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By H. D. Hess, C. P. Mabie

This report describes in detail the results of petrographic research conducted on 21 phosphate ores representing important deposits in southwestern Montana , southeastern Idaho , and northeastern Utah . The ores are described and categorized by mineralogical and chemical composition , thermal behavior of organic carbon , and textural constitution . Descriptive and genetic classification schemes applicable to western phosphate ores are discussed ; results from related studies made of the collophane mineralogy are also presented . The latter studies were centered on determining unit - cell dimensions and CO₂ , P2O5 , and fluorine content of collophane concentrates of 11 high - grade phosphate- rock hand specimens selected solely for this purpose . On the basis of this investigation , operational methods have been developed for quantitatively describing textural and compositional features that are likely to be significant in determining the response of phosphate ores to conventional beneficiation treatments ; systems for classifying the ores in relation to these features have been proposed . Studies to date point out distinct textural and compositional variations in the western phosphates and illustrate their importance in determining optimum beneficiation procedure .

Jan 1, 1964

By John C. Hartley

Three systems that monitor ventilating fans are described. These electronic monitoring systems automatically perform most of the operations required to conform with the provisions of the Federal Mine Safety Code in the event of fan failure or slowdown.

Jan 1, 1964

By R. S. Fowkes

Jetstream pressure distributions and coal cutting rates were determined for a number of nozzles and under different operating conditions. The jetstrearn pressure distribution data were fitted to an assumed curvilinear equation by the utilization of a numerical least-squares technique with the aid of a digital computer. Subsequent manipulation of the approximation equation showed that the total force of the jetstream, rather than its maximum pressure or total kinetic energy per unit Lime, was the most significant quantity affecting the coal cutting rate. A shorter method for assessing the ability of a nozzle to cut coal was found.

Jan 1, 1968

By John Nagy

Experience and research have shown that an effective way to reduce structural damage from explosions is to provide adequate pressure-relief vents in the walls of equipment and buildings within which explosions might occur. In general, free or unrestricted openings represent the most efficient type of vent. However, in many manufacturing operations it is impractical to use free vents, and it becomes necessary to cover the openings with diaphragms or blow-out disks, hinged panels, or other devices, in order to give protection against weather changes, to prevent the efflux of dusts or vapors from equipment during normal operations, or for other reasons. A few data on the pressure-relieving capacities of hinged panels and a paper diaphragm were published in Bureau of Mines Report of Investigations 3924, which covered the first phase of the dust-explosion venting study made by the Bureau. The present report describes recent experiments that were made to determine the relative effectiveness of an unrestricted vent and 22 types of closures, including various paper, cloth, and metal-foil diaphragms, hinged doors or panels, and several kinds of scored and unscored glass panes. The tests showed that many of the vent closures were effective in releasing the explosions rapidly during their incipient stage, so that the development of destructive pressures was prevented. Vents of this type should prove useful in safeguarding industrial equipment from severe explosion damage. The experiments disclosed that the venting capacities of the diaphragms are approximately inversely proportional to their static bursting strengths.

Jan 1, 1950

By John W. Brown

Electrical resistivity surveys were conducted at three sites in Wyoming in an attempt to detect underground rubble zones in oil shale and to determine their size and resistivity contrast. The zones were detected at Rock Springs sites 4 and 5, but none were detected at Green River site 1. The resistivity of the rubble zones at sites 4 and 5 is greater than that of the surrounding rock. The zones at sites 4 and 5 are concluded to be roughly ovaloid in shape, with a horizontal diameter of 33 m and a vertical thickness of 24 m. Both rubble zones and the blasting that created them are considered to be centered at a depth of 24 m.

Jan 1, 1972

By Earl L. Hastings

Although the principal market for diatomite in the United States is in the East,4 production of the material is presently restricted to the West, because the deposits are larger, mining costs are cheaper, and the quality of product is better than that obtained from other domestic deposits. However, Tallahatta diatomite, occurring in Choctaw and Clarke Counties, Ala., has a freight rate advantage, which should encourage competition for those market that are now being supplied with the purer diatomites from the western deposits. For this reason, diatomite occurrences in the Tallahatta formation were examined by the Bureau of Mines and physical properties of samples from the deposit were determined to obtain additional data for use by any potential producer who wished to evaluate the material for its commercial possibilities. In 1894 K. M. Cunningham5 found that the buhrstone formation (now known as the Tallahatta formation) contained "siliceous shells of marine diatoms, radiolaria and foraminifera, thus being rather of the nature of tripoli or diatomaceous earth than of a true clay." Cooke6 and Semmes7 also reported the Tallahatta formation to be composed principally of diatomaceous earth with accompanying beds of sand, clay, and sandstone.

Jan 1, 1963

By P. M. Sullivan

This report describes a new application of electroamalgam metallurgy in recovering all the zinc as refined metal from galvanizers' sal skimmings. Pure zinc was recovered by electrolysis of skimmings leach liquors in amalgam cells. The following information was gained as a result of literature studies and subsequent laboratory investigations. 1. Reports in the literature indicate that pure zinc can be recovered from chloride solutions with the aid of amalgam cells. From Europe it was reported that amalgam cells could be used to recover pure zinc and chlorine from leach liquor obtained from pyrite cinders following a chloridizing roast.

Jan 1, 1956

By R. T. Johansen, R. J. Heemstra

In water flooding the gradual accumulation of insoluble materials on the sand face causes the injection pressures to increase while decreasing the amount of water injected . This plugging material often is composed primarily of insoluble precipitates of calcium , iron , and magnesium . Treatment with sodium tripolyphosphate ( STP ) either eliminates or reduces the formation of precipitates . Field tests are discussed showing the almost immediate effects of using STP in the injection water . Methods of treatment , solubility of STP in fresh water and brines , and precautions to observe when starting to treat a waterflood with this chemical are given . Laboratory data show that the preferential wettability of a crude oil for reservoir rock can be reversed by adding a small amount of STP to the flooding water . This reversal in wetting tendency should not only decrease the injection pressures but also increase oil recovery by improving the sweep efficiency of a water flood .

Jan 1, 1964

By R. S. Dean

[Methods s of preparing the manganese metal that has been used in chemical and metallurgical investigations have passed through a cycle. Most of the investigations made e before the turn of the century, used Moissan's pyrophoric man manganese.3/ This material was made b; electrolysis into a mercury cathode and distillation in vacuo. The material was essentially pure, and investigations in which it was employed (with proper precautions against oxidation) led to accurate results on tie intrinsic behavior of metallic manganese.]

Jan 1, 1941

By O. C. Blade

The use of Diesel fuel as a source of power is continuing to increase in the United States. The latest available figures indicate that refineries are delivering in excess of 10,000,000 barrels of this type of fuel per month. Factors contributing to this increased consumption are conversions by a number of railroads from steam to Diesel locomotives and the growing use of Diesel engines in buses, trucks, tractors, earth-moving machinery, water craft, and stationary power plants. The increasing importance of Diesel fuel has led to a need for more information on its characteristics, particularly on the grades and qualities currently being marketed. To supply this information the American Petroleum Institute and the Bureau of Mines, United States Department of the Interior, under a cooperative agreement, are conducting annual surveys of Diesel fuels produced in refineries in this country. Samples of Diesel fuel were analyzed by the manufacturers in accordance with instructions from the Motor-Fuels Survey Panel of the Automotive Research Committee of the American Petroleum Institute. Results of the analyses were transmitted to the Bureau of Mines where the data were studied am compiled as shown in the tables of this report. The first survey was made in 1950 and was published as a Bureau of Mines report. The present report shows the results of a similar survey made during 1951.

Jan 1, 1951

By G. V. Sullivan

The Bureau of Mines conducted preliminary beneficiation studies of a gold-bearing graphitic schist from Blue Hill, Tallapoosa County, Ala. The average analysis of the material was 0.08 oz/ton gold. Tabling of minus 35-mesh material recovered 83 to 94 percent of the gold at grades of 6.925 to 2.165 oz/ton, respectively. A combination of jigging and tabling resulted in a concentrate assaying 24.3 oz/ton gold and contained 87 percent of the total gold. Treatment of the material by jigging, tabling, and amalgamation recovered 86.5 percent of the gold.

Jan 1, 1969

By F. M. Goodwin, John Campbell, G. W. Jones

"INTRODUCTION In cooperation with the Boston Edison Co. and the Boston Consolidated Gas Co. of Boston, Mass., a survey has been conducted continuously since 1929 by the Bureau of Mines to determine the general hazards of combustible gases and vapors in manholes of the Boston Edison Co. The New England Telephone & Telegraph Co. also has cooperated in the investigation, and tests have been made in its manholes from May 1, 1933, to October 15, 1937. Yearly reports. 6/ on the results obtained since the beginning of the survey have been published.The methods and procedure of conducting the survey in 1937 were the same as heretofore."

Jan 1, 1939

By Jos. R. Guiteras

The present discussion first presents data to justify the fireproofing of mine shafts. This is followed by a brief outline of fireproofing methods with examples from practice. A summary of authoritative recommendations on fire prevention concludes the discussion. Acknowledgment is made to D. J. Parker, district engineer, Mine Safety Station, Salt Lake City, Utah, for his valuable criticism of the paper. Fireproofing a mine shaft implies lining the shaft with fireproof material or rendering fireproof the material already composing the shaft lining. A brief study of the part mine shafts and shaft stations have played in disastrous end tragic underground fires furnishes convincing evidence that every possible effort to make all mine shafts fireproof is amply justified. The fire hazard in coal minus obviously is much greater than in metal mines. In this discussion the point of views is mainly that of the metal miner; it is tine opinion of the writer that all fires in metal mines are preventable.

Jan 1, 1939

By E. J. Lintner, J. R. Thoenen

During the period 1937-40 and until peacetime research was superseded in 1941 by wartime activities , the junior author was engaged in studies regarding the relative efficiency of operating methods in quarries producing crushed stone for mineral aggregates . The results of some of these studies were published as reports of investigations in 1939 and 1940 ; / others were discontinued due to war demands on personnel and time . The published reports discussed the efficiency of particular quarry operations with respect to the time consumed and without reference to costs or mechanical factors . • At the time , the field data were collected for the published reports other data were collected relative to the relationship of the numerous variable factors inherent in the operation of a churn drill to the ability of the drill to produce blast holes . The churn drill is essentially a crusher and depends. for its performance upon the foot-pounds of energy it can impart to the cutting edge of its bit . The gravity stamp mill , so well-known in western gold mines , is essentially the same type of crusher . The ratio of foot- pounds necessary to crush the rock , to the total theoretical energy developed by the falling churn- drill tools , affords a good means of evaluating the efficiency of the tool . This does not include to tal over-all efficiency involving the mechanical equipment of the drill itself or its power unit .

Jan 1, 1947

By Jr. Herty

As the problem of inclusions in steel has become increasingly important, more and more attention has been paid to the source of the oxide inclusions in steel. In killed steels the oxide inclusions are traceable to the reaction of deoxidizers with the iron oxide dissolved in the steel during the refining period of the open-hearth heat. In a large class of steel known as "rimming steel" the action of the steel during solidification depends entirely on the gas evolved, and this evolution in turn is controlled by the amount of iron oxide in the liquid steel in the mold. It is therefore of great importance to be able to determine the amount of iron oxide dissolved in steel and to devise methods for the control of iron oxide in any class of steel. The object of the present investigation was to obtain a true value of the oxygen con-tent of liquid steel. If the steel has not been deoxidized, the greater percentage of the oxygen is present as iron oxide in solution.

Jan 1, 1932

By W. G. Pariseau

A two-dimensional finite element program has been modified and extended to account for some of the rock mechanics complexities associated with single entry development of longwall coal mine panels. Program capability includes arbitrary assignment of element properties without regard to element ordering, anisotropic elastic, plastic and brittle rock properties that may be time dependent (aging), arbitrary mining sequences and provision for the effects of artificial support on the adjacent strata. Failure is according to an extended von Mises criterion that may be linear or quadratic in form; flow rules are obtained from the yield function taken as the plastic potential, but brittle behavior is treated as a discontinuous process of material properties change with deformation. In either case the extent of failure is calculated from the external boundary conditions. Application of the program to essentially two-dimensional problems resulted in lose agreement between calculated displacements and field measurements in the double entry system. Bleeder entries were stable in one locality and not in another. Artificial support had little influence on stability.

Jan 1, 1978

By D. Bienstock

In connection with air-pollution studies, the Bureau of Mines is cooperating with the U.S. Public Health Service in investigating the use of solids for removing sulfur dioxide in concentrations of less than 0.5 percent from combustion and waste gases. Removal of sulfur dioxide at flue-gas tempera¬tures would no longer result in the cooling of scrubbed gas, which is inherent to liquid scrubbing processes used exclusively in industry today. Results are reported of extensive investigation, using metallic oxides as absorbents, adsorbents, and oxidation catalysts at 130° and 330° C. (temperatures at which flue gas may be treated in powerplant practice). The most active absorbents tested were the oxides of manganese, cobalt, copper, and alkalized alumina; 23 to 33 grams of sulfur dioxidn were removed by 100 grams of absorbent at 130° C., while scrubbing more than 90 percent of the sulfur dioxide from a simulated flue gas, and 19 to 61 grams of sulfur dioxide were removed at 330° C. A more detailed study is reported on absorption and regeneration, using manganese oxides and alkalized alumina. Adsorption of sulfur dioxide on activated carbons and molecular sieves at elevated temperatures is considerably less efficient than removal by absorption--a maximum of 7 to 8 grams of sulfur dioxide could be removed with 100 grams of adsorbent at 130° C. A potash-promoted vanadium pentoxide is effective in converting sulfur dioxide to trioxide; complete conversion in a simulated flue gas containing 0.35 percent sulfur dioxide was obtained at 365° C. Pilot-plant and cost studies are being made by the Bureau to determine the economic feasibility of removing on an industrial scale the sulfur dioxide present in gases in low concentrations.

Jan 1, 1961

By J. C. Franklin

The Spokane Mining Research Center of the Federal Bureau of Mines is placing major emphasis on chemical stabilization as part of the ground support program. Development of polymeric material suitable for bonding rock fractures around the mine opening is one phase of the program. Some of the problems that must be considered are viscosity, applicability, adhesion, cure times, strength, toxicity, and flammability. Epoxies and polyesters were investigated, but shrinkage in polyesters caused redirected effort toward epoxies. Test results with the latter showed that bonded fractures in mine-roof strata were stronger than the virgin rock. Further tests showed that polymeric materials have good potential for bonding, and in conjunction with polymer roof bolts, are expected to result in an economic and useful new support concept.

Jan 1, 1974

By M. R. Geer

The use of the cyclone as a dense-medium cleaning device was first described by Driessen6/ in 1945, after development of the process in the Netherlands during the German occupation of World War II. A pilot plant was built in the Netherlands soon thereafter, and the first commercial plant was built in 1948. By 1958, 18 plants were operating or under construction.7/ Thus, economic factors in Europe, where the high cost of coal places a premium on efficient cleaning, dictated rapid adoption of the cyclone. American reception of the process differed. The Bureau of Mines presented the results of its own small-scale cyclone experiments in 1946;8/ showing a sharp separation between coal and impurity; adoption by industry now is taking place. There is now much greater emphasis on the efficient cleaning of fine coal, and the first American cyclone plant has begun operating; others are planned or under construction. With the present interest in improved treatment of fine coal, the Bureau of Mines felt that additional performance data on the cyclone would be helpful to industry. Therefore, a complete, open-circuit pilot plant was built to make cleaning trials on American coals covering a wide range of washability characteristics. Five raw coals and one middling product were included in the investigation, and each was cleaned at several densities; 17 cleaning trials are reported.

Jan 1, 1961

By P. M. Sullivan

The principles and application of amalgam electrolysis to the recovery of zinc and tin from secondary products were studied; this Bureau of Mines project was one phase of investigating the development of more efficient methods for processing iron-bearing zinc and tin to produce both base metals of high purity. Zinc of 99-99-percent purity was recovered from galvanizer's dross with recovery efficiency of 98 percent. Tin of 99.9-to 99.99-percent purity was recovered from hardhead with recovery efficiency of 81 percent. Both materials were treated by the same method in separate systems. Mercury was used to leach zinc from dross and tin from hardhead to form amalgams of each metal, both of which were subsequently refined electrolytically to produce high-purity metal. Impurities that were contained in both secondary products behaved as theoretically predicted; impurities that were insoluble in mercury remained as sludge in the leaching column. Except for lead, the readily amalgamated impurities were prevented from fouling the electrolyte by the blocking action of the amalgam electrode. Lead impurity in the tin-refining system dissolved and immediately precipitated as the sulfate. The primary advantage of the amalgam refining method lies in direct recovery of the extremely pure base metal from highly contaminated secondary material.

Jan 1, 1961