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By L. E. Snow, L. F. Pett

AT the Utah Copper Pit of Kennecott Copper Corp. a versatile mobile drill unit has been developed and tested. Through increased drilling speed and additional available drilling time, an improvement of 233 pct in drill performance has been realized. Operators using drill power can quickly and easily convert the unit from a vertical to a toe hole drill. Drilling is done with the machine in line with the unit or at right angles to it. Table I covers the 1950 drill record at the mine, showing the types of machines used and the footage obtained. Development of the new units was prompted by a desire for solution of the following problems: 1—The ever-expanding operations within the Utah Pit, requiring some 65 miles of transmission pipe lines radiating from a central compressed air plant, have now taxed this compressor plant beyond capacity. While 100 lb per sq in. pressure is maintained at compressors, transmission losses from innumerable small leaks result in low terminal pressure at the drills. Fig. 1 illustrates that while terminal pressure varies according to size of air hose and fittings used, the average drill is operating on air pressures within the 60 to 70-lb range. The compressor plant is operated primarily for air rock drills. All drilling is done on day shift, but it is necessary to run two of the three 3720 cu ft capacity compressors during night shift in order to prevent drastic loss of pressure through leaks. On day shift all three compressor units are operated at capacity, so that there is no reserve safeguard available for extensive repairs to any compressor. The calculated volume of compressed air required for operation of 25 drills is but 33 pct of three day-shift compressors. While compressed air is being used to a minor extent for purposes other than drilling, it is felt that satisfactory substitute facilities could be pro- vided in the event that air lines were no longer available. 2—Drill performance has increased beyond the capacity of present 3-in. drifter machines. 3—The installation, maintenance, and moving of air lines in routine mining is a growing problem. The 2-in. level lines are placed outside electrification towers and must be moved to new location upon completion of each shovel cut. In addition to these moves it is often necessary to dismantle level lines so that excessive shovel spillage, or material covering track following a blast, can be pushed in the clear with bulldozers. Where level room is limited, it is often necessary to remove air lines in giving bulldozers room to prepare grades for wagon drills. In spite of precautions taken, many level lines become buried, twisted, and constricted, with excessive air loss resulting. Excessive back break in blasting often leaves several sections of air line suspended in mid-air. Occasionally air lines come in contact with defective electric transmission towers, so that holes are burned through pipe. 4—Rail-handling of drilling equipment such as wagon drills from one location to another requires considerable locomotive crane crew time. Any new unit developed should travel under its own power. 5—Present practice requires accessory material including hose, water pressure tanks, water barrels, drill steel, and bits to be transported by means of push cars when drill locations are changed on any level. 6—In order to supply numerous drill locations with material, many stock piles of new drill rods, drill bits, and other essentials must be left at strategic points, usually in the vicinity of powder magazines. This practice makes for poor housekeeping and contributes to the loss of supplies. Planning the Unit It was felt that a mobile drill unit which would rectify the foregoing problems should meet certain demands: 1—It must furnish compressed air to operate a 4-in. rock drill at a pressure of 90 to 100 lb.

Jan 1, 1953

By Cleo G. Rall

The value of brine analyses in the study of petroleum-engineering problems was recognized early in the history of petroleum. The Bureau of Mines before 1928 had indicated in several reports.3/ ways in which analyses might be used. Because of the confusion resulting from attempts to correlate the work of different chemists using greatly varying methods of analysis and systems of computation and expression of results, a paper presenting the methods used by the Bureau of Mines was prepared and published in 1928. This system of determining the characteristic constituents of oil-field waters and of calculating and reporting results has been widely adopted by the petroleum industry. The earliest and most obvious use of water analyses is determination of the source of water infiltrating into petroleum and natural-gas wells. For this purpose it is necessary that an analysis of the connate water of the formation from which the oil is produced be available and that an analysis of the contaminated water be made. By comparing these analyses with those of connate waters from formations higher in the structure, the formation from which the infiltrating water comes may be identified.

Jan 1, 1953

By Charles A. Steen

Publication of this information circular results from an invitation extended to the Bureau of Mines by the Utex Exploration Co. to visit the company mine, on the Mi Vida claim about 39 miles southeast of Moab, in the Big Indian mining district, San Juan County, Utah. The Bureau is pleased to present this record of the Utex mine -- a property that in the relatively short period of 4 months has become one of the major uranium-ore producers on the Colorado Plateau. The ore deposit was discovered in July 1952 by Charles A. Steen, a geologist-prospector, now chief geologist of the Utex Exploration Co., in tae course of drilling the first diamond-core borehole in the Big Indian district. High-grade ore, 14 feet thick, was penetrated by the borehole. Sinking of a shaft, from which to develop the ore body, was begun in October, and the first shipment of ore left the property December 6, 1952. Ore production, as recorded on ore-settlement sheets received by the company up to July 15, 1953, totaled 16,000 tons averaging, 0.51 percent U305 and 1.25 percent V205. Discovery of the ore body and the large production of ore were achieved without any financial assistance from the Government.

Jan 1, 1953

By Herbert H. Kouns, Harlan W. Nelson, Bruce O. Buckland

GASIFICATION of coal under pressure produces a gas that may be used as the fuel in a gas turbine. The pressure produced by a gas-turbine compressor (5 to 9 atm) should allow the use of high firing rates without unreasonably high solid carry-over rates. Hot make-gas with the tars contained in it in the vapor form can be used in a gas turbine. Most of the ash can be removed through a grate, and only a small portion of the ash and any of the solid combustible material carried over by the make-gas requires separation. The gas stream from which separation is required is a small portion of the total flow of a gas-turbine plant and hence the separator size will be small. The gas stream is reducing and will not, therefore, allow separator fires to occur. The response of the producer to rapid load changes is satisfactory. Only the air rate must change substantially in synchronism with the load. The coal feed, the steam addition to the blast, and the ash-removal rate can follow the load changes with time lags in the order of minutes. The necessary control equipment is simplified by these producer characteristics. With these possibilities in mind, the Steam Turbine Division of the General Electric Co. made arrangements with Battelle Memorial Institute in January 1945 to investigate the problems of the gasification process. A number of tests were made during this investigation on an updraft producer with a grate area of 1 sq ft. The equipment used has been described and the results of the tests made between 1946 and 1950 have been reported.1 The testing with this small producer was recently completed. The concluding tests were run to determine the effectiveness of a clinker-grinding grate and the effect of the operating conditions on the amount and character of the solid carry-over. The present paper describes the producer as modified, and gives the results of the tests using three coals. Another method of using coal in gas turbines is to pulverize it and burn it directly in the combustion chambers. This plan is being tried by the Loco- motive Development Committee of the Bituminous Coal Research, Inc., whose investigation has reached the stage of tests of full-sized equipment.

Jan 1, 1953

By L. T. Sanchez, W. T. Rogers

This paper presents the results of a production experiment evaluating the effect of the use of oxygen in the bessemer converter with respect to its relation to blowing time, amount of steel scrap or cold pig iron which can be melted and teeming temperatures of the molten steel. THE simplest and probably the most efficient and economical means for producing steel from molten pig iron is the bessemer converter. This process is essentially a mechanism for bringing oxygen into contact with the molten metal thereby oxidizing the elements silicon, manganese, and carbon. The source of oxygen is that contained in the air and is limited by that amount. In theory, there is an intermediate chemical reaction due to the mass action of iron and air which is represented by the equation: 2Fe + O2- = 2Fe0 The FeO then becomes the oxidizing agent and reacts with the silicon, manganese, and carbon to produce silicon dioxide (SiO,), manganese oxide (MnO), and carbon monoxide (CO), in the order mentioned. The balancing of the various chemical reactions shows that in the ordinary bessemer process more than sufficient oxygen is delivered to satisfy these reactions, which indicates that a further increase in the oxygen content of the air would serve no useful purpose. In spite of this reasoning, however, it will be demonstrated that when melting stelel scrap, commercially pure industrial oxygen introduced into the normal air blast will permit the melting of a larger proportion of steel scrap than is possible with air alone and also will increase the production rate by a substantial reduction in blowing time. It will also be shown that when melting cold pig iron, it is possible to melt up to twice as much pig iron with the use of oxygen as can be melted without added oxygen with a nominal increase in blowing time. At the plant where this study was made, oxygen is purchased from a nearby supplier and piped directly into the plant. It is supplied to the bessemer converter by being introduced directly into the blast line through an automatic control system which may be adjusted by the bessemer operator or "blower." Normally, iron is supplied by five blast furnaces to an open hearth shop containing twelve 165-ton capacity stationary furnaces and a bessemer converting shop having three 30-ton converters. The molten metal from the blast furnaces is allocated to one shop or the other in a manner to best provide for maximum production. At various times, it is desirable to direct the maximum amount of available blast furnace production to the open hearth shop. This has the effect of reducing the production of the bessemer shop. When this condition exists, it is desirable to supplement the reduced iron charge at the bessemer with steel scrap or cold pig iron to the maximum possible extent in order to maintain high total ingot production. This condition becomes aggravated when one of the blast furnaces is taken out of production for any repair job and particularly for extended periods such as when relining is necessary. The purpose of the investigation and experimentation with oxygen was to determine whether or not it would contribute to increased flexibility in the use of the raw materials, molten iron, steel scrap, and cold pig iron. In addition to the effect of oxygen on flexibility of operation, it was also necessary to determine the relation of its use to production rate or "blowing time," final finishing temperature of the steel or "teeming temperature," and steel quality.

Jan 1, 1953

By M. H. Forester

The Bituminous Coal Industry has for the past year been faced with a most serious problem. I am sure that you have had your own individual and local problems, as do we all. In my thirty years of practical experience with coal mining, I have never found an operating man nor a coal mine without problems. The very nature of mining, with so many unknown factors involved, precludes the absence of problems. But they are not insurmountable, and one should not dwell on them interminably. They should be recognized as a challenge to our ability and ingenuity to solve them, and once the proper solution is found, it should be applied and the problem dismissed. However, we find ourselves at the moment in the midst of a serious challenge to our very existence. In the early thirties, many in the industry welcomed the re-establishment of Unionism as a balance wheel, in the belief that the stabilization of wage scales would also stabilize prices and eliminate disastrous price cutting practices. The ultimate effects of having twenty-six years of benevolent paternalism in the administrative branches of Federal and State Governments with their labor courting policies, could hardly have been anticipated. And so with wages spiralling under government sponsorship, we have finally reached the point where competitive fuels, such as natural gas and oil are more attractive to the consumer, from the economic angle of cents per BTU cost, than coal.

Jan 1, 1953

By J. Venter

The history of firedamp is the same as that of coal: The initial stage was the accumulation of vegetation, which was converted into peat under certain local conditions, then lignite, bituminous coal, and finally anthracite. These deposits ceased to increase owing to inundation that deposited earthy sediment, sometimes as much as several tens of meters (several tens of yards). The vegetable matter, whether it was covered with sediment or not, began to ferment. The basic organic components of the vegetable matter are: Cellulose, lignin, and wax and resin in varying proportions, according to the different kinds of vegetable matter. There are, in addition, some impurities, generally mineral.

Jan 1, 1953

In the years prior to the outbreak of war in 1939 Australia's production of copper had declined from a peak of about 80,000 tons in 1911-1915 to approximately 25,000 tons in 1939. This production met the need of the slowly growing national requirement and gave an excess for export. However, with the intensification of the war effort in 1942 due to the imminence of a Japanese invasion of this country, or at least a blockade of the sea lanes, it became necessary to expand production of armaments, and consequently the demand for copper increased beyond the capacity of the industry. Importation of copper to Australia during the period 1940-1944 was 131,000 tons.When exploration of the Mount Isa orebody was first being carried out in 1928, No. ID diamond drill disclosed the presence of some copper ore lying outside the limits of the Black Star orebody2, but it was not until 1941-1942 that the development of No. 7 level in the Black Star orebody enabled the existence of a lode of copper ore of economic grade to be established. At the request of the Commonwealth Government of the day a programme of development for copper production was undertaken whilst lead smelting was continued as before the war.A series of flotation tests on up to 1,500 tons of ore at a time, was undertaken and the concentrate so obtained was stockpiled. These tests were conducted, using one section of the lead mill, and demonstrated that a concentrate grade of 22-23% Cu with a recovery of 80-85% might be expected.These recovery figures were afterwards much improved, and 93-95%was obtained before the close of smelting in 1946.

Jan 1, 1953

By The Honourable George Prudham

"I AM PLEASED indeed to be present with you here today and to be taking part in the proceedings of your convention. You have been greeted and welcomed to the Province by Premier Manning who is also provincial Minister of Mines and Minerals, and to this City by Mayor Hawrelak. As Minister of Mines and Technical Surveys in the federal government and as Member of Parliament for Edmonton West, I have been asked to share the honour of extending greetings and a cordial welcome to all.It is a happy coincidence that this representative national gathering, indicative of the growing strength and significance of a great basic Canadian industry, is taking place in the Macdonald Hotel, the new addition of which marks another important step forward in the progress of this City and district.This happens to be the third national convention of the C.I.M. that I •have had the pleasure of attending and I trust that I am not presumptuous in expressing the hope that I will have the opportunity of attending many more conventions of the Institute in my present capacity.Dr. Kidd has bestowed on me a high honour by asking me to be Co-Chairman of this Inaugural Session of the Convention and thus to share with him the responsibility of presiding over the proceedings of this afternoon."

Jan 1, 1953

By S. W. Zoldok

[The Bull Valley iron-ore district lie,; in the northern part of Washington County, Utah, approximately 30 airline miles southwest of the highly productive Iron Springs area (fig. 1). Iron-ore occurrences in the district have been known for many years, but they have not been mined, largely because of the inaccessibility of the area. The Bureau of Mines established a development project in the Bull Valley district in September 1941. Two separate areas, the Pilot and the Cove Mountain, were investigated. The work was planned to increase iron-ore reserves for steel production in the Western United States. During the project period three diamond-drill holes aggregating 1, 000 feet were completed (fig. 2). The program also included 6 408 linear feet of surface trenching and 171 feet of underground work (figs. 2 to 8, inclusive). Analyses were made of 460 samples from the diamond-drill holes and surface and underground excavations. The results of the analyses are given in tables 1, 2, 4, and 5, and the logs of the diamond-drill holes are shown in table 3. Field. work was completed in September 1942.]

Jan 1, 1953

By Ruddle R. W.

Magnetite occurs in the reverberatory furnaces, blast furnace and converter (a) as the result of its presence in the materials charged, and (b) as the result of oxidation of the FeS in the charge in the absence of sufficient SiO2 to slag the FeO as it is produced and thus prevent its subsequent further oxidation. Magnetite is reduced by FeS according to FeS+3Fe3O4=10FeO+SO2 and similar reactions. This reaction is markedly affected by temperature and does not proceed to any important extent below about 1200°C. To ensure comparative freedom from magnetite it is therefore necessary to raise the temperature of the furnace to the highest practicable figure and to use plenty of siliceous flux. Since the maximum operating temperature is likely to be limited by the resistance of the refractories to attack by the slag, investigation of the factors affecting this attack should be helpful. It is reasonable to suppose that the formation of magnetite might be minimized by ensuring intimate admixture of matte and slag during conversion so that silica is readily available for combination with ferrous oxide as the latter is formed. The literature gives no clue to the importance of this factor and some experimental work on this aspect might be fruitful

Jan 1, 1953

By J. W. Putman, N. J. Grant, D. S. Bloom

SEVERAL recent determinations of the melting S point of pure chromium have been reported which give values of 1845°C1; 1895°C,² 1930°C,³ 1860°C,' and 1890°C.5 because of this wide spread of values, it appeared desirable to make one additional attempt to obtain a more accurate, reliable figure. bloom and Grantx recently reported a phase transformation in chromium:.--- it was desired to check this, too, in the course of checking the melting point. To accomplish this, a much higher purity chromium was required. Electrolytic chromium containing about 0.5 pct 0 was crushed to a finer size and was then annealed in highly purified, dried hydrogen at 1375°C for 100 hr. This treatment produced chromium with about 0.008 pct 0, 0.002 pct N, and negligible carbon. The balance of the impurities was 0.3 pct Fe, 0.03 pct Si, 0.004 pct S, and less than 0.001 pct Mo. This chromium was melted in a stabilized zirconia crucible under pre-purified argon, using induction heating. Temperature measurements were made with annealed wolfram-molybdenum thermocouples and a Leeds and Northrup Speedomax Recording Potentiometer. The thermocouples were annealed for 1 min in hydrogen at a temperature of about 2400°C. Each leg of the thermocouple was immersed in an ice-water mixture using mechanical connectors to the lead wires. The thermocouple tip was immersed in the molten chromium in a zirconia protection tube which introduces an error of about 3°C as a temperature drop through the walls of the tube. The weight of chromium was about 183 g. The dimensions of the melt in the crucible were about 1.25 in. diam x 2 in. high. The tip of the thermocouple was held about ½ in. from the bottom of the crucible. Two new thermocouples were used with the above set-up giving the results shown in Table I. Since this chromium is purer than that used by Greenaway, Johnstone and McQuillan,' by Carlile et al.,4 and other investigators,²,3 it is believed to be the more accurate. Thermocouple aging effects which are believed responsible for the high value of 1930°C³ were avoided in this work. This value of 1903°C is correct to about ±10°C. The right hand column lists the temperature of the a ? ß transformation on heating and the ß ? a on cooling.3 A sample curve is shown in Fig. 1. The value so determined is 1840°C + 15°C. Fig. 1 gives adequate evidence that there is a transformation in chromium at high temperatures.' References 'H. T. Greenaway, S. T. M. Johnstone, and M. K. McQuillan: High Temperature Thermal Analysis USing the Tungsten-Molybdenum Thermocouple. Journal Inst. Metals (November 1951) 19, p. 109. ²J. W. Putman, R. D. Potter, and N. J. Grant: The Ternary System Chromium-Molybdenum-Iron. Trans. A.S.M. (1951) 43, p. 824. ³D. S. Bloom and N. J. Grant: Chromium-Nickel Phase Diagram. Trans. AIME (1951) 191, p. 1009; Journal of Metals (November 1951). ' S. J. Carlile, J. W. Christian, and W. Hume-Rothery: The Equilibrium Diagram of the System Chromium-Manganese. Journal Inst. Metals (1949) 76, p. 169. 5G. Grube and R. Knabe: Ztsch. Elektrochemie (1936) 42, p. 793.

Jan 1, 1953

By R. F. Mehl, R. W. Parcel

THE rate of the decomposition of austenite in eutectoid steels, forming only pearlite, may be expressed fundamentally in terms of the rate of nucleation and the rate of growth of pearlite nodules. This matter has received much attention in recent years. (The basic references are listed in ref. 1; references of particular import to the present work will be given separately.) Systematic data have been developed for plain carbon eutectoid steels.:! Although the physical factors affecting the rate of nucleation, N, in case of plain carbon steels have presumably been identified, they cannot as yet be evaluated quantitatively.' Several somewhat successful attempts, however, have been made to calculate the rate of growth, G. In the latter case the important factors determining the edgewise growth of pearlite have been assumed to be: 1—the interlamellar spacing; 2—the concentration extremes and concentration contours of carbon in austenite in front of the growing pearlite interface; and 3—the rate of diffusion of carbon in austenite.* The only systematic data on N and G for pearlite in alloy eutectoid steels are those for Co-steels;6 there are no data on alloy eutectoid steels in which the alloying element is known to decrease the rate of formation of pearlite, apart from a few scattering data reported earlier' for steels containing manganese. This paper reports a systematic study of N and G for eutectoid alloy steels containing molybdenum and nickel, respectively. In order to provide information of help in understanding the results, new data are presented on the effect of molybdenum on the interlamellar spacing of pearlite, So; data on the effect of nickel on So have already been published.' The alloys used were in five groups: 1—Pure Fe-C-Mo alloys (Table I) were supplied by the Climax Molybdenum Company of Michigan, Detroit. They were made from Armco ingot iron of standard analysis, Acheson graphite, and ferro-molybdenum, melted in silica-lined crucibles in a high frequency induction furnace. The ferromolyb-denum was added to the melted steel, followed in 5 min by 0.08 pct Al. The ingot as-cast measured 23/4x 31/4x10 in.; it was hot-forged at 1150°C to a bar 1 in. sq.

Jan 1, 1953

By R. B. Burt, J. A. Barr, I. S. Tillotson

THE pumping of solids in water suspension is an important part of many metallurgical and mining operations. In most cases, it is still in the rule of thumb category for which no universal formula has been developed, and much research is needed. Because of the limited and incomplete data available, this article may be classed as an experience paper, which is presented with the hope that some contribution will be made toward the development of the so-called universal formula. This formula, if and when developed, may be evolved from several factors, many of which are not now available for general application. The designing engineer is interested in obtaining accurate forecasts on: 1—the minimum velocities needed to prevent choke-ups in the pipeline, which in turn dictates pipe sizes, 2—power required for pumping, 3—pump selection. The basic factors for a given problem will include: 1—weight per unit of time of solids to be handled, 2—specific gravity of solids, for calculation of volume, friction and power, 3—screen analysis of solids with the colloidal acting, i.e., the slime fraction, a very important factor, 4— shape of particle or some means of determining a friction constant, 5—effects of percentage of solids, 6—development of a viscosity factor to be used in the overall calculations, 7—calculation of the lower limits of pipeline velocities permissible, 8—calculation of total head, pump horsepower, and 9—setting up of pump specifications. In certain limited cases horsepower and total heads and minimum velocities may be computed and a suitable pump selected from basic data, but in many cases, as in mining of Florida pebble phosphate, experience rather than a hydraulic formula still should be used as a basis of selection. Pumping Florida Pebble Matrix Pumping at the Noralyn mine of International Minerals and Chemical Corp. will be used as an example. Other areas will vary as to the characteristics of the matrix, especially the slime content. A typical screen analysis of this matrix is: +14 mesh, pebble size,* 2.1 pct; —14 +35 mesh, 11.4 pct; -35 +I50 mesh, 60.5 pct; -150 mesh, 25.0; total, 100 pct; moisture in bank, 20.0 pct; weight per cu ft in bank, 120 lb. The —150 mesh fraction may increase to as much as 35 pct in adjacent areas. When thoroughly elutriated, the matrix has a relatively slow settling rate, which is an important factor in permitting lower pipeline velocities without choke-ups. Exact data is not available to evaluate settling rates. For a factor of 100 a suspension of clean building sand in water is suggested. When pumping long * Pebble is a commercial designation for the coarser fraction of finished phosphate from a washer, usually +14 mesh. distances, a quick settling matrix allows the coarser solids to settle out along the bottom of the pipeline, causing drag, turbulence, and increased friction. With a slow settling matrix as at Noralyn, turbulence acts to keep the solids in suspension at a lower friction head, regardless of the pumping distance. When the pebble content of the matrix, i.e., the + 14 mesh fraction, is in excess of 10 pct of the total solids, trouble may be expected from settling out even in normal pumping distances. To prevent choke-ups and maintain tonnage, an additional pump must be added in the long runs, where one pump would otherwise be satisfactory. A typical pulp handled is: total volume, 7800 gpm; water, 4500; solids pumped per hr, 4200 lb; sp gr pulp, 1.4; percent solids in pulp, 46.; pipe size, 16-in. ID; pulp velocity, 12.85 fps; probable critical velocity, 10 fps, as below this minimum velocity choke-ups would be numerous. In calculating friction heads the Armco handbook is used where a roughness factor based on 15-year-old pipe is set up. Because the pipe used in pumping matrix is smooth and polished because of the scouring action of the phosphate and its silica content, the head losses in the Armco table for water are practically the same as in pumping the Noralyn matrix through smooth pipe, plus the fact that conditions vary widely over short periods, making accurate determinations difficult to obtain. New pumps and pump changes are being tested continuously and a wealth of data built up. This has resulted in a substantial improvement and lower relative costs in pumping matrix. The Florida phosphate industry is constantly seeking to offset higher wage and material costs with improved technique. Until a few years ago a 12-in. discharge pump was commonly used, with heads as low as 80 ft. Sizes have gradually increased and heads more than doubled. For example, the following pump was placed under test at the Noralyn mine: make, Georgia Iron Works; size, suction 16 in., discharge 14 in.; impeller, 39-in. diam; motor, 600 hp, slip ring; full load speed, 514 rpm. The results were increased head, higher capacity than the older design, with fewer pumps in the line from mine to washer.

Jan 1, 1953

By Milton H. Fies

THE writer wishes to acknowledge at the outset his great sense of obligation to those who contributed so broadly and expertly to the preparation of this paper: Dr. Albert DeSmaele, Chairman of the Board of Directors of Socogaz, Belgium; Dr. Julien Venter, Director of the National Institute of Coal Mining, and Coal Utilization Industry, Belgium; Dr. Roger Loison, Chief Engineer, French National Coal Research Board, France; and Dr. Erich Sarapuu of the Sinclair Coal Co., Kansas City, Missouri. Liberal use has been made in this paper of a recent publication on Russian, Italian, Belgian, and French experiments prepared jointly by the Centre d'Etudes et Recherches des Charbonnages de France (Cerchar) and the Institut National de I'Industrie Charbonnière of Belgium (Inichar) .l The writer is particularly indebted to Dr. E. T. Wilkins, of the Fuel Research Station, London, and to Mr. James L. Elder, of the Alabama Under- ground Gasification Experiment at Gorgas, Alabama, for their unfailing patience and effective support. Not only did these experienced and capable men edit and revise this discussion, but much of its content is a direct contribution quoted in full from their memoranda. Without the assistance of all these colleagues, this presentation would not have been possible. It has been a privilege to serve and work with them and to acknowledge repeatedly their loyal cooperation. The recovery of the energy inherent in coal beds throughout the world has been done through the years by methods that today may be justly regarded as primitive. While the techniques of coal mining through the application of machines and the enhancement of information and skills have advanced to an extraordinary extent, particularly during the past 20 years, the underlying means is essentially the same as when man first began to mine coal. Despite this progress in the manner of coal mining, it continues today as a hazardous, toilsome, grimy task. Coal mining per se has advanced at a greater and more rapid stride in the past 25 years than the mining of any other mineral, but the basic method is fundamentally the same as it was the first day a miner took a pick into his hands many centuries ago. This situation presents a challenge to mining engineers everywhere, from

Jan 1, 1953

By E. P. Carman

This: report gives data on the installation and operation of a packaged-unit heat-pump installation in a residence in McLean, Va., a suburb of Washington, D. C. The original equipment, installed in January 1947, was one of the first of 50 experimental Marvair units manufactured by the Muncie Gear Works, Inc., Muncie, Ind. The compressor unit of this installation was replaced by the company in September 1947, with a modified commercial model. The commercial unit and the original pump and fan accessories have been used as the sole means of heating (and cooling in summer! the. residence for the subsequent five winters and summers. The conclusions and data given herein, therefore, cover 6 winters sad 6 summers of heat pump operation, including 1 winter when temperatures averaged below normal for 2 months and the following summer when temperatures were above normal.

Jan 1, 1953

By Dart Wantland

"AbstractThe scope of geophysics in civil engineering and the nature of exploration geophysics are briefly discussed. Engineering problems amenable to geophysical attack are illustrated by specific examples. The various methods available, accuracy of results, and costs are treated. The possibilities of new uses of geophysical techniques are pointed out.IntroductionTHE SCOPE of geophysics in engineering is different than in oil or mining exploration. In civil engineering, geophysics solves specific problems; as for example, what is the depth to bed-rock along the axis of a proposed dam? The area to be surveyed is of limited extent, and the subsurface information .sought is relatively near the surface. The engineering geophysicist is not called upon to investigate geological basins or extensive mineralized areas or to probe for data to thousands of feet in depth. The geophysical tools employed in the three fields are, however, quite similar; the differences are mainly in the objectives.The Natural Geophysical ExplorationThe terms geophysics and geophysical exploration have been used heretofore and will .be employed in what follows. The question is, therefore, What is geophysical exploration?Geophysical exploration is a line of field work where measurements are made at the ground surface with special instruments to get geological subsurface information. Briefly stated, geophysics is a form of exploration that supplements geological work. It is a blend of physics and geology since physical measurements are made •at the surface of the ground that can be interpreted in terms of subsurface conditions."

Jan 1, 1953

By B. P. Martinez

A process for regenerating spent pickle liquor is proposed in which some of the water is evaporated at atmospheric pressure and ferrous sulfate is precipitated as monohydrate crystals..Equilibrium conditions are set for a slurry of crystals in a mother liquor containing 5 percent FeS04 and 45 percent E2S04, by weight, and boiling at about 235° F. The slurry is pumped continuously to a filter, and the mother liquor from the filter is pumped back for reuse in the pickling tanks. The net result of the process is to remove ferrous sulfate in the regeneration plant at the same rate ac it is produced in the pickling tanks. This process is integrated with the steel-pickling operation and controlled by the pickling requirements for particular steels. Spent pickle liquor is removed for regeneration continuously from both batch and continuous picklers at higher acid concentrations than would be dumped to waste because no acid is neutralized or discarded. However, the process is not designed to keep a sulfuric acid concentration stronger than 25 percent in any pickling tank. To retain flexibility in the pickling operation, all acid makeup is added to the pickling tanks. Rinse waters are used as water makeup for the pickling tanks. To further minimize waste of acid in the rinse waters, improvements of rinsing practices are outlined.

Jan 1, 1953

By W. D. Walker

The trend toward encouragement of worker participation in accident prevention in the coal mines of the United States is not new; however, it has been given added impetus in recent years and is now definitely progressing. It has been found by experience that, although there are many approaches to a mine-safety program that will include the workers themselves as well as their supervisors, no one way is suitable under all circumstances. It requires the concerted efforts of many agencies working along parallel lines toward a common goal. The following seven principal agencies, using somewhat different methods, are listed to illustrate how this problem is approached throughout the coal-mining industry 1. Federal Bureau of Mines. 2. State mining departments (in individual States where coal is produced). 3. Programs conducted by individual mine operators. 4. Programs conducted by mine workers' organizations (unions). 5. Institutes, societies, and other educational organizations. 6. Coal operators' associations (regional and national). 7. Universities, college, and high schools. Each of the seven approaches to safety are discussed briefly, and their methods end contributions, such as publications and other activities, are listed.

Jan 1, 1953

By Constantine C. Popoff

The Hermada antimony deposit is in the Sewtooth Range in southwestern Idaho, about 77 miles by road northeast of Boise. Stibnite mineralization occurs over an area one mile wide from west to east and two miles long. It is locally referred to as the Swanholm district. In 1947 high- grade stibnite ore was discovered on the East Fork of Swanholm Creek. Since then, ore in commercial quantity has been produced by the Hermada Mining Co. The total output for 1947-50 was about 5,000 tons of ore, containing 640 short tons of antimony metal.

Jan 1, 1953