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By F. Peter

Technical progress takes place in two directions: the improvement of methods, affecting the quality of the product; and increase in the economy of operations, affecting its cost. In the iron-industry, practice is pretty well settled, and revolutionary changes of method are, for the present, not to be expected. Hence, in this industry, the principal endeavor is to reduce costs by the use of labor-saving inventions, such as the machines brought into use during the last decade. But it is not alone necessary to reduce the labor-cost; complete economy requires also a saving in raw material. Under this head we may rank the coal employed as metallurgical fuel; and it follows that progress includes the economic use of fuel, so managed as not to injure quality of product. In the present paper it will be shown how, by suitable utilization of the heat from the furnace, a large portion of it may be made available for other purposes. Such utilization of waste-gases is important in all industries which employ furnaces (especially heating-and smelting-furnaces); and in the first rank of these stand the iron-, glass-, and porcelain-manufactures. The following pages are devoted chiefly to the waste-gases of smelting-works, and especially to those reverberatory-furnace gases which are not combustible.' The object of metallurgical furnaces is either to fuse the material charged or to bring it to a high temperature required for further mechanical manipulation. Leaving out of consideration for the present the reverberatory fusion-furnaces, we have to do with the heating-furnaces employed in connection with rolls, hammers, or hydraulic presses. The temperature to which the material must be

Jan 1, 1914

By R. E. Zimmerman

THE separation of fine sizes of coal from its impurities by means of various flotation methods has become of increasing importance in the coal industry. This, no doubt, will be even more so in the future as the quantity of high grade coal is depleted, particularly that used for metallurgical purposes. The purpose of this paper is to describe and report the results of research work done under the auspices of the Pittsburgh Coal Co. to determine the amenability of their bituminous fine sizes of coal to flotation, to investigate the value of various reagents and factors affecting their use, and compare the results between froth flotation and bulk oil flotation. Compared with the preferential flotation of complex minerals, or ores, the flotation of coal is comparatively easy. However, this statement should not lull one into the feeling that there are no special problems involved. For instance, the separation of coal from pyrite in high sulphur coals is still far from being 100 pct successful. Size consist has considerable effect on reagent consumption and recovery. Other factors will be described and finally it must be remembered that in the flotation of coal a low priced material is being treated and thus economic considerations govern more closely its application than is generally the case in treating other minerals. As a result of the research work done by the Pittsburgh Coal Co. on the flotation of coal, it was concluded that it was practical to clean the -48-mesh coal commercially by froth flotation and after several different types of flotation units and circuits were investigated by means of pilot plants, large scale units were installed at their Champion Nos. 1, 4 and 5 Preparation Plants for the cleaning of -48-mesh slurries. These large scale operations have been recently described by D. H. Davis. 1 C. P. Proctor and C. B. Carlson2 in their chapter on Froth Flotation of Coal in the AIME Seeley W. Mudd series book on Coal Preparation describe some of the practical applications of our Pittsburgh Coal Co. laboratory work in actual plant practice as well as summarizing part of the investigational work. The author presents this paper, however, as a supplement to their reports, and records the basic research accomplished in the laboratory investigational work as well as the results of experi¬ments using bulk oil flotation. In presenting this work the author wishes to state much more work must be done in applying the principles of flotation to cleaning coal, especially in view of recent studies and practices in other mineral beneficiation fields. METHODS OF CONDUCTING LABORATORY TESTS The bulk of the research work was conducted in the laboratory of the Champion No. r Preparation Plant. This plant has elaborate facilities for sampling and analyzing coal and proved to be an admirable location

Jan 1, 1948

By Harold L. Hinds

The Homestake Ledge or Lead was discovered by Fred and Moses Manuel on April 9, 1876. They recovered a small amount of gold from the quartz outcrop, but, unfortunately, they were prospectors not hardrock miners. Their claim was sold to a group of experienced California mining men in 1877. These mining men incorporated their holdings as the Homestake Mining Company. This was the beginning of one of the greater gold mining enterprises of the Western World. Metallurgical operations progressed over the years from an eighty- stamp grinding circuit using amalgamation for recovery to the more complex circuit of today. The Homestake Mine, today, is an underground mine with the deepest winze reaching the 8,000-foot level. The ore is hoisted to the surface by two primary shafts, the Ross Shaft and the Yates Shaft. See Figures 1 and 2. It is crushed in three-stage crushing plants located in the headframes. From here, it is trammed to the mill fine- ore bins by electric locomotives. The Lead grinding plant milling circuit, known as the South Mill, receives ore from the crushing plant at minus 112 inch (Figure 3). This material is dumped into overhead fine-ore bins from five- ton rail cars. The fine-ore bins have a live capacity of about 3,700 tons. The South Mill bins can also be fed by a conveyor system which reclaims ore from an 80,000-ton capacity stockpile. This stockpile is built up from peak mining production periods and available surface low grade material. It is then reclaimed during low mine production periods. The grinding circuit at the South Mill consists of four rod mills in open circuit followed by four ball mills in closed circuit. Three of the rod mills are 6-foot by 12-foot Marcy's. The other is

Jan 1, 1983

By D. L. Albright, R. W. Kraft

A technique is described whereby the study of crystal perfection through the use of conventional X-ray rockite curves is extended to three dimerzsions. Specinzens of unidirectionally solidified eutec-tic alloy which consist of a nearly perfect parallel arrangement of alternating Platelets of Al and CuAl2, but which contain lamellar faults have been analyzed by this technique in conjunction with X-ray microscopy. Analysis of the data has shown that some rotational symmetry about the growth direction occurs, that small groups of lamellae between faults diffract as a unit, and that the misorientation caused by a fault is on the order of a degree of arc. A eutectic-grain can be defined as that portion of a eutectic specimen in which the crystallographic orientation of each phase AND the microscopic or met-allographic orientation of the phase particles have fixed angular relationships one to another. Eutectic-grains of the A1-CuA12 eutectic, which is a normal lamellar eutectic, have been grown by unidirectional solidification and identified as such.1-3 To a first approximation, a eutectic-grain in this system consists of two interpenetrating single crystals which are related to each other and to the lamellae themselves as follows:

Jan 1, 1962

By Edward Wichers

THE purpose of this paper is to set forth the matters of principal interest in connection with work done in the past few years on the purification of the metals of the platinum group, including the study and modification of methods already in the literature and the development of new procedures. For the most part, the results will be given in summary form, reserving the publication of detailed data and directions for a forthcoming paper to be issued by the Bureau of Standards. In recent years increasing interest has been shown in the preparation of the pure platinum metals, both by those concerned with the manufacture of the metals and their alloys for scientific and industrial purposes and those who are engaged in the study of the chemical or physical properties of the elements. The purification of the metals usually has been regarded as a matter so involved and difficult as to require the attention of specialists. It is hoped that this paper will show that any of the metals can be prepared in any desired degree of purity by relatively simple straightforward chemical methods. For the most part, it is thought that the methods given are suitable for small-scale refineries as well as for the laboratory; also, that they will bring the time required for the purification of any of the metals within reasonable limits. The new procedure suggested for purifying platinum should prove to be much shorter than any methods described in the literature.

Jan 1, 1928

By Oswald J. Heinrich

THIS question having been repeatedly raised, and particularly revived in a discussion at the last meeting of the Institute, I beg to submit the following remarks, based partly upon personal experience, partly upon the results of large works in Europe, establishing, years ago, the practicability of certain methods, which may therefore be considered to have passed the stage of mere experiment. Before entering upon the merits of one system or the other, it is indispensable to lay down some recognized principles, which ought to serve as guides, in arriving at fair judgments in questions of this character. In a profession like that of mining, locally so much influenced by combinations of circumstances too various to mention, it is difficult to do more than lay down the main features of a system based upon general laws and recognized facts, leaving the details to the sound judgment and experience of the engineer, who, by virtue of his education, ought to be able to make such choice and such modifications in the plans of a mine as the particular case demands. Mineral resources, in some countries the sole property of the owner of the soil, in others controlled by the strong hand of a government, are nevertheless a gift of nature, in which, indirectly, the whole of the human race has as real an interest as the immediate owner himself. This interest requires, at least, that no unnecessary waste of

Jan 1, 1874

By H. Conrad, E. Stofel

The fracture behavior of 60-deg-oriented sapphire crystals was investigated for both tension and compression. Plastic flow on the basal plane was found to be a factor in reducing the tensile stress required to produce fracture in the temperature RECENT experiments1-' have shown that single crystals of a alumina (sapphire) can deform plastically, particularly at temperatures greater than 1000°C. The effect of this plastic flow on the fracture behavior of sapphire was not established, but range 1100º to 1500ºC. Mechanical twins, both (0001) and (0111) types, were produced by compression in the temperature range 1100" to 1300°C. Cracks propagated more readily along the twin boundaries than in the nontwinned crystal. experiments with other ceramic crystals4'5 have shown that plastic flow can initiate cracks that lead to catastrophic failure. This suggests by analogy that plastic flow might also be an important factor in the fracture of sapphire crystals. A recent experimental investigationS undertaken to determine the mechanism of plastic flow in sapphire provided an opportunity to study the type of fracture produced after various amounts of plastic shear strain. The results of this study of fracture are reported in the present paper. During the course of

Jan 1, 1963

By F. E. Harris

IT has been said that carbon is "ubiquitous" with reference to iron alloys. Certainly at temperatures where carbon and iron form the solid solution, austenite, it may be readily added to, or removed from, steel surfaces. Differences in concentration potential are the sole requirements for carbon flow. To measure the rate of carbon flow, a proportionality factor, D, is arbitrarily expressed in units of (length)2 X (time)-1. If the term used for carbon concentration is weight pct C, as is customary, then a factor must be found, changing this term to one of weight per unit volume when the diffusion coefficient, D, is used in flow formulae. The determination of D values for carbon is complicated since D varies with the concentration itself. The Matano method has often been employed for systems involving a variant D. This method expreses an evaluation of unsteady flow whereby .0 is given a relationship with the numerical value of C-X slopes. The author contends that this solution is incorrect, except when D is invariant. The primary purpose of this paper is to support this contention. Here diffusion is controlled under two conditions of flow. The first part deals with the steady state; the second part considers unsteady flow under definite restrictions. Beginning with the fundamental concept, the development is continued until equations for C-X curves are obtained. The solution is then subjected to experimental data. It is realized that a great amount of reliable data is required for a rigorous proof. No such research is claimed. Instead an attempt is made to set forth the physical significance of the diffusion mechanism, and particularly to express the factors which influence the flow of carbon in austenite. Of equal significance is the implication that gaseous media may be employed with reasonable accuracy in making these determinations. THE STEADY STATE DIFFUSION OF CARBON IN AUSTENITE The fundamental experiment defining diffusion in solid metals may be readily performed for carbon in gamma iron.1 For this experiment a thin plate of medium carbon steel is chosen. The surfaces of this plate may be taken as two parallel planes which may be considered infinite for points well in the center of the planes. These two planes are held at different concentrations of carbon at a constant temperature. This temperature, 1700°F for example, is one where the single phase, carbon in solution with gamma iron, exists. When these conditions are held for a sufficient time the concentration of carbon of the different points of the solid settles down towards its steady state value. At points well removed from the ends, the concentration will remain the same along planes parallel to the surfaces of the plate.

Jan 1, 1947

The American Mining Congress, 841 Munsey bldg., Washington, D. C. J. F. Callbreath, Secretary. The American Mining Congress is a trade association rather than a technical society and as such does not issue scientific papers. Aside from the articles appearing in the monthly Mining Congress Journal, and the Proceedings of the Annual Meetings, only two works have been issued. They are: The standard handbook on mining methods, practice and equipment. $3.

Jan 1, 1933

By George S. Rice

IN other countries, research involving testing in various phases of ground movement and lessening its damaging effects, as by roof control, is going on more intensively than in this country, as evidenced by official mining papers and general articles appearing- in .Great Britain, Germany, France, and South Africa. One most important bulletin, "Some Aspects of Deep Level Mining on the Witwatersrand Gold Mines with Special Reference to Rock Bursts,"' was published by the Association of Mine Managers of the Transvaal, Johannesburg, under date of June, 1933, though not received in this country until 1.934. Since the deepest mining in the world is being done on the Rand-several mines over 7000 ft. deep and the Robinson mine 8000 ft.-the studies made are of intense interest to all mining men who have to deal with heavy ground pressure. In the discussion following the papers differences of opinions are shown on a number of problems; for example, on the ade¬quacy of sand-filling to prevent rock bursts and whether compressible or rigid artificial supports are best; also whether pressure bursts are due to the doming of strata and collapse of a lag of the dome or to induced shear cracks in the hanging wall. The problem of obtaining some means of warning of an impending rock burst led to testing with height indicators to find whether warning might be obtained by the lessening of distance between hanging wall and footwall. The indicators used are similar in idea but not in detail to the "convergence recorders" developed by the Safety in Mines Research Board of Great Britain for their roof-control studies in coal mines. Success at several Rand mines is claimed in that indicator records give some degree of warning when the lessening of height is rapid, although, on the other hand, when this happens bursts do not always occur.

Jan 1, 1935

By Leo J. Vogel, E. D. Hummer

INTRODUCTION by E. D. HUMMER An efficient refuse-disposal system is a necessary part of the modem cleaning plant. The large-scale refuse system and disposal area, engineered for the lifetime of the plant, has become more important due to the greater tonnages of refuse produced from increased quantities of mechanically mined and prepared coal. Laws and increased government regulations have affected the design and operation of disposal systems. THE EFFECT OF MINE AND PLANT OPERATION Refuse disposal starts at the mining face. The mining system, the type of roof support, the machinery used, and the degree of discipline at the face contributes to the amount and type of refuse that must be removed through the disposal system. Economies gained through modification of the mining system or mining machinery may be partially offset by increased dilution of the mined coal with impurities from associated rock formations. In some cases the change in the mining system and equipment has reduced the dilution. In all cases the ratio of impurities that must be removed from the raw-coal feed to the plant not only affects the maintenance and operating costs of the plant, but greatly affects the design of the refuse disposal system. The design of a mine and plant should include the location and the estimated capacity of the disposal areas for the life of the property or plant. Complete evaluation of the disposal system and an estimate of its annual cost of operation over the life of the property or plant should be incorporated in the plant and mine evaluation. Plant design should be as simple as possible, consistent with the efficient production of clean coal. Material transfer points, crushing, screening and pumping operations should be kept to a minimum to reduce degradation and the subsequent increased difficulty and cost of refuse removal. The maintenance of good process control by operating management will result in a minimum of misplaced material in both refuse and clean coal. Reduction of misplaced float material in the plant refuse is an important factor in preventing combustion in the refuse storage pile. THE REFUSE DISPOSAL AREA Combustion in refuse piles occurs when air enters the pile in sufficient quantity to support oxidation. At certain rates of air in-filtration, the heat produced by the oxidation process is not dissipated and temperature rises.

Jan 1, 1968

By C. R. Holmgren

A large consolidated sand core was used in this investigation. Four groups of experiments including gas drives, water drives, and water drives combined with gas injection, were made. The results of the gas-drive experiments indicate that greater ultimate recovery may be obtained by higher pressure gradients. However, other considerations challenge the absolute veracity of this conclusion. Results indicate that with connate water present and a low pressure gradient during a gas drive, less gas is required to produce a given amount of oil. The saturation gradient determined during a gas drive is presented. Results of the water-drive experiments indicate that the recovery of oil is not a function of either gradient Or input rate. The presence of initial gas saturation resulted in a slightly lower final oil saturation. Injection of sufficient gas to maintain the initial gas saturation during a water drive resulted in lower final oil saturation. Introduction With the demand for petroleum products reaching an all-time record high and the location and exploitation of new reserves becoming more difficult and expensive, the oil industry must look to more thorough and efficient methods of producing the petroleum already located. Much of the previous work along these lines is exploratory and suggests a more complete investigation. For example, a great amount of laboratory work has been done on flooding sands initially saturated roo pct with oil. Since sands saturated roo pct with oil rarely, if ever, exist in nature, and because the water content is a vital factor in the ultimate recovery from the sand, laboratory investigations on cores without water must be supplemented by comparable work on cores with water present.1'2 Other investigators have done a considerable amount of laboratory work using gas and water drives.3 Krutter and Day4 have reported results of investigations using cores saturated IOO pct with oil and have concluded that " the ultimate recovery obtained, using air drive, from a completely oil-saturated core depends on the pressure gradients used. The higher the pressure gradient, the greater will be the recovery until a certain Pressure range is reached above which the reward of increased recovery is much smaller for similar increments in pressure." Yuster and Day6 conclude that less gas and less time are required to produce a given quantity of oil at high pressure gradients than at low pressure gradients; they also conclude that an increase in the viscosity of the oil requires a proportionate increase in the gas needed for recovery. Their results indicate that the gas required to produce a given quantity of oil is greatly reduced by the presence of connate water. R. C. Earlougher2 concluded, based on results of water-flooding a large number of

Jan 1, 1949

By C. A. Mitke

In the Southwest, mcchanical ventilation of metal mines has been receiving consideration for many years. The United Verde Copper Co., in Jerome, has used large mine fans for ventilation and fire-fighting purposes for at lcast 15 years, while the Copper Qucen Branch of the Phelps Dodge Corpn. commenced installing mechanical ventilation in its various divisions 10 years ago.' Since then, with few exceptions, every large mine in this part of the country has installed and put in operation a mechanical ventilating system. The properties of some of these companies consist of from two to six divisions, or separate mines, each of which requires an independent ventilating system. In other words, thirteen copper mining companies, with an aggregate tonnage, when operating at capacity, of approximately 50,000 tons a day, have installed mechanical ventilating systems in their mines. All these mines are within a radius of approximately 200 miles, which constitutes the largest copper-producing area in the world. The capacities of mechanical ventilating installations in these mines range from 100,000 to 300,000 cu. ft. of air per minute, depending on the size of the mine, character of the workings, tonnage produced, etc. The latter varies from 300 to 20,000 tons per day. The mines include both high- and low-grade deposits, the greatest depth of the former, at present, being approximately 2500 ft.; and of the latter, 1200 ft. The volumes of air at present being coursed through the mines are from 60,000 up to 225,000 cu. ft. of air per minute,which, in their relation to the undcrground working force, range from 200 to 800 cu. ft. of air per man, per minute. While not to be taken as criteria, these figures are indicative of the character of the ventilation furnished.

Jan 1, 1923

By C. A. Mitke

In the Southwest, mcchanical ventilation of metal mines has been receiving consideration for many years. The United Verde Copper Co., in Jerome, has used large mine fans for ventilation and fire-fighting purposes for at lcast 15 years, while the Copper Qucen Branch of the Phelps Dodge Corpn. commenced installing mechanical ventilation in its various divisions 10 years ago.' Since then, with few exceptions, every large mine in this part of the country has installed and put in operation a mechanical ventilating system. The properties of some of these companies consist of from two to six divisions, or separate mines, each of which requires an independent ventilating system. In other words, thirteen copper mining companies, with an aggregate tonnage, when operating at capacity, of approximately 50,000 tons a day, have installed mechanical ventilating systems in their mines. All these mines are within a radius of approximately 200 miles, which constitutes the largest copper-producing area in the world. The capacities of mechanical ventilating installations in these mines range from 100,000 to 300,000 cu. ft. of air per minute, depending on the size of the mine, character of the workings, tonnage produced, etc. The latter varies from 300 to 20,000 tons per day. The mines include both high- and low-grade deposits, the greatest depth of the former, at present, being approximately 2500 ft.; and of the latter, 1200 ft. The volumes of air at present being coursed through the mines are from 60,000 up to 225,000 cu. ft. of air per minute,which, in their relation to the undcrground working force, range from 200 to 800 cu. ft. of air per man, per minute. While not to be taken as criteria, these figures are indicative of the character of the ventilation furnished.

Jan 1, 1923

By A. N. Chirico

This paper reviews the three major distillation processes: multiple effect (LTV) evaporation, multi-stage flash distillation and vapor-compression forced circulation evaporation. Scale preventative measures are discussed for all saline water applications. Operational data is presented on the Freeport, Texas, demonstration plant, which is the first government facility to produce one million gallons per day of fresh water for a municipality. There has been much publicity concerning the water crisis that confronts many peoples today. There is little doubt that the arid regions - which include the Middle East, parts of Africa and the Caribbean — have suffered to no slight extent for the lack of this most precious commodity. But what about our own country? Government experts have extrapolated demands and flatly predict that by 1980 we will be faced with a shortage of 80 billion gal per day. The validity of this prediction has been disputed by others; however, it appears certain that there will always be a natural abundance in some areas, a shortage of supply in other areas. Distributing our total natural water resource equitably would be impossible. Transmission of water by means of aqueducts can be an expensive undertaking. The controversial Feather River Project in Calif. is an example. The estimated cost for this venture is a staggering three billion dollars. As our population continues to increase and our standard of living rises, agricultural and industrial requirements will be proportionate. What can be done to avoid a crisis? We can conserve and use our water for industrial and irrigation purposes more judiciously: we can attempt to eliminate pollution of our natural resources from sewage and industrial wastes; we can develop, while there is time, saline water conversion processes for the massive production of low cost fresh water. The scope of this paper will be limited to only the distillation type processes that are commercially feasible. The first step in making potable water is to find a source of raw material. An inexhaustible supply is provided by oceans in coastal regions, but the supply of water is more critical in the inland communities of our country. The source of raw material in these. regions is brackish well water and this must be utilized. There is a significant process difference when handling brackish water compared to seawater and this brings out an important fact: No single conversion method can be universally applied to solve all the water problems. Composition of the raw water and degree of distillate purity are factors which must be considered before a particular process is selected. Local conditions at the plant site, fuel costs, labor costs, disposal facilities, etc. are other equally important factors which must be evaluated. WATER CONVERSION PROCESSES Conversion processes commercially feasible today are: 1) multiple effect evaporation, 2) multiple flash distillation, 3) vapor compression distillation and 4) electrodialysis. The first three are distillation processes which take potable water out of the raw water, while the fourth is a membrane process which takes out the salt. In addition to the above there are a good number of other promising methods for production of potable water, many of them in the basic research stage. Freezing is another promising process with commercial potential. This process hinges upon the formation of ice crystals which are free of salt occulsions. Separation and washing of the crystals are problems that must be solved before this process can be considered commercially feasible. Freezing processes have several advantages mostly attributable to the low temperature of operation. This low temperature reduces the scaling and corrosion problems encountered in higher temperature operations. Several different freezing processes are being considered and will be tested in the pilot plant at Wrightsville Beach. One process is a flash freeze process, a second uses a secondary refrigerant such as butane for freezing, and a third process employs a secondary refrigerant particularly controlled to produce large ice crystals. Of the above processes, only the distillation processes are reliable when water of high purity is re-

Jan 1, 1963

By Ira Joralemon

THE Ajo copper district is in the heart of the Arizona desert, near the western boundary of Pima county. Gila Bend, the nearest railroad point, is 43 miles north of the camp, and the little Mexican border town of Sonoita is 30 miles south. Between Gila Bend and Sonoita, Ajo is the only settlement save for one or two small cattle ranches and the uncertain villages of nomadic Papago families. The Little Ajo mountains rise a few hundred feet above wide desert valleys, beyond which are lava mesas. The camp itself lies at an elevation of about 1,900 ft. above sea level, in a little basin on the east side of the range, separated from the open desert by low hills. In the center of the basin the brilliantly iron and copper stained rocks of Copper mountain rise 150 ft. above -the village. Many varieties of cactus and low desert bushes cover the hills, while in the large valleys there are clusters of mesquite paloverde, and ironwood trees which furnish limited amounts of fairly good fuel. A scanty supply of water is obtained from wells in the desert and from prospect pits in the camp. The nearest abundant source of water is the Gila river, 50 miles north of Ajo. (See Fig. 1.) HISTORY OF THE AJO DISTRICT The Ajo, next to Santa Rita, New Mexico, is claimed to have been the first copper district in the Southwest worked by Americans. In the '60's or even earlier high-grade native copper and cuprite Ore was mined from shallow surface workings and hauled by bull team 400 miles across the desert to San Diego. From there it was carried in sailing ships to Swansea, Wales. Later, the ore was hauled to Yuma, floated down the Colorado river to the Gulf Of California, and shipped to Swansea. Bat-infested old workings and the massive axles of the bull carts are shown to prove the truth of the stories.

Jan 8, 1914

By Carl Zapffe

The manganese ore reserves of Lake Superior, because of their location and nature, have recently achieved a rnarked degree of importance as compared with the world's manganese reserves. To appreciate fully the significance and the adequacy of this reserve, one should understand how such ores are used, where obtainable, the quantity used, possible avenues for increasing use or application, and the chemical and physical characteristics of the available ores. Only with those data at hand, is it possible to arrive at a convincing answer to the question whether the reserves of manganiferous iron ores are adequate to satisfy the annual demand of the presently known iron ores for the full life of the latter. That they should last is vital; and to ascertain whether they will last was the purpose of the present investigation, which marks the first attempt to study these Lake Superior reserves. The Lake Superior region possesses and supplies the full assortment of iron ores needed for the conversion of ore into pig iron and steel ingots and castings. These ores are named bessemer, low-phosphorus and high-phosphorus non-bessemer, manganiferous and siliceous; and to include the term aluminiferous would be in keeping with the most recent nomenclature adopted by some dealers. About 35 or 40 years ago, perhaps less, most of the Lake Superior ore which is being used today was the material then considered either useless or too poor for immediate use; perhaps it was considered no more than a future reserve. An examination of the analyses of ores and the guarantees in the sales of those older times convince one that the opinions of those days must have been governed by only small differences in analyses. Some grades of ores used today in substantial amounts were used most sparingly only one or two decades ago. The relative quantities of the different ores used are ever changing; and, bit by bit, the metallurgy and the opinions are ever changing and the prejudices against certain ores and practices decrease. This is unquestionably more pronounced for the manganiferous ores than for any other kind. If, when using the present data for manganiferous ores, we will only be content to make allowances for the same experiences other kinds of ores

Jan 1, 1927

By J. B. Clark

The oil industry has long recognized the need for increasing well productivity. To meet this need, a process is being developed whereby the producing formation permeability is increased by hydraulically fracturing the formation. The "Hydrafrac" process, as it is now being used, consists of two steps: (1) injecting a viscous liquid containing a granular material, such as sand for a propping agent, under high hydraulic pressure to fracture the formation; (2) causing the viscous liquid to change from a high to a low viscosity so that it may be readily displaced from the formation. To date the process has been used in 32 jobs on 23 wells in 7 fields, resulting in a sustained increase in production in 11 wells. INTRODUCTION Need For Process Although explosives, acidizing, and other methods have long been used, there still exists a need for artificial means of improving the productive ability of oil and gas wells, particularly for wells which produce from formations which do not react readily with acids. This paper discusses the development of a hydraulic fracturing process, "Hydrafrac", which shows distinct promise of increasing production rates from wells producing from any type of formation. The method is also considered applicable to gas and water injection wells, wells used for solution mining of salts and, with some modification, to water wells and sulphur wells. Requirements of Process In considering such a possible process, it appeared that certain requirements must be met. Some of these are as follows: A. The hydraulic fluid selected must be sufficiently viscous that it can be injected into the well at pressure high enough to cause fracturing. B. The hydraulic fluid should carry in suspension a propping agent, such as sand, so that once a fracture is formed, it will be prevented from closing off and the fracture created will remain to serve as a flow channel for oil and gas. C. The fluid should be an oily one rather than a water-base fluid, because the latter would be harmful to many formations. D. After the fracture is made, it is essential that the fracturing fluid be thin enough to flow hack out of the well and not stay in place and plug the crack which it has formed. E. Sufficient pump capacity must be available to inject the fluid faster than it will leak away into the porous rock formation. F. In many instances, formation packers must be used to confine the fracture to the desired level, and to obtain the advantages of multiple fracturing. Development of Process As a necessary step in the development of this process, it was deemed advisable to determine if the Hydrafrac fluids were actually fracturing the formation or whether these special fluids were merely leaking away into the surrounding formation. To determine this, a shallow well, 15 feet deep, was drilled into a hard sandstone. Casing was set, the plug drilled, and the well deepened in the conventional manner. A fracturing fluid dyed a bright red was used to break down the formation. Sand mixed with distinctively colored solids was injected into the well with the fracturing fluid to prop open any fracture made in the formation. A simulated gel breaker solution dyed a bright blue was then pumped into the well to determine if the gel breaker would follow the first solution. The results are shown in Figure 1. It was noted that a fracture was formed about the well bore, that the propping agent was transported back into the break, and that the breaker solution did actually follow the fracturing gel out into the fracture. While it is realized that this shallow well test is probably not exactly equivalent to a deep test, the results were interpreted as being a definite indication of what happens down the hole during a Hydrafrac job. Of interest in this connection is an investigation reported by S. T. Yuster and J. C. Calhoun, Jr.' This study, re~orted after the Hydrafrac work was under way, presents some excellent field data supporting the theory of fracturing a formation with hydraulic pressure. METHOD Steps of Hydrafrcu: Process Figure 2 shows a simplified cross-sectional view of a well treated by one version of the process. The first step, formation breakdown, is done with a viscous fluid, usually consisting of an oil such as crude oil or gasoline, to which has been added a bodying agent. Due to availability and price, war-surplus Napalm has been used in the majority of experiments to date. Napalm is the soap which was used in the war to make "jellied gasoline". The next step consists of breaking down the viscosity of the gel by injecting a gel-breaker solution and then after several hours, putting the well back on production. Figure 3 shows diagram-matically, a typical field hookup. The oil or gasoline is unloaded into the 10 bbl. tank shown on the left rear of the truck. This base fluid is picked up by the mixing pump and pumped through the jet mixer, where the granular soap is added. Next it goes into a small mixing tub, from which the high-pressure pump takes suction. The solution is then pumped into the well. The breaker solution is then taken from an extra tank and is displaced into the well immediately following the gel. When required, additional trucks may

Jan 1, 1949

By J. B. Clark

The oil industry has long recognized the need for increasing well productivity. To meet this need, a process is being developed whereby the producing formation permeability is increased by hydraulically fracturing the formation. The "Hydrafrac" process, as it is now being used, consists of two steps: (1) injecting a viscous liquid containing a granular material, such as sand for a propping agent, under high hydraulic pressure to fracture the formation; (2) causing the viscous liquid to change from a high to a low viscosity so that it may be readily displaced from the formation. To date the process has been used in 32 jobs on 23 wells in 7 fields, resulting in a sustained increase in production in 11 wells. INTRODUCTION Need For Process Although explosives, acidizing, and other methods have long been used, there still exists a need for artificial means of improving the productive ability of oil and gas wells, particularly for wells which produce from formations which do not react readily with acids. This paper discusses the development of a hydraulic fracturing process, "Hydrafrac", which shows distinct promise of increasing production rates from wells producing from any type of formation. The method is also considered applicable to gas and water injection wells, wells used for solution mining of salts and, with some modification, to water wells and sulphur wells. Requirements of Process In considering such a possible process, it appeared that certain requirements must be met. Some of these are as follows: A. The hydraulic fluid selected must be sufficiently viscous that it can be injected into the well at pressure high enough to cause fracturing. B. The hydraulic fluid should carry in suspension a propping agent, such as sand, so that once a fracture is formed, it will be prevented from closing off and the fracture created will remain to serve as a flow channel for oil and gas. C. The fluid should be an oily one rather than a water-base fluid, because the latter would be harmful to many formations. D. After the fracture is made, it is essential that the fracturing fluid be thin enough to flow hack out of the well and not stay in place and plug the crack which it has formed. E. Sufficient pump capacity must be available to inject the fluid faster than it will leak away into the porous rock formation. F. In many instances, formation packers must be used to confine the fracture to the desired level, and to obtain the advantages of multiple fracturing. Development of Process As a necessary step in the development of this process, it was deemed advisable to determine if the Hydrafrac fluids were actually fracturing the formation or whether these special fluids were merely leaking away into the surrounding formation. To determine this, a shallow well, 15 feet deep, was drilled into a hard sandstone. Casing was set, the plug drilled, and the well deepened in the conventional manner. A fracturing fluid dyed a bright red was used to break down the formation. Sand mixed with distinctively colored solids was injected into the well with the fracturing fluid to prop open any fracture made in the formation. A simulated gel breaker solution dyed a bright blue was then pumped into the well to determine if the gel breaker would follow the first solution. The results are shown in Figure 1. It was noted that a fracture was formed about the well bore, that the propping agent was transported back into the break, and that the breaker solution did actually follow the fracturing gel out into the fracture. While it is realized that this shallow well test is probably not exactly equivalent to a deep test, the results were interpreted as being a definite indication of what happens down the hole during a Hydrafrac job. Of interest in this connection is an investigation reported by S. T. Yuster and J. C. Calhoun, Jr.' This study, re~orted after the Hydrafrac work was under way, presents some excellent field data supporting the theory of fracturing a formation with hydraulic pressure. METHOD Steps of Hydrafrcu: Process Figure 2 shows a simplified cross-sectional view of a well treated by one version of the process. The first step, formation breakdown, is done with a viscous fluid, usually consisting of an oil such as crude oil or gasoline, to which has been added a bodying agent. Due to availability and price, war-surplus Napalm has been used in the majority of experiments to date. Napalm is the soap which was used in the war to make "jellied gasoline". The next step consists of breaking down the viscosity of the gel by injecting a gel-breaker solution and then after several hours, putting the well back on production. Figure 3 shows diagram-matically, a typical field hookup. The oil or gasoline is unloaded into the 10 bbl. tank shown on the left rear of the truck. This base fluid is picked up by the mixing pump and pumped through the jet mixer, where the granular soap is added. Next it goes into a small mixing tub, from which the high-pressure pump takes suction. The solution is then pumped into the well. The breaker solution is then taken from an extra tank and is displaced into the well immediately following the gel. When required, additional trucks may

Jan 1, 1949

By AIME AIME

FOR the development of a mine, a shaft of small cross-section is usually sunk, of no larger size than is absolutely necessary. After the mine has been developed and put on a production basis it is a common practice to sink a shaft of larger cross-section for hoisting and use the original shaft for the handling of men and material into the mine. While that ar¬rangement is usually expedient, the small size of the supply cages presents a problem in the handling of ma¬terial. Where a cage is, say, 4 by 4 ft., which is not an uncommon size, all lengthy and bulky material must be handled piece by piece several times from the supply department to the underground stations. Thus drill steel and timbers over 4 ft. long will be loaded on cars at the supply department and wheeled to the shaft, where each piece must be unloaded from the cars and stood up in the cage. They are then lowered to the shaft station, unloaded piece by piece and placed in cars, run to the supply station and again unloaded and stored until called for. In such a case handling becomes a major item in the cost of supplies.

Jan 1, 1930