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By B. K. Parekh, W. M. Goldberger

Silicon carbide (Sic), produced by heating rice hulls to elevated temperatures, contains a mixture of beta crystalline silicon carbide whiskers, particles, and unreacted carbon. The silicon carbide whiskers are 0.5 micron in diameter and 50 to 100 microns in length and have been found useful for reinforcing metal and other composite materials. The carbon can be removed by combustion, but this makes separation of the silicon carbide whiskers from particles difficult and a high grade whisker product cannot be made. However, a clean, high grade SiC whisker product can be obtained from the pre-burned converted rice hulls using physical separation processes that are based on differential wetting. Recovery of Sic whiskers from the pre-burned material was found to exceed 90%. A modification of the froth flotation process developed during this study is now being used commercially to separate silicon carbide whiskers and particles and to recover a high grade whisker product.

Jan 1, 1986

By R. L. Loofbourow

The objectives of this report are (1) to indicate what is known of natural rock temperatures as deep as 5000 ft below the surface, (2) to indicate methods for estimating such temperatures in localities where directly measured temperatures are un- available, and (3) to outline as far as possible, areas in the 48 states within which rock temperatures are likely to be low and high. The usual object of temperature measurements in deep mines and wells is to learn the temperature of air or another circulating medium. This usually differs significantly from the undisturbed rock temperature. The subject is complicated further by the variety of the thermal properties and structures of rock masses, the migration of fluids within them, the diversity of the history of rock masses and of the processes which have been at work on them during that history.

Jan 1, 1966

By Edward H. Williams

In the middle of the eighteenth century John Frazier and wife, Sarah Ingraham, removed from Boston, Mass., to Philadelphia, Pa., where he was held in such esteem that we find him one of the Committee which arranged the ball at Washington's inauguration. Their son, John Nalbro Frazier, was prosperous in his mercantile career and fortunate in his wife, Anne West, who was an important personage in the early life of Professor Frazier. This cultured lady brought into the family an atmosphere of religious enthusiasm, of thoroughness and of unity of purpose. Her son, Benjamin West Frazier, inherited her traits and displayed them during a short and active life. Like his father, he engaged in mercantile pursuits, and was a member of the firm of Zimmerman, Frazier & Co. In their interests he lived for a short time in Montevideo, and on

Jan 1, 1906

By Franc R. Joubin, D. H. James

Uranium exploration in the North Shore area of Lake Huron goes back to 1847 when J. L. LeConte, a distinguished American geologist, identified a pitchblende-like mineral which he called coracite from specimens sent from a locality north of Sault Ste. Marie. In 1948 a search for the LeConte occurrence resulted in discovery of the Camray field, some 70 miles north of Sault Ste. Marie. Prospecting the Camray field yielded about 30 pitchblende occurrences spread over approximately 200 sq miles. Almost without exception these discoveries consisted of narrow, short, pitchblende-filled fractures, within or along the contacts of diabase dykes cutting pre-Cambrian Archean granite and gneiss. Eight discoveries were diamond drilled and three were explored underground, but none proved to be of economic value. Uranium prospecting at this time spread far afield, and it was in 1949 that radioactive conglomerate was discovered in Long Township of the Algoma district midway between and 90 miles from Sault Ste. Marie and Sudbury. F. Joubin examined this discovery at that time but could not interest capital in its development.

Jun 1, 1956

The Library of the above-named Societies is open from 9 A.M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its, Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly anti in more usable shape.

Jan 1, 1918

The library of the above-named Societies is open from 9 A. M. to 10 P. M. except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 12, 1918

By Rudolph G. Wuerker

With stepped-up work in rock mechanics, more and more data on strength and elastic properties of rocks has become available. Results of measurements of tensile strength, in addition to determinations of compressive strength, allow us to deter- mine, even if only in an approximate way, the third property influencing failure of a brittle material: shear strength. It is fairly generally agreed upon in rock mechanics, in drilling and blasting research, that Mohr's theory provides an acceptable method for explaining the failure of a brittle material. Mohr states that a material may fail either 1) through plastic slip when shearing stress Y in the planes of slips has reached a limiting value (which in general depends on the normal stress, X, acting normal to the surface), or 2) when the largest normal tensile stress has reached a limiting value. The mode of failure depends upon which of the two stresses is the smaller.

Jan 10, 1959

By C. E. Feltner

In a recent note, Meleka and Hiarris1 have reported that the application of a constant strain rate Ad a superimposed cyclic stress to 99.99 pct polycrystal-line zinc at room temperature produced some marked effects in the resultant behavior. In their work, one end of the specimen was pulled in tension at a constant strain rate while the other end was subjected to a sinusoidally varying load (20 cps) of constant amplitude. For the slower strain rates and the larger superimposed cyclic loads, it was observed that the specimen could withstand strains prior to failure more than 100 pct greater than the fracture strains obtainable in simple unidirectional straining. This ductility effect was interpreted as being due to a cyclic stress enhanced thermal recovery process. It is the purpose of the present note to describe some related effects in 99.99 pct polycrystalline cadmium. Specimens were loaded in repeated tension at room temperature with a stress of sufficient magnitude to cause failure in about 1000 cycles and the accumulated strain was measured as a function of cycles and time. In addition, some specimens were subjected to a steady creep stress equal in magnitude to the peak value of the cyclic tensile stress. The resultant strain-cycle and strain-time curves for both types of test are shown in Fig. 1. It should be noted that the static creep specimen failed in about one third the time required to produce a cyclic failure but in the cyclic test the specimen was able to withstand a uniform strain before necking more than 50 pct greater than that possible

Jan 1, 1963

By Ronald D. Hill, Janet L. Auerbach

It is estimated that the mining industry generates over 2.1 petrograms per year of solid waste. These wastes are overburden, waste rock, low grade ore, concentrate (tailing), sludges from treatment facilities and wastes from support facilities. Concentrate wastes present the greatest environmental problem. Three recent federal laws impact the disposal of waste from mining: Resource Conservation and Recovery Act of 1976 (RCRA), Surface Mining Control and Reclamation Act of 1977, and Uranium Mill Tailings Radiation Control Act of 1978. RCRA specified a special study on mining waste which was to include an analysis of: (1) sources and volumes of waste produced, (2) present disposal practices, (3) potential dangers to health and the environment, (4) alternate disposal methods, (5) cost of disposal, and (6) potential for use of waste.

Jan 1, 1980

By Dwight L. Baker, Alexander Knoll

The work herein reported shows that galena in certain organic solutions of fatty acids becomes coated with lead soaps, and that this coating is not only highly water-repellent but is also repellent to certain organic liquids, particularly those of high surface tension; i.e., nitrobenzene, diphenylmethane. Wetting Properties of Galena in Nonaqueous Fatty Acid Solutions When a "captive bubble"I is withdrawn from a polished, plane galena surface under a nitrobenzene solution of stearic acid, the air bubble shows a decided tendency to "cling" to the mineral surface. The contact angle, therefore, was greater than zero, although it was not large enough to be measured quantitatively by the captive-bubble method." When pure nitrobenzene was substituted for the nitrobenzene-stearic acid solution, no clinging of the bubble was observed; viz., contact angle = zero. Although the contact angle developed in air-galena-nitrobenzene-fatty acid solution was small, the organic solvent repellency of the galena surface was great enough to enable good recovery in a laboratory flotation cell2 In Table I are given the results of flotation experiments using several different fatty acids dissolved in nitrobenzene.

Jan 1, 1943

By Alexander Knoll, Dwight L. Baker

THE work herein reported shows that galena in certain organic solutions of fatty acids becomes coated with lead soaps, and that this coating is not only highly water-repellent but is also repellent to certain organic liquids, particularly those [ ] of high surface tension; i.e., nitrobenzene, diphenylmethane. WETTING PROPERTIES OF GALENA IN NONAQUEOUS FATTY ACID SOLUTIONS When a "captive bubble"' is withdrawn from a polished, plane galena surface under a nitrobenzene solution of stearic acid, the air bubble shows a decided tendency to "cling" to the mineral surface. The contact angle, therefore, was greater than zero, although it was not large enough to be measured quantitatively by the captive-bubble method.* [ ] When pure nitrobenzene was substituted for the nitrobenzene-stearic acid solution, no clinging of the bubble was observed; viz., contact angle = zero. Although the contact angle developed in air-galena-nitrobenzene-fatty acid solution was small, the organic solvent repellency of the galena surface was great enough to enable good recovery in a laboratory flotation cell.2 In Table I are given the results of flotation experiments using several different fatty acids dissolved in nitrobenzene.

Jan 1, 1941

By Alexander Knoll, Dwight L. Baker

The work herein reported shows that galena in certain organic solutions of fatty acids becomes coated with lead soaps, and that this coating is not only highly water-repellent but is also repellent to certain organic liquids, particularly those of high surface tension; i.e., nitrobenzene, diphenylmethane. Wetting Properties of Galena in Nonaqueous Fatty Acid Solutions When a "captive bubble"I is withdrawn from a polished, plane galena surface under a nitrobenzene solution of stearic acid, the air bubble shows a decided tendency to "cling" to the mineral surface. The contact angle, therefore, was greater than zero, although it was not large enough to be measured quantitatively by the captive-bubble method." When pure nitrobenzene was substituted for the nitrobenzene-stearic acid solution, no clinging of the bubble was observed; viz., contact angle = zero. Although the contact angle developed in air-galena-nitrobenzene-fatty acid solution was small, the organic solvent repellency of the galena surface was great enough to enable good recovery in a laboratory flotation cell2 In Table I are given the results of flotation experiments using several different fatty acids dissolved in nitrobenzene.

Jan 1, 1943

The Library of the above-named Societies is open from 9 A. M. to 10 P.M., except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information, will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will he sent more promptly and in more usable shape.

Jan 8, 1917

By John D. Ridge, Robert C. Barwick

The quantities and destinations of the metallic ores and concentrates and partially or fully refined metals in international trade result from the interaction of many factors, of which geographic location is only one. How far the processes of concentration and refining are to be carried in the country in which the mining is done and what dictates the destinations to which the more or less completely processed raw materials will move are determined not only by present-day geologic, political, and economic conditions, but also by the patterns set up by these same conditions as they obtained in the past. The first generalization that can be made regarding trade in metal raw materials-one that affects the form in which the material is transported, rather than the patterns followed by that trade-is that concentration is carried out for all low grade ores, nonferrous or ferrous, in the country in which they originate. (Rule 1.) Economic considerations alone almost always require that this be done; only high grade iron, manganese, and chromite ores can be shipped as they are mined.

Jul 1, 1955

By S. P. Sharples

Under the act providing for the taking of the Tenth Census, the superintendent was authorized to appoint experts to inquire into special industries; accordingly Professor Charles S. Sargent was appointed to gather statistics in relation to the forest industries. As chief of the Department of Forestry of the Tenth Census he has been busily engaged in this work since the fall of 1879. Soon after his appointment he became convinced that it would be desirable to make an examination of the fuel-value of the various woods of the United States, and this work was placed in my hands. At the same time I made the suggestion that while we had the opportunity, it would be well to test also the strength of these woods. The suggestion was adopted and Professor Sargent at once set his agents to work in various parts of the country to collect specimens of all the trees growing in their localities, employing as a rule botanists who were familiar with the flora of the region in which they were at work. The result of this work was the collection of over thirteen hundred specimens of wood, comprising over four hundred species and varieties, nearly one hundred of which had not before been described as trees existing in the United States.

Jan 1, 1883

By John W. Tieman

Coal is a term applied to vegetable matter (trees, grasses, etc.) which was subjected to heat and pressure through geologic ages. This resulted in a change in both the physical and chemical properties. Because its chemical composition is variable, geologists classify coal as a heterogeneous mineral rather than a homogeneous mineral. Peat represents the initial, unconsolidated stage in the development of coal. This coalification continues with time and the application of temperature and pressure to lignite, subbituminous, bituminous, and anthracite toward the theoretical graphite end member. PHYSICAL PROPERTIES OF COAL The physical properties are concerned with the characteristics of coal in its natural state, or prior to its end use as a fuel. For example, the hardness and grindability of coal determine the maintenance cost for coal mining, handling, and pulverizing equipment; the specific gravity of coal and its associated minerals determines the coal preparation technique used in a cleaning plant as well as the capacity of coal bins, boats and size of cargo, and other coal storage facilities. The physical properties are, of course, dependent on the chemical constituents of coal, and all properties are interrelated. Specific Gravity The specific gravity (sp gr) of a solid is the ratio of the weight of a cubic foot of the solid to the weight of a cubic foot of water. The specific gravity of pure coal has been reported to range between 1.23 to 1.72 and increases with the change in rank from lignite to anthracite. This means that it is 1.23 to 1.72 times heavier than water.

Jan 1, 1981

By Ray W. Ballmer, K. H. Matheson

Since start-up in 1906, Bingham had been a rail pit, beginning with steam locomotives and converting to electric locomotives in 1923. Ore production was maintained by effective utilization of avail- able rail equipment. From time to time, as it became necessary to deepen the pit and as stripping ratios increased, studies of alternative material haulage systems such as diesel locomotives, conveyor belts and trucks were made. Conversion from rail haulage with electric locomotives could not, however, be justified. Because of a gradual decline in ore grade, a program was approved in 1963 to raise ore production to 108,000 tpd. The decision posed a serious problem: due to built-in inflexibility and other limitations, a parallel expansion of the rail haulage system was impractical. (Track and trolley wire relocation causes greater shovel downtime than required for normal maintenance; instability of the dumps and the resulting additional track maintenance increases greatly as the daily volume of waste material increases.) Studies indicated that economically the most favorable course of action would be the replacement of rail haulage on the upper levels of the mine by truck haulage.

Jan 11, 1965

Swedish mining companies are noted for their excellence in underground mining practice, and this classification certainly has to be applied to their design of crushing plants also. All these mines are highly mechanized with either rail or truck haulage, and typical examples of underground crushing plants designed for each of these haulage practices are presented here. Almost all the primary breakers are of the overhead eccentric, single- toggle jaw crusher type with units as large as 55 by 71 in. (1400 by 1800 mm) being used. In contrast to North America, where jaw crushers are almost always preceded by apron or vibrating feeders, many of the. Swedish crushers are choke fed with the dump pocket being located directly above the crusher. This practice results both from excellent knowledge of the ore characteristics and the ability of the overhead eccentric crusher to also act as a feeder. An excellent example of a crushing plant of this design is shown by the sketch of the LKAB Alliansen Crusher No. 64 at Malmberget, Sweden. Forty-six st (42 mt) trucks dump magnetite ore into a 91.6 cu yd (70 m3) dump pocket mounted over a 55 by 71 in (1400 by 1800 mm) Morgards- hammar overhead eccentric crusher using a 180 hp (132 kw) motor and belt drive. Crushed ore at 10 in. (250 mm) size drops onto an air- operated tipping chute which diverts the ore to either of two 1962 cu yd (1500 m3) pockets equipped with 3 ft 11 in. by 7 ft 11 in. (1200 by 2000 mm) Schenk vibrating feeders. Dust is drawn into a wet scrubber and exhaust air is combined with mine exhaust air. Because the crusher must be assembled underground, a 45/5 ton crane is installed over the crushing installation. A crusher above ground such as at Sacaton can easily utilize a smaller crane. Capacity of this 'most interesting crushing installation is 1653 st (1500 mtph) .

Jan 1, 1978

By John F. Blandy

ALTHOUGH the question of the "waste of anthracite coal mining" has been so frequently discussed, and a committee was appointed at the first meeting of this Society to consider and report upon the subject, still but little progress seems to have been made in arriving at a conclusion as to how it can be reduced. That committee made a preliminary report at the August meeting, 1871, in which it divided the question into three parts, namely Waste in mining, in preparing for market, and in transportation. I shall not here refer to the first item, as so much depends upon the peculiar features of each separate mine, and the skill of those in charge; but in reference to the second, that of preparing the coal for market in breaker and screens, I wish to make some remarks. There is no use considering the question, whether the coal should be broken up to suit the fancy of consumers; all miners are satisfied that it should not be, but the consumers decide that they want it that way, and the miner must submit, and simply utter his maledictions upon the head of the man who first suggested a breaker or screen, if that is any consolation to him. What is called waste in this process of preparation, is the dust and fine coal, which results from the breaking and screening, and, as we all know, this is a very important percentage of what passes from the slope to the top of the breaker. Now, if this dust and fine coal can be utilized-the slate which is' picked out is not to be taken into consideration as waste-then we get rid of this item entirely. There is no question in my mind that this article can and will be used as a steam generator at least, and I think, therefore, that in depositing

Jan 1, 1877

By Sir John Cadnan

The production from the Maidan-i-Naftun area for the year ending March, 1928, was 5,340,000 tons (40,210,200 bbl.), an increase of nearly 13 per cent. over the production for the year ending in March, 1927. The production by years since the opening of the field in 1912 is given in the following table: [1 ton = 7.53 bbl.] Year Ended MaRch Tons Year Ended March Tons 1912 (7 months)............. 43,084 1920....................... 1,354,631 1913........................ 80,800 1921....................... 1,767,070 1914........................ 273,635 1922....................... 2,310,098 1915........................ 375,977 1923....................... 2,913,908 1916........................ 449,394 1924....................... 3,583,000 1917........................ 644,074 1925....................... 4,221,000 1918........................ 897,402 1926....................... 4,470,000 1919....................... 1,081,919 1927....................... 4,735,000 1928....................... 5,340,000 The actual production represents only a small proportion of the potential production. The Masjid-i-Suleiman Field The present producing unit, the Masjid-I-Suleiman, is an anticline some 20 miles in length by 4 miles in width, including three domes as so far proved. The producing horizon is a very open, dolomitic limestone, which, while showing much variation in texture and porosity, is so connected that the lowering of pressure in one section of the field quickly affects the whole area. The topography of the field is broken, with differences of well elevations of as much as 1100 ft. The depths to the limestone vary from about 800 to about 5000 ft. The closed-in pressure of the oil wells varies from zero to 50 lb. per sq. in. and that of the gas wells is about 450 Ib. Although the static oil level may be several hundred feet below ground level, in oil wells of high elevation, all the wells flow continuously or intermittently after they are once started—the majority continuously. The gas is very high in hydrogen sulfide in gas-oil wells of low pressure.

Jan 1, 1929