Search Documents

By James L. Elder, J. P. Capp, James J. Dowd

The Bureau of Mines and the Alabama Power Co., jointly, conducted the first experiment undertaken in the United States in underground gasification of coal in place, at Gorgas, Ala. Milton H. Fies, manager of coal operations, Alabama Power Co., proposed the cooperative investigation to Arno C. Fieldner, chief, Fuels and Explosives Branch, Bureau of Mines; and assisted in supervising the experiment. The objectives of the experiment were to determine whether coal in place could be burned successfully and whether the burning could be controlled; the effect of the fire on the coal bed and the overlying strata; and the yield and quality of gas that could be obtained.

Aug 1, 1947

By Ralph L. Brown

The chemical properties of the unsaturated members of the aliphatic series of hydrocarbons are such as to render them " made to order" starting points or basic . materials for the synthesis of hundreds of important organic chemicals . The tremendous quantities of these unsaturated compounds that are being produced daily in the various coal carbonization and oil refining processes , and which at present have little value other than that of fuel , render a survey of the identity and ex- tent of occurrence of these compounds important from the viewpoint of economic utilization and resource conservation The increased need of liquid fuel and the relatively early exhaustion of petroleum resources will eventually require every utilization of liquid fuel products obtainable directly or indirectly from coal . Accordingly , the Bureau of Mines took advantage of an opportunity for examining the gaseous unsaturated hydrocarbons found in the gas obtained when a mixture of water- Collection of the material gas tar and coal is distilled in a gas-making retort . for examination was made possible through the courtesy of the Trent Process Corporation , Washington , D.C. , which was at that time carrying on at the Georgetown Gas Works , distillation of " amal gams " prepared from various coals and oils by the Trent process for cleaning coals . Kanawha gas coal ( 70%) and water gas tar ( 30 % ) from the Washington Gas Light plant were used in the " amal gam" being distilled at that time . The results obtained in this examination are presented here .

Feb 2, 1922

By Richard F. Link, George S. Koch

Through the use of statistical methods, estimates of metal content and tonnage of an ore body made by using data from 18 diamond-drill holes are compared with actual values established with data from 1,829 drift samples. The reliability of the estimates made from the drill holes is assessed in several ways. The relationship of metal content (assay-width product) to grade is explained. It is concluded that useful estimates can be made from 18 drill holes provided that reasonable assumptions are made and certain risks accepted. The ore body investigated is the Don Tomas vein of the Frisco mine, San Francisco del Oro, Chihuahua, Mexico.

Jan 1, 1964

By BUREAU OF MINES

In 1948 the United States became a net importer of oil. Coupled with an unpre- cedented domestic production of 5,900,000 barrels daily, imports approximating 500,000 barrels made available a total supply of 6,400,000 barrels a day. Thus, by herculean effort, the oil industry was able to meet an extraordinary demand at home and, in addition, to ship abroad almost 400,00 barrels daily of petroleum and products. The country's oil position now differs greatly from that prevailing at the be- ginning of World War II. Then, actual oil production averaged about 4 million bar- rels a day, and productive capacity probably was greater than 5 million barrels a day. As the demand of the military and industrial machine grew with the rising tempo of the drive toward victory, the United States not only met its own needs but pro- duced about two-thirds of the total oil requirements of the Allied Nations, excluding Russia. As a people, we can be deeply grateful that the Nation's petroleum resources were adequate and sufficiently developed to support such a tremendous effort. Even in those critical hours when immediate needs were the paramount issues, a prudent Congress paused to contemplate the importance of an assured long-term supply of liquid fuels. From these deliberations came the Synthetic Liquid Fuels Act of 1944, which authorized research and development work on new sources of oil coal, oil shale, and agricultural and forestry products. ce World War II, a civilian demand for 6 million barrels of petroleum prod- ucts has become the order of the day every day. By drilling as many as 39,000 new wells a year, the production rate has been increased enough to meet domestic require- ments by a bare margin. Some imports were necessary, however, to fill both domestic and foreign demands, and these doubtless will increase. Is this policy of exploration within the United States and the development of oil in foreign countries adequate insurance for the fulfillment of our future national needs? This question has two aspects one purely civilian and economic in character and the other significant from the standpoint of our national defense. There are now approximately 4,000 producing oil fields in this country. At first thought, it would appear that production could decline in a considerable number of these fields without materially affecting the over-all daily output. However, 48 percent of the oil comes from only 111 major fields which contain 50 percent of the total proved domestic reserves. It is apparent, then, that the flow from large fields - having proved reserves of 100 million barrels or more each must be sustained if daily production is to be kept at the present levels. Essentially, this means that new major fields must be discovered about as rapidly or perhaps more rapidly than the older ones lose productive capacity. From 1940 through 1947, only eight major fields with estimated reserves of more than 100 million barrels each, were discovered and proved - an average of one such field a year. The total estimated reserve of these eight fields was less than 1 year's supply at the present rate of use. As drilling continues, some existing fields ultimately will prove reserves larger than those now known. Without a pronounced increase in the num- ber of major discoveries, however, the prospects for increasing our present productive level are not encouraging. Any gap that appears between domestic productive capacity and demand could be filled with supplies from proved oil resources abroad. Assuming cheap pipe-line and tanker transportation to the United States, freedom from exorbitant taxes and charges

Jan 1, 1949

By D. E. Redmon

Linear programing provides a mathematical technique by which activities can be planned in such a way that an optimal result is obtained. Routine applications of linear programing require only a knowledge of algebra. However, a complete understanding of the fundamentals of linear programing requires a knowledge of advanced mathematics. The purpose of this publication is clarification of terminology and illustration of applications in comparatively simple mining problems. Two mining situations are considered: Mine stopes from which ore is to be produced at a minimum production cost; also, uranium mines from which ore is transported to one mill, a maximum monetary value is desired. The details of data arrangement for solution by linear programing are described and the solutions are presented. Results of these solutions indicate successful applications of linear programing to mine production scheduling.

Jan 1, 1964

By John H. Soule

Although known since 1902 , the Capitan iron deposits have not been mined mainly because of the low grade of the ore . A small amount of exploratory work carried on at an early date was reported . C. E. Johnson , district engineer of the Bureau of lines for New, Mexico , visited this propert , and as a result of preliminary sampling and mapping by the Bureau3/ and the Federal Géological Survey , an exploratory project was conducted during March , April , and liay 1944. Further mapping and logging of the vagon -drill samples was done by V. C. Kelly , geologist , of the Survey .

Mar 1, 1947

By Hans M. Cassel

The specific objective of research presented in this report was clarifi- cation of physicochemical fundamentals of the mechanism of dust explosions. The equipment, techniques (chiefly photographic), and dusts (chiefly graphite and light metals) employed are described. From behavior of individual par- ticles, conclusions are drawn as to their cooperative function in ignition and combustion of dust clouds. Results are interpreted using thermal theory as accepted for combustible gas mixtures. Radiative transfer across the flame front, as a characteristic of dust flames, is given particular atten- tion. Related studies by other investigators are discussed.

Jan 1, 1964

By R. T. Stull, G. A. Bole

Previous Work . The Bureau of Mines reported a survey of bond clays for graphite crucibles at the American Mining Congress which met at St. Louis in November , 1919 *** . The report contained information in regard to : (a) tests carried on to determine the effect of substituting Canadian and Alabama graphites for Ceylon graphite in varying proportions . The data indicated that Alabama graphite is superior to Canadian graphite and further , that Alabama can be substituted for Ceylon graphite to a large measure without lowering the quality of the ware . These tests were made on No. 70 size brass melting crucibles and were carried out under foundry practice . (b ) Tests were reported in which an attempt was made to modify the nature of Alabama graphite by heat treatment so as to resemble Ceylon graphite . Little advantage from the treatment was reported . With this general information as a basis , the experimental work proceeded along two lines : A study of bond clays for steel -melting crucibles and for brass -melting crucibles . Twenty- one sets of standard-size crucibles were made up of a body containing Ceylon graphite as standard , bonded with 21 bond clays . These tests were carried out under foundry practice as were the former tests . Three domestic clays proved to be superior to the standard Klingenberg clay formerly used in brass -melting practice while in the steel - melting industry , 13 domestic clays gave service superior to Klingenberg clay .

Aug 1, 1923

By Leonard Obert

A triaxial procedure is described for measuring the modulus of elasticity and Possion's ratio of stress relief cores , that is , the concentric hole cores obtained by the overcoring technique . The elastic constant determinations can be made at stress levels comparable with those encountered in underground mining . The results from tests on an aluminum alloy calibration specimen and four rock specimens are included .

Jan 1, 1964

By R. R. Sayers

The effect of comparatively low concentrations of carbon monoxide for short periods and under normal air conditions.of temperature and humidity , with the subject at rest , was studied by Dr. Yandell Henderson and his co -workers . In making recommendations to the New York and New Jersey tunnel commissions * he advised that , if the New York New Jersey vehicular tunnel be so ventilated that persons passing through the tunnel would be exposed to not more than 4 parts of carbon monoxide in 10,000 parts of air for not longer than 45 minutes , they would experience no ill effects . supplementary experiments , carried out by us in connection with our studies at the Bureau of Mines experiment station at Pittsburgh, substantiated this advice . ** In continuing our studies on low concentrations of carbon monoxide , we made a few experiments in a gas chamber where the conditions could be accurately controlled . The factors investigatel were : ( 1 ) The effect of long exposure in low concentrations of carbon monoxide ; ( 2 ) The effect of strenuous exercise ; ( 3 ) The effect of high temperature and humidity in low concentrations of ccarbon Lonoxide .

Mar 1, 1922

By R. D. Berkenkotter

This report describes a weighted method for evaluating the mean and variance of assay data from samples of different length . The method , which produces unbiased estimates from which valid confidence limits can be computed , is appropriate for bedded deposits of variable bed thickness and for vein deposits of variable vein width . Assay data from the bedded Florida phosphate deposit is used to illustrate the procedure .

Jan 1, 1964

By H. B. Brunot

One of the many difficult problems that confront the present day coal-mine operator is the safeguarding of his employees and property from disasters such as fires, explosions, squeezes, and inundations. Those operators having gaseous or ev en dusty mines have a double responsibility resting upon them in this respect. The introduction of electrical machinery and appera tus in mining operations has been very rapid, and at the present time it is difficult to mention any kind of mining work in which electrical machinery is not used. This extended introduc- tion of electrical equipment has added not a little to the mine operators' safety problem, and it is the desire of the United States Bureau of Mines to aid the mine operator, and the inspection departments having jurisdiction, in solving their electrical safety problems. With this idea in mind, the Bureau has prepared and published schedules setting forth the qualities it considers essential to the safety of various classes of mining equipment, and the conditions under which it will test and give the stamp of its approval to satisfactory designs. Portable electric lamps of the permissible* type are almost universally used in gaseous mines, but the use of permissible electrical machinery has not been so widespread. Until recently the Bureau had issued approvals for only one class. of machinery involving the use of electric motors that is, permissible coal- cutting machines. However, the day is undoubtedly not far distant when the operator, who so desires, will be able to obtain a permissible room hoist, pump, or coal- loading outfit. During the year 1921 the first of a growing list of storage-battery locomotive approvals was granted by the Bureau, and it is with considerable satis- faction that the Bureau how announces the approval of a third class of motor equip- "merit- namely, slectric drills.

Jan 1, 1923

By Kenneth G. Skinner, Hewitt Wilson, Thomas L. Hurst

Although chromite deposits occur in California , Oregon, Washington, Montana, Wyoming , Pennsylvania, Maryland , New Mexico , North Carolina, Alaska, and the Phillippine Islands , less than 1 percent of the ore used in the United States is obtained from these deposits . Most of the ore in peacetime has been supplied by imports from South Africa, New Caledonia, Turkey, and Cuba . The mineral chromite , the most important chromium ore , is an isometric spinel with an ideal composition of FeO Cr2O3 , but commercial chromite has the variable composition (Fe , Mg) Oʻ (Cr , Al , Fe) 203. Chromite has a black color , a specific gravity of 4.4 , and a hardness of 5.5 . In thin section the color is reddish -brown to black . Chromite occurs in dunite and pyroxenitic ultrabasic rocks , which are composed of iron- magnesium silicate minerals such as olivine , saxonite , serpentine , and enstatite . These are also the gangue minerals . Com mercial ore occurs at random in the country rock in kidney- or lens - shaped deposits , which have no apparent relationship to each other . Stringers , veins , and bands often cut the country rock without regard either to fracture or to other deposits . Some beach sands , such as those in southern Oregon, contain chromite .

Mar 1, 1943

By Wesley T. Holmes II, Lloyd H. Banning

Electric - smelting studies were made on titaniferous materials obtained from the Klukwan and Snettisham , Alaska ; Choteau , Mont .; and Iron Mountain , Wyo . , deposits with the objective of determining the feasibility of producing pig iron and an enriched titania slag in one test series and pig iron alone in another test series . In addition , related studies were conducted to determine the amenability of Choteau crude ore to wet -magnetic separation and to determine the quality of steel that could be produced from the titaniferous pig iron . The continuous smelting tests were made in a three - phase , submerged - arc , electric furnace , and the laboratory steelmaking tests were made in a singlephase electric - arc furnace . A continuous , belt - type , wet - magnetic separator was used in conjunction with a ball mill and a spiral classifier in recovering titaniferous magnetite from the crude Choteau ore . Pig irons containing less than 0.05 percent phosphorus or sulfur were readily produced from the titaniferous materials ; iron recoveries ranged from 92 to 98 percent . The Choteau ore was ground to minus 65 - mesh to produce a concentrate containing 60 percent or more iron . The steel produced from the titaniferous pig iron was a high - quality product .

Jan 1, 1964

By F. R. Cattoir, T. A. Sullivan

Commercial uranium metal was electrore fined to a high- purity product using molten- salt electrolytes in an inert atmosphere cell . Electrorefined uranium that contained , after consolidation , less than 30 ppm of metallic impurities was prepared . A method of leaching the electrolyte crystals to remove the salts was developed . Cathode current efficiencies from 90 to 100 percent were obtained . Two molten- salt electrolytes were prepared and evaluated : (1 ) lithium chloride - potassium chloride - uranium trichloride and ( 2 ) sodium chloridepotassium chloride - uranium trichloride . Very little difference was found in the purity of the uranium metal produced in either system . The lithium chloride - potassium chloride - uranium tri - chloride electrolyte was preferable from an operational standpoint .

Jan 1, 1964

By P. L. Woolf, J. P. Morris, E. Foerster, G. R. Zellars

Measurements of vapor pressure can be used to determine the thermodynamic activities of the components of metallic solutions . The determination of activity by this method requires accurate values for the vapor pressure of the pure component and for its partial pressure above the alloy solution . This investigation was conducted to measure the vapor pressure of liquid manganese for use in future studies of the activity of manganese in various liquid alloys . In related investigations in the Bureau's Pyrometallurgy Laboratory , vapor pressures of copper , iron and nickel have been measured and activit 4 5 6 have been determined in the iron- copper and iron- nickel systems . Difficulties were experienced with manganese which were not encountered in the previous investigations . Manganese oxidizes readily and greater care was needed to maintain an oxygen- and moisture - free atmosphere in the furnace . In addition , liquid manganese wet the refractories and there was a tendency to foam and splash on introduction of the carrier gas . Because of these difficulties several variations in the experimental procedure were studied . These were first tested with silver which has a vapor pressure of the same order of magnitude as manganese but is relatively inert at high temperatures . Although no significant changes in the original procedure resulted from this work, considerable data were obtained for silver and have been included in this report . Bauer and BBrruunnnneerr7/ have reported the only extensive investigation of the vapor pressure of liquid manganese . However , their results are not consistent with the data obtained by McCabe and Hudson for solid manganese . Measurements of the vapor pressure of silver have been reported by McCabe and Birchenal1,2/ Schadel and Birchenall , 10/ Harteck , 11 / Fischer , 12/ and von Wartenberg.13 / Generally , these investigators conducted their measurements at lower temperatures than were used in this study .

Jul 1, 1960

By T. N. McVay

The various applications of beryllium and its compounds in atomic - energy technology and a growing recognition of possible increased utilization of the metal in the aircraft and space - missile fields have resulted in increased interest in domestic and world reserves of beryllium . Unfortunately, little dependable data on beryllium resources and reserves are available , as past consumption of the element has been small and only limited prospecting and exploration work has been done . The scarcity of resource information is attributed partly to the difficulty of recognizing beryllium minerals in the field . These minerals frequently do not have distinctive characteristics of specific gravity, color , or other physical properties , that enable ready identification by the average prospector . This is particularly true of fine - grained minerals . As a result , a simple field test for identifying beryllium- bearing rock is needed . Recognizing this , technologists of the Federal Bureau of Mines investigated several of the proposed qualitative chemical tests for beryllium . This report describes various modifications of one of these methods to make it more suitable for use in the field . In the modified method , duplicate samples are fluxed -- one with potassium bifluoride and one with potassium bisulfate -- followed by dissolution of salts in water , conversion of the solution to an alkaline condition, addition of morin , and examination of the solution for fluorescence under short -wave ultraviolet light . This method provides a fast , dependable field test for beryllium minerals containing as little as 0.2 percent beryl or its equivalent . The test involves no radiation hazards , and it can be performed by persons having no technical training ; therefore , it should be useful to prospectors in discovering beryllium mineralization .

Jul 1, 1960

By M. M. Wong, J. E. Klosterman

Scrap beryllium chips ( nominally 96 to 97 percent Be ) were electrore fined in a prototype cell with 408 lb of electrolyte composed of 52.4 mole - percent LiCl , 36.3 mole - percent KC1 , and 11.3 mole - percent BeCl2 . The cell temperature was 500 ° C. In a typical 10-3 /4 - hour deposition cycle , 0.415 pound of metal was produced ; the metal contained impurities in parts per million as follows : C , 700 ; 0 , 610 ; Al , 34 ; Ca , 32 ; Cu , 20 ; Fe , 25 ; Mg , 9 ; and Mn , 23 . Operation of the prototype cell for 2 years demonstrated that adapting the electrorefining process to an enlarged scale of operation presented few difficulties in mechanical functions , maintenance of optimum operating conditions , and control of product purity . After the spent anode feed was leached in a 5 - percent nitric acid solution and the fine - sized particles were removed , it was recycled in some tests . The metal produced was somewhat higher in impurities than metal from the fresh scrap chips .

Jan 1, 1964

By John Gross

The Alaska Station of the Bureau of Mines has recently conducted tests on two tailings from black sand which had been treated previously at the Station. The results of this previous treatment have be on given in a paper entitled "Recovery of Gold from Black Sand by Classifier Concentration." The gold in these tailings was intimately united with quartz, and was so finely divided that it could not be detected with the naked eye, nor even by P&nn ing unless the material was ground. Its fineness is further shown by the assºy result, which reported only lz per cent of the gold content as "metallics", Wºorea's the assay of the original sand reported 36 per cent of the gold as "metallics." The fact that the gold was in such fine particles, closely united with quartz, precluded further recovery by amalgamation without grinding. On the other hand, the small content present, as well as the lack of grinding appliances at the placer mines of Alasia, made it necessary that the material be cheaply handled if at all. With these facts in mind the experiments described below were undertake.n.

Oct 1, 1920

By T. L. Turner, Daniel T. Rogers

As part of a program to investigate technology for the extraction of studied HNO3 alumina from abundant domestic ores , the Bureau of Mines leaching of calcined Georgia kaolinitic clay . In this investigation , iron impurities were removed from the aluminum nitrate pregnant leach liquor by solvent extraction , and the purified liquor was evaporated to prepare a suitably concentrated crystallizer feed liquor . Aluminum nitrate nonahydrate was crystallized from the liquor to separate the aluminum from undesirable trace elements and excess water . Continuous crystallization at 40 ° C in a pilot plant vacuum evaporative unit was performed for 5 days to observe the effects of impurity buildup under minimum bleed- stream conditions . Liquor feed rate was 26 lb/h and AAll (( NNOO33 )) 33..99HH22O0 ((AANNNN)) crystal production rate was 17 lb/h . Fe 203 and Cr203 were not effectively separated from the crystals , and P205 , MgO , and K20 impurities must be removed by recrystallization . Other impurities did not excessively contaminate the crystals . Washing the crystals with water or aqueous HNO3 gave an equivalent increase in crystal purity levels by displacing mother liquor . Theoretical equations , applicable to any continuous evaporative crystallization of developed to produce material balances for engineering ANN , were applications .

Jan 1, 1965