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By S. A. Ford

A SHORT and accurate method for the estimation of manganese in iron and steel is of great advantage to Bessemer works, and I think it may be of interest to some of the members of the Institute to give in detail the process in use in the laboratory of the Edgar Thomson steel works. The process is based on the reaction first described by Beilstein and Jawein.* The steel, spiegel, or iron is dissolved in strong nitric acid, sp. gr. 1.4. Evaporation to dryness is not necessary, unless the amount of silicon is large, as in the case of certain pig irons. Then, as a clogging of the filter in the subsequent filtra¬tion is apt to follow, dissolve first in a dish in hydrochloric acid, quickly evaporate to dryness, redissolve in the strong nitric acid, boil, and while boiling throw in crystals of chlorate of potash from time to time. Violent action ensues, yellow fumes are given off, and binoxide of manganese is precipitated, since it is insoluble in strong * Berichte der deutschen chemisehen Gesellschaft, vol. xii, page 1528.

Jan 1, 1881

By John Tyssowski

IN 1925, Harry Howard Stout, then metallurgist for Phelps Dodge Corporation, while investigating the cleaning of cathode copper by various gases at elevated temper-atures below the melting point of the metal, observed in the laboratory that particles of pure copper heated in a closed tube filled with hydrogen seemingly "stuck together." By further investigation he found that there was actual crystal growth across the boundaries of the particles of pure metal; in other words, there was a complete new crystal realignment and growth throughout the newly formed copper mass. It was coalescence, not adhesion; the several parti-cles had become one unit. From this dis-covery has been developed the coalescence process, whereby copper of cathode purity is squirted out in semifabricated form from an extrusion press, by the appli-cation of about 3000 tons pressure on a 10-in. piston. Stout decided that cathode copper pro-duced by electrolytic deposition was the logical source of the pure copper required for the coalescence process, but as there was no way of reducing the ordinary tough commercial cathodes to the small particles required he was confronted by a serious problem at the outset. Under his direction, this problem was solved by William H. Osborn and Harry Howard Stout, Jr. They developed the process and technique for producing cathode copper in brittle, friable

Jan 1, 1940

By M. C. Fuerstenau, W. F. Cummins

The flotation response of quartz in the presence of calcium chloride and various fatty acids is presented. Flotation is not effected with lauric acid until calcium laurate is precipitated in solution, while flotation is obtained with the 9, 10, and 11-carbon members before precipitation of the calcium carboxylate. The active species responsible for flotation is suggested to be a basic aqueous complex, e.g. Ca(OH) (RCOO) (aq), and a possible mechanism of adsorption is given. Most of the previous work on activation in non-metallic flotation systems has involved the use of high molecular weight collectors, such as oleic acid or alkyl aryl Sulfonate.1-7 In these studies the levels of addition of collector and activator required for flotation were much above the concentrations necessary for precipitation of the metal-collector salt. In fact, Clemmer, Clemmons, Rampacek, Williams, and Stacy1 have stated, "Our experiments on a variety of materials have demonstrated that the metal salts which react with anionic collecting agents, as soaps and alkyl sulfates, to form relatively insoluble compounds may be employed as activating agents provided an optimum quantity is used at a proper pH." On the other hand, Gaudin and chang8 obtained flotation with additions of barium and lauric acid below the level required for barium lautate precipitation.

Jan 1, 1968

By H. K. Livingston

A technique has been developed which makes it possible to determine the spreading pressure of liquids and solids, for simple systems. Data for surface tensions, interfacial tensions, spreading pressures, and contact angles for water, heptane, and silica are tabulated.' These results can be applied to the evaluation of capillary rise and displacement pressure in a petroleum reservoir. Appropriate equations are presented and the application of these equations is discussed. The presence of surface-active components affects both capillary rise and displacement pressure and also seems to influence the rate of fluid flow. The purpose of this paper is to supplement and bring up to date the last article on the subject of the surface chemistry of petroleum reservoirs, that of Garrison in the 1935 Oil and Gas Journa1.1 A discussion of the "adhesion tension" concept used by Garrison has been presented in another publication,2 together with the reasons for the recommendation that the term "adhesion tension" be abandoned. In view of the fact that some of the data used by Garrison have been superseded by more recent work, it seemed advisable to call attention to this fact and present the more important data currently believed to be correct. In the earlier paper, Garrison set up the equations that 'relate solid-oil and solid-water interfacial tensions to each other, and applied data from Bartell and Miller3 to these equations. However the adhesion tension measurements made by Bartell and Miller involved a confusion of symbols, so that they did not actually measure the spreading pressure, ?s — ?sf.2 The spreading pressure is a convenient method of indicating the amount by which the surface energy of a solid surface is lowered on immersion in a liquid or vapor. Since the initial value of the free surface energy is represented by the symbol ?s and the final value is ?sF, the spreading pressure is ?s — ?SF. A technique has now been developed4 that makes possible the determination of ?s — ?sF for simple systems. This method would be very difficult to carry out with a multicomponent system such as exists in the petroleum reservoir. However, already results have been obtained for ?s — ?sF for water and heptane in contact with silica and graphite. These values will be of the same order of magnitude as those in the petroleum reservoir. Accordingly, it is possible for the first time to discuss the surface-energy relations of the petroleum reservoir on a semi-quantitative basis. Preliminary Generalizations A petroleum reservoir may contain the following four phases: gas, hydrocarbon liquid, aqueous liquid, and solid. The three fluid phases are dispersed through the solid reservoir rock. If gravity were the only force acting, it is obvious that the

Jan 1, 1943

By H. K. Livingston

A technique has been developed which makes it possible to determine the spreading pressure of liquids and solids, for simple systems. Data for surface tensions, interfacial tensions, spreading pressures, and contact angles for water, heptane, and silica are tabulated.' These results can be applied to the evaluation of capillary rise and displacement pressure in a petroleum reservoir. Appropriate equations are presented and the application of these equations is discussed. The presence of surface-active components affects both capillary rise and displacement pressure and also seems to influence the rate of fluid flow. The purpose of this paper is to supplement and bring up to date the last article on the subject of the surface chemistry of petroleum reservoirs, that of Garrison in the 1935 Oil and Gas Journa1.1 A discussion of the "adhesion tension" concept used by Garrison has been presented in another publication,2 together with the reasons for the recommendation that the term "adhesion tension" be abandoned. In view of the fact that some of the data used by Garrison have been superseded by more recent work, it seemed advisable to call attention to this fact and present the more important data currently believed to be correct. In the earlier paper, Garrison set up the equations that 'relate solid-oil and solid-water interfacial tensions to each other, and applied data from Bartell and Miller3 to these equations. However the adhesion tension measurements made by Bartell and Miller involved a confusion of symbols, so that they did not actually measure the spreading pressure, ?s — ?sf.2 The spreading pressure is a convenient method of indicating the amount by which the surface energy of a solid surface is lowered on immersion in a liquid or vapor. Since the initial value of the free surface energy is represented by the symbol ?s and the final value is ?sF, the spreading pressure is ?s — ?SF. A technique has now been developed4 that makes possible the determination of ?s — ?sF for simple systems. This method would be very difficult to carry out with a multicomponent system such as exists in the petroleum reservoir. However, already results have been obtained for ?s — ?sF for water and heptane in contact with silica and graphite. These values will be of the same order of magnitude as those in the petroleum reservoir. Accordingly, it is possible for the first time to discuss the surface-energy relations of the petroleum reservoir on a semi-quantitative basis. Preliminary Generalizations A petroleum reservoir may contain the following four phases: gas, hydrocarbon liquid, aqueous liquid, and solid. The three fluid phases are dispersed through the solid reservoir rock. If gravity were the only force acting, it is obvious that the

Jan 1, 1943

By Walter Miller

Construction of new large refineries was small in 1937, but extensive modernization and expansion of existing plants were made, bearing out the observation of the Bureau of Mines that the trend is strongly toward fewer and larger refineries. Building the first large combination skimming and cracking unit of 20,000-bbl. capacity was a startling achievement four or five years ago, but it has been exceeded many times since, and at least four units with a capacity of 30,000 bbl. or more were contracted for during 1937, as well as many other units of smaller but still substantial capacity. Installation of polymerization plants for producing high-antiknock blending naphthas from refinery gases progressed at an accelerated rate in refineries affording sufficient raw gas to make the use of the process profitable. The total productive capacity of polymerization units built and contracted for in the United States is now about 25,000 bbl., equivalent to the gasoline production from approximately 55,000 bbl. of crude oil a day. Octane Fuels Also utilizing refinery gases—the butylene fractions in particular—the plants for manufacture of iso-octane increased in number to such an extent that the combined capacities will enable the air forces of the United States shortly to go entirely to the use of 100-octane fuel, indications being that the Army will reach that position in 1938, with the Navy not far behind. Commercial air-lines are expected to take advantage of the greater power of high-antiknock fuels to gain the increased power and increased pay loads possible with their use. Work done on producing fuels with octanes beyond the 100 point has recently been reported, and their production can be expected, although at high cost, when the economics of the situation justifies and engines capable of utilizing them efficiently are available. In the field of motor fuels, important work was reported to the A.P.I. at its annual meeting, on the effect of altitude on antiknock requirements

Jan 1, 1938

By R. S. Shoemaker, F. W. McQuiston

MAGMA COPPER COMPANY San Manuel Division The San Manuel Division of Magma Copper Company is located about 40 miles north of Tucson. Tons of ore milled in 1973 .were approximately 19 million at a rate of 63,000 tons per day. From this, about 42,600 tons of copper concentrate was produced as saying approximately 1.070 MoS2 and 28.5% Cu. As with many copper ores, the San Manuel ore contains a small amount of gold, but in this particular case, much of the gold follows the molybdenite. Separation of the molybdenite from the bulk sulfide concentrate by flotation produces a moly concentrate containing 9170 MoS2, just under 1.070 Cu, and 0.44 oz Au per ton. Cyanidation of this material for gold recovery is the only practice of its kind known to the authors of this Monograph. After thickening, the final moly concentrate is filtered for subsequent repulping with cyanide and lime. Gold dissolution takes place in three agitators in series with the pulp from the agitators being filtered in two stages in disc filters. Between filtration stages, the cake is repulped with barren solution. Filtrate from both filters is the pregnant solution. The Merrill-Crowe recovery unit is comprised of two solution tanks and the usual clarifying filter, vacuum tower, zinc dust feeder and Merrill precipitate press. Because of the presence of finely divided sooty chalcocite in the molybdenum concentrate, the cyanide consumption of 55 pounds per ton is extremely high. A compensating factor, however, is the low copper, moly concentrate produced. Precipitation of the gold from the highly copper-contaminated solution requires 0.56 pounds of zinc dust and 0.28 pounds of lead acetate per ton, high figures when compared to normal cyanidation practice. The Merrill- Crowe precipitate assays approximately 28.5% Cu, 8% Zn, 156 oz Au and 197 oz Ag per ton. The San Manuel cyanidation plant is an outstanding and innovative development.

Jan 1, 1975

THE 144th* meeting of the American Institute of Mining and Metallurgical Engineers was held in New York, Feb. 18 to 21, 1935. It consisted of the annual business meeting, 45 technical sessions at which 216 papers were presented (approximately the same number of sessions and papers as at the previous annual meeting), two sessions of the Board of Directors, three meetings of Section delegates, two formal lectures and two addresses, luncheon Monday, Tuesday and Wednesday for members and guests, six group dinners and eight group luncheons, ten committee meetings, the annual reception and dinner dance, an informal dance, a smoker-dinner and the annual meeting of the Woman's Auxiliary. Attendance was generally greater than for the two preceding meetings; the statistics follow (figures are in the order 1935-1934-1933); total registration, 1609-1534-1475; dinner dance, 577-543-426; dinner-smoker, 490-425-394; informal dance, 279-295-250; women's registration, 179-160-133; general luncheons, 1132-1034-734. The Coal Division held two general sessions on Monday and a symposium on coal-mine ventilation on Tuesday morning. The Committee on Bituminous Planning, Edward Steidle, chairman, presented a report at the Monday morning session. C. B. Huntress, President of Appalachian Coals, Inc., was the principal speaker at the luncheon on Monday, at which Eli T. Conner, Chairman of the Division, presided. Mr. Huntress was preceded by Howard N. Eavenson, President of the Institute, who spoke briefly. The Sectional Committee on Classification of Coal met Wednesday afternoon. A feature of the meeting concerning three Divisions-Iron and Steel, Institute of Metals, Petroleum-was the symposium on Use of Metals in the Petroleum Industry, Thursday morning and afternoon. Five of the papers presented at this symposium have been published in METALS TECHNOLOGY'. Another feature, of general interest, was the Tuesday morning session in the Auditorium, devoted to Federal Government and Mineral Industries. Dr. C. K. Leith delivered the principal address, on "A, Mineral Policy for the United. States." . The Institute of Metals Division held technical sessions Tuesday afternoon and Wednesday. morning and afternoon and on Thursday

Jan 1, 1936

By A. A. Smith

THE application of indium to bearings was first advocated by C. F. Smart1 in 1938, for the purpose of inhibiting corrosion of certain bearing alloys. He found that a thin layer of indium plated on the bearing surface and subsequently diffused at elevated temperatures markedly decreased the rate of corrosion in lubricating oils containing organic acids. Most of his work was done on cadmium-base alloys, although he showed that the treatment was also effective for copper-lead and other alloys. Since their introduction, indium-treated bearings have found considerable use, particularly in connection with airplane motors.2 Undoubtedly the effectiveness of the indium plate in resisting corrosion depends upon its relative concentration on the bearing surface after the diffusion treatment and after prolonged use at operating temperatures. Some diffusion experiments were made on a number of base metals that had been indium plated, to determine the depth of penetration after heating for reasonably long periods of time. As only the practical aspects were desired, no attempt was made to determine actual diffusion constants. METHOD Two different series of experiments were carried out to study the diffusion of indium into several base metals. Cast cylinders about one-inch diameter were machined to 0.750-in. diameter, so as to remove all surface imperfections, and final finishing was done with oo sandpaper. The original diameters were very carefully measured with micrometers and then a layer of indium was electrolytically deposited on the cylinders from a sulphate bath.3 In the first series of experiments, about 0.002 in. of indium was deposited and diffusion was carried out at 150°C. for a period of 500 hr. in a thermostatically con- trolled electric oven. After the diffusion period, successive layers were machined from the specimens and analyzed spectro- graphically and chemically-the spectro- graphic examination serving as a guide to determine which layers should be chemically analyzed. Apparently there was some surface oxidation of the indium plate due to the long heat-treatment, which may have had some effect on the diffusion. Also, the cadmium alloy showed some incipient melting, which probably was caused by the formation of a low-melting eutectic. To eliminate these factors, another series of experiments was carried out by heating in an electrically heated, automatically controlled, oil bath at lower temperature. The preparation of the specimens was the same as before except that a layer of indium 0.0001 in. thick, an amount commonly used commercially on bearings, was deposited on each of the cylinders. Diffusion was carried out at l20°C. for a period of 200 hours.

Jan 1, 1944

By William J. McCaughey, Richard L. Barrett

FOR sixty years-in fact, ever since the inception of the basic steelmaking process -basic slags have been the subject of study by chemists, metallurgists and petrographers, with the purpose of providing a better understanding of the reactions between the slag and the metal during the refining process. The result of this work and of the researches of mineralogists and physical chemists into the chemistry of oxide systems is a considerable body of literature dealing not only with slags themselves but with equilibrium relationships in systems synthesized from pure components. Since any actual slag is a multicomponent system more complex than any yet worked out in the laboratory, a complete solution to the problem is still far away. The writers have recently published a paper1 which they believe sheds light on the role of the slag in the elimination of phosphorus and it is the purpose of the present paper to discuss the metallurgical applications of that work. Since the pioneer investigations on the constitution of basic slags carried on by Stead and Risdale, Carnot and Richards, Hilgenstock and others in the 1880's, a considerable body of literature on this subject has appeared. Many of the more important of these papers were summarized in the previous paper,' therefore they will not be reviewed here. PETROGRAPHIC STUDY The present writers have had occasion, over a period of years, to examine petrographically a great number of basic steel- making slags having a very wide range of chemical compositions and made under various conditions of operating practice. Although certain of these slags exhibit some unusual features, it is a remarkable fact that the great majority of mature slags show certain typical characteristics, which persist throughout the wide range of chemical compositions. The typical mature slag usually appears under the microscope to consist of two phases. The phase of primary crystallization is light colored and doubly refracting. If separated mechanically and subjected to chemical analysis, it is found to consist essentially of SiO2, CaO, and P2O5. Sometimes, although not usually, two such silicate-phosphate phases are found. The other conspicuous phase is dark in color and optically isotropic, and occurs as the interstitial material between the grains of the light colored phase. This dark colored interstitial phase when analyzed is found to consist essentially of FeO,Fe2O3, MnO, and MgO. In some slags high in iron oxide, particularly those from low-carbon heats, dicalcium ferrite is found. This phase is dark reddish brown in color and anisotropic.

Jan 1, 1944

By J. E. Tobey

UNQUESTIONABLY, manufactured gas will stage a comeback of such huge proportions as to dwarf its previous history. Timing will depend on two things: the diminishing supply of natural gas and the perfecting of processes for large-scale production of high-Btu gas from, coal. What the timing will be, and how soon the new era will begin for manufactured gas, no one knows. It may be just around the corner and it may be several years, but it is certain to come. It will depend on economic changes, and any major world upheaval might accelerate it tremendously. Supplemental gas for pipelines will come no doubt from two sources at least: (1) synthetic-fuel plants of the coal-chemical group, which produce chemicals and liquid fuels with a tail gas high in methane as a by-product; and (2) large-scale gasification plants, which will produce high-Btu gas entirely or as a major product with chemicals and liquid fuels as by-products. There is important activity at the present time, in the development of new processes and the improvement of those now in existence. The first large-scale gasification plants of the second category probably will be strategically located in the coal fields on or near the long-distance transmission gas lines, and these plants probably will operate jointly with large natural gas storage fields. Inasmuch as virtually all the major gas-transmission lines cross one or more coal fields, such locations will not be difficult to find. It will be a practical necessity to produce a high-Btu gas -that is, 750 to 1000 Btu-in order to maintain the capacity of the main transmission lines and local city distribution systems and further to eliminate the problem of appliance changeovers in the cities. If gasification plants on a medium or smaller scale prove to be economical, local gas utilities no doubt will consider .the construction of such plants to supplement their supply of natural gas. If low-temperature distillation processes like those now being developed by the Pittsburgh Consolidation Coal Co. are successful, and there is reason to believe that they will be, utilities that supply both gas and electricity to communities would find this method particularly attractive, as they could burn the char product directly under power boilers, thereby minimizing thermal

Jan 1, 1953

By William P. Blake

In addition to uintaite, the Uintah Mountains contain a deposit, or vein, of the peculiar hydrocarbon mineral, to which I have given the name wurtzilite, * in honor of the chemist, Henry Wurtz, Ph.D., of New York, who, in 1865, described grahamite, and who has added to our knowledge of the composition of the hydrocarbon minerals. Wurtzilite and uintaite are very similar in appearance, but are very different in their physical and chemical properties. Both are black, splendent and shining in fresh fracture; but the wurtzilite has a decided toughness, and a degree of elasticity, especially when warmed, which suggests to some persons a resemblance to caoutchouc. It was at first, at Salt Lake, believed and reported to be a mineral form of India-rubber, and great expectations of its value as a substitute for crude rubber were indulged in. It was, however, found that it would not act like rubber with sulphur; it would not incorporate with it and become "volcanized," and it was very refractory and insoluble in the ordinary solvents of rubber and of uintaite. The elasticity, though unlike the elasticity of rubber, led to the reference of the mineral to the species elaterite, the only name under which an elastic bitumen is described in the mineralogies; and it is so called in the list of the mineral products of Utah, given in the last message of the Governor of the Territory. The name elaterite, as used by Dana, covers at least three differing substances, ranging in specific gravity from 0.905 to 1.223. Two of the varieties are soft and elastic, much like India-rubber, and one is occasionally hard and brittle, imbedded in the softer kinds. All are rare, and comparatively unknown, and not generally represented in mineral collections. One of the varieties referred to here is the subterranean fungus from Derbyshire, described by Lister as early as 1673.

Jan 1, 1890

Technology has no recognized rank in what is called polite literature; the subject-matter of engineering is not supposed to lend itself to artistic treatment; we are the hewers of wood and drawers of water to the high-priests of learning that live on the cold summit above our humbler dwellings. Therefore the hierophants smile at the notion of 'style'- “that curiously personal thing”--in technical writing. The "great art" of Pater, the "inevitable phrase" of Raleigh, the "note of distinction" that Arnold demanded are said to be beyond the scope, as they are supposed to be beside the need, of a writer on geology or engineering. This is a narrow view. Science, no less than belles lettres, calls for the best exercise of the human intelligence; the art of writing should be employed as skilfully and as earnestly in a description of the structure of the Sierra Nevada, or of the construction of a tunnel through the range, as in a rhapsody welcoming the rosy fingers of the dawn. The idea still lingers that fine writing does not befit technology, even though the masters of the Victorian period- Huxley, Tyndall, Ruskin-proved that science is worthy to be arrayed in the best robes that the looms of thought can weave. At the beginning of these lectures I quoted Barrie's remark touching the inability of the scientific man to express himself. That imputation has been passed to the technologist, whose utilitarian pursuits are supposed to make him too clumsy for the refinements of human speech. We may not have acquired the self-consciousness of those writers on Art whose "power of expression is so cultivated that their sensual caterwauling may be almost mistaken for the music of the spheres"; nor can we imitate the politicians, who have the ability to speak far beyond anything that they may have to say; but we too have a litera-

Jan 1, 1931

By James Norman, Benjamin S. Lindsey

BaritE (BaSO4) is the most important industrial barium mineral from the standpoint of quantity consumed. In 1938 the amount was 365,000 tons. Its uses are numerous, some of the 'more important being in the production of pigments, as an inert filler in a wide variety of products, as a weighting material in oil-well drilling muds, in the manufacture of some kinds of glass, and in the production of barium chemicals. The barite studied in this investigation occurs as the massive variety in a shale replacement formation near Magnet Cove, Ark. It is intimately mixed with quartz and small amounts of iron oxide and residual shale. Complete liberation of barite and quartz is not obtained when the rock is ground to 100 per cent through 325 mesh. The crude rock with which all test work was done assayed 85.1 per cent BaSO4, II.II per cent SiO², and 2.85 per cent R²O3. Its specific gravity was 4.03. It was found in the course of the investigation that the barite contained a small amount of uniformly distributed carbonaceous material, so intimately dispersed that it could not be seen with the microscope, but gave a definite gray cast to the barite concentrates. The color of the barite in polished sections of the crude rock ranged from gray to almost black, while finely ground powder was a reddish gray. The reddish hue was due to the iron oxide present. In 1939, under the supervision of Oliver C. Ralston,* the Bureau of Mines, in cooperation with the Milwhite Company, of Houston, Texas, undertook to study the flotation of barite from Magnet Cove, Ark. Flotation of several southern barite ores had already been investigated by the Bureau of Mines.' The Magnet Cove barite was unique, however, in that it had to be ground to such an extremely small particle size for liberation. The flotation of non-metallic minerals in the presence of a large amount of slime is usually very difficult, and when done is an innovation calling for conditions different from those under which granular material is scparated. Laboratory Flotation Work Preliminary investigation showed that the flotation reagents recommended by O'Meara and Coe1 for separating barite and siliceous material were suitable, but much larger quantities of reagents were required to separate such finely divided material. Moreover, it was found that careful control of the frothing was necessary. When oleic acid and sodium silicate were used a voluminous froth was observed at the beginning of a test, and toward the end there was not enough froth to effect complete recovery of barite. The addition of pine oil as a frother gave proper frothing for the duration of the test, and the substitution of coconut fatty acid (crude lauric acid) for oleic acid produced a more heavily burdened froth. Two different paper-mill fatty-acid products were tested

Jan 1, 1942

By Benjamin S. Lindsey, James Norman

BaritE (BaSO4) is the most important industrial barium mineral from the standpoint of quantity consumed. In 1938 the amount was 365,000 tons. Its uses are numerous, some of the 'more important being in the production of pigments, as an inert filler in a wide variety of products, as a weighting material in oil-well drilling muds, in the manufacture of some kinds of glass, and in the production of barium chemicals. The barite studied in this investigation occurs as the massive variety in a shale replacement formation near Magnet Cove, Ark. It is intimately mixed with quartz and small amounts of iron oxide and residual shale. Complete liberation of barite and quartz is not obtained when the rock is ground to 100 per cent through 325 mesh. The crude rock with which all test work was done assayed 85.1 per cent BaSO4, II.II per cent SiO², and 2.85 per cent R²O3. Its specific gravity was 4.03. It was found in the course of the investigation that the barite contained a small amount of uniformly distributed carbonaceous material, so intimately dispersed that it could not be seen with the microscope, but gave a definite gray cast to the barite concentrates. The color of the barite in polished sections of the crude rock ranged from gray to almost black, while finely ground powder was a reddish gray. The reddish hue was due to the iron oxide present. In 1939, under the supervision of Oliver C. Ralston,* the Bureau of Mines, in cooperation with the Milwhite Company, of Houston, Texas, undertook to study the flotation of barite from Magnet Cove, Ark. Flotation of several southern barite ores had already been investigated by the Bureau of Mines.' The Magnet Cove barite was unique, however, in that it had to be ground to such an extremely small particle size for liberation. The flotation of non-metallic minerals in the presence of a large amount of slime is usually very difficult, and when done is an innovation calling for conditions different from those under which granular material is scparated. Laboratory Flotation Work Preliminary investigation showed that the flotation reagents recommended by O'Meara and Coe1 for separating barite and siliceous material were suitable, but much larger quantities of reagents were required to separate such finely divided material. Moreover, it was found that careful control of the frothing was necessary. When oleic acid and sodium silicate were used a voluminous froth was observed at the beginning of a test, and toward the end there was not enough froth to effect complete recovery of barite. The addition of pine oil as a frother gave proper frothing for the duration of the test, and the substitution of coconut fatty acid (crude lauric acid) for oleic acid produced a more heavily burdened froth. Two different paper-mill fatty-acid products were tested

Jan 1, 1942

By John W. Hughes

During the course of any truck loading operation, it will become necessary to replace hauling and loading units. Timing of replacement can be selected on the basis of necessity, or guesswork, or on a schedule derived from past performance records. Replacing units too soon results in high capital costs per hour. Waiting too long results in high maintenance costs per hour. As with any phase of a mining operation, a planned schedule can reduce overall costs and keep breakdowns within reason.

Jan 10, 1976

By Richard P. Rothwell

At the Boston Meeting of the American Institute of Mining Engineers in February last, Mr. George W. Mansfield read an interesting paper on " The Electric Motor in Mining Operations," and he entered into the calculations of power required and cost of transmitting energy in great or small quantities to a considerable distance. I do not intend to go over this ground, or to enter into any discussion of the technical details of transmitting power by electricity, but merely to set up a milestone on the road of progress to show where we now are, how far we have come, and if possible

Jan 1, 1889

Jan 1, 1903

There were present eleven Directors, the Secretary and Assistant Secretary of the Institute, and eleven guests. The Secretary, Bradley Stoughton, was appointed the representative of the Institute on the Board of. Directors of the American Bureau of Welding. A communication from a member of the Institute regarding simplified spelling was laid on the table. The following appropriations were made for the year. 1919: $250 to the Institute of Metals Division, $250 to the St. Louis Section, $100 to the Columbia Section. An invitation was received from the Western Society of Engineers to the Institute to use the facilities of that society during the A. I. M. E. Meeting in Chicago. The Bulletin of the Institute was presented to the French Congress of Engineers. There were elected twenty-eight members, eighteen associates, and three junior associates. The status of one member was changed from junior associate to associate. Four members were reinstated. An extension of time was granted to one member for payment of dues. The dues of four members on active military duty were suspended. Dues were remitted of four members who have been paying over thirty years, and who are each over seventy years of age.

Jan 5, 1919

By John H. Melvin

THE Omaha District, Corps of Engineers, has been doing subsurface exploration work for a number of years, both by contract and with its own forces. Certain practices and procedures concerning the recovery of large diameter cores have been developed which will be described in this paper. GEOLOGY Most of the drilling to date has been in connection with structures on the main stem of the Missouri River above Sioux City, Iowa. A wide variety of subsurface conditions has been encountered. The bedrock formations appear in regular order from the oldest to the youngest, traveling upstream; or in other words, the general regional dip is to the northwest. The oldest formation is the Carlile shale, a compaction or noncemented waxy shale of Cretaceous age. Because of its uncemented, soft nature this shale has a tendency to grind or wash away when drilled. It also has a tendency to rebound or expand when the overlying pressures are removed. A 25-ft bed of sharp, friable sandstone called the Codell member is present near the top of the Carlile shale. This member is a cemented sediment, but in drilling, many of the sand grains are broken loose and exert extensive abrasive action on the core barrel and bit. Above the Carlile shale is the Niobrara chalk, a soft calcareous deposit with shaly horizons and some thin beds of bentonitic clay. The average thickness of this deposit is about 145 ft. It is soft enough to be sawed or bored with ordinary woodworking tools, yet is compact enough to be used as building block. The Pierre shale, the formation above the Niobrara chalk, is over 800 ft in thickness and is the most widespread material in the area. It is a dark colored, compaction shale containing numerous thin bentonitic clay seams and at certain horizons, hard manganese concretions. The shale has numerous faults and in addition, along the valley walls, has undergone considerable - slumping. Joints, fault planes and slickensided surfaces are common features encountered in drilling and add to the difficulties of high core recovery. East of the Missouri River the bedrock is generally covered with from 100 to 200 ft of glacial till, composed of clays, silts, sands, gravels and boulders. The valley itself is filled with alluvial deposits, mostly of the sand and gravel sizes, and contains a buried preglacial or interglacial channel over 100 ft in depth. The overburden deposits require sampling in connection with engineering studies and must also be cased before the underlying bedrock can be cored. The diameter of the required overburden samples can thus have an indirect effect on the size of core recovered from the bedrock. West of the river, which in most cases is the western boundary of glaciation,

Jan 1, 1947