Search Documents

By J. W. Stewart

THE aim of this paper is to point out the various ways in which design is taught in standard four-year mining engineering curricula in American colleges and universities; to discuss the reasons apparently justifying the great diversity of procedure that exists along this line; and to indicate possible solutions to the difficulties now attending the teaching of design. A study was made of typical four-year mining engineering curricula in 15 colleges and universities of the United States (Table I). Great diversity in content of the various design courses, if taught as described, became apparent immediately. It appeared that it might be both interesting and instructive if the cause for this colorful variety could be found. Was the cause local mining conditions, departmental individuality, or actual necessity? Study of the school catalogues revealed that the various design courses could be classified into two fairly distinct types; namely, (I) those dealing with mine equipment or structures, and (2) those dealing with underground layout of mine workings. It seemed reasonable to label the first type of course "mining design" and the second type "mine design." Some such distinction must have been in the minds of mining educators, for we find both names (i.e., mine design and mining design) used to designate the design courses included in the various mining curricula. Unhappily, the name and the apparent content of such courses do not, in all instances, conform to the classification made here, although in most instances such conformation does obtain (Table I). It is possible that in the exceptional case the method of teaching a design course, and consequently the content of it, may have been changed at some time without change in the name of the course. Apparently only 3 of the 15 schools made an effort to cover both types of design in their curricula (Table I). Two other schools did not list or describe any course of study that could with certainty be taken as a design course. Of the remain¬ing to schools, 9 gave a mining-design type of course and one gave a strictly mine-design type. Obviously, the preponderance of design courses afforded are of the mining-design type. Why? To answer this question, it is necessary to make a study of the prerequisites for the two types of design courses taught. In all schools the design courses were taught in the senior year; in eight, design was taught throughout both semesters; in two, it was taught during the first semester only; and in three it was taught during the second semester only. Consequently, excepting the last three cases noted, it is obvious that all prerequisites for a design course should be completed by the end of the junior year. PREREQUISITES What are the probable prerequisites for the different kinds of design courses as they appear to be taught? Let us take first the case of the mine-design type of course, having to do with layout of underground workings. Here it would seem that logical

Jan 1, 1941

By Donald L. Katz, Marshall B. Standing

Density data are reported on 16 saturated hydrocarbon vapors at Pressures ranging from 1000 to 8220 Ib. per sq. in. and at temperatures ranging from 35° to 250°F. These data have been used to extend the compressibility-factor chart for natural gases up to 10,000 lb. per sq. in. The relatively large quantity of high-boiling constituents present in high-pressure vapors in equilibrium with crude oils makes it necessary to include in the analysis of the gas the molecular weight, density, and possibly boiling range of the heptanes and heavier fraction. Relationships have been presented by which the density of gases may be obtained directly from the temperature, pressure, and gas gravity provided the gases have a common source or are similar in composition. Introduction The densities of natural gases are necessary in many engineering in in petroleum production and utilization, Gas reserves, changes in reservoir pressure, gradients in gas wells, metering of gases, pipeline flow, and compression of gases are typical problems requiring the density of the gas. A decade ago, engineering computations used ideal gas laws with deviations up to 500 Ib. per sq. in.4 Recent discoveries of pools having Pressures UP to 7500 lb. Per sq. in., and installation of pressure-maintenance and recycling plants, have increased the need for data On gas density at high pressures. Methods of Computation The accepted method of computing the density or specific volume of natural gases is the use of the ideal gas law corrected by a compressibility factor. The method proposed by Kay7 of correlating compressibility factors for gaseous mixtures on pseudocritical properties5 appears to be satisfactory for natural gases.2 The meth-me-compressibility factor has been shown to deviate systematically from the behavior of natural gases2 and a chart giving these corrected factors is available. A method of computing specific volume of gaseous mixtures from partial molal volumes has been reported by sage and Lacey.8 Complete data for the computation are not yet available for all hydrocarbon gases. Most- of the reported data on gas densities have been in the single-phase region removed from the dew point or saturation condition. Since most gases in the reservoir Or while on contact with liquid '''ring flow are saturated, the determination of densities under conditions of saturation is particularly important. Although there is no reason to believe that the saturated gases differ in behavior from those consider. ably removed from their dew points, the usual experimental determinations find difficulty on approaching the dew-point conditions, This paper reports the density of I6 saturated gases in equilibrium with crude oils. The relationships developed to compute the density of gases to high pressure' have been modified and enlarged. A simpli-fied method of obtaining gas density is presented in the Form of charts, which apply for specific groups of gases.

Jan 1, 1942

By J. W. Stewart

THE aim of this paper is to point out the various ways in which design is taught in standard four-year mining engineering curricula in American colleges and universities; to discuss the reasons apparently justifying the great diversity of procedure that exists along this line; and to indicate possible solutions to the difficulties now attending the teaching of design. A study was made of typical four-year mining engineering curricula in 15 colleges and universities of the United States (Table I). Great diversity in content of the various design courses, if taught as described, became apparent immediately. It appeared that it might be both interesting and instructive if the cause for this colorful variety could be found. Was the cause local mining conditions, departmental individuality, or actual necessity? Study of the school catalogues revealed that the various design courses could be classified into two fairly distinct types; namely, (I) those dealing with mine equipment or structures, and (2) those dealing with underground layout of mine workings. It seemed reasonable to label the first type of course "mining design" and the second type "mine design." Some such distinction must have been in the minds of mining educators, for we find both names (i.e., mine design and mining design) used to designate the design courses included in the various mining curricula. Unhappily, the name and the apparent content of such courses do not, in all instances, conform to the classification made here, although in most instances such conformation does obtain (Table I), It is possible that in the exceptional case the method of teaching a design course, and consequently the content of it, may have been changed at some time without change in the name of the course. Apparently only 3 of the I5 schools made an effort to cover both types of design in their curricula (Table I). Two other schools did not list or describe any course of study that could with certainty be taken as a design course. Of the remaining 10 schools, 9 gave a mining-design type of course and one gave a strictly mine-design type. Obviously, the preponderance of design courses afforded are of the mining-design type. Why? To answer this question, it is necessary to make a study of the prerequisites for the two types of design courses taught. In all schools the design courses were taught in the senior year; in eight, design was taught throughout both semesters; in two, it was taught during the first semester only; and in three it was taught during the second semester only. Consequently, excepting the last three cases noted, it is obvious that all prerequisites for a design course should be completed by the end of the junior year. PREREQUISITES What are the probable prerequisites for the different kinds of design courses as they appear to be taught? Let us take first the case of the mine-design type of course, having to do with layout of underground workings. Here it would seem that logical

Jan 1, 1941

By Marshall B. Standing, Donald L. Katz

Density data are reported on 16 saturated hydrocarbon vapors at Pressures ranging from 1000 to 8220 Ib. per sq. in. and at temperatures ranging from 35° to 250°F. These data have been used to extend the compressibility-factor chart for natural gases up to 10,000 lb. per sq. in. The relatively large quantity of high-boiling constituents present in high-pressure vapors in equilibrium with crude oils makes it necessary to include in the analysis of the gas the molecular weight, density, and possibly boiling range of the heptanes and heavier fraction. Relationships have been presented by which the density of gases may be obtained directly from the temperature, pressure, and gas gravity provided the gases have a common source or are similar in composition. Introduction The densities of natural gases are necessary in many engineering in in petroleum production and utilization, Gas reserves, changes in reservoir pressure, gradients in gas wells, metering of gases, pipeline flow, and compression of gases are typical problems requiring the density of the gas. A decade ago, engineering computations used ideal gas laws with deviations up to 500 Ib. per sq. in.4 Recent discoveries of pools having Pressures UP to 7500 lb. Per sq. in., and installation of pressure-maintenance and recycling plants, have increased the need for data On gas density at high pressures. Methods of Computation The accepted method of computing the density or specific volume of natural gases is the use of the ideal gas law corrected by a compressibility factor. The method proposed by Kay7 of correlating compressibility factors for gaseous mixtures on pseudocritical properties5 appears to be satisfactory for natural gases.2 The meth-me-compressibility factor has been shown to deviate systematically from the behavior of natural gases2 and a chart giving these corrected factors is available. A method of computing specific volume of gaseous mixtures from partial molal volumes has been reported by sage and Lacey.8 Complete data for the computation are not yet available for all hydrocarbon gases. Most- of the reported data on gas densities have been in the single-phase region removed from the dew point or saturation condition. Since most gases in the reservoir Or while on contact with liquid '''ring flow are saturated, the determination of densities under conditions of saturation is particularly important. Although there is no reason to believe that the saturated gases differ in behavior from those consider. ably removed from their dew points, the usual experimental determinations find difficulty on approaching the dew-point conditions, This paper reports the density of I6 saturated gases in equilibrium with crude oils. The relationships developed to compute the density of gases to high pressure' have been modified and enlarged. A simpli-fied method of obtaining gas density is presented in the Form of charts, which apply for specific groups of gases.

Jan 1, 1942

Colorado School of Mines Scientific Society held its first meeting on Friday evening, Jan. 14.1916. H. C. Parmalee gave an interesting talk on the Loss of Cyanide by Hydrolysis. F. E. BRIBER, Secretary. The School of Mines Society of the University of Minnesota held a meeting on Thursday evening, Jan. 13, 1916, at which Fred A. Jordan gave a talk on Magnetic Concentration of Iron Ores. Mr. Jordan is at present testing the new magnetic concentrator designed at the. School of Mines Experiment Station. This apparatus, if successful, will open up an enormous tonnage of ore on the Cuyuna and Mesabi ranges. ADOLPH DOVRE, President. At the College of Mines, University of Washington, Seattle, 33 mining men, with experience varying from one to 25 years, have enrolled in the 19th Annual Three Months' Short Session. At the annual smoker tendered the Short Session miners by the student branch of the American Institute of Mining Engineers, Capt. R. H. Stretch of the Alaska Bureau, Seattle Chamber of Commerce, delivered an address on The Mineral Belts of Alaska.

Jan 3, 1916

Meeting of April 24, 1914.-President Thayer announced the appointment of the Committee on Safety and Sanitation. The Committee on Nominations for officers for 1915 was appointed, as follows: William J. Cox, Chairman; H. Poster Bain, Joseph Daniels, Charles E. Mills, R. V. Norris, E. Gybbon Spilsbury, and Herbert A. Wheeler. The request of twenty residents of Salt Lake City and vicinity for permission to establish the Utah-Nevada Local Section was granted and R. C. Gemmell was appointed Chairman of the Committee on Organization. The following resolution was adopted: Resolved: That under authority of Article V, Section 7, of the Constitution, a special Committee be and hereby is appointed, to consist of the President and six other members of the Institute, to be named by him, Who shall be authorized to appear before the proper authorities at Washington and urge that Mining Engineers be appointed upon the proposed Commission for revision of the Federal Mining Laws. Further Resolved: That the activities of this special Committee be restricted to the authority given in this resolution.

Jan 6, 1914

By J. K. Brooke, R. M. Dreyer

For mining engineers and geologists accustomed evaluating metallic mineral deposits, the problems inherent in determining the worth of non- metallic industrial minerals deposits for the chemical processing industry often comes as a rude shock. These difficulties lead to different, and often much greater, problems in financing the development of such deposits than would normally be anticipated for economic sources of copper, molybdenum, iron, nickel and other metallic minerals. The chemical processing industry is one of the two principal consumers of non-metallic mineral production, the other being the construction industry. In the last decade, the volume of industrial minerals consumed by chemical processers has in- creased by 30%, and further increases are forecasted. To satisfy this growing demand, many new sources of these minerals must be found and developed. For those of us who will become involved in such work, the following brief analysis of the major problems to be expected may be of help in developing a realistic approach to evaluating and financing such a deposit and selling the product to consumers.

Jan 8, 1962

By George H. Cook

(Read at the Wilkes-Barre Meeting, May, 1877.) AT first sight this subject seems to belong to pure theoretical geology, but examination will soon show that it has important practical and economic interest to the mining engineer. The conclusion that all the northern portions of our country, as well as of the eastern continent, have, in the later periods of geological history, been covered with a thick bed of ice, is now accepted by geologists. This bed of ice, except in its greater magnitude, was like the modern glaciers of the Alps, and other mountains which extend above the line of perpetual snow. The marks it has left upon the surface show that it was comparatively thin on its southern. edge, but that its thick¬ness was much greater a little further north, and that it was several thousand feet thick at its heaviest parts. This variation of its surface would give it a descending slope towards the south, and cause the mass of ice, like a semifluid substance, to move in that direction.

Jan 1, 1878

The following rules, upon approval by the Board of Directors, shall serve as guides in the practical applications of the Bylaws for the operation of the Institute and have the full power and effect of Bylaws, however, these rules may be changed, modified, re¬pealed or amended when deemed necessary by the Board of Directors Any change or alteration of these Rules shall be published in the Journals of the Institute within three months after such alteration is adopted ARTICLE I-ORGANIZATIONS OF THE INSTITUTE Section 1-Societies Rule 1-Governing Body Each Society shall form its own governing body composed of an Executive Committee, or similarly designated executive body, duly elected officers, and a Nominating Committee for the nomination of Institute officers as provided by the Bylaws of AIME and of each Society approved by the Board In all correspondence and printed matter the Society Boards of Directors shall be specifically identified For ex¬ample, the Mining Board of Directors or the Board of Directors of the Society of Mining Engineers Using simply the "Board of Directors" could cause confusion

Jan 1, 1960

By N. B. Wittman

The working of blast-furnaces is always of interest to many members of the Institute, for which reason I present an account of the working of the furnaces of the E. and G. Brooke Iron Company, of which I have had charge for the past four years. Although there are no phenomenal runs to record, there have been long periods of satisfactory work, and also periods—altogether too long—when one of our furnaces has behaved in a way which may be described as "nagging." All the conditions were apparently normal,but only a very light burden could be carried, which of course resulted in a high fuel-consumption to the ton of iron, as well as increased cost of labor. The two active furnaces of this company have the following dimensions and equipment : No 2. No 3. Feet. Feet. Height ....55 60 Diameter at bosh,.....- 15, 16 " hearth,...... 8 74 " stock-line,..10 91/2 Height of bosh,..23 23 " tuyeres,. 5 5 Diameter of bell,.7 6 Front,....closed open Both furnaces are blown with I. P. Morris condensing-engines, sim

Jan 1, 1890

YUGOSLAVIA is one of the smaller countries in Europe-about twice the size of Pennsylvania -but one of the richest nations in variety and quantity of minerals on the Continent. The country, just now beginning the pangs of a real industrial birth, has a mining history that goes back as far as the sixth century, B. C. Among others, the Romans exploited Yugoslavia's lead and zinc deposits, and there was intensive mining during the Middle Ages. But until now, the country's industrial development was such that it made no great demand on the mining industry for development or expansion. Conversations with Yugoslavian officials in New York give the impression that they are interested in two things. They need money and they need trained engineers to solve their mining problems. Yugoslavia appears to be attempting to attract both foreign money and foreign technical skill. They want financial aid in the form of loans. The U. S. Government has given aid to Yugoslavia in the shape of armaments, foodstuffs, and equipment. Recently, American banks have advanced funds.

Jan 5, 1954

By V. T. Stringfield

ONE of the earliest investigations of ground water in Florida was made in 1513 when Ponce de Leon arrived at St. Augustine in search of the Fountain of Youth. The history of the development of the water resources of the State shows that the large artesian reservoir that underlies Florida was discovered in the latter part of the last century. Part of that history is given by L. C. Johnson1 who states that the first successful artesian well in Florida was drilled at St. Augustine between 1880 and 1882. After the City of Jacksonville failed to obtain a flow of artesian water at a depth of nearly 400 ft and abandoned the drilling, R. N. Ellis, City Engineer, and L. C. Johnson, using Johnson's knowledge of the geologic structure of the artesian reservoir, estimated correctly that artesian water could be obtained at a depth of about 500 ft. Thus began the development of the large artesian system in the northeastern part of the State. In 1908, the Florida Geological Survey issued its first report on the ground water of central Florida.

Jan 6, 1951

By Jack C. Jones, Hemendra N. Kalia

This paper is partially based on a comprehensive ground control investigation that was conducted by Harza Engineering Company under a contract from the Bureau of Mines. This investigation required in- stalling several types of ground movement indicating devices on the surface and in the mine. The major instrumentation systems consisted of hydraulic borehole pressure cells, multi-point extensometers, in- clinometers, convergence indicators, Jack pressure recorders time domain reflectometers, and a 200 station subsidence network. The investigation demonstrated the versatility of the system. We were able to install pressure cell s to a depth of over 200 feet in the coal bed and we were successful in installing 10 pen mechanical recorders to monitor differential strata movement. In this paper, we have briefly discussed data from 18 borehole pres- sure cells, two time domain reflectometer cables and four subsidence lines. The data collected showed that the front and rear abutment pressures were approximate1 y 1000 feet (304.81~1) to 1200 feet (356.76111) from the active face. The peak pressure was about 4 times the over- burden pressure.

Jan 1, 1983

By William Kelly

THE objeet of this paper is to describe the electric equipment at the iron-ore mines of Penn Iron Mining Co., Vulcan, Mich. and of Republic Iron Co., Republic, Mich.; to give the result's of tests; and to discuss the methods in use from an operating as well as from an efficiency standpoint. Electricity was introduced at the Penn mines for pumping, hoisting, and compressing air in the spring of 1907, upon the completion of a hydro-electric plant built by that company on the Menominee river about 4 miles from the mines. This plant was described in a paper1 presented before the Lake Superior Mining Institute. A paper2 presented at a meeting of the same Institute describes some of the operating features, and the safety devices of the electric hoist at the Curry shaft were briefly described in the Proceedings of the First Co-operative Safety Congress held under the auspices of the Association of Iron and Steel Electrical Engineers at Milwaukee, Wis., Sept. 30 to Oct. 5, 1912.

Jan 2, 1914

By Marshall B. Standing, Donald L. Katz

DENSITY data are reported on 16 saturated hydrocarbon vapors at pressures ranging from 1000 to 8220 lb. per sq. in. and at temperatures ranging from 35° to 250°F. These data have been used to extend the compressibility-factor chart for natural gases up to 10,000 lb. per sq. in. The relatively large quantity of high-boiling constituents present in high-pressure vapors in equilibrium with crude oils makes it necessary to include in the analysis of the gas the molecular weight, density, and possibly boiling range of the heptanes and heavier fraction. Relationships have been presented by which the density of gases may be obtained directly from the temperature, pressure, and gas gravity provided the gases have a common source or are similar in composition. INTRODUCTION The densities of natural gases are necessary in many engineering computations in petroleum production and utilization. Gas reserves, changes in reservoir pressure, gradients in gas wells, metering of gases, pipeline flow, and compression of gases are typical problems requiring the density of the gas. A decade ago, engineering computations used ideal gas laws with deviations up to 500 lb. per sq. in.4 Recent discoveries of pools having pressures up to 7500 lb. per sq. in., and installation of pressure-maintenance and recycling plants, have increased the need for data on gas density at high pressures. METHODS OF COMPUTATION The accepted method of computing the density or specific volume of natural gases is the use of the ideal gas law corrected by a compressibility factor. The method proposed by Kay7 of correlating compressibility factors for gaseous mixtures on pseudocritical properties5 appears to be satisfactory for natural gases.2 The methane-compressibility factor has been shown to deviate systematically from the behavior of natural gases2 and a chart giving these corrected factors is available. A method of computing specific volume of gaseous mixtures from partial molal volumes has been reported by Sage and Lacey.8 Complete data for the computation are not yet available for all hydrocarbon gases. Most of the reported data on gas densities have been in the single-phase region removed from the dew point or saturation condition. Since most gases in the reservoir or while on contact with liquid during flow are saturated, the determination of densities under conditions of saturation is particularly important. Although there is no reason to believe that the saturated gases differ in behavior from those considerably removed from their dew points, the usual experimental determinations find difficulty on approaching the dew-point conditions. This paper reports the density of 16 saturated gases in equilibrium with crude oils. The relationships developed to compute the density of gases to high pressure' have been modified and enlarged. A simplified method of obtaining gas density is presented in the form of charts, which apply for specific groups of gases.

Jan 1, 1941

Q: It is May 1961 at Bill Wrather's Washington house. Bill, think back to your first job after college. Wrather: Perhaps I ought to go back a little bit further than my first job. I entered the University of Chicago with the idea of studying law. My intention was to take a 4-yr liberal arts course and superimpose a law degree on that. But during my undergraduate work I fell under the influence of R. D. Salsbury. He decided I had some talent as a geologist and influenced me to take a geological course. Nevertheless, I did not give up the idea of law. While in school I took a spell of typhoid fever and almost died. The doctor recommended outdoor exercise, so a geological job seemed logical. W. H. Emmons was a graduate student in the University and he interceded with Dr. Hayes of the USGS. I went on the payroll as assistant packer at $60 a month. I had one of the most glorious summers I ever spent in my life. That fall and the following year I took law courses and became thoroughly convinced that I was cut out for a geologist rather than a lawyer. I finished up my law work in 1908 while waiting for a job with Bill Emmons, who was doing a careful study of Goldfield and Tonopah.

Jan 4, 1964

By J. H. Faulk

An examination is made of the various factors influencing drilling rate and drill bit life in various diameter holes. It is concluded that drill bits in the size range 4% to 6 1/4 in. can be used to attain substantially the some daily drilling progress as conventional size bits in soft rock drilling operations. An examination of the most important factors influencing "hazard of losing the hole" in the different hole size results in the conclusion that the smaller hole sizes can probably be drilled at reasonably low risk. However, this risk will be somewhat greater in the smaller diameter holes, requiring that special drilling and mud engineering practices be used to make small diameter holes practicable in soft rock drilling operations. An engineering analysia is made of the power and hydraulic requirements of several drill string-hole combinations to test the feasibility of drilling .small diameter holes in soft rock areas. Large econormies in rig power requirements appear possible by drilling .smaller .size holes in these operations. INTRODUCTION The industry now is re-examining the utility of small diameter holes in the light of substantial technical advances made in recent years. Faced with increasing cost of finding reserves and with proration after developing them, the industry must either develop methods of economizing or receive a lower rate of return on investments. Small diameter holes appear to involve an attractive method of economizing. Our objective is to determine if this is technically possible in soft rock operations. Soft rock, as used in this report, refers to those formations of a "drill-ability" corresponding to that of all Gulf Coast formations shallower than and frequently including much of the Eocene rock system. An important phase of technology which we shall examine is relative drilling rate and bit footage which may be obtained with various size bits. Rig operating efficiency, particularly as influenced by hazard, is also discussed in detail. The technical conclusions resulting from these examinations are used to develop sample drill string design and rig horsepower requirements for drilling holes as smaH as 4 3/4 in. and larger. The principal criterion used for the drill string design is that approximately the same daily drilling progress would be possible in all size holes in soft rock operations. This facilitates a comparison of rig size required for drilling the hole sizes in the range between 4 3/4 and 8 3/4 in. BROAD PROBLEM OF DRILLING RATE AND BIT FOOTAGE The three factors controlling daily drilling progress are: (1) drilling rate of bit while on bottom turning, (2) bit footage, and (3) rig operating efficiency. Let us look now at the first two of these factors. Drilling technology has progressed to the point that a semi-quantitative analysis of the effect of various operating variables upon these factors can be made. Those factors which apparently limit both drilling rate and bit footage for bits now in use are: (1) bit design, (2) weight on bit, (3) hydraulic cleaning capacity for bit cutting surfaces and hole bottom, and (4) rotary speed. (We neglect the effect of mud and formation properties because these factors arc the same for the various size bits.

Jan 1, 1957

By Elmer R. Kaiser

G. A. Vissac (Consulting Engineer, Vancouver, B. C.) —Some of the data presented in this paper, in connection with cost studies of washed coals, should be clarified and qualified. Washing a raw coal down to a low ash content may mean higher losses in refuse, but the cost of the operation may be more than compensated by the increased value of the resultant product. However, careful engineering and accurate machinery are required to insure maximum profits. Washing at a low gravity separation demands a very accurate automatic process, chiefly when the small sizes of coal are being handled. Coal consumers today are buying mostly on a Btu basis, cognizant of the fact that low ash contents result in lower installation costs and in savings in handling and transportation charges. The attached Table X gives the actual balance sheets of the various cleaning operations corresponding to various ash contents for the two coals presented in the paper, using the old technique of a two-products separation. or the new technique, now commonly used in Europe, of a three-way separation made possible by new methods and new equipment. Savings in capital costs, handling, and transportation have been calculated on the basis of a delivered cost f.O.b. plant of $10.00 per ton of coal at 16.5 pct ash (actual 1953 average price reported by Consolidated Edison, N. Y.), and of $3.50 at the mine also for 16.5 pct ash coal. In both cases this corresponds to values of 126 and 4.26 per 1 pct of combustible and per ton, respectively, on delivered and on at the mine prices. As an example, the middle western coal at 16.5 pct ash, raw, washed down to 4 pct ash in a two-way process will give 53.75 pct of clean coal at 4 pct ash and 46.25 pct of refuse at 31 pct ash. The value of the losses will be 0.4625x(100—31)x0.042 = $1.34. Add the cost of washing, capital, and operation, which is $0.35. The total cost will then be $1.69. But with a three-ways separation we will have 53.75 pct of first-grade coal at 4 pct ash, 37.25 pct second-

Jan 1, 1955

The following is an incomplete list of members and guests who called at Institute headquarters during the period June 10, 1918 to July 10, 1918. F. C. Alsdorf, Tucson, Ariz. Emory M. Marshall, Camp Raritan, N. J. Juan F. Brandes, Santa Barbara, Cal. Jacques S. Negru, Camp Niagara, Ont. .H. Smith Clark, Kansas City, Mo. Arvid E. Nissen, High Bridge, N. J. J. S. Cunningham, Charleston, W. Va. Richard G. Place, So. Strafford, Vt. W. G. Eberhardt, Tucson, Ariz. Frank H. Probert, Berkeley, Cal. M. Eldredge, Bombay,. India. Martin A. Roudabush, Osterburg, Pa. A. D. R. Galloway, Accra, W. Africa;. P. H. Royster, Minneapolis, Minn. F. Hanst, Harrisburg, Pa. J. L. Schueler, Peoria, Ill. B. B. Hood, Chrome, N.. J. Henry B. Smith, New Britain, Conn. Paul S. King, Wilmington, Del. W. G. Sommer, Peoria, Ill. E. D. Kinney, Anaconda, Mont. A. L. Toenges, Roanoke, Va. E. W. Kohl, Jr., Philadelphia, Pa. G. D. B. Turner, Butte, Mont. James W. Love, Knoxville, Tenn. A. T. Ward, Bellefonte, Pa. Edwin A. Austin, formerly with the Yukon Gold Co., is superintendent of the Elkoro mine at Jarbidge, Nev. John W. Beard is now with the Cia Minera de Penoles, Ojuela, Dgo., Mexico, via Mapimi. R. S. Bonsib has accepted a position with the United States Emergency Fleet Corporation as District Safety Engineer, San Francisco, Cal. Albert Burch has been appointed by the Bureau of Mines to encourage the mining of chrome. F. B. Caldwell is working for the U. S. Bureau of Mines, under Albert Burch, in the investigation of chromite deposits. W. A. Carlyle has taken over the duties (in addition to his own) formerly assigned to E. P. Mathewson with the British America Nickel Corporation, at Sudbury, Canada. R. M. Catlin received the honorary degree of Doctor of Science at the recent commencement of Rutgers College, New Brunswick, N. J. S. K. Dahl is giving up his position as mill superintendent with the Messina Mines, which have been suspended, and is returning to this country. Algernon Del Mar has become manager of the Techatticup mines, El Dorado Canyon, Nev. Robert Dye has succeeded D. L. Forbes as manager of the Teck-Hughes at Kirkland Lake, Ont., Canada. J. O. Elton, superintendent of the Anaconda company's electrolytic zinc plant at Great Falls, Mont., is doing special work with the U. S. Bureau of Mines. R. B. Caples takes charge of the plant in his absence. George H. Gibbs has resigned his position as engineer at Messrs. T. & 1. Bradley & Sons, Ltd., Darlaston blast furnaces, Darlaston, and is now located at "Belmont." Litchfield Road, Rushall, Walsall, England. William D. Gordon, for the past 7 years manager of The Mine & Smelter Supply Co. at El Paso, has been elected president of Camphuis, Rives & Gordon,. Inc., and has opened American headquarters for the company at 81 New Street, New York, N. Y. E. Harms, for the past 16 years inn charge of metallurgical operations of the Torreon, Mexico; lead and copper smelter, has resigned and is now located at El Paso, Tex.

Jan 8, 1918

By John A. Gann

The following investigation constitutes a brief réumé of the more important binary magnesium alloys from the standpoint of metallo-graphic technique, and the effect of heat treatment on structure and properties. The comparative newness of the subject justifies this procedure as a preface to a more detailed study of each individual series of alloys. The work was started with the idea of practical application in the industry rather than as a theoretical investigation. The alloy compositions studied were selected as those most likely to show whether heat treatment would produce beneficial results. Furthermore, it was considered satisfactory to use commercial 99.9 per cent. magnesium, the best commercial grade of alloying ingredients, and to limit the time of heat treatment at the expense of incomplete equilibrium. These facts must be kept in mind when examining the results obtained, and the conclusions drawn. Preparation of Alloys All melts were made in an oil-fired cast-steel pot, approximately 12 in. dia, by 12 in. deep. Approximately 15 lb. of flux and 50 lb. of magnesium were melted and the calculated amount of alloying metal was added. After thorough alloying and puddling, the metal was chill cast in a graphite mold with four 1/2 by 1/2 by 4 in. bars fed from a common sprue and runner. The next higher composition alloy in a given series was made by adding the calculated amount of metal to the heel from the preceding cast. The pot was thoroughly cleaned after each series and new flux then introduced, thus avoiding possible contamination from earlier melts. The percentage compositions given in Table 1 are the calculated values. While not all alloys were analyzed, enough were checked to indicate that the reported compositions are correct to a few tenths of one per cent. A more detailed description of the foundry methods employed has been given in a previous paper. 1

Jan 1, 1929