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By J. W. Halley, T. S. Washburn

RIMMING steels derive their name from their action during solidification in the molds. As a result of incomplete deoxidation, gas is evolved during freezing, and the metal has a characteristic rolling action. The metal rises along the mold walls and descends in the center of the ingot. This action keeps the top of the ingot open and the advancing rim of solid metal can be seen. The rim grows until the rolling action is insufficient to prevent the top of the ingot from freezing or until the action is stopped by capping the ingot with a heavy plate. The violence of the reaction and its characteristics, such as growth or drop in the molds, are determined by the composition, the furnace practice, and the deoxidation in the ladle and in the molds. Though rimming steels represent a large proportion of the amount of plain carbon steel made, they have received comparatively little attention in the technical literature. The manufacture of rimming steels has been described by Hibbard, 1, 2 Fleming,3 Pierce4 and Jackson.5 The reactions occurring during rimming have been considered from the theoretical point of view by Chipman and Samarin.7 The structure of rimmed-steel ingots has been discussed by Nead and one of the present authors.6 Meyer,8 in studying segregation, investigated the distribution of carbon, sulphur and phosphorus in rimmed-steel ingots by analyzing the rim and core of blooms. In their studies of segregation, the Joint Committee of the Iron and Steel Institute and the British Iron and Steel Federations studied distribution in one billet and one ingot of rimmed steel.. A detailed study of the distribution throughout the ingot has not been published. The present investigation was undertaken to determine accurately the distribution of carbon, manganese and sulphur in normal rimmed ingots and the general distribution of other common elements present. The study included some work on the effect of pouring conditions and furnace practice on the distribution, though there is still much to be done in this direction. The structure of a rimmed ingot that has been split by dynamiting and a schematic diagram of the zones in the ingot are illustrated in Fig. 1.

Jan 1, 1938

By R. L. Skaggs, R. A. Molsberger

DARKEN1 has pointed out that in most binary liquid metal systems the thermodynamic behavior is relatively simple in the terminal regions. Between the terminal regions. the thermodynamic behavior is more complex. To describe this behavior. he has defined the stability and the excess stability as shown: Qualitatively, an inflection in the free energy of mixing curve results in a change in sign, from positive to negative, of the stability function and is associated with a phase separation. Conversely, a large, positive stability over a narrow composition range is indicative of compound formation. Darken has shown a number of binary systems where the excess stability is constant in the terminal regions and varies sharply in between. The work described in this communication was undertaken to study the variation of stability and excess stability in a binary system as a function of temperature. In addition, this work provides means for the direct comparison of previously existing equilibrium (activity) and calorimetric (molar heat of mixing) data on the Hg-Sn system. Hildebrand2 measured the vapor pressure of mercury over Hg-Sn alloys at 595°K. Calorimetric studies were made by Kawakami3 at 523°K and by Kleppa4 at 423°K. In this work, the equilibrium vapor pressure of mercury was measured over a series of Hg-Sn alloys at 453" and 503°K by use of fused salt manometer with one arm exposed to mercury vapor. Deflections of the fused salt manometer were balanced by argon pressure on the other arm. Argon pressure was subsequently measured with a dibutyl phthalate manometer. Tin activities were determined by graphical integration of the Gibbs-Duhem equation making use of the familiar Darken5 a function. The activities of mercury and tin showed positive deviation from Raoult's law at 453 and 503°K as Hildebrand observed at 595 K. In Fig. 1 are plotted log activity of mercury and tin vs reciprocal temperature. The plot contains activities obtained from calorimetric studies. Hult-gren6 has calculated activities from Kleppa's4 data, and Kubaschewski7 has similarly treated Kawakami's7 data. Presumably. in each case a regular solution was assumed. For regions where a two-phase field

Jan 1, 1970

Unlike the bituminous part of the coal industry, the production of anthracite has been fairly well publicized; in fact until about 1845 whenever the coal industry of Pennsylvania was mentioned in papers, magazines or books, anthracite only was meant. Beginning with shipments by river in 1820 fairly complete records of shipments were published each year, and as this variety of coal was the only one used for domestic purposes east of the mountains and north of the Potomac, there was considerable interest in the producing fields on the part of the public. Transportation of anthracite was the cause of the building of the early canals in the state, and later, of some of the earliest railroads. In most publications it has been assumed that commencement of shipments in 1820 was the beginning of the industry; this is far from being so, and it is with the earlier developments this chapter will deal, leaving the later and better known records to existing publications. (See Table No. 53.) The first reference to coal in Pennsylvania by Gabriel Thomas in 1698 has already been mentioned,1 it could only have been anthracite in that section; although of course, he never saw any coal there. Little coal was used excepting by smiths for many years after that. In 1728 the Coventry Forge paid the expenses of a man "to town for Sea Coall and Steell for ye hammer;”2 in 1729 New Castle coal was sold in Philadelphia;3 in 1740 an advertisement mentioned, "very good Pitt and Sea Coal at 18 pence a bushel; at which price 'tis allowed to be cheaper Fewel for Hearth Fireing than Wood at the present Rates,"4 a view not shared by most of the people there for about eighty years; in 1752 Newcastle coal was again mentioned.5 There are no references to coal in the writings of any of the Moravian missionaries, although some who settled near Mauch Chunk in 1746 said that the Indians there made their pipe heads of a soft black stone, which was much more apt to have been slate than anthracite." Several stream

Jan 1, 1942

Discussion of the paper of K. Huessener, (Trans., vol. 53, pp. 402 to 4333, and of the papers of Linn Bradley, H. D. EGbert and W. W. Strong, pp. 303, 319. R. J. WysoR, So. Bethlehem, Pa. (communication to the Secretary*). —At our plant (Bethlehem Steel Co.), we have had several Bradshaw burners under course of construction and erection for some time, but up to the present we have not had opportunity to put them in service. I regret that I can not take part in the discussion with some actual results from these burners. Mr. Huessener properly emphasizes the importance of obtaining the highest combustion temperature practicable in boiler practice, which demands a near approach to perfect combustion conditions. The ideal burner is the one which, while meeting the various mechanical requirements, fulfills the above condition under a wide range of gas pressure. The question as to the relative value of hot raw gas and cold washed gas for boiler use is a very interesting one. I think that in the past the importance of low temperature of washed gas sometimes has been overemphasized. Mr. Huessener has pointed out that so far as temperature is concerned, no advantage accrues in washing gas below 100" F. In many plants, there is a notable operating economy in using furnace cooling water, which is appreciably warmer than the supply water. However, in a given type of washer, other conditions being constant, the lower the exit gas temperature the lower will be the dust content; this is equivalent to saying that the more washing water is used, other conditions being constant, the lower will be the dust content of the exit gas. For each type of washer there is a certain desired average temperature difference between inlet water and exit gas, concomitant with known average dust and moisture contents, and with economical operation. With the present tendency toward smaller stove checkers, it is generally agreed that gas for stove use should be cleaned to a dust content of 0.20 grain or less. The method employed and extent of gas cleaning are clearly problems for individual furnace plants. As a general proposition, wet washing is decidedly more attractive for furnaces smelting soft, fine Lake ores than for those reducing chiefly hard, lumpy ores, such as the foreign and domestic magnetites. In the former case the average moisture content of the gas is probably 35 grains per cubic foot, the dust content is relatively high and the top temperature relatively low. In our plant, the ore mixtures consist almost exclusively of hard magnetites. The average dust content of the gas leaving the dust catcher will average only about 2 grains and the moisture about 12 grains per cubic foot, corresponding to saturation at about 83" F. The temperature is fully 100" F. higher

Jan 1, 1917

By J. W. Halley, T. S. Washburn

Rimming steels derive their name from their action during solidification in the molds. As a result of incomplete deoxidation, gas is evolved during freezing, and the metal has a characteristic rolling action. The metal rises along the mold walls and descends in the center of the ingot. This action keeps the top of the ingot open and the advancing rim of solid metal can be seen. The rim grows until the rolling action is insufficient to prevent the top of the ingot from freezing or until the action is stopped by capping the ingot with a heavy plate. The violence of the reaction and its characteristics, such as growth or drop in the molds, are determined by the composition, the furnace practice, and the deoxidation in the ladle and in the molds. Though rimming steels represent a large proportion of the amount of plain carbon steel made, they have received comparatively little attention in the technical literature. The manufacture of rimming steels has been described by Hibbard,1,2 Fleming,3 Pierce4 and Jackson.5 The reactions occurring during rimming have been considered from the theoretical point of view by Chipman and Samarin.? The structure of rimmed-steel ingots has been discussed by Nead and one of the present authors6 Meyer: in studying segregation, investigated the distribution of carbon, sulphur and phosphorus in rimmed-steel ingots by analyzing the rim and core of blooms. In their studies of segregation, the Joint Committee of the Iron and Steel Institute and the British Iron and Steel Federation9 studied distribution in one billet and one ingot of rimmed steel. A detailed study of the distribution throughout the ingot has not been published. The present investigation was undertaken to determine accurately the distribution of carbon, manganese and sulphur in normal rimmed ingots and the general distribution of other common elements present. The study included some work on the effect of pouring conditions and furnace practice on the distribution, though there is still much to be done in this direction. The structure of a rimmed ingot that has been split by dynamiting and a schematic diagram of the zones in the ingot are illustrated in Fig. 1.

Jan 1, 1938

By J. W. Halley, T. S. Washburn

Rimming steels derive their name from their action during solidification in the molds. As a result of incomplete deoxidation, gas is evolved during freezing, and the metal has a characteristic rolling action. The metal rises along the mold walls and descends in the center of the ingot. This action keeps the top of the ingot open and the advancing rim of solid metal can be seen. The rim grows until the rolling action is insufficient to prevent the top of the ingot from freezing or until the action is stopped by capping the ingot with a heavy plate. The violence of the reaction and its characteristics, such as growth or drop in the molds, are determined by the composition, the furnace practice, and the deoxidation in the ladle and in the molds. Though rimming steels represent a large proportion of the amount of plain carbon steel made, they have received comparatively little attention in the technical literature. The manufacture of rimming steels has been described by Hibbard,1,2 Fleming,3 Pierce4 and Jackson.5 The reactions occurring during rimming have been considered from the theoretical point of view by Chipman and Samarin.? The structure of rimmed-steel ingots has been discussed by Nead and one of the present authors6 Meyer: in studying segregation, investigated the distribution of carbon, sulphur and phosphorus in rimmed-steel ingots by analyzing the rim and core of blooms. In their studies of segregation, the Joint Committee of the Iron and Steel Institute and the British Iron and Steel Federation9 studied distribution in one billet and one ingot of rimmed steel. A detailed study of the distribution throughout the ingot has not been published. The present investigation was undertaken to determine accurately the distribution of carbon, manganese and sulphur in normal rimmed ingots and the general distribution of other common elements present. The study included some work on the effect of pouring conditions and furnace practice on the distribution, though there is still much to be done in this direction. The structure of a rimmed ingot that has been split by dynamiting and a schematic diagram of the zones in the ingot are illustrated in Fig. 1.

Jan 1, 1938

By L. D. Jaffe, John H. Hollomon

THE hardenability concept has become widely used during the last few years for the choice and substitution of steels. Before the work of Grossmann,1 the systems for predicting hardenability from chemical composition could be used only over a narrow range of composition. Grossmann introduced a comprehensive system, which has been effective in calculating the hardenability of most types of moderate or low-alloy steels. However, occasions .often arise that require the calculation of the hardenability of high-alloy steels from their chemical compositions. Experimental determinations of the hardenabilities of such steels indicate that the Grossmann system predicts much greater hardenabilities than are realized. The fact that cases do arise in which the Grossmann method does not, apply indicates that the fundamental hypothesis of the system may not be generally applicable. It seems advisable to re-examine not only Grossmann's system but also the concept of hardenability itself. HARDENABILITY If steel parts are to possess a martensitic structure after quenching, they must first be austenitized and then cooled through the pearlite and bainite transformation ranges sufficiently rapidly to avoid the formation of pearlite, bainite, and proeutectoid products.* If, on cooling, these transformations are avoided, the resulting structure can consist only of martensite (and retained austenite). The hardenability of a steel is measured in terms of the severity of the cooling conditions necessary to avoid the pearlite and bainite transformations. The less rapid is the cooling necessary to prevent the formation of bainite and pearlite, the higher is the hardenability. The pearlite and bainite reactions appear to be differently affected by the alloying elements. Not only is this indicated by the published isothermal transformation data, but recent work by Zener2 affords a rational interpretation of the differing effects of the alloying elements. Manganese,3 for example, appears to decrease the rates of the pearlite and bainite transformations by equal percentages, while molybdenum4,5 is approximately 10,000 times more effective in retarding the pearlite than in retarding the bainite transformation, on the basis of isothermal measurements. In some steels, the formation of bainite restricts the formation of martensite while

Jan 1, 1946

By C. D. Hunter, J. B. Browning

During the year 1934, Kentucky oil and gas operators have partly overcome their past depression fears and in the oil industry, with possibly more abandonments of old oil producers than the completion of new oil wells, produced 4,814,904 bbl. of oil in 1934 against 4,501,511 bbl. in 1933. In the gas industry of eastern Kentucky, 115 gas wells were completed during 1934. This production is delivered through two 20-in., one 16-in., one 12-in., one 10-in., and two 8-in. pipe lines to supply both domestic and industrial markets in Cincinnati, Ohio; Louisville, Lexington, Frankfort, Winchester, Ashland, Covington and other Kentucky towns; Washington, D.C., and other eastern cities. The largest percentage of these gas wells and production are from the Devonian black shale area of Floyd, Pike, Knott, Martin and Magoffin counties, Kentucky. In this area the largest percentage of 1889 wells, developing 421,-215 acres, has been completed in the past 10 years, of which 55.3 per cent produce from the 400 to 550 ft. of Carbonaceous Devonian black shales. The successful results obtained from these Devonian shales are due to the physical effects of the 5000 to 6000 lb. of gelatinated nitroglycerin with which the entire 400 to 550 ft. of shale is shot. A very small number of the shale wells are natural producers and do not require shooting. Other than the Devonian shale gas production, the remaining 44.5 per cent of the gas in this field is encountered throughout the entire strati-graphic section above this horizon; namely, salt sands of Pennsylvanian age and Maxon, Big Lime and Weir of Mississippian Age. A very small percentage is encountered in the Corniferous Devonian lime and the Silurian Big 6 below the black shales. In western Kentucky, in the counties of Henderson, Webster, Hopkins, McLean, Christian, Muhlenburg, Ohio, Daviess, Hancock, Brecken-ridge, Hart, Barren and Warren, many gas wells have been completed, but, because of insufficient market, activity has been somewhat desultory. The area is served by the pipe lilies of the Kentucky Natural Gas Corporation, with headquarters at Owensboro. Their market is increasing and the gas is delivered to Owensboro, Henderson, Madisonville, and many

Jan 1, 1935

THERE is probably no phase of basic open-hearth steelmaking that is more of an art and less of a science than mold and pouring practice. It varies widely from plant to plant; consequently it is obviously impossible to set down in detail in this chapter the many ramifications of practice that are now used. The discussion that follows therefore attempts only to give an outline of the more common methods, with examples sufficient to indicate some of the variations in procedure, and to emphasize a few of the many underlying problems that face the open-hearth operator at the pouring platform. MOLD DESIGN Ingot molds are hollow castings of considerable wall thickness. Despite this, non-uniformity in wall thickness should be strictly avoided to prevent the setting up of unnecessary stresses. Molds are cast in various forms, sizes, and shapes depending on the type of steel, and on whether the ingot is to be withdrawn from the mold or the mold from the ingot. The selection of ingot-mold material, which is usually cupola or blast-furnace iron containing approximately 3.5 per cent carbon, 1 per cent silicon, 0.9 per cent manganese, 0.2 per cent phosphorus, and 0.07 per cent sulphur, is governed by numerous considerations that affect mold life. (1) Factors in addition to wall thickness that should be given primary consideration at the foundry are casting skin, shrinkage stresses, and casting temperature. Factors in Mold Design. In use, mold thickness is of greatest importance, for it must be heavy enough to freeze the molten metal rising in the mold and to reduce the temperature of the steel below that of the melting point of cast iron to prevent the inner surface of the mold from melting, which would result in the welding of the ingot to the mold. The skin of an ingot, which solidities immediately upon contact with the relatively cold walls of the mold, must soon become thick enough to contract on the fluid mass and pull away slightly from the sides of the mold. The separation of the ingot from the mold depends entirely on the heat taken up by the mold from the steel.

Jan 1, 1944

By Milton Williams

It is generally recognized that fluid is lost from rotary drilling muds to permeable strata during normal drilling operations;1,2-3 but that this fluid is the filtrate from the mud, rather than the mud itself, has been shown by various workers.1,4,5 The presence of this filtrate in oil-bearing or gas-bearing strata is undesirable and harmful. The decreased permeability of the stratum to oil effected by the presence of water has been pointed out by several investigators,6,7 and since, in the production of the reservoir fluid, the greatest pressure drop occurs immediately adjacent to the borehole, it follows that infiltered water is particularly objectionable in this region. Again, this filtrate tends to make electrical logs less reliable, since oil in the proximity of the borehole is probably flushed out to an appreciable extent by the water.8 Observation of side wall cores may be misleading for the same reason. Drill-stem tests in low-pressure areas may be of doubtful value where no oil is recovered, unless sufficient time is allowed for production of water lost from the mud. The infiltered water may hinder drilling operations by softening shales and causing sloughing; the ['tight hole" occasioned by excessive deposition of filter cake in the hole is a common occurrence. The filter cake remaining on the face of the producing formation may itself sometimes be detrimental to production.9 In view of these implications of the importance of filtration of mud, an investigation was undertaken to determine the factors involved in the infiltration process, and to correlate these in such a manner that the values obtained in routine filter tests employing a conventional filter of the "wall-building tester" type,10 together with data on size of hole, drill pipe, and rate of mud circulation, could be used to estimate water loss and distance of penetration of the filtrate into strata. Quantitative relations of filter-cake permeability, filtrate viscosity, and rate of filtration have been developed for filtration in the simple laboratory filter.4a,11,12,13 It is obvious, however, that the conditions

Jan 1, 1940

By Milton Williams

It is generally recognized that fluid is lost from rotary drilling muds to permeable strata during normal drilling operations;1,2-3 but that this fluid is the filtrate from the mud, rather than the mud itself, has been shown by various workers.1,4,5 The presence of this filtrate in oil-bearing or gas-bearing strata is undesirable and harmful. The decreased permeability of the stratum to oil effected by the presence of water has been pointed out by several investigators,6,7 and since, in the production of the reservoir fluid, the greatest pressure drop occurs immediately adjacent to the borehole, it follows that infiltered water is particularly objectionable in this region. Again, this filtrate tends to make electrical logs less reliable, since oil in the proximity of the borehole is probably flushed out to an appreciable extent by the water.8 Observation of side wall cores may be misleading for the same reason. Drill-stem tests in low-pressure areas may be of doubtful value where no oil is recovered, unless sufficient time is allowed for production of water lost from the mud. The infiltered water may hinder drilling operations by softening shales and causing sloughing; the ['tight hole" occasioned by excessive deposition of filter cake in the hole is a common occurrence. The filter cake remaining on the face of the producing formation may itself sometimes be detrimental to production.9 In view of these implications of the importance of filtration of mud, an investigation was undertaken to determine the factors involved in the infiltration process, and to correlate these in such a manner that the values obtained in routine filter tests employing a conventional filter of the "wall-building tester" type,10 together with data on size of hole, drill pipe, and rate of mud circulation, could be used to estimate water loss and distance of penetration of the filtrate into strata. Quantitative relations of filter-cake permeability, filtrate viscosity, and rate of filtration have been developed for filtration in the simple laboratory filter.4a,11,12,13 It is obvious, however, that the conditions

Jan 1, 1940

By M. Streat, R. Y. Qassim

Summary This paper reviews the developments in uranium process technology as a result of modern trends in the design of ion exchange equipment. The operation of the Cloete-Streat fluidised bed contactor is described and pilot-plant development of this contactor for uranium slurry work at Imperial College is outlined. The properties of a suitable ion exchange resin for slurry treatment are discussed, together with a description of relevant rheological properties of ore suspensions. A prediction of ion exchange resin- slurry behaviour is presented in order to establish the feasible operating limits for this type of R-I-P contactor.

Jan 1, 1973

By Kendall E. Born

Production of crude oil in Tennessee during 1942 was approximately 8600 bbl., a decrease of 6500 bbl. from the production of 1941, and the lowest since 1934. As usual, the greater part of the production was from the Mississippian limestone pools in Scott and Morgan Counties. Some half dozen wells in Fentress and Clay Counties pumped intermittently produced about 1000 barrels. Natural gas was marketed from wells in Morgan and Fentress Counties for consumption in the Sunbright and Jamestown areas respectively. Figures are not available for the Morgan County production but 7,378,000 cu. ft. of natural gas was produced in the Jamestown gas field from six wells. The production of oil by counties is shown in Table I. Developments Drilling activities reached the lowest ebb since 1933. Only 10 wells were spudded during the year, one of which was drilling on Dec. 31, 1942. Of the nine completions, two were gas wells in the proven area south of Jamestown in Fentress County and seven were dry holes. The total footage drilled during the year was 14,198 ft.; the average depth of wells was 1578 ft. The completions are listed in Table 2. The distribution of tests according to physiographic divisions is given in Table 3. East Tennessee.—One well was drilled to 4219 ft., the second deepest well in the state, in Campbell County. The test was in the highly disturbed Valley and Ridge Province, an area long considered the most unfavorable in the state for the accumulation of oil and gas. Cumberland Plateau.-—There were no completions in the Cumberland Plateau area, although an old well drilled deeper found oil from 935 to 965 ft. in the Mississippi lime. This test has created a considerable amount of interest in the area and an active leasing campaign was underway early in 1943. Eastern Highland Rim.—Five completions on the Eastern Highland Rim brought in two small gas wells in Fentress County, which will be used to augment the supply for Jamestown. The producing horizons are shaly limestones of Ordovician (Trenton) age. Two wells in this area were drilled to the upper part of the Knox dolomite group. The most significant test during the year was the Stanolind Oil and Gas Company's test in Putnam County. This well, on a well-defined surface structure, was abandoned in the upper Knox dolomite group at 2130 ft. A show of oil was logged in the Knox at 1653 to 1661 ft. Northern Highland Rim.—Three tests widely separated in the Northern Highland Rim were dry.

Jan 1, 1943

By Kendall E. Born

Production of crude oil in Tennessee during 1942 was approximately 8600 bbl., a decrease of 6500 bbl. from the production of 1941, and the lowest since 1934. As usual, the greater part of the production was from the Mississippian limestone pools in Scott and Morgan Counties. Some half dozen wells in Fentress and Clay Counties pumped intermittently produced about 1000 barrels. Natural gas was marketed from wells in Morgan and Fentress Counties for consumption in the Sunbright and Jamestown areas respectively. Figures are not available for the Morgan County production but 7,378,000 cu. ft. of natural gas was produced in the Jamestown gas field from six wells. The production of oil by counties is shown in Table I. Developments Drilling activities reached the lowest ebb since 1933. Only 10 wells were spudded during the year, one of which was drilling on Dec. 31, 1942. Of the nine completions, two were gas wells in the proven area south of Jamestown in Fentress County and seven were dry holes. The total footage drilled during the year was 14,198 ft.; the average depth of wells was 1578 ft. The completions are listed in Table 2. The distribution of tests according to physiographic divisions is given in Table 3. East Tennessee.—One well was drilled to 4219 ft., the second deepest well in the state, in Campbell County. The test was in the highly disturbed Valley and Ridge Province, an area long considered the most unfavorable in the state for the accumulation of oil and gas. Cumberland Plateau.-—There were no completions in the Cumberland Plateau area, although an old well drilled deeper found oil from 935 to 965 ft. in the Mississippi lime. This test has created a considerable amount of interest in the area and an active leasing campaign was underway early in 1943. Eastern Highland Rim.—Five completions on the Eastern Highland Rim brought in two small gas wells in Fentress County, which will be used to augment the supply for Jamestown. The producing horizons are shaly limestones of Ordovician (Trenton) age. Two wells in this area were drilled to the upper part of the Knox dolomite group. The most significant test during the year was the Stanolind Oil and Gas Company's test in Putnam County. This well, on a well-defined surface structure, was abandoned in the upper Knox dolomite group at 2130 ft. A show of oil was logged in the Knox at 1653 to 1661 ft. Northern Highland Rim.—Three tests widely separated in the Northern Highland Rim were dry.

Jan 1, 1943

US 4,132,635 -In the froth flotation beneficiation of low- grade siliceous iron oxide ore, an aqueous pulp of undeslimed ore is conditioned first with a reagent formed by incorporating a water-soluble polyvalent metal salt into an aqueous solution of sodium silicate and then with oleic acid or other anionic collector and optionally pine 011 or other frother. The conditioned pulp is subjected to flotation to concentrate Iron oxide values in the froth D. C. Yang, assigned to Michigan Technological University Jan 2, 1979 7 pp (209-1 66) Filed 1-1 3-77 (759,094) Drawing below.) [ ] US 4,133,038-In the froth flotation beneficiation of copper sulfide ore or other ores, an aqueous suspension of a mineral sample of uniform grain size and composition is conditioned with a strongly adsorbable collector in an amount which is a fraction of the amount sufficient to create a monomolecular layer on the mineral grains, and the conditioning continued until the entire amount of collector is adsorbed The conditioned pulp is subjected to flotation, the floated particles separated at timed intervals, and the flotation rate coefficient determined. By varying the degree of adsorption in repeated treatments, the dependence of the flotation rate coefficient on the degree of adsorption may be determined A Nieml Jan 2, 1979 10 pp (364-502) Filed 12-7-77 (858,353) Priority Finland, 5-26-75 (75/1,525) Same: British 1,533,723, dated Nov 29, 1978 Same Canadian 1,065,066, dated Oct 23, 1979 US 4,133,746System and method for maintaining substantially steady state conditions in the froth flotation beneficiation of copper ore, molybdenum ore, or other metal ores The mass flow of flotation concentrate from the cell is monitored continuously, and the rate of admission of aeration air into the pulp in the cell is varied inversely with respect to variations in the mass flow control of rougher flotation cells is accomplished with a single valve G W Dopson, assigned to Magma Copper Co Jan 9, 1979 6 pp (209-1) Filed 11- 23-76 (744,306

Jan 1, 1980

By B. D. Cullity, J. T. Norton, M. Telkes

THIS investigation of antimony-selenium alloys was undertaken in an attempt to find a suitable material for use in power-generating thermocouples. The chief requirements for such a material are high thermoelectric power, low electrical resistivity and low thermal conductivity. Measurements of the first two properties mentioned are usually sufficient to determine whether or not a material is suitable for use in a thermoelectric generator. As a first approximation the requirements are: 1. Thermoelectric power greater than 200 microvolts per °C. 2. Electrical resistivity less than 0.002 ohm-cm. 3. Thermal conductivity less than 0.015 watt per cm per "C. These quantities are averages for the Operating temperature range. Previous Work Experimental investigations of equilibrium in the antimony - selenium system have been summarized by Han-sen². These investigations extended from 1906 to 1921. In Hansen's judgment, the most accurate phase diagram is that determined by Parravano, in 1913 and this is reproduced in the upper part of fig. 1. The most notable parts of this diagram are the liquid miscilibility gap, extending from about 12 to 36 wt pct selenium, and the intermediate phase Sb2Se3 containing 49.3 wt pct selenium. The crystal structure of Sb2Se3 has not been determined. Pelabon3,4 made measurements of the electrical resistivity of a few antimony-selenium alloys but his investigation was not very complete. He found that the resistivity increased with the selenium content and became very large as the composition of Sb2Se3 was approached. For alloys containing less than 50 at. pct (39.3 wt pet) selenium, he found that the resistivity increased regularly with temperature. For alloys containing larger amounts of selenium, he found various results: in some cases, the resistivity decreased with increas-

Jan 1, 1951

By B. M. Bird

ONE of the problems studied by the U. S. Bureau of Mines in cooperation with the University of Washington has been the re-treatment of table middlings. Hydraulic classification has given the best results. Instead of using the classifier to prepare the feed to the tables, as has been the practise for many years in ore dressing, it is used to separate part of a middling product that cannot be re-treated successfully on the table. Middlings are desirable in a table plant because the separation according to specific gravity is incomplete; that is, in the products of the table there is always an overlapping of free particles of coal and refuse that can be distinguished with heavy liquids such as are used in the float-and-sink test. The causes of this overlapping may be divided into two groups, those outside the table separation itself and those inherent in the table separation. The first of these groups includes, among other causes, the following: (1) poor adjustments of the table, (2) overloading or underloading the table, (3) irregularities in the quantity and quality of the feed, (4) irregularities in the power and water supply, and (5) a vertical danc-ing motion of the table deck due to weak foundations. These causes of overlapping are largely unnecessary in a properly designed and constructed plant; but whenever they are present they materially affect the character of the middling product, and hence the problem of re-treatment. The other group includes three additional causes: (6) small differences in specific gravity between coal and impurities, (7) a size-specific-gravity relationship of the coal and refuse particles in the table feed such that the sizing action of the table opposes the separation according to the specific gravity, and (8) shapes of particles that prevent a separation. The sixth, small differences in specific gravity, may be a very important reason for an incomplete separation. The change in specific gravity from coal to shale is always gradual and the designation of one part as coal and another part as refuse is arbitrary. If some specific gravity, such as 1.45, is chosen as the dividing point between washed coal and refuse,

Jan 1, 1928

By F. C. Clapp

Although many oil fields have been, and still are being, discovered in Oklahoma, the geology and structure of most of them have not become familiar to the general public because of the delay in securing government geological surveys and the reluctance of oil companies and other intercsted parties to give out their "inside information " Therefore, until official surveys are available, it behooves us to publish geological results as soon as possible. Fortunately the writer has been authorized by the Cement Field Oil Co. to publish his data on the Cement field, Caddo County, at this time. Locality and Description The Cement field is situated in the part of Oklahoma known generally until recently, as "Healdton fields," and lies 60 mi. (96 km.) northwest of the Healdton field proper. Like the Healdton field, it forms an approximate ellipse, trending northwest and southeast through the village of Cement on the St. LouisSan Francisco Railroad, on which it is reached in 21/2 hours from Oklahoma City. In its geological structure, the field constitutes an anticline over 13 mi. (21 km.) long and from 1 to 3 mi. wide; the point of greatest width being not far from its intersection by the above-named railroad. The major axis trends north 75' west from the village of Cement; but eastward appears deflected (if field interpretations are correct) to about south 45" east. About 5 mi. south lies an approximately parall el syncline, which may be conveniently called the Cyril syncline, the south and west boundaries of which may be distant many miles, but forming a closed basin south of the Cement anticfine. The positjon of the offsetting synclinal axis, which is believed to lie north and east of-Cement, has not been discovered. TOPOGKAFHY In the southwest part of the state, nearly all maps of Oklahoma show two mountain areas—Arbuckle and Wichita—which are conspicuous geological and topographic landmarks. In addition, some maps show a third, and smaller, range, named the Keechi Hills, in the vicinity of Cement. These hills also form a conspicuous feature in the landscape; but for some reason they have been neglected by geologists, and the

Jan 1, 1921

By D. L. Albright, R. W. Kraft, J. A. Ford

HE unidirectional solidification of A1-CuAl, eutec-tic specimens to produce an essentially parallel lamellar structure has been described previously.' Ingots solidified in this manner ordinarily exhibit three macroscopic zones. In Zone I, at the head end of the ingot, a large number of slightly elongated grains occur in which the lamellae are highly distorted and twisted. After a few centimeters of growth, this distribution gradually changes to a small number of coarse grains elongated in the growth direction and in which the lamellae are quite regular, Zone 11. Zone 111, at the tail end of the ingot,

Jan 1, 1963

By Franklin J. Kay

Introduction The methods used in surface, mining vary throughout the world, depending on many variables such as: the types of over- burden materials, the depth of the overburden, the thickness of the seam, and other operational choices, both financial and functional. However, the stripping machines are typically draglines, stripping shovels, excavators, scrapers, loaders, and bulldozers. In all cases the economic feasibility of mining thin seams depends on the market needs, the market location, the equipment used, the mine management, the quality of the coal, and the labor market. Slight negative combinations of these parameters have closed many mines while positive combinations allow others to exist. The limited mobility or slow movement of large stripping shovels, draglines, and bucket wheel excavators make them more economically fitted to areas where large quantities of overburden are to be moved. This is necessary to keep the transfer and setup time between pits a negligibly small percent of the total operational time. Equipment such as the scrapers, loaders, backhoes, trucks, and bulldozers that are either very mobile or can be trailered is more versatile and can be used in the smaller area mines.* Mobile equipment is also more practical in areas with shallow overburden because of the constant movement required while removing overburden. In thin coal seams the equipment is usually paired such that the operational equipment can be listed as: (1) dragline-loader, (2) shovel-truck- loader, (3) scraper-loader. (4) loader-truck-loader, or (5) loader-loader. In these operations the overburden is removed with the first machine(s) of the pairing and the loader or loaders are used for coal production. Recent articles in Coal Age (Chironis, 1978) and Mining Engineering (Wiebmer, 1978) have discussed varying philosophies in mining similar seams of coal. One operator uses draglines for competitive mining while the other uses scrapers for the same purpose. Both cite strong cases sup- porting their choice of equipment as good sound economic decisions and their success supports their choices. The drag-line operation is adding new larger draglines to decrease the cost of mining, rather than to increase coal production. The scraper operation has also gone to more and larger scrapers for basically the same reasons. These operations and all

Jan 1, 1981