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By J. D. Price, W. M. Bertholf

THE central washing plant of the Colorado Fuel & Iron Corp. was first operated in 1918 to furnish coal for two 60-oven batteries of Koppers design. Prior to that time the coke for the blast furnaces had been secured from a number of beehive operations, some with their own washeries. The original washery had four Elmore jigs, which did not do as well as had been expected. In 1923 the jigs were taken out and replaced by Deister Plat-O tables, with various changes in auxiliary equipment. In 1936 the throughput of the plant was considerably increased by the installation of vibrating filters for recovery and drying of fine coal, thereby reducing a large recirculating load of fine coal which passed through the screens of the Carpenter driers.

Jan 12, 1954

By Thomas R. Cunningham, A. B. Kinzel

Silicon, unfortunately, is not in the same category as some other metals with respect to the absolute value of the highest purity material prepared. Tucker, in England, and Becket, in this country have developed procedures for the purification of silicon, and Becket's process has made industrially available silicon of a purity of 99.8 per cent or better. However, even the term "silicon metal" may be a paradox to some people, although not more so than the term "amorphous" as applied to silicon. These terms come from commerce, and "metal" is used to distinguish industrially high-purity silicon from ferrosilicon, silicon-aluminum, and other high-silicon alloys. Alloys of iron and silicon with 95 per cent Si or less are known as ferrosilicon, with a designation of silicon content where necessary, arid the term "silicon metal" is invariably applied to the grades containing 96 per cent Si and higher. The Becket method of purification was referred to in a monograph on the Alloys of Iron and Silicon, and the Tucker procedure was described in some detail in that publication.' In order to get silicon of still higher purity, a sample, prepared by the Becket method, analyzing 99.84 per cent Si, 0.020 Fe, 0.016 Al, 0.005 Ca, 0.025 C, 0.033 per cent 02, 0.006 H2, 0.006 N2, and 0.001 per cent Mn, was crushed to pass a 100-mesh sieve and further purified by a modification of Tucker's procedure. This modification differs from Tucker's method in that after treatment the 100-mesh alloy was centrifuged to remove the last traces of acid. Our directly determined analysis of this purified sample shows: Si, 99.952 per cent; Fe, 0.009; Al, 0.012; Ca, 0.003; C, 0.006; or 99.982 per cent. Silicon by difference equals 99.97 per cent. The variation between silicon by difference and silicon as directly determined is important. Although Tucker mentions the amount of insoluble matter in commercial silicon both before and after his treatment, he does not mention the existence of carbon in the alloy; nevertheless, he reports silicon by difference. Any final figure as to purity obviously results from agreement between direct determination and

Jan 1, 1940

By A. B. Kinzel, Thomas R. Cunningham

Silicon, unfortunately, is not in the same category as some other metals with respect to the absolute value of the highest purity material prepared. Tucker, in England, and Becket, in this country have developed procedures for the purification of silicon, and Becket's process has made industrially available silicon of a purity of 99.8 per cent or better. However, even the term "silicon metal" may be a paradox to some people, although not more so than the term "amorphous" as applied to silicon. These terms come from commerce, and "metal" is used to distinguish industrially high-purity silicon from ferrosilicon, silicon-aluminum, and other high-silicon alloys. Alloys of iron and silicon with 95 per cent Si or less are known as ferrosilicon, with a designation of silicon content where necessary, arid the term "silicon metal" is invariably applied to the grades containing 96 per cent Si and higher. The Becket method of purification was referred to in a monograph on the Alloys of Iron and Silicon, and the Tucker procedure was described in some detail in that publication.' In order to get silicon of still higher purity, a sample, prepared by the Becket method, analyzing 99.84 per cent Si, 0.020 Fe, 0.016 Al, 0.005 Ca, 0.025 C, 0.033 per cent 02, 0.006 H2, 0.006 N2, and 0.001 per cent Mn, was crushed to pass a 100-mesh sieve and further purified by a modification of Tucker's procedure. This modification differs from Tucker's method in that after treatment the 100-mesh alloy was centrifuged to remove the last traces of acid. Our directly determined analysis of this purified sample shows: Si, 99.952 per cent; Fe, 0.009; Al, 0.012; Ca, 0.003; C, 0.006; or 99.982 per cent. Silicon by difference equals 99.97 per cent. The variation between silicon by difference and silicon as directly determined is important. Although Tucker mentions the amount of insoluble matter in commercial silicon both before and after his treatment, he does not mention the existence of carbon in the alloy; nevertheless, he reports silicon by difference. Any final figure as to purity obviously results from agreement between direct determination and

Jan 1, 1940

By R. W. Raymond

Franklin Guiterman was born March 7, 1856, in Cincinnati, Ohio, where his father, William Guiterman, was at that time engagcd in the wholesale dry-goods business. Both of his parents were natives of Bavaria, but the inspiration of America was upon them, as they gave to their son a peculiarly American name, symbolizing thrift, individualism and scientific knowledge. Franklin Guiterman received his general education in the grammar schools and the Hughes High School of Cincinnati. He finished the latter course in the early 70's of the last century, when the great demand for mining and metallurgical experts in this country naturally led his parents to direct his further studies in that direction. Accordingly, he went to Europe, and studied at the Royal Saxon Mining Academy of Freiberg, where he completed the course in 1877, at the age of 21, and returned to the United States to engage in mining and metallurgical practice. Going to Colorado, he became assayer for the Terrible mine, at Georgetown, and in 1878, for the Little Chief mine at Leadville. The position of assayer, particularly at that period and in that region, was the door to much valuable knowledge of mines and ores. Besides learning the nature and value of the different classes of ore from the mines of his own company (if he was employed by a company) the assayer, had the first chance, through his outside customers, of seeing and testing the specimens brought by prospectors, and thus learning of important new discoveries. Moreover, if he possessed metallurgical knowledge, he might advance to the position of a metallurgical manager. Guiterman stayed in Leadville four years, and during that period was assayer or chemist for several different companies. Then for about a year he superintended copper-mining operations at Hartville, Wyo. In 1884, he had charge of sampling works at Silverton, colo.—an admirable opportunity for gaining wide knowledge of the varied ores of the San Juan country. In 1885, he was Superintendent of the Mingo plant of the Pennsylvania Lead Co., at Sandy, near Salt Lake City, Utah. The foregoing list of employments, each occupying not more than a year, certainly looks like the history of a rolling stone, gathering no moss. But the cause of these frequent changes was not inefficiency in each new position. In that time and period, a man who lost his place for such a reason was not likely to get another in the same neighborhood might away. And as for gathering "moss," the kind of "moss" that

Jan 1, 1918

By J. E. Hackford

In some research work carried out by the writer, certain results have been obtained which bear on the fundamental nature and origin of coal and the relationship between coal and petroleum. Without entering into a discussion of the details of the experiments, which were conducted on petroleum and derived bitumens, there are given here, by way of definition, some of the relations that the writer has established between certain classes of bitumens of petroliferous origin. Bitumen.—-A natural organic substance, gaseous, liquid, or solid, consisting of hydrocarbons and the oxy-or thionic derivatives of the same, or of a mixture of all three. Diaspha1tenes.—-Those portions of bitumens that are soluble in ether or carbon disulfide, but are insoluble in a mixture of equal parts of ether and alcohol. Diasphaltenes are produced by the oxidation or thionization of petroleum oils; they have, as the name indicates, twice the molecular weight of asphaltenes, into which they are converted when subjected to moderate temperature. For example, an artificially produced diasphaltene, which was readily soluble in pentane and ether, was quite insoluble in either of these solvents after heating for three weeks at a temperature of 100" C., and was converted into an insoluble asphaltene. Aspha1tenes.—Those portions of bitumen that are insoluble in ether or ether alcohol but are soluble in carbon disulfide. Aspha1tites.—Those solid or semisolid natural bitumens that are composed, for the most part, of asphaltenes or diasphaltenes. A pure asphaltitel would be composed wholly of asphaltenes and diasphaltenes, but most asphaltites contain small percentages of oil and wax, which have not yet been converted into asphaltenes; they may also contain A small percent.age of kerotenes, which represent the next stage of the metamorphosis of asphaltenes. Among the naturally occurring oxyasphaltites may be mentioned grahamite; and among the thioasphaltites, gilsonite.

Jan 1, 1921

By R. S. Rickard

Chemical processing of ores has gained new im¬petus in recent years. The reasons are many. They range from the need to process ores that are difficult to beneficiate to the avoidance of pollution. Although many think of chemical processing as a hydrometallurgical operation there are other techniques. An example is chlorination. Chlorination, although examined and discarded by many investigators, is again being considered as a means of extracting uranium1, treatment of silver-lead ores2, and the recovery of base metals from pyrite cinder and ores3. Segregation roasting of copper and nickel ores, a process similar to chlorination, is another chemical treatment being revived.

Jan 1, 1970

The Army Reorganization Act, which became effective July 1, 1916, contains a provision authorizing the organization of an Officers' Reserve, in which will be included a Corps of Reserve Engineers. There will also be an Enlisted Reserve of skilled workmen in technical lines. The special provisions of the bill relating to the Engineer Officers' Reserve were formulated with the help of the Joint Committee of the several national engineering societies, which has been at work on the matter for over a year with the War Department and Committees of Congress. Recognizing that engineering science is the basis of success in modern

Jan 8, 1916

By Alan Morris

The investigation of the hot-working properties of metals and alloys furnishes a problem which has been attacked in many ways. Tensile, impact and hardness tests on heated specimens have furnished interesting data, but in most cases either the tests are difficult to make or the results hard to translate into terms of practical value. Some investigators have used the drop hammer to advantage. It furnishes a rapid and simple method of comparing the plasticity of metals at elevated temperatures. The indications obtained by its use are of value only in so far as their significance is understood and they can be intelligently used to predict the behavior of a given metal under given hot-working conditions. The work reported here was undertaken not only to add something to the existing volume of such data but also to contribute to our understanding of the results. Doerinckel and Trockels1 used cylindrical specimens and determined the work required to reduce the specimen to one-half the original height. Ellis2 studied the effect of constitution on the malleability of steel at high temperature. His method and that of Kent3 were similar to the one used in the present work. The tests described by Kent were made on samples of tin, zinc, aluminum, copper, lead, 70:30 and 60:40 brasses, with and without a small quantity of lead. He concluded that the test would "indicate whether a material can be forged at a given temperature without cracking." This interpretation must be used with caution. While it is probably true within limits, one must consider the severity of the forging operation. Again, it will not apply strictly to forms of hot working other than forging. For instance, an alloy running 61.0 per cent. copper, 3.25 per cent. lead, remainder zinc, will crack badly in the test, yet, it is extruded commercially. When the possibility of hot-working a new alloy is being considered a study of its drop-hammer test should help

Jan 1, 1931

By A. M. Johnson

Dewatering is a major operational cost at some mines. Under certain conditions, costs associated with water disposal may continue beyond the productive bye of the mine. For mines with mineralized waters, this is of special concern. Since 1974 experience has been gained from examination of a number of closed underground metal mines that exhibited drainage problems. It was observed, in certain cases, that had appropriate steps been taken prior to closure, the resulting drainage problems could have been largely avoided. Reclosure steps would have involved alteration to the 'plumbing system" of the mines; i.e., the drifts and crosscuts interconnecting the mine workings. This could have best been accomplished by the placement of bulkheads and/or selective drifting. In addition to reconfirming that hindsight is 20-20, a lesson learned from these case studies shows that a relatively simple hydrologic evaluation prior to mine closure may avoid a troublesome and costly drainage problem.

Jan 1, 1985

By C. W. Phillips, R. S. Busk

WITH most cast metals the grain size may vary within wide limits, depending upon the conditions at the moment of freezing. These conditions are subject to control in magnesium-base alloys, by proper melting and superheating techniques, enabling production of quite uniform and fine-grained castings, almost independent of section thickness. However, such variations of grain size as do exist, in common with all metals, are reflected in corresponding changes in mechanical properties. It is the intent of this paper to present data giving the relationship between grain size and mechanical properties. Data are also included on the combined effects of grain size and microporosity. In addition, a short discussion of factors influencing the grain size of sand castings is included. MEASUREMENT OF GRAIN SIZE By grain size is meant the statistical distribution of volumes occupied by the individual crystallites in a metal section. Since this is almost always impossible of direct measurement, several methods of estimating and expressing the size have been evolved. Most exact methods make use of the microscope. This involves study of a single plane cut at random through the metal. What is seen in the microscope are polygons, each the cross section of a grain. The diameters or areas of these polygons are then measured and the grain size is expressed as an average diameter, number of grains per unit area, average area per grain, or, rarely, average volume per grain. Rutherford, Aborn, and Bain3 have discussed extensively the errors involved when using a plane section to estimate volume. They clearly point out that the tendency is to underestimate the true grain size because of the nature of the measurement. The A.S.T.M.. recommends that measurement be made by comparison with a standard chart, by means of Jeffries' planimetric method' or Heyn's intercept method. The Society recommends that the notation be in terms of the number of grains per unit area (as is the grain-size number used for steel) or as an average diameter, expressed in inches or millimeters (as for copper and brass). The method of measurement used for this study was comparison with a standard chart, which has been described by P. F. George.', The chart was constructed by photographing at i00 diameters a uniform specimen with an average grain diameter of 0.003 in. The average diameter of this specimen was determined by numerous measurements, using both the Jeffries and Heyn methods. The other grain sizes were then obtained by appropriate enlargement of the master sample. Careful comparison of the chart method with other methods on identical samples indicates that though the differences be-

Jan 1, 1945

The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Trustees, Inc. When Mr. Carnegie made. his gift ?for the erection of a suitable home? for the engineering societies,

Jan 1, 1944

By Eliot Blackwelder

For the purposes of this paper, the boundaries of China and Siberia will be taken as they stood about 1907. Except in the Caspian region, it is doubtful if all the oil ever produced in these countries would equal one day's flow of a good Texas well. Considering the vastness of the regions and the variety of strata, it seems strange that these two countries should have made so small a showing in the petroleum industry. No doubt the condition is caused partly by lack of prospecting and of modern methods of development; in larger measure, however, it is evidently because of unfavorable geological conditions over nearly all of east-central and northern Asia. CHINA The known oil occurrences in China are very few. For many years, perhaps a barrel a day has been obtained by primitive methods from wells near the city of Yenchang in the northwestern province of Shensi. A like amount was obtained from wells bored for salt water in the vicinity of Kiating in southwestern Szechwan. The little oil was separated from salt water by allowing it to stand in jars. The salt wells yield also considerable natural gas, which is used to evaporate the salt and also for domestic purposes. There is evidence that wells were bored in this part of China before the third century. It is said that more than 1200 wells have been sunk in that district to depths of 1600 to 2000 ft. (485 to 610 m.) in connection with the salt industry. The scarcity of petroleum in China may be ascribed to three general geologic conditions: First, China contains practically no marine sediments of Mesozoic or Cenozoic age; second, the Paleozoic sediments are not for the most part of the types that generally contribute petroleum; third, the rocks of nearly all ages have been strongly folded, faulted, and more or less intruded by igneous rocks in all parts of China except certain areas in the west and northwest.

Jan 7, 1922

'The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Trustees, Inc. When Mr. Carnegie made his gift which made possible a home for the engineering societies, a separate corporation was organized to act as a holding company and to manage the common property. This was long known as the

Jan 1, 1932

By H. R. Spedden, A. M. Gaudin, M. P. Corriveau

A preliminary study of silver ion adsorption by sphalerite in ion exchange column with influent electrolyte marked with radiosilver is described. Rapid ion exchange occurs at first followed by slow reaction controlled perhaps by solid state diffusion. One experiment with radiocopper instead of radiosilver is reported briefly. IT has been known for many years that sphalerite is floated after it has been activated by a metallic cation, particularly copper.' The activation of sphalerite by copper is known to be an exchange of an atom of copper for an atom of zinc at the surface of the sphalerite.2,3 It has been estimated from various guesses of the available mineral surface that the depth of the copper-bearing coating is of the order of thickness of one atom. However, the exact mechanism of the activation process is unknown. A number of metals other than copper act in the same general manner."' " In particular, it has been known that silver replaces zinc at the surface of sphalerite. As copper is usually divalent, whereas silver is monovalent, it may well be assumed that there are differences, perhaps major differences, in the detailed scheme of activation by these two cations. Furthermore, since silver has unusual photoelectric properties and may be a contributor to the fluorescence of sphalerite, a study of its activating mechanism might open up some interesting avenues for exploring these other phenomena. The choice of silver as an activator of sphalerite was suggested also by the fact that its radioactive tracer, silver 110, is particularly convenient in that it has a long half-life and is energetic enough to permit counting through a counter window. The experimental technique selected, therefore, included the preparation of solutions of silver nitrate con- taining a proportion of active silver nitrate sufficient to give convenient counting data. In further considering the method to be used, a desirable choice seemed the use of batch experimentation in which a given solution was allowed to act on a certain lot of mineral for a given length of time at a given temperature, this period of mutual reaction being followed by analyses of the separated solid and solution. But an alternative method seemed more attractive. This is the method now so familiar to the users of ion-exchange resins, which was first made famous by the Russian chromatographer, Tswett.6-8 It consists in forming the mineral into a porous column through which the solution is allowed to flow at a constant rate. The usual method of allowing a batch of solid to react with solution is the equivalent of a single plate distillation operation while the chromatographic or ion-exchange column is a multiple-plate method—the multiplicity of the plates being represented by the reciprocal of the rate of flow of solution through the column. It seemed to us that the chromatographic method had such

Jan 1, 1952

By R. S. Dean

THE numerous theories of hardening which have been advanced in recent years are all satisfactory in accounting for some of the phenomena observed in hardening metals, but none so far presented account for all of the facts observed. Some years ago one of the authors, R. S. Dean,1 presented a theory to account for some of the properties accompanying work hardening. The present paper develops this theory further in the light of recent experimental, work and extends it to other forms of hardening. Many of the ideas included have come from the writings and personally communicated thoughts of others. We have attempted to give proper credit in every case, but it is possible that we have not always done so. As an historical basis it is desirable here to review very briefly the hardening theories which have been current. The first comprehensive theory of work-hardening phenomena was due to Sir George Beilby.2 He contributed the idea that with cold work part of the structure of the metal was rendered amorphous and that it was to this amorphous material that the cold-worked metal owed its difference in properties. According to Beilby's theory this amorphous material was a super-cooled liquid and, therefore, had the characteristics of a vitreous material. That such a theory is not capable of explaining the property changes in metals has been repeatedly pointed out. This theory also allowed a slip to take place only once on a given plane, which, as has been pointed out by Jeffries and Archer,3 is not consistent with the observed length of an individual slip and the amount of elongation which can be obtained by wire drawing. The modifications, which have been proposed to this hypothesis to make it coincide with the experimental facts, have to a considerable extent robbed the theory of its clean-cut characteristics. The commonest of these modifications replaces the amorphous phase with an

Jan 1, 1927

By Adrian C. Dorenfeld

Factorial design is a mathematical method of drawing valid conclusions from a series of tests made in a predetermined pattern. It is applied to flotation ore testing using, in this case, five variables, each varied twice, requiring a total of 32 tests. Representative conclusions are checked by repeat testing.

Jan 12, 1951

By Walter L. Rice

It is a pleasure to report that the light metals industries are running well ahead of the growth schedule projected by the President's Materials Policy Commission. In the compilation of this survey on the five-year growth of our light metals industries, some gratifying facts come to light. By 1956, for instance, light metals consumption had increased more than 20 pct beyond Paley report expectations-a growth not anticipated by the study until the year 1960.

Jan 9, 1959

By W. C. Lacy

The last crop of graduates from our colleges and universities who sought employment in the mineral industries found that they needed to hustle to find a job. There was no longer a list of waiting employers to choose from. Some of them became discouraged and drifted into other fields; many are still looking for employment. Word has gotten around that there are no jobs available in the mineral industries, and enrollment in the various colleges of mines and mineral industries has started to drop. Even established professional men are finding themselves suddenly out of work because of unstable metal prices and rising costs. All these people-students beginning to search for a career, young engineers not yet established-face the same problem: "What is the future of the mineral industries, and what type of training will best qualify the scientist or engineer for this changing field?" This question was posed to a number of leaders in different phases of the industry. Their comments are summarized as a guide to those considering a career in the finding, extraction, or beneficiation of mineral products.

Jan 1, 1960

By Joseph A. Gill, Ernest A. Curth

The Government and Leeco concluded a cost-sharing agreement in 1976 to demonstrate longwall mining of a thin coalbed, 1 m or less, in a mine near Hyden, Ky. A premining investigation laid the groundwork for mine design and equipment specifications. Four- legged shields, a face conveyor, a stage loader and an in-web shearer were selected to operate on a 183 m face. Lengwall mining began in 1979 and initially was slowed by low mining height and equipment problems. A rock mechanics program provides early warning capability and criteria for future mine design. Monitoring of surface effects is included.

Jan 1, 1981

By A. E. Himebaugh

A SEMI-AUTOMATIC hoist has been installed at the 2966 station of the Copper Queen mine, since neither the bulk of supplies handled nor the number of men engaged in developing the 3100 level justifies the constant attendance of two cagers and two hoist operators. The connecting service shaft between the 2966 and 3100 levels is actually a two-compartment raise. Below the 2966 level the shaft is 7x13 ft-slightly oversize to permit downcast ventilation and provide space for the 16-conductor flexible control cable. The raise extends 52 ft above the 2966 level for a 3-ft diam head sheave. Another 3-ft sheave is mounted as an idler between the hoist and head sheave, eliminating the need for an inclined cableway. The main compartment serves as a cageway; the other compartment provides a manway and space for service lines. Since vertical travel is limited, rope speed is of minor importance.

Jan 5, 1958