and again." Sprengel explosives, in which some of the undesirable sensitivity of the chlorate was minimized by coating the crystals with a liquid reducing agent, received some attention after a patent was issued to Dr. Herman Sprengel in England in 1871.4/ A somewhat similar explosive, known as Rack-a-

Jan 1, 1945

By Jr. Blake

This work was done to determine the technical feasibility of using the Pedersen process to produce cell-grade alumina and an iron byproduct from the high-silica and titania bauxites of the Pacific Northwest. Smelting of these bauxites with lime and coke at about 1,750° C in an electric arc furnace produced calcium aluminate slags in which at least 80 percent of the alumina was leachable by sodium carbonate solution. After a lime-desilication of the sodium aluminate leach liquors, neutralization of these solutions with carbon dioxide resulted in precipitation of an alumina hydrate of sufficient purity for calcination to cell-grade alumina. Recoveries of byproduct iron averaged over 90 percent; however, the iron contained about 1 percent phosphorous and would require additional refining. Additional small scale tests on these slags showed the following: (1) Titania had little effect on leachability if sufficient additional lime was added to form calcium titanate (CaO.TiO 2); (2) a slag containing about 14 percent silica required a slower cooling rate than one containing 7 percent silica for formation of high percentages of soluble aluminates; and (3) high-silica slags leached better at room temperature for long periods than at 65° C for shorter periods, but low-silica slags leached well by either method.

Jan 1, 1967

By John C. Machisak

THE INJURY data and experience at quarries and related plants of the United States are presented in this publication under the following general sections (A) General injury experience: Tables 1-3: Current data on number of injuries, injury-frequency rates, location, accident agency, degree of injury, and related employment data. (B) Injury experience at different kinds of quarries: Tables 4-5: Current data on number of injuries, injury-frequency rates, location, accident agency, degree of injury, and related employment, data. (C) Injury experience by States: Tables 6-20: Current data on the number of injuries, injury-frequency rates, accident agency, degree of injury, and related employment data. (D) Selected injury data: Tables 21-30: Current data on various selected factors of operating conditions at different kinds of quarries, including employment size-groups, length of shifts, comparative severity of injuries, and injury data and related employment experience at dimension-stone and nondimension-stone quarries and at underground quarries. (E) Historical injury experience: Table 31: Injury and employment data on the quarrying industry for 1911 through 1957. Statistical data on injuries and related employment in the quarrying industries have been collected annually from the operating companies since 1911. Reporting to the Bureau of Mines is voluntary; there is no Federal law compelling operators of quarries and related plants to supply such data. Data presented herein may not be complete for the entire industry. They are however, believed to be representative of the hazards common to all quarry and related workers. Moreover, the figures are comparable as between States-a significant fact in view of the lack of uniformity among the States with regard to the classes of injuries covered by State reports and other factors that tend to make it impracticable or impossible when using State records to

Jan 1, 1960

By Arthur Crowfoot

This paper describing t o concentrating practice of the Phelps Dodge Corporation, Morenci Branch, at Morenci, Ariz., is one of a series of articles on concentrating methods and posts being prepared by the Bureau of Mines. The Morenci concentrator, locally known as No. 6 concentrator, treats 5,000 dry tons of ore per 24-hour day by primary tabling followed by two stages of flotation treatment, at 48-mesh size and 65-mush size respectively.

Jan 1, 1931

By Jr. Koch

As a part of a larger study of the distribution of metals within ore deposits, the geometry of distribution of gold, silver, lead, copper, and zinc in five veins of the Fresnillo mine, Zacatecas, Mexico, was established. The purpose was to obtain basic data necessary for evaluation of geological theories about processes of vein formation and useful for practical mining applications in ore estimation and prediction of ore beyond present workings. The Bureau of Mines investigation comprised statistical analysis of 64,000 assay values from some 16,000 mine samples. The samples were taken at 2-meter intervals in drifts exposing the veins through a vertical range of some 750 meters. Within individual veins, the metals are distributed in dome¬like patterns with highest metal contents tending Lo occur in oreshoots at the centers of the developed parts of the veins. However, in the block of ground containing all five veins, base metals define mathematical domes with highest contents near the center; precious metals define mathematical basins or troughs with low contents near the center. The ratio of silver assay values to lead assay values corresponds to two geographically distinct types of mineralization: one in which silver is closely related to lead, and another in which silver is independent of lead. Other metal ratios also vary regularly from one place to another. The statistical methods employed in this study would be useful for other geologists or engineers who need to analyze large amounts of assay or similar numerical data.

Jan 1, 1967

By Robert H. Peters

Several significant problems associated with employee turnover among underground miners are described in this Bureau of Mines report. Although a vast amount of research has been conducted on turnover among employees in nonmining industries, there has never been an attempt to empirically investigate the causes of turnover among underground miners. This report presents the results of empirical research on employee turnover in other industries and describes and critiques the research methods that have been used to investigate turnover. Using the findings on employee turnover in other industries and known data about miners and the mining industry, a conceptual model of the factors that cause turnover among miners was generated. This model, which is expected to provide a basis for later empirical studies, is presented. Several recommendations for controlling miner turnover are also presented.

Jan 1, 1986