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By F. R. Archibald, C. F. Jackson

THE prospect of winning aluminum from clay was recorded almost a century ago at a time when the metal was no more than a curiosity.? As the industry developed, and it has probably developed faster than that of any other metal, the expanding need for raw materials was adequately met by the ample supplies of bauxite ore. As with the other metals older in industry, however, lower grade ores have gradually entered the raw-material field through improvements in ore dressing, insufficienoy of high-grade ore supplies, favorable geographic location, or national necessity for domestic supply. So with aluminum, or alumina, which has been established as the requisite intermediate, the time may have come when a satisfactory process, with favorable location and suitable raw materials, can hold a sound place both in metallurgy and economics. It is the purpose of this paper to describe the Ancor process and its proposed application in treatment of clay in a plant now under construction at Harleyville, South Carolina, by the Defense Plant Corporation. DEVELOPMENT OF THE ANCOR PROCESS The Ancor process has developed through successive stages of laboratory investigation, pilot-plant demonstration using nepheline syenite and pilot-plant demonstration using kaolin-type day from South Carolina, and is now in preparation for unit trial on an operating plant basis using the latter material. The laboratory studies were carried out over a number of years in the laboratory of the American Nepheline Corporation in Rochester, N. Y., and for the same company in the ore-dressing laboratory of Beattie Gold Mines, Que. Ltd. at Duparquet, Quebec. Both companies are associated with Ventures Ltd., Toronto, and its associated American companies. The work was originally undertaken with a view to recovery of alumina and alkalies from nepheline syenite as an adjunct to the American Nepheline Company's established business in the glass and ceramic trades, but as a process developed the possibility of application to clay and other aluminous raw materials become apparent and the laboratory studies were broadened to include these as well. Under the more pressing impetus of wartime needs and possibilities, pilot-plant operations were undertaken at the Canadian Bureau of Mines Ore Dressing Laboratories in Ottawa, and for purposes of demonstration under joint sponsorship of the Canadian Bureau of Mines, The American Nepheline Corporation, and The Aluminum Company of Canada Ltd.

Jan 1, 1944

By Carl Scholz

Discussion of the paper of Carl Scholz, published in Bi-monthly Bulletin, No. 22, July, 1908, pp. 551 to 559. HOWARD N. EAVENSON, Gary, W. Va. (communication to the Secretary*) :-For some time before the publication of Mr. Scholz's paper, I had been collecting data bearing upon its subject, and I now take pleasure in presenting my results to the Institute in the form of a discussion. It has long been a matter of common opinion among mining-men that mice-explosions are, more frequent during the colder, or winter months, than during the warmer ones, and it is a matter of common knowledge among them that the air-ways and road-ways in most mines are much drier and are more in¬clined to be dusty during the winter than during the summer. In many mines, places which are wet and sloppy in the summer are dry and sometimes dusty during the winter. These changes, of course, can only be due to atmospheric conditions, and are caused by differences in temperature and humidity. Until recently, however, very little attention has been paid to the part that atmospheric conditions may play in mine-explosions, or, rather, to the effect they may have in rendering mine-conditions peculiarly dangerous, and in spreading and rendering more disastrous the effects of what would otherwise probably have been .small explosions. To show the difference in mine-conditions during sunnier .and winter months, I have tabulated in Table I. the results of 24 observations of hygrometric conditions in several different mines at different times of the year. Mines Nos. 1, 2, and 6 are located in the Pocahontas.coal -region, in McDowell couuty, W.Va., the first one being a shaft-mine shaft mine and the others drift. Mines 1A and 2A are drift-mines located in Logan county, W. Va. All of these are mines of fair size, but none of them has been in operation more than six years,

Jun 1, 1909

By Pol Duwez, Howard E. Martens

INTRODUCTION THE high temperatures encountered in the operation of jet engines have imposed most drastic requirements upon the materials used in their construction. There are two different approaches to the materials problem connected with the design of parts in contact with high temperature gases. The first approach is to use a material which will perform satisfactorily at a temperature comparable to that of the gas. The second approach is to use a cooling system so that the material is maintained at a temperature appreciably lower than that of the gas. Besides the conventional method .of cooling by means of a liquid in contact with the material exposed to a high rate of heat transfer, a less orthodox method consists of making the part to be cooled of a porous material, so that the cooling fluid can be forced through the pores. In this scheme, the temperature of the coolant moving in a direction opposite to that of the heat flow increases gradually while passing through the porous material, and the coolant forms a protective layer on the surface exposed to heat. This method, referred to as "sweat cooling," was proposed at the jet Propulsion Laboratory in September 1944, and the experimental work on the preparation of porous metals was started early in 1945. The sweat cooling method opens new lines of research in powder metallurgy by extending the field of application of porous metals. The porous metals available at the present time are used mostly as bearings or filters, and a rather limited number of alloys are made for these applications. In addition, the fabrication of bearings or filters does not require a very dose control of the permeability, while in the case of sweat cooling such a control is of primary importance. In designing a sweat cooled part it is imperative to assure a given rate of flow of coolant under certain conditions of pressure drop. Generally, the proper pressure drop and the rate of flow of coolant are deduced from heat transfer and design considerations, and consequently the permeability of the porous metal to be used is also determined. It is therefore necessary for the designer to have available a continuous series of porous metals covering a range of permeability as wide as possible. Contrary to the requirements established in the fabrication of filters, the actual pore size of a porous metal intended for sweat cooling is of little consequence, except for its effect on permeability. The tensile strength is likely to be of great importance for some applications. Since the tensile strength of a porous alloy decreases with increasing porosity, an important problem is to develop porous alloys having the maximum permeability with minimum porosity.

Jan 1, 1948

By Ellis Clark

DURING the winter of 1877-78 the Glendon Iron Company, by the advice of the superintendent, Mr. Frank Firmstone, decided to make the experiment of exploding a heavy blast of gunpowder in their limestone quarry at Cedar Hill, Palmer Township, Northampton County, Pennsylvania. The amount of limestone used in the five furnaces of the company is about 60,000 tons per annum, and it was thought that with successful results; this entire amount or more would be thrown down at a single operation, disintegrating the mass to a greater or less extent, and obviating the necessity of blasting and boring the rock from the face of the cliff, both of which operations are slow, and therefore, costly. The rock at the quarry is Auroral limestone, or No. 2 of the old Survey. No fossils have ever been found in the quarry, nor in the immediate vicinity. The nature of the rock varies considerably in

Jan 1, 1879

By Frank A. Crossley

The work described has one serious shortcoming: grain size was not monitored during heat up to the temperature (1675°F) of isothermal anneal. The chief obstacles to p grain growth in titanium a-ß structures are the a grains. Heating a structure such as that shown in Fig. 1 to a temperature close to ß transus causes dissolution of a grains in order to adjust the a/ß ratio, compare Figs. 1 and 2. During this process there is a concomitant growth of the ß grains—otherwise ß grains would have to be nucleated in order to adjust the a/ß ratio. When the annealing temperature is reached the a/ß ratio stabilizes and this initial phase of ß grain growth ceases. After an incubation period growth resumes as described. Some 0 grain boundaries can be clearly seen in Fig. 1. (Skilled metallography commonly produces photomicrographs which show more structural detail than direct observation.) These boundaries suggest that the average ß grain size is approximately 0.002

Jan 1, 1970

By Halbert Powers Gillette

FROM the known laws of physical chemistry I believe it can be shown that progressive mass movement of water solutions in channels has seldom been the means of ore-concentration in veins. It is my purpose in this paper to show that the force known as “osmosis” has been the principal factor in ore-formation. Convection-currents have doubtless supplemented osmosis, and the two working together have been the agencies that have gathered the scattered particles of rare minerals into the larger masses which are called ore. Osmosis is commonly thought of as a vague, feeble force that causes slow diffusion of dissolving matter through the solvent. That it is a measurable force, often of great intensity, few know, except those who are familiar with the laws of modern physical chemistry. Therefore, I may be pardoned for going briefly into the elementary mathematics of osmotic pressure and of convection-currents. The velocity of water moving through any channel is given by the Chézy formula: (1) v = c [/rs], in which r is the hydraulic mean radius; s, the slope of the channel in which gravity is the sole propulsive force; and c, the coefficient of roughness of the sides of the channel. From this formula it is evident that the smaller the channel, the smaller the velocity of water under a constant head. In rock-crevices, therefore, where the head is constant, water moves much more slowly than in large fissures, and in moving through sand or porous rock it is to an even greater degree retarded. Hence, if a mass of water-saturated sand be heated, the finer the sand-grains, the more slowly will the temperature rise at parts remote from the source of heat. Conversely, cooling is retarded the smaller the interstices or channels through which the convection-currents move. The importance of this

Jan 1, 1913

By Charles H. Thurman

THE data given herein were first included in a paper read before San Francisco Section, A.I.M.E., in October 1940, and are applicable to conditions existing until the gold-dredging industry was temporarily suspended by Order L-208 of the War Production Board in the fall of 1942. There is no doubt that gold dredging will be resumed at some future time, and on a scale equivalent to that of the recent past, but the cost data given herein will be affected to some extent by conditions existing at that time, and by labor rates and prices for materials then prevailing. DRAGLINE VS. BUCKET-LINE Dragline dredges should not be considered for mining large areas of low-grade placer gravel. In such deposits a dragline operator with a 5-cu. yd. dragline would be doing well to maintain an operating cost of 6¢ per cu. yd., while a bucket-line dredge with buckets no smaller than 7 cu. ft. each could be operated for less than 4¢ per cu. yd. By operating costs, I mean only field charges such as direct operating and overhead, which includes pay roll, power or fuel, repairs and maintenance, insurance, land clearing and general expenses, but not including such items as prospecting, depletion, depreciation of equipment, State Franchise Tax, or Federal Income Tax. It is not to be inferred that a dragline dredge cannot make a profit in small low-grade deposits, where the extent of a given property is too small to justify the use of the more costly bucket-line dredge. Consider small deposits of 10¢ gravel. It is obvious that a deposit of 5,000,000 cu. yd. of such gravel could not be mined profitably with a new, 7-cu. ft. bucket-line dredge, costing upward of $250,000, and with operation costs at 4¢ per cu. yd., paying for land or royalties out of earnings; nor could a new combination 5-cu. yd. dragline and washing plant, worth upward of $125,000 and working at 6¢ per cu. yd., make a profit. These comparisons are made because the hourly capacity of both types of dredges is nearly the same. The bucket-line dredge averages 93 per cent operating time in 24 hr., as against about 80 per cent or less for the dragline dredge. These percentages of operating time are important factors in making a comparison of this kind. The bucket-line dredge has greater efficiency in cleaning soft bedrock, usually characteristic of dredging deposits, and a 7-cu. ft. bucket-line dredge can be efficient to a total digging depth of 80 ft. (65 ft. below water, 15 ft. above). A 5-cu. yd. dragline dredge is limited to about 30 ft. of efficient digging depth, 5 ft. of which could be above water. In small areas of gravel not over 30 ft. deep, a 5-cu. yd. dragline dredge could make a profit where a bucket-line dredge could not do so. As an example: compare the dredging of 3,000,000 cu. yd. of 10¢ gravel 28 ft. deep with bucket line, costing 4¢ per cu. yd., and with a 5-cu. yd. dragline dredge operating at 6¢ per cu. yd. Because of small yardage, new equipment is not warranted, therefore we can assume that the dredges of both types are used equipment, fully depreciated. Dismantling, mov-

Jan 1, 1945

By Charles Goodale

With notes on other mines of the Marysville district by WALTER McDERMOTT, London, England, and F. L. Sizer, Dos Cabezas, Ariz. (Salt Lake Meeting, August, 1914) THE purpose of this paper is to review the history of the Drumlummon, one of the famous old mines of the West. Mining engineers, when sent to examine new mines in old districts, or to decide whether an old property, under new conditions, will pay to re-open, have had difficulty in learning anything authentic regarding workings which are under water, and historical facts about the working character of the ore, the total production, and the value of the ore with increasing depth. Not many years elapse after the pumps are pulled, before maps, books and records are destroyed, and the value of the publications of the Institute would be increased if they contained the history of many old mines now abandoned. The unsuccessful efforts of the writer quite recently in trying to obtain reliable information about a gold mine which was reported to have produced several million dollars between 1880 and 1888, the workings of which are now partially caved and under water, impressed upon his mind the desirability of having a permanent record of old properties. In this particular case, the owners insisted that under present conditions of improved methods of treatment -particularly by the use of cyanide, which was not an applied process when the mine was operated, the property. could be made to pay a handsome profit on ore left in sight in the old workings, but no assay records could be found to confirm these assurances, and even the records of bullion shipments had been destroyed. If surveys and maps were made as the work progressed, no trace of them could be found, and therefore opening of the ground through a new shaft and drifts therefrom would be attended by some risk while exploring near the old workings. Fatal accidents by flooding under these conditions have occurred, and as an evidence that miners have fears of such dangers, it was urged upon the Mining Committee during a recent session of the Montana Legislature, by a delegation of

Jan 8, 1914

THE transformation, in a sample of levitation melted iodide titanium, has been studied with a Leitz hot-stage microscope. The specimen was etched in HF:HNO3: glycerine, (1:1:2) giving a structure shown in Fig. 1, and was then heated at approximately 5OC per min. At 870°C (±5OC) the etching product disappeared, the a-grain boundaries showed in relief, and some new grain boundaries (presumably of ß) appeared (Fig. 2, see arrow). Some evidence of ß-grain growth is indicated by the apparent longitudinal movement of a ß-grain boundary shown in Figs. 2 and 3 (see arrows). The specimen was later heated to 1000°C and then cooled at 2°C per min. At 845°C rumpling of the surface was first noticed, Fig. 4, and continued at constant temperature. The photomicrograph reproduced in Fig. 5 was taken 6 sec after Fig. 4, at 845°C. Fig. 6 shows the structure after cooling to room temperature. The room-temperature structure, showing a rumpled surface has been observed by previous investigators.' These structures presumably indicate a sheer transformation ß - a, athermally nucleated, but capable of isothermal progression.

Jan 1, 1960

By AIME AIME

SCANDINAVIAN countries seem somehow to furnish an amount of talent and leadership far be- yond their population and among them Sweden is possibly at the top. The United States has many eminent citizens born in the latter, country or who are of Swedish descent and the engineers may claim their full share. In fact, the number is so large that a flourishing Swedish-American Engineering Society has been formed, including a number of A. I. M. E. members. Dr. Waldemar Lindgren is more scientist than engineer, though his work in economic geology has contributed directly to the development of many mines, and he is the valued- adviser of a number of our larger companies. Probably he, himself, values most highly the contributions he has been able to make to scientific theories of the occurrence and genesis of ore deposits. His fellow scientists have placed upon these the high mark of approval by electing him to the National Academy of Sciences, and Princeton University in 1916 recognized his position by conferring on him the degree of Doctor of Science.

Jan 1, 1931

By John W. Tieman

Coal is a term applied to vegetable matter which, through geological processes of heat and pressure, has had both its physical and chemical properties changed. Because its chemical composition is variable, geologists classify coal as a rock rather than a mineral. Peat represents the initial stages in the development of coal, although not classified as coal itself. PHYSICAL PROPERTIES OF COAL The physical properties are concerned with the characteristics of coal in its natural state, or prior to its end use as a fuel. For example, the hardness of coal determines the maintenance cost on coal handling equipment; the specific gravity of coal determines the coal preparation techniques used in a cleaning plant as well as the capacity of coal bins, boats and size of cargo, and other coal storage facilities. The physical properties are, of course, dependent upon the chemical constituents that make up coal, and thus all properties are interrelated. Specific Gravity The specific gravity of a body is the ratio of the weight of the body in air and the weight of an equal volume of water. The specific gravity of pure coal ranges between 1.25 and 1.70, generally increasing with rank. The most important use of this physical characteristic is the part that it plays in the cleaning of coal by wet wash methods. The basic principle on which these operate is that the specific gravity of coals differs from their associated impurities and that there is a relationship between the velocity of the fall of particles in water and their density. Since the specific gravity of slate is around 2.5 and pyrite is about 5.0, pyrite and slate will fall to the bottom of a container filled with water more rapidly than coal. If the water is given a pulsating motion by

Jan 1, 1973

By David J. Selleck, Eugene P. Pfleider

9.61. Introduction. Open pit mining methods produce more than 80% of all raw materials today in the United States. Much of this comes either from properties that formerly employed underground methods and were converted to open pit or from mines that ultimately must go underground when the economic stripping limit is reached. Generally the ores are transported over large vertical distances and techniques have been developed to do this economically. One approach is to combine conventional surface trucking, over relatively level roads, with the use of gravity and underground facilities. There are various modifications, depending upon the character of the orebody and the topography. Several schemes, as used in Sweden, Canada, and the United States, merit describing. One of the critical problems involved in the transference of ores from surface to underground is that of flow of bulk solids. Must it be crushed? Will it hang up in the transfer? What size and inclination of ore pass are required. How is the ore best fed onto the transporting device underground? As an example, the planning engineers for the Carol Project of the Iron Ore Company of Canada faced these problems in making their designs for the production and transportation of some 55,000 tpd from their Smallwood Mine in Labrador. Other operations, facing somewhat similar conditions, used other approaches of interest. This chapter describes some of the factors involved in the design, construction, and operation of a combination surface underground transportation system as applied to open pit mining operations. 9.62. Tunnel-Ore Pass Systems. The type, shape, dip, and size of the orebody, as well as the surface topographic features, generally estab-

Jan 1, 1968

By P. B. Bucky

IN this day of steady progress in the mining industry, especially along mechanical lines, the question of whether to discard present equipment for that of a new type often engages the minds of many officials of mining companies. The rapid strides made from year to year sometimes cause this question to be brought up within a year after new equipment has been purchased and installed. It is a moot question whether a machine that has been purchased last year should be replaced by a new one put on the market this year. As I see it, the reasons for the replacement of present equipment may be summed up as follows: (1) because of increased safety; (2) because of legal regulations; (3) because of increased profits. I think all of us, as engineers, will endeavor to put in as safe equipment as it is possible to devise. The tendency of mining companies in that direction is very gratifying.

Jan 1, 1930

By ANDREW CARNEGIE

Although the noble building provided in New York City by Mr. Carnegie for the United Engineering Society has been pushed to about half-completion, the ceremony of laying its corner-stone was not performed until Tuesday afternoon, May 8, 1906. The stone lies just back of the southeast corner of the building, on the north side-of West 39th Street. Among those present were Mr. and Mrs. Carnegie, Miss Whitfield, the sister of Mrs. Carnegie, Ralph W. Pope, Secretary of the Institute of Electrical Engineers, Frederick R. Hutton, Secretary of the. Society of Mechanical Engineers, Rossiter W. Raymond, Secretary of the Institute of Mining Engineers, Charles H. Haswell, the first Chief Engineer of the United States Navy (1836-1851), now in his ninety-seventh year, John Fritz, of the Bethlehem Steel Company, William H. Fletcher, President of the Engineers' Club, E. E. Olcott, President of United Engineering Society, and other interested friends. After an inspection of the interior of the building, the group formed about the corner-stone, which had been draped with the American flag. The exercises were opened by Mr. Olcott, who appropriately welcomed Mr. Carnegie, and briefly expressed the essential value of the building, saying, in part " The societies to be housed underneath this roof have as their aim the pre¬serving and putting in tangible form of the records of scientific accomplishments so as to avoid the repetition of mistakes. The possibility of finding the records of these results all at one center, so near the great Public Library of our city, will be an inestimable advantage to all professions. It is an occasion of no ordinary moment, therefore, when we can welcome Mr. Carnegie and have him lay for us the corner-stone of this great building which his liberality has provided." Mr. Carnegie responded in happy vein, thanking the committee for their greeting, and expressing his pleasure. in being able to do what he had done to further so worthy a cause. Among other things, he said

May 1, 1906

By C. M. Schwartz, A. E. Austin, W. B. Wilson

High-temperature X-ray diffraction studies were conducted with Th-U alloys with up to 10 wt pet U. The solid solubility of uranium in thorium as a function of temperature was determined by the method of lattice parameters. Thorium will dissolve up to 2.5 wt pet U at 950°, 4.5 wt pet U at 1150°, and 7.5 wt pet U at 1250°C. Determinations were made of the temperature of the transition of thorium and of the effect of uranium upon the transition. The a to ß transition for thorium was observed to occur at 1330' ±20°C. Mean coefficients of expansion were calculated for thorium and two alloys, and for ThO2 in contact with the thorium, using X-ray lattice-parameter data. Values obtained at 950° C for thorium and Tho2 were 12.1 and 9.40 X 10-6 per OC, respectively. Impurities obtained during the X-ray exposure were identified by diffraction and were essentially Tho2 and ThC, with two additional unknown phases being detected. The effect of the impurities upon the results is discussed. DIRECT investigation (i.e., high-temperature X-ray diffraction studies) of the phase diagram of thorium-rich uranium alloys has been shown to be necessary since recent work1 - has disclosed the presence of an allotropic transformation near 1400°C in pure thorium with the room temperature face-centered-cubic phase transforming to a body-cen-tered-cubic structure at the elevated temperature. The effect upon the transition of the addition of uranium to thorium and of the solubility of uranium in thorium at high temperatures remained unknown, yet was of interest in understanding fabrication procedures and elevated temperature use. The present work was undertaken to provide information in this area by determining the transition temperature, the effect of uranium on the transition temperature, and the solubility of uranium in thorium as a function of temperature. Experimental Work The high-temperature diffraction data were obtained using a camera especially designed for the purpose3 and capable of reaching temperatures in excess of 2000°C at pressures as low as 1 x 10." mm Hg. Temperature regulation was provided by regulating the power input to ±0.1 pet variation, and by regulating the water flow through the camera jacket to provide a constant thermal load. The X-ray sample was a rod nominally 80 mil diam, which was further turned down to 20 mil and then etched to 18 mil over 1/2 in. of one end. This was placed in the sample holder and mounted on the camera so that the smaller part was surrounded by a cylindrical tantalum-sheet radiation-type heating element. Diffraction from the sample was recorded on film after passing through a slot in the heating element and radiation-baffle shield and through beryllium vacuum windows. The X-ray film mounting was of the Straumanis type4 with a camera diameter of 114.59 mm. Since previous work of Chiotti' indicated that impurities considerably alter the transition temperature, chemical analysis of the arc melted iodide crystal-bar thorium samples was obtained prior to testing. The analysis disclosed the material to contain as low as 0.001 ±0,0002 wt pet H and 0.007 ±0.001 wt pet 0. Carbon was 0.003 wt pet and nitrogen less than 0.002 wt pet. This material was sealed in mild steel in an inert atmosphere and subsequently hot rolled to 3/8-in. diam rods at a temperature of 732°C. Following removal of the jacket, the material was pickled and cold swaged to 1/8-in. rods, from which the diffraction samples were prepared. The alloys were similarly prepared, with the uranium being added during arc melting. The uranium analyses of the alloys prepared appear in Table I. The experimental procedure for diffraction examination of the three samples of high-purity thorium differed from those of the Th-U alloys. The original practice, later modified, consisted of pumping down the camera with the diffusion pump on and then admitting liquid nitrogen to the cold trap of the system. This was modified for the Th-U alloys by maintaining liquid nitrogen in the cold trap at all times before and while the diffusion pump was heated. This minor change produced a reduction in the amount of carbon pickup by the sample during exposure to the diffusion-pump vapors. The sample was brought to the desired test temperature and exposed for 21/2 hr at pressures which were usually 2 x 10-6 mm Hg, or lower. Exposures were made at

Jan 1, 1959

By J. Chipman, N. J. Grant, R. Rocca

Desulphurization of liquid iron by reducing slags of the electric-furnace type was studied from 65 heats. Variations were made in basicity over a wide range and in FeO up to about 5 pct for their effects on desulphurization. The role of FeO in desulphurization from the blast furnace, to the electric furnace, to the oxidizing conditions of the open hearth is shown to fit a relatively simple pattern of behavior. THE mechanism which controls the desulphurization of molten iron by basic slags has been the object of several investigations. In particular, equilibrium determinations have been made both in the field of basic open-hearth slags, which have a high iron-oxide concentration, and in the field of blast-furnace slags which have a very low iron-oxide concentration. In both cases the desulphurization ratio has been found to increase with increasing basicity of the slags; however, the mechanism of desulphurization differs in the two cases. In basic open-hearth slags desulphurization occurs mainly as a partition of iron sulphide:&apos; FeS * (FeS) and the desulphurization ratio is approximately independent of iron-oxide concentration in the slag. In blast-furnace slags the concentration of iron oxide is very low as a result of the highly reducing conditions in which they are formed. The controlling reaction for desulphurization is then:2,3 FeS + (CaO) <=* (CaS) + (FeO) The slags of the reducing stage in the electric furnace have an iron-oxide concentration which is intermediate between blast-furnace and open-hearth slags. The study of the mechanism of desulphurization for these slags has been the object of this investigation. The importance of low (FeO) in the slag for desulphurization was first verified by Bardenheuer and Geller,& who found that high desulphurization ratios were obtained in highly reduced slags. It was recognized" hat iron oxide in the slag becomes a controlling factor in desulphurization only at FeO concentrations approximately under 5 pct. A recent investigation conducted by Buehl,7 upon the suggestion of one of the authors, confirmed this opinion from the results obtained from a heat conducted in a small arc furnace. In the present investigation, slags of very high basicity, such as often are encountered in the basic electric furnace, could not be studied, but equilibrium data have been obtained for slags in a wide basicity range. The iron-oxide concentration in these slags ranged from 0.08 to 15 pct and was controlled by the addition of silicon to the metal. Other constituents of the slags were mainly CaO, MgO, SiO2, A120,, and CaF,. The experimental technique was essentially the same as that of previous investigations.1 8-lo In an open magnesia-lined induction furnace, 65 lb of Armco ingot iron was melted. An atmosphere of hydrogen was maintained over the melt for 1 hr to bring the carbon content down to approximately 0.010 pct maximum. The bath then was exposed to air for 25 min to remove hydrogen. The electrodes were put in place, and the furnace was operated from this point on in an atmosphere of nitrogen. A synthetic slag was added to which additions of silicon and iron sulphide were made. A rate study conducted at the beginning of this investigation had

Jan 1, 1952

By Dorsey Hager

THE possibility of oil and gas production in Alabama has been little considered as yet. Gas and some oil have been found in northwestern Alabama, near Birmingham, in the Pennsylvanian beds, but the oil and gas possibilities in the Cretaceous beds are not generally appreciated. The recent activity of oil companies in that State has attracted much attention, and in this paper the main structural and the general stratigraphic features are described. Four favorable areas are outlined. These contain folds of major interest. There are other favorable areas which have not been mapped. Commercial pools discovered in this area would have the advantage of being near tidewater. Mobile, Ala., on the Gulf, of Mexico, would be the logical site for refineries and shipping facilities. A pipe line could readily be laid to that city from the Hatchitigbee and the Jackson areas. The logical outlet for the Geneva and the Gordon areas would be Panama City, Fla., on the Gulf of Mexico.

Jan 2, 1918

By Fred Porter

Pollution problems from smelters may be unique in industry since the pollutants cover the wide range of SOx, particulates, carcinogens (arsenic), plus a number of heavy metals, the health implications of which are not clearly understood. In addition to this wide range of pollutants, many of the plants are extremely old; and fugitive emissions may, in fact, be the most significant air pollution problem. The Environmental Protection Agency, both in an in-house and contract effort, has assessed the quantity of pollutants emitted and evaluated the health impact. This paper will review the status of EPA&apos;s regulatory efforts in both new and existing smelters in light of these pollutant assessment studies.

Jan 1, 1976

By L., Ormsby

DRILLING and blasting practices in the Morenci open pit have undergone considerable modification in recent years. Changes in the character of the ground being mined, modifications of working conditions, and continuous experimentation have been the contributing factors.

Jan 1, 1950

By C. Gatlin, N. E. Garner, A. Podio

Experimental data from single chisel blows on Leuders limestone are presented. A pressure chamber, similar in design to well known microbit drilling chambers, was utilized to impose variorcs stress states on the sample. Confining pressure of zero to 10,000 psi and borehole pressures from zero to 5,000 psi have been used in the studies. Pore pressure was zero and the rock samples dry in all instances. Force-displacement records and visual examination of the craters indicate that the mode of failure depends on both confining and borehole pressure in certain ranges, ranging from brittle, through a transition, to near plastic. The mode of failure is reflected in the observed blow force and energy data, as well as the shape of force-penetration curves. INTRODUCTION A previous paper&apos; presented initial data from the project on which this paper is the second report. While the first paper dealt with impact studies on synthetic rocks, the literature cited there is also pertinent to this paper, but will not be listed again in order to avoid needless repetition. This paper presents experimental data from single chisel impacts on limestone at certain simulated wellbore stress states. Specific variables investigated were combinations of borehole and confining pressure, crater geometry, a narrow range of impact velocity and the forces required to drive the chisel into the specimens under the varying conditions. EXPERIMENTAL PROCEDURE The same basic apparatus described in our earlier paper, except for the pressure vessel, was used in this study. Fig. 1 shows the complete experimental system. Fig. 2 shows details of the pressure cell, which is quite similar to the well known microbit drilling chamber. The confining (overburden) pressure system provides independent pressure control over the sample except for two, 21/4 in. diameter areas located on the sample ends. These two areas provide a pore pressure entrance on the bottom and a striking surface on the top where borehole pressure can be controlled. The ends are isolated from the confining pressure by O-ring seals. The borehole and pore pressures are related through the striking surface; they will be the same unless a seal is deposited on the borehole surface, either a mud cake or some other impermeable membrane. In these studies pore pressure control was not used, as the rocks were dry and unsaturated in all cases. Rock samples were prepared from 4-in. cubes as illustrated by Fig. 3. The circular disks of adhesive vinyl plastic protected the impact surface from the resin coating (Scotchcast No. 2) and were removed just prior to each test. This procedure insured a fresh uncontaminated surface for the impact. Fig. 4 shows the dimensions and loading of the sample, including the concentrations around the "borehole" periphery (O-ring seal). The rock used in this study was Leuders limestone, of Permian age (Leonard), quarried near Leuders, Tex. Geologically, Leuders limestone is a light gray, fossili-ferous limestone (oolitic foraminifera1 biosporite). Its fossil content is 80 to 90 per cent and consists primarily of calcitornellid, ostracods, pelecypods and oolites with the remaining part intraclasts. There are hematite or limo-nite rims on some of the intraclasts. The porosity is approximately 20 per cent, but the permeability is less than 1 md. There is no apparent orientation in the structure. Triaxial tests have been conducted to determine the variation of the physical properties of Leuders limestone in three orthogonal directions&apos;, and it is known to be unusually isotropic and uniform. Physical parameters for this rock are: uniaxial compressive strength = 9,700 psi; F = 32 and C = 2,700 psi; where + and C are Coulomb equation values (t = C+u tan +). Impact tests were run under the combinations of confining and borehole pressures shown in Table 1. Samples were dry with atmospheric pore pressure in all cases. Tests, in which elevated borehole pressures were applied, used a single layer of household Saran-Wrap to prevent horehole fluid invasion into the sample. This proved to be simple and reliable. The blunt wedge used in all the tests was 0.75 in. long and had an included angle of 60" with a 0.05-in. flat. In addition, a sharp 60" wedge was used for all confining pressures at zero borehole pressure. The chipper speed