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By R. S. McFarland

OKLAHOMA, in 1924, recorded the largest single increase of any state; the total oil production for the year being 176,206,397 bbl. (Oil & Gas Jnl.), which gives an increase over 1923 of about 9 per cent. Oklahoma ranked second in total amount, California being first, and produced almost 25 per cent. of the total production of the United States. This gain in production is accounted for entirely by the rapid development, deeper drilling, and efficient management of productive areas known at the beginning of the year, for, due to the small number of wells drilled, few new pools were discovered and developed up to any important stage during the year. Three major pools, Burbank, Tonkawa and Cromwell, furnished 37 per cent. of the total production. Burbank led by a wide margin, having the largest production of any single pool; there was a steady increase in production until September. The close. development of the pools in Okfuskee, Seminole, and Hughes Counties, together with the new deep-sand production at Tonkawa and increased drilling operations in Osage County, accounted for the big increase shown during the year. In January, 1924, the shutdown movement and curtailment of production in Hewitt and Tonkawa, which had been effective during the year of 1923, were stopped. The shutdown movement and curtailment of operations in 1923 does not give a fair comparison with 1924, as undoubtedly a great deal more oil would have been produced in 1923 had it not been for these measures. The sensational developments during the year, which were certainly beyond the prediction of the oil industry, were the Cromwell field, which started the year with 10,478 bbl. for January and increased rapidly to 1,267,032 bbl. for. December, and the discovery of the Wilcox productions below 4000 ft. in the Tonkawa field in May, which by the end of the year had produced 11,650,000 bbl. In this connection, it can be safely said that 1924 was a banner year for the Wilcox sand series; it has been estimated that between 40,000,000 and 50,000,000 bbl. of the production for the year came from this sand. Although numerous Wilcox pools were opened throughout the state, the big Wilcox production came from. the Tonkawa and Stroud pools. Oklahoma's deepest well, the Kingwood Oil Co. No. 1 Barnett in the northwest corner of the northeast quarter of the southeast quarter of Sec. 7 T. 7 N. R. 10 E., Hughes County, was abandoned in January, at 5281 ft. with numerous good shows recorded, which have stimulated-further drilling in the locality.

Jan 3, 1925

By A. L. Holley

The occurrence of this gas, in quite appreciable quantities, has been observed for many years in its escape along the creeks of Western Pennsylvania, and more recently, in much larger quantities, from the oil wells in and near Venango County. Within about five years several gas wells have been struck, from which the gas has escaped continuously in prodigious quantities and at great pressure. During the last year a systematic attempt has been made to utilize the flow of gas from one of these wells, and results have been reached which were quite unexpected. This well, near Leechburg, Armstrong County, is about twenty miles northeast of Pittsburgh, on one of the side tributaries of the Alleghany River. It had been drilled in search of oil to a depth of 1250 feet in 1871, but none was found. A great flow of gas was developed, however, accompanied by a slight spray of salt water, and this has continued with little or no diminution to the present time. The gas in its escape has been discharged through a 5-inch pipe, and at a pressure of from 60 to 80 Ibs. per square inch, but no exact determinations, either of the pressure or quantity, have been made. The rolling mill of Messrs. Rogers & Burchfield is on the opposite side of the river, and it has been for some years devoted to the production of fine grades of sheet iron from charcoal pig metal, by puddling and in knobbling fires. The usual weekly product of the mill has been 30 tons of No. 30 tin plates, and 50 tons of No. 24 to 28 sheets. The well was bought by this firm for $1000, and the gas is led across the river, a distance of about 500 feet, through a 3-inch pipe. It is distributed through half-inch pipes, and at a pressure of about 45 Ibs. per square inch, to several of the furnaces, but a large fraction of the total flow of gas is still wasted at the well. No essential alteration in any of the furnaces has been found necessary in the use of the gas fuel, except to brick up the firebridge and to put in the gas and air pipes. The old grate used for coal is loosely covered with bricks and cinder, so that a slight percolation of air may take place through them. The gas is admitted through a half-inch pipe, and blows toward the fire-bridge through 18 or 20 one-eighth inch jets. The air is blown in at about 2 lbs.

By T. A. Wright

The sampling of waste materials containing copper, lead and tin has taken on a new significance within recent years, and is of increasing importance, on account of the entry of some of the copper refineries into this field and the tendency towards consolidations among the smelters. In the past, such material was sold on the basis either of a rough or grat) sample or of casual inspection of the lot. The two principal sources of this waste are the processes of fabrication and the scrapping of automobile, electrical, plumbing, railroad and other equipment. In both cases rnuch material can bc sorted, salvaged and sold by classification and grade to be melted "as is" or with the addition of new or virgin metal. The increasing care in classifying exercised in the large manufacturing plants tends to incrcase the proportion of this usable scrap; on the contrary, the increasing use of more complex and special non-ferrous alloys tends to makc sorting and grading more difficnlt in turnings, borings, clippings, etc., and conseqllcntly is making sampling of more moment. In tin, lead, alumiinum, and zinc furnace by-products such as ashes, drosses, skimmings, etc., the trade practice of evaluation has not varied much. For instance, tin drosscs, battery lcad, and aluminunl skimmings are ordinarily sold on what is called "metallic button" or "metallic recovery" or "metallic yield." Coppcr and Icad wastcl, howcvcr, is being sold more and more on actual copper and lead contents bascd on sarrlple and chemical analysts. This paper will be dcvotctl chiefly to the sampling of niaterials suitablc only for refining and recovery of one or more of the metals present. The methods described are often bascd on thc fact that but one, metal, such as copper, is to be paid for. The loss of volatile constituents in melting does not appreciably affect thc final copper result, as the "after-melting" assay can be readily calculated to the "bcfore-nltltingl' basis, but if smelter efficiency continues to increase, so that in tiltie zinc, for instance, may be rccovrred on a paying basis, thc method of sampling dirty brass, for example, will have to bc changed also. As a matter of fact, we may cxpect that improved refining proresses will make possible the partial reeovrry of lcad and tin which are now lost

By L. R. Blair

Many hydrated silicates have been synthesized and sold for commercial use. However, this paper discusses only hydrated calcium silicates and, to a lesser extent, hydrated magnesium silicates. Synthetic calcium silicates were first formed by man when he found that mixtures of silica or silicates and lime in water set up to form cements. The material which was responsible for the cementing properties was calcium silicate hydrate, although this fact was not recognized until early in this century. In the early 19001s, synthetic calcium silicates, reinforced with fibers and formed simply by reacting calcium hydroxide and silica in water with fiber at atmospheric or under low pressure autoclave conditions, found increased use in thermal insulations and in building products. These insulations were found to have a low thermal conductivity and would withstand temperatures up to 650°C. This, combined with their very low densities (from 8 to 50 Ib per cu ft) and fairly high strength, also made them suitable for use as building products. Following the disastrous Morro Castle fire of the 1930Js, calcium silicate board products were used as partitioning material in all shipboard construction in the U.S. As autoclaving techniques were improved and developed, it was: learned that under hydrothermal conditions new and useful calcium silicates which could be used under more extreme temperatures (up to 980' C) could be prepared. These had high surface areas and other unique properties which suited them for use as fillers, pesticide carriers, low temperature insulating materials, and adsorbents for the removal of fatty acids from various solutions. Hydrated magnesium silicates have not been studied as extensively as the calcium compounds. Their first important use was in the filtration of dry cleaning solutions for the removal of fatty acids. With the introduction of detergents, it was found that these products lost their advantage because of their high affinity for the detergent chemicals. However, in recent years these chemicals are finding increasing use as decolorizing agents for fats and anti-caking agents for resins. Some materials with very high surface are finding new use as adsorbents. CALCIUM SILICATE HYDRATE COMPOUNDS AND THElR CONDITIONS OF FORMATION Within the past ten years much has been done in the field of calcium silicate hydrate chemistry. As a result of this work it has been found that at least 25 different forms of calcium silicate hydrate can either be formed synthetically or found as naturally occurring materials. The stability and composition relationships among these 25 compounds present a very complicated picture, and many of these very closely resemble other forms and are difficult to dis-

Jan 1, 1962

PRESIDENT Mrs Oliver Bowles 5000 Massachusetts Avenue N W. Washington 16, D C FIRST VICE-PRESIDENT RECORDING SECRETARY Mrs David E" Park Mrs Thomas T Read 115 East 67th Street 9 Windmill Lane New York 22, N Y Scarsdale, N Y

Jan 1, 1951

By H. H. Kellogg

An invitation to address you on the occasion of the one-hundredth anniversary of AIME represents an honor, a challenge and an opportunity: an honor that you judge me worthy; a challenge that I present to you a picture of extractive metallurgy in the years ahead that contains some ideas of value; and finally, an opportunity for me to express some deeply felt beliefs about our profession and our industry. My topic concerns the technology of metal production in the future - the processes, new and old, that will be used to extract metals. The nature of these processes will be shaped by many forces - some technical, some economic, some political or social. A forecast of future technology must recognize the role of each of these forces, and I have endeavored to do this in the analysis that follows. In brief, my outline consists of an analysis of the forces (perhaps better called "problems") that will influence the future of our industry, followed by consideration of likely lines of technological development to meet them. Let me dwell for a moment on the nature of this industry and the profession that serves it. I have been engaged in the profession of extractive metallurgy - teaching, researching and consulting - for 30 years. I have always found the subject stimulating and rife with challenges of a scientific, engineering, economic and socio-political nature. It is a big subject - it encompasses most of the elements of periodic table; we measure the U. S. production of six metals in millions of tons per year; new plant costs range to $100 million and more. The supply of metals from our extractive plants plays an essential role in our modern industrial economy. We could do without DDT, or phosphate detergents or 300-page Sunday newspapers; we cannot do without a huge and increasing supply of metals. The Basic Goal of Extractive Metallurgy Understanding of some basic forces that shape this industry can be gained by consideration of the question: What determines the utility of metals to man? We think immediately of the inherent properties of metals - strength, ductility, electrical conductivity and so forth - but these tell only part of the story. Metal price and the available supply play equally

Jan 1, 1971

By Robert Wamsley, W. E. Jones

One of the earliest problems in the life of any community is the provision of an adequate supply of water sufficiently free from all types of contamination to be suitable for domestic purposes. Generally speaking, the location of most communities is determined to a great extent by the availability of an adequate supply of satisfactory water. For a mining camp, that consideration cannot be foremost. Here, the ore takes first place, and the men who mine it must do the best they can under the existing conditions. If there is no local source of water, it must be brought from some distant source or must be found by sinking shafts or drilling wells. Fortunate indeed is the mining company that discovers a commercially valuable ore deposit beside a never failing creek full of pure water, with sufficient water rights available. because the acquisition of water in any other manner nearly always involves not only a considerable period of time but the expenditure of considerable money. The experience of Climax Molybdenum Co. demonstrates the measures that sometimes are necessary in order to provide a suitable supply of water. The Climax mine and mill are on the Continental Divide! about 13 miles northeast of Leadville. The elevation of the domestic part of the camp varies from a minimum of 11,320 ft. to a maximum of approximately 11,550 ft. above sea level, and, as is common at such altitudes, the near-by streams that might be suitable for a water supply are small and intermittent, usually flowing only during the summer months. The only streams of any size in the immediate vicinity of Climax are the Ten Mile and Arkansas Rivers The headwaters of Ten Mile River are on the Company's property, and its water has been used for the domestic supply. The headwaters of the Arkansas River are about 2 miles distant and have not been used as a source of supply by the company. During the past 11 years of the production of molybdenum at Climax, the number of families living there has increased from about 45 to 283, and the population has increased from about 200 to 1200 persons. Consequently, the capacity of the water-treatment facilities, and the amount of water available, had to be increased to meet the requirements of the camp. As early as 1932 it was recognized that the water in Ten Mile River would not continue to be adequate for domestic purposes and after considerable discussion it was decided to drive a drift through the major fault in an effort to find additional water. This drift was completed in 1935 and tapped sufficient water to make the supply adequate. This water was treated in a tank underground, where lime was added, and was then piped into the domestic supply lines. At about the time this line was completed, the presence of fluorine in harmful concentrations was discovered in the water. This problem was submitted to the International Filter Co. and in November 1937 a plant of its design was put in operation for treating the water to remove the fluorine. This plant proved entirely successful,

Jan 1, 1946

By T. M. Olson, B. G. Lewis

The adsorption of selenite on bentonite, kaolinite, and an iron--coated illite was studied to determine the importance of several soil variables on selenite removal from uranium mill tailings pond seepage. Adsorption capacities of the clays of selenite varied by orders of magnitude and decreased in the following order: illite > kaolinite > bentonite. Maximum adsorption of selenite on the clays was observed between pH 2.5 and the clay's zero-point-of-charge. Substantially less selenite was adsorbed on these clays in actual mill tailings solutions than in model systems. Virtually all selenite was removed from the tailings at pH 7. The principal removal mechanism at this pH is suggested to be the adsorption of selenite on freshly precipitated metal hydroxides. It is concluded that selenite can be removed from tailings seepage in soil or in clay liners in the presence of kaolinitic clays and iron oxides. Selenite would also tend to be removed from tailings seepage in calcareous strata.

Jan 1, 1984

By Norman B. Pilling

The technical difficulties hampering the metallographic analysis of silicon steels are chiefly the result of the extreme corrodibility of these alloys. The addition of silicon to iron in increasing quantities, up to about 6 per cent., rapidly increases the susceptibility of the alloy to chemical attack, not only in acid solution, but in water. This renders the preparation of metallographic sections very difficult, because of a non-selective attack upon the finely polished surface by the water used as a lubricant in polishing. This water attack masks the true structural details revealed by suitable etching reagents. It is thus necessary to use alcohol as a polishing lubricant in the last stages of preparation and to avoid all etching reagents having an aqueous base. A specific reagent for the identification of iron carbide in ferrous alloys, and the one hitherto used almost' exclusively by metallurgists, is an alkaline aqueous solution of sodium picrate, which stains this constituent selectively. Its application to silicon steels has not proved successful, as its distinctive selective action is more or less completely hidden by the general attack of the aqueous solvent on the silico-ferrite, greatly accentuated by the fact that this reagent must be used at its boiling temperature (105' C.). Thus, a powerful metallographic aid to the study of the higher silicon alloys, such as transformer steels, is lost. A new reagent has been developed for the purpose of overcoming this difficulty. It is with some hesitation that the list of etching reagents, already overburdened, is increased, but the properties of this new reagent are advantageous in several ways and a definite field for it may be found in the metallography of ferrous alloys. The reagent consists of a dilute solution of nitric acid and methyl alcohol in nitrobenzol. It is a great advantage to secure an anhydrous solution, as a tendency toward acidic etching has been traced to small amounts of water. A convenient method of preparation is to make an anhydrous stock solution of nitric acid in methyl alcohol in the proportion 20 per cent. acid by weight (12.5 per cent. by volume). The alcohol can

Jan 1, 1924

By A. W. Furbank

IN reviewing the aerial cameras produced in different countries, it becomes apparent that in nearly all of them an attempt has been made to secure the greatest possible angle of view. This angle, of course, is determined by the objective. The objectives most commonly in use in aerial cameras have a maximum angle of 65º. The objective developed for this new Zeiss camera combines freedom from distortion and brilliant definition, with an angle of 95º. Aerial mapping, it is claimed, has been placed on a different economic basis, and new possibilities presented, particularly in connection with automatic stereoscopic plotting instruments, to which some short references are made. One way of enlarging the angle of view is to couple several instruments with their axes convergent, thereby producing a multilens camera. Typical of cameras of this sort in the United States is the Bagley four-lens camera, which later was developed into the five-lens camera (T3-A) of the U. S. Air Corps. More recently, in order to get away from the unfavorable Maltese cross image field of the five-lens camera, and to obtain a more practical form, two five-lens cameras were combined. By using them in tandem and rotating them by 45º relatively to each other, a ten-lens camera was produced, covering an octagonal ground area, with a total angle of view of 140º. Similar designs have been evolved in other countries. In all of them, however, a number of difficulties have arisen, quite apart from their large weight and high cost. Because of their complex mechanism, numerous shutters and magazines, and the high precision with which these parts must be interadjusted and synchronized, these cameras are far from dependable Moreover, a multilens camera by itself does not yet constitute a complete outfit for producing pictures suitable for photogrammetric survey. Because all the component pictures, except the central one, are obliques, it is always necessary to employ rectifying apparatus which transforms the marginal views to the perspective of the central one. In multilens cameras with many individual magazines, it is not convenient to

Jan 1, 1938

By A. W. Furbank

In reviewing the aerial cameras produced in different countries, it becomes apparent that in nearly all of them an attempt has been made to secure the greatest possible angle of view. This angle, of course, is determined by the objective. The objectives most commonly in use in aerial cameras have a maximum angle of 65". The objective developed for this new Zeiss camera combines freedom from distortion and brilliant definition, with an angle of 95". Aerial mapping, it is claimed, has been placed on a different economic basis, and new possibilities presented, particularly in connection with automatic stereoscopic plotting instruments, to which some short references are made. One way of enlarging the angle of view is to couple several instruments with their axes convergent, thereby producing a multilens camera. Typical of cameras of this sort in the United States is the Bagley four-lens camera, which later was developed into the five-lens camera (T3-A) of the U. S. Air Corps. More recently, in order to get away from the unfavorable Maltese cross image field of the five-lens camera, and to obtain a more practical form, two five-lens cameras were combined. By using them in tandem and rotating them by 45" relatively to each other, a ten-lens camera was produced, covering an octagonal ground area, with a total angle of view of 140". Similar designs have been evolved in other countries. In all of them, however, a number of difficulties have arisen, quite apart from their large weight and high cost. Because of their complex mechanism, numerous shutters and magazines, and the high precision with which these parts must be interadjusted and synchronized, these cameras are far from dependable. Moreover, a multilens camera by itself does not yet constitute a complete outfit for producing pictures suitable for photogrammetric survey. Because all the component pictures, except the central one, are obliques, it is always necessary to employ rectifying apparatus which transforms the marginal views to the perspective of the central one. In multilens cameras with many individual magazines, it is not convenient to

Jan 1, 1941

By A. W. Furbank

In reviewing the aerial cameras produced in different countries, it becomes apparent that in nearly all of them an attempt has been made to secure the greatest possible angle of view. This angle, of course, is determined by the objective. The objectives most commonly in use in aerial cameras have a maximum angle of 65". The objective developed for this new Zeiss camera combines freedom from distortion and brilliant definition, with an angle of 95". Aerial mapping, it is claimed, has been placed on a different economic basis, and new possibilities presented, particularly in connection with automatic stereoscopic plotting instruments, to which some short references are made. One way of enlarging the angle of view is to couple several instruments with their axes convergent, thereby producing a multilens camera. Typical of cameras of this sort in the United States is the Bagley four-lens camera, which later was developed into the five-lens camera (T3-A) of the U. S. Air Corps. More recently, in order to get away from the unfavorable Maltese cross image field of the five-lens camera, and to obtain a more practical form, two five-lens cameras were combined. By using them in tandem and rotating them by 45" relatively to each other, a ten-lens camera was produced, covering an octagonal ground area, with a total angle of view of 140". Similar designs have been evolved in other countries. In all of them, however, a number of difficulties have arisen, quite apart from their large weight and high cost. Because of their complex mechanism, numerous shutters and magazines, and the high precision with which these parts must be interadjusted and synchronized, these cameras are far from dependable. Moreover, a multilens camera by itself does not yet constitute a complete outfit for producing pictures suitable for photogrammetric survey. Because all the component pictures, except the central one, are obliques, it is always necessary to employ rectifying apparatus which transforms the marginal views to the perspective of the central one. In multilens cameras with many individual magazines, it is not convenient to

Jan 1, 1941

By J. D. A. Morrow

This discussion relates to the distribution of coal under the di , of the U. S. Fuel Administration beginning Apr. 1, 1918. At t' L a definite method of controlling and directing distribution was put int effect. Prior thereto, although some of the machinery utilized was in operation, especially in the few weeks immediately preceding' Apr. 1, distribution had not been effectively and comprehensively organized. The writer was called to the Fuel Administration by Dr. Garfield about the first of February, 1918, to assume general direction of the distribution of coal for the Fuel Administration, to develop the general plans, and to obtain practical men to assist in this work and in carrying through the program finally devised. A study of the situation and conferences with the Fuel Administrator and leading men in the business made it plain that it would be necessary to begin at the bottom, measure the undertaking, develop plans to meet the need thus shown, and build an organization to effect the distribution required. This work had to be done under war pressure in the midst of a bad coal shortage. The successful performance of such a task is always primarily a matter of putting competent men in the right places and giving them the power and opportunity to function properly together. In the Distribution Division of the U. S. Fuel Administration, the men who were chiefly responsible for whipping plans into practical form and then for carrying out these plans were A. W. Calloway, of Baltimore, President of the Davis Coal & Coke Co., who served as the Director of Bituminous Coal Distribution; S. Lovell Yerkes, of Birmingham, Alabama, Secretary of the Grider Coal Sales Agency, who assumed general charge of distribution while the new plans and organization were being perfected and then became the Assistant Director of Bituminous Coal Distribution; Warren S. Blauvelt, of Detroit, who was Director of Coke Distri. bution; A. S. Learoyd of New York, Director of Anthracite Distribution, in connection with the Anthracite Committee, consisting of Joseph P. Dickson, President of Dickson & Eddy, Chairman; S. D. Warriner, President of the Lehigh Coal & Navigation Co., and W. H. Richards,

Jan 1, 1920

By William F. Harris, Joseph Easha

FOR many years basic control of refinery operations depended on visual observation of small chill specimens poured at various intervals during processing. The oseto of these samples was related to the physical and chemical properties of the metal. Since the =setn is dependent on many factors other than oxygen content, this method, while giving a general indication of the condition of the copper, does not accurately measure the oxygen content. For the last 3 years a modified vacuum fusion procedure which enables the operator to determine the oxygen content of the copper within 1 5 min of sampling has been in use at the Westinghouse Copper Mill. For use with this apparatus a sampling technique has been developed which gives oxygen values representative of the oxygen content of the wire bar. The sampling technique is based on a statistical study, which compared the oxygen content of the laboratory sample of copper poured at the same time a wire bar was being poured, with the oxygen content of the wire bar. The apparatus used for the determination of oxygen in copper is shown in Fig. 1 and is essentially the same as previously described but with one important modification. A very porous fritted glass disc has been inserted in the tubing between the manom- eter and 40/50 ground glass joint. The fritted disc retains the copper vapor and copper particles in the furnace section and prevents contamination of the mercury in the manometer. Without the disc the manometer became difficult to read after a few weeks of operation. In earlier work1 it had been established that the simplified vacuum fusion apparatus used at the Copper Mill gave essentially the same results as a con-vential vacuum fusion apparatus. However, for this study it was necessary to determine the difference, if any, between the oxygen content of the wire bar and the oxygen content of the small chill sample used for the oxygen analysis. This correlation was established by taking a chill sample at the same time wire bars were being poured. The wire bar being poured at the time the chill sample was taken was marked and removed for further analysis. The copper is sampled at various times during refining and cast into laboratory size samples with the mold shown in Fig. 2. The mold is made of cold rolled steel and is 2 in. high and 2 1/2 in. in diam. The large upper portion of the cast sample is used for measurement of the conductivity of the copper, The lower portion which is a rod about 1/4 in. diam by 3/4 in. long is used for determination of the oxygen content. This portion of the sample weighs about 5 g which is approximately the size sample used for the analysis. The only preparation neces-

Jan 1, 1962

By F. F. Aplan, D. W. Fuerstenau

This chapter presents modern concepts of the flotation of nonmetallic minerals. In particular, it is concerned with such minerals as metal oxides, silicates, sulfates, carbonates, and halides. It is not the purpose to duplicate the two excellent, recent treatises by Gaudin l and by Sutherland and ark,^ but rather to expand their correlations of data, particularly in view of recent, ex- citing new experiments which are shedding new light on the principles of non- metallic flotation. Outstanding success has been achieved over the past 50 years in separating one sulfide from another or from the gangue constituents using a minimal amount of reagents. In contrast to this, selective flotation in nonmetallic systems is often difficult in that one class of compounds alone, the carboxylic acids, may float nearly the entire array of nonmetallic minerals under the appropriate conditions. Moreover, while lime, cyanide, sodium sulfide, and copper sulfate constitute the principal modifiers used to obtain selectivity among the various sulfides, the nonmetallic mineral flotation engineer is con- fronted with a vast array of modifying reagents. In sulfide and native-metal flotation, a strong chemical adsorptive bond is generally formed between the mineral and sulfhydral collector. In fact, re- cent radio-tracer studies show that below monolayer coverage as much as 98% of added mercaptan is adsorbed on the surface of gold.? Contrasted to this, Bloecher's data indicate that for the quartz-amine system only about 60% of the collector is adsorbed.4 This greater residual concentration in the solution results from weaker forces of adsorption in the quartz-amine system. In the flotation of nonmetallic oxide minerals, collector adsorption results from rather weak physical forces, primarily electrostatic attraction and van der Waals attraction between hydrocarbon chains. In the flotation of salt-type minerals, carboxylic acids are adsorbed both by physical and chemical forces. It is a study of the effect of the electrical forces superimposed on the chemical adsorptive forces that contributes most toward understanding nonmetallic mineral flotation. The need for quantification of general rules for the flotation of nonmetallic minerals is so great that Taggart 5 with unmasked sarcasm suggested that after trying anionic and cationic collectors:

Jan 1, 1962

Discussion of the paper of CHARLES T. MALCOLMSON, presented at the New York meeting, February, 1915, and printed in Bulletin No. 98, February, 1915, pp. 271 to 289. E. W. PARKER, Washington, D. C.-The briquet or boulet, or coalette (whatever name is used) has come to stay as a part of the fuel supply, particularly for domestic purposes. During the past winter I have had some personal experience with the use of boulets made from anthracite coal. All of this winter I have used boulets in my furnacee and in my grate at my home in Washington. One reason for doing so is that we get the boulets at a price considerably cheaper than the prepared sizes of anthracite coal. The fuel has proved entirely satisfactory. One advantage possessed by the boulet is its absolutely uniform size, which makes the ventilation of the firebed practically perfect. The boulets burn until entirely consumed. There is not, even in an open grate fire, if the fire is kept constantly going, any unconsumed fuel passing through the grate bars. The boulets hold their form until entirely consumed and then break away into a clean white ash, with absolutely no clinker. That in itself is a particularly favorable recommendation to the housekeeper. Mr. Malcolmson has mentioned the fact that notwithstanding the smokeless character of anthracite, the boulets made from it emit smoke. The emission of smoke is due to the coal-tar pitch used as a binder. This is particularly noticeable if the fireman is somewhat careless, or wants to save labor, and feeds too much of the fuel on the fire at one time, cooling it down and thus causing an unnecessary amount of smoke. The smoke lasts but a short time, however, and if the fire is fed a little more frequently, with a small quantity of fuel at one time, the smoke is reduced to a minimum. I believe it will not be long before some of our engineers will have overcome the objectionable smoke; and will produce either from anthracite or from the so-called smokeless New River and Pocahontas semi-bituminous coals, a briquet which will be as smokeless as anthracite for all. practical purposes.

Jan 5, 1915

By Julian Szekely

Through the simultaneous statement of Maxwell's equations. the turbulent Navier-Stokes equations and the differential thermal energy balance equation, a mathematical representation has been developed for heat transfer and fluid flow in electric arc furnaces. In broad outline the theoretical predictions appear to be consistent with experimental measurements. A discussion is presented of the general arc furnace control and optimization problem, together with the potential for the incorporation of the mathematical model given in the paper, into future control and optimization schemes. ELECTRIC ARC FURNACE STEELMAKING accounts for about 24% of the total steel produced in the U.S., consuming about 550kw-hr/ton of steel which amounts to about 1.4x1010 kw-hr annually. The percentage of steel produced by the electric arc furnace route has doubled since 1960 and is expected to increase further in the foreseeable future, particularly with the more extensive use of direct reduction technology. Table I shows, in terms of percentages, the principal items that contribute to the cost of running an electric arc furnace. It is seen that in addition to the fixed costs (labor, depreciation, taxes etc.) electrode costs and power consumption are the dominant inputs, and it follows that process changes that would ultimately reduce any of these cost components would have a significant impact on the efficiency of the operation. There are three main areas where progress in arc furnace design and operation must be directed in the next decade (Committee on Technology, 1981). 1. Increased furnace productivity 2. Reduction in processing cost 3. Improvement in the thermal efficiency of the furnace An estimate of the current operating efficiency of the electric arc furnaces may be obtained by comparing the theoretical minimum energy consumption per ton of steel with those achieved in operational practice. Theoretically 330-360 kw-hrs of electricity are required to melt one ton of cold scrap. For superheating, 8-12 kWh per 100°F are required. The actual energy requirements are given in Table II. It is seen that furnaces currently operate at 70-80% efficiency, with the major heat loss from the furnace resulting from the waste gases (Committee on Technology, 1981). While it is apparent that operational experience has produced a technology that is reasonably energy efficient this has been achieved in the almost complete absence of any detailed knowledge concerning the fundamental heat transfer mechanisms occuring in the furnace. The purpose of the present paper is to present a case for the usefulness of mathematical models in increasing the thermal efficiency of furnaces by investigating these heat transfer mechanisms and then combining this knowledge with existing electrode regulator mechanisms to produce truly efficient power cycles for melting and refining. In particular, existing mathematical models describing convection, radiation, and electro-magnetism in the furnace should be employed, and the development of optimization models which balance the cost of electrodes and energy against the thermal efficience of the furnace should be undertaken. Recent work in this laboratory (Szekely, McKelliget, 1981, 1982, 1983; Szekely, McKelliget, Choudhary, 1983) has made a useful start towards solving the problem of heat transfer within the electric arc furnace but the work still needs to be directly related to existing furnace power cycles and tested against plant scale measurements.

Jan 1, 1984

By John W. Buch

NeaRly 25 years ago operating officials in the northern anthracite field were confronted with the problem of profitably mining virgin beds of thin coal (those 48 in. and under) or destroying them by mining underlying thick beds. To solve this problem costly hand-mining methods were replaced by cheaper mechanical methods, which eliminated the need for the lifting of bottom or the brushing of top in excessive quantities, which was essential if proper height for hand loading1 was to be provided. During this period long-face mining was an outstanding development. In its favor in comparison with any other method were the ease with which undercutting machines could be used, a differential in powder cost of about fifteen cents per ton in favor of this method over mining from a solid chamber or pillar face, and a greater production per day from a single working place, resulting in lower capital expenditures for a given total production, closer supervision and lower transportation cost. The long faces were drilled by jackhammer and undercut by machines. The coal from the cut was loaded into mine cars placed on the gangway road by means of a double-drum mechanical scraper engine and a mechanical V-type scoop. A tugger hoist was used to spot empty cars at the loading point from a supply placed at the operation by an electric mine locomotive. During loading the roof was supported by vertical wooden props paralleling the face. After the loading was completed the scraper engine and the ropes that had been used to propel the scoop in the loading of coal transferred the props to and along the face. A row of unfilled cogs was then built parallel to the new face and about 6 ft. from it. These cogs were usually made 6 by 3 ft., the longer dimension paralleling the face; they were placed on an average at 12-ft. centers. These wooden cogs were left in place and were buried later by falling roof. Attempts to remove them were never successful. When a new long face was started, the cog spacing would be increased to about 20-ft. centers. As successive cuts were made, weight would begin on the cogs, and they

Jan 1, 1940

By John W. Buch

NeaRly 25 years ago operating officials in the northern anthracite field were confronted with the problem of profitably mining virgin beds of thin coal (those 48 in. and under) or destroying them by mining underlying thick beds. To solve this problem costly hand-mining methods were replaced by cheaper mechanical methods, which eliminated the need for the lifting of bottom or the brushing of top in excessive quantities, which was essential if proper height for hand loading1 was to be provided. During this period long-face mining was an outstanding development. In its favor in comparison with any other method were the ease with which undercutting machines could be used, a differential in powder cost of about fifteen cents per ton in favor of this method over mining from a solid chamber or pillar face, and a greater production per day from a single working place, resulting in lower capital expenditures for a given total production, closer supervision and lower transportation cost. The long faces were drilled by jackhammer and undercut by machines. The coal from the cut was loaded into mine cars placed on the gangway road by means of a double-drum mechanical scraper engine and a mechanical V-type scoop. A tugger hoist was used to spot empty cars at the loading point from a supply placed at the operation by an electric mine locomotive. During loading the roof was supported by vertical wooden props paralleling the face. After the loading was completed the scraper engine and the ropes that had been used to propel the scoop in the loading of coal transferred the props to and along the face. A row of unfilled cogs was then built parallel to the new face and about 6 ft. from it. These cogs were usually made 6 by 3 ft., the longer dimension paralleling the face; they were placed on an average at 12-ft. centers. These wooden cogs were left in place and were buried later by falling roof. Attempts to remove them were never successful. When a new long face was started, the cog spacing would be increased to about 20-ft. centers. As successive cuts were made, weight would begin on the cogs, and they

Jan 1, 1940

By John Buch

NEARLY 25 years ago operating officials in the northern anthracite field were confronted with the problem of profitably mining virgin beds of thin coal (those 48 in. and under) or destroying them by mining under-lying thick beds. To solve this problem costly hand-mining methods were replaced by cheaper mechanical methods, which eliminated the need for the lifting of bottom or the brushing of top in excessive quantities, which was essential if proper height for hand loading' was to be provided. During this period long-face mining was an outstanding development. In its favor in comparison with any other method were the ease with which undercutting machines could be used, a differential in powder cost of about fifteen cents per ton in favor of this method over mining from a solid chamber or pillar face, and a greater production per day from a single working place, resulting in lower capital expenditures for a given total production, closer supervision and lower transportation cost. The long faces were drilled by jackhammer and undercut by machines. The coal from the cut was loaded into mine cars placed on the gangway road by means of a double-drum mechanical scraper engine and a mechan-ical V-type scoop. A tugger hoist was used to spot empty cars at the loading point from a supply placed at the operation by an electric mine locomotive. During loading the roof was supported by vertical wooden props paralleling the face. After the loading was completed the scraper engine and the ropes that had been used to propel the scoop in the loading of coal transferred the props to and along the face. A row of unfilled cogs was then built parallel to the new face and about 6 ft. from it. These cogs were usually made 6 by 3 ft., the longer dimension paralleling the face; they were placed on an average at 12-ft. centers. These wooden cogs were left in place and were buried later by falling roof. Attempts to remove them were never successful. When a new long face was started, the cog spacing would be increased to about 20-ft. centers. As successive cuts were made, weight would begin on the cogs, and they

Jan 1, 1939