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By Park Wright

THE fact that granite has been encountered by the drill by those in search of oil and gas in Kansas is becoming more and more a matter of interest, not only to the oil producer but to everyone directly and- indirectly connected with the oil business. It is, therefore, time that someone should offer an explanation for its presence and form a definite opinion based on all the data available in regard to the effect it will have on the future prospects of the area affected as probable oil- and gas-producing territory. At present there seems to be no consensus of opinion. To the writer's knowledge, only one attempt has been made to explain; by Erasmus Haworth, State Geologist of Kansas, in a paper entitled Bulletin, Number Two on Crystalline Rocks in Kansas. The purpose of the present paper is to offer a theory for the presence of the granite and to draw conclusions which will aid in determining the prospective oil and gas value of the area in question. In taking up this question it will be well to consider first the tests in which granite has been reported, with a general history of each. The accompanying map (Fig. 1) shows the location of all wells described. The first well in which granite was reported was that drilled just south of Zeandale in section 27, township 10 south, range 9 east, by a local company which had taken up a block of leases in that vicinity. At a depth of 958 ft. (291.99 m.) granite was encountered. Drilling was continued to a depth of 1,093 ft. (333 m.) in the same formation, at which depth the hole was abandoned. Another well was started 1 mile east of the first well and the same rock was found at a depth of 945 ft. (288 m.). Drilling was continued to a depth of 1,200 ft. (365.76 m.) with the bit in the sane formation. Samples of the drill cuttings have been examined and they are undoubtedly crushed granite. The next well in which granite was found was that drilled by DeLaat and Shepard, independent wildcat operators, in section 34, township 19 south,. range 7 east, near the town of Elmdale. Granite was struck at 1,707 ft. (520 m.) and the hole was abandoned in the same formation at 2,525 ft. (769 m.). Mr. DeLaat watched the drilling of this well very closely and he has described to me in some detail the formation immedi-

Jan 8, 1917

By J. B. Hedrick

In 2004, rare earths were not mined in the United States. The major supplier, Molycorp, continued to maintain a large stockpile of rare-earth concentrates and compounds. Major uses for these commodities were in automotive catalytic converters, petroleum fluid-cracking catalysts, permanent magnets, glass-polishing compounds, ceramics, metal-alloying additives, phosphors and rechargeable batteries. Consumption of refined rare-earth products decreased. The United States was a major importer and exporter of rare earths in 2004. Yttrium was not mined or refined in the United States in 2004. Imports from China, France and Japan accounted for most of the U.S. supply of yttrium compounds for refined yttrium products.

Jan 1, 2005

By J. W. Thompson

OWNERSHIP OF ORE-CONSTRUCTION OF CONTRACT. A contract between the Republic Mines Corporation and the Quilp Gold Mining Co. provided that upon forfeiture of its rights under a contract the Republic Mines Corporation was required to give a good and sufficient deed conveying to the Quilp Gold Mining Co. all ore bodies of every description lying east of the west line of the Quilp Mining Co. claim extended downward vertically and lying south of the north end line of the Quilp claim extended downward vertically and which may apex within the lines of the Surprise, an adjoining mining claim. It must be presumed that the contracting parties under such circumstances had in view their statutory rights as provided by the mining statutes of the United States, and that both were familiar with the provisions as to extra- lateral rights granted by the statute to locators of mining claims. This contract means to include all ore bodies of every description lying east (or easterly) of the west (or westerly) line of the Quilp claim extended downward vertically and south (or southerly) of the north end line of the Quilp claim extended downward vertically within the Quilp claim excepting the part that was overlapped by the Surprise claim, owned by the Republic Mines Corporation. Quilp Gold Min. Co. v. Republic Mines Corp. (Washington), 165 Pacific 57, p. 61. PURCHASE OF GAS-REFUSAL TO DELIVER SALE TO OTHERS. A gas company that had entered into a contract to purchase a quantity of natural gas refused to receive and accept the gas that was tendered on the ground that it did not conform to the requirements of the contract; subsequently the company refused to sign a writing by which it was asked to consent to the sale of such gas to other persons. But the refusal of the purchasing company to sign such a writing giving its consent or its refusal to consent to such sale did. not affect the rights of the seller to dispose of the gas elsewhere and to other persons. OWNERSHIP OF MINERALS IN HIGHWAY. All mineral deposits within the limits of a highway belong to the owner of the fee and he is entitled to remove them so long as he does not interfere with the public use of the highway. City of Scranton v. Scranton Coal Co. (Pennsylvania), 100 Atlantic 813, p. 819. SALE AND CONVEYANCE. SALE AND CONVEYANCE EXCEPTION AND RESERVATION. The owner of an undivided interest in oil and gas lands conveyed the same to certain named grantees by deed containing a clause excepting and reserving all the oil and gas produced from the undi- vided interest in the land described. The language is not apt for the creation of either an exception or a reservation, but is rather that of a layman unfamiliar with legal distinctions. Strictly and literally construed, it affords a basis for a contention that that which was excepted and reserved was not realty in any form or anything inci- dent thereto, but personalty produced from the land. Immediately following the description of the tract, the grantor excepted and reserved something from the land described. What he excepted and reserved, he excepted and reserved then, and it was from his interest in the land. The clause expressed according to the evident intention of the grantor would read: "Excepting and reserving from the above all oil or gas which may hereafter be produced therefrom." No other construction can reasonably be placed upon the language used. The carving out of a separate estate in the oil and gas in land is a common occurrence in oil and gas producing fields. Mandle v. Gharing (Pennsylvania), 100 Atlantic 535, p. 536. RESERVATION CONSTRUED AS AN EXCEPTION. Where apt words of reservation are used in a deed they will be construed as an exception where this is the evident intention of the parties to the instrument. Although an exception and a reservation differ in legal effect, yet in their creation there is no magic in words, and if the meaning is clear either expression will operate for the purpose designed. The technical distinction between an exception and a reservation is frequently disregarded in the ordinary use of the word, and whether the language used creates an exception or a reservation must be determined from the intention of the parties ascertained from the entire instrument.

Jan 1, 1917

By Mirian Mamani

El presente texto describe una base de datos geológica que comprende: geología integrada, estructuras definidas en campo de mediciones y edades en actividad, ocurrencia de minerales metálicos, mediciones de aeromagnetometría y geocronología de rocas ígneas y metamórficas donde es importante delimitar los dominios geotectónicos para la exploración de yacimientos. En ese sentido, el presente texto describe las nuevas zonas propicias para la exploración en el sur del Perú a través de la identificación de fallas corticales y dominios geotécnicos dentro del proyecto GR1: Geología de la Costa Sur y vertiente oeste de la Cordillera Occidental de la Dirección de Geología Regional del Ingemmet.

Feb 1, 2012

Distribution of Settling Velocity of Irregular Particles and its Effect on Jig Separation Efficiency

Sep 13, 2010

By Neil Schofield

"The Pine Creek gold mineralization is associated with saddle reefs and quartz and quartz sulphide veining within the Enterprise Anticline. The anticlinal structure is complex and the mineralization was considered prior to development to be dominantly strata controlled. Gold grades vary up to 160 gin 1.5 m core samples with coefficients of variation in excess of three.The estimation of ore reserves for such a deposit must account for both the geological complexity and the extreme variability of gold grade.This paper describes the structural and variogram analysis of the gold grades and demonstrates the importance of incorporating the geological model in such an analysis. Variogram interpretation is greatly improved and greater insights into the finer geological structure areprovided. Part 2ofthis work presents the application of multigaussian kriging to reserve estimation for deposits with highly variable grade and which consequently demand highly selective mining operations. IntroductionThe Enterprise Gold Mine is situated some 220 km southeast of Darwin in Australia's tropical north. Gold is believed to have been discovered there in 1869 during the construction of the overland telegraph line.From 1894to 1915, some 75 000 ounces of gold were produced from 121 000 tonnes mined mainly by Chinese leaseholders. From 1906 to 1915, government-sponsored drilling led to the sinking of the Enterprise Shaft to 79 m and several drives were developed. Mining ceased because of war.Since late 1980, Goldfields Exploration Pty. Ltd. had explored on several mining tenements near Pine Creek under joint venture with the title holders, Enterprise Mines NL. This work culminated in the development of the current mine which opened on October 29, 1985.Feasibility studies to determine the economic viability of mining were based on ore reserves generated by project geologists using a sectional polygonal approach tuned to the interpreted geological control of the mineralization.The study motivating this two-part paper covers are-estimation of the recoverable reserve s using the geostatistical approach of multigaussian kriging developed at Stanford University, (Verly, 1984)."

Jan 1, 1988

By Duberney Hincapié-Ladino

O presente trabalho estuda os parâmetros de permeabilidade de hidrogênio de um tubo API 5L X80, e uma chapa de aço grau X80, onde a principal diferença está na composição química, o primeiro contém 0,07%C e 0,04%Nb e o segundo 0,04%C e 0,102%Nb. As amostras foram cortadas com espessura de aproximadamente 1 mm, lixadas e recobertas com um filme de níquel, em uma das faces. Nos ensaios de permeabilidade foi utilizada uma célula modificada tipo Devanathan-Stachurski, com a solução A da norma NACE TM0284, com injeção de H2S no lado de geração e 0,2M NaOH no lado de detecção. As curvas de corrente em função do tempo obtidas passaram por tratamentos matemáticos (método tlag), permitindo a obtenção dos parâmetros de difusividade aparente, concentração máxima de hidrogênio e número de traps (sítios de ancoramento). Tais parâmetros mostraram-se iguais para os dois materiais. As curvas foram normalizadas e modificadas de maneira a eliminar o efeito da espessura das amostras. Estas novas curvas foram comparadas com o modelo teórico da segunda lei de Fick. A comparação evidenciou que o procedimento inicial para a obtenção dos parâmetros de permeabilidade mostra-se eficiente e vantajoso por apresentar maior praticidade. Pôde-se concluir que a semelhança no comportamento dos parâmetros de permeabilidade foi devida às similaridades nas suas microestruturas. Os resultados obtidos no presente trabalho evidenciam que o tipo e quantidade de traps nestes materiais são determinados pela microestrutura.

Aug 17, 2017

By W. W. Roepke

One phase of Bureau of Mines research deals with reduction of primly respirable dust generated by bit cutting action at a coal seam face. This paper presents a summary of coal cutting technology addressing this problem. All aspects of the cutting system affecting miner health and safety are discussed. Cutting design concepts are considered that minimize dust generation, energy used, and Ignitions, while maintaining production. With present equipment, an operator can maintain production and minimize dust energy and conditions by cutting at maximum depth (maximum sumping or advance rate) at all times, at minimum rpm with fewest possible bits, and with lowest possible included bit tip angle, i.e., minimum bit wear.

Jan 1, 1985

By T. Alan O'Hara

"Annual mining revenue can be computed by formulae relating metal prices, smelting schedules, concentrate grade and recovery to known ore grade and an assessment of core samples. Operating costs at different daily tonnages are related to orebody shape, mining method, milling process and general plant services. Capital costs are related to sizing of mining equipment, mine development, plant-site topography, climate and accessibility, plant services and personnel housing. IntroductionA crude guide to the average 1978 cost of mine projects is shown in Figure 1, but the costs of many mine projects have differed widely from the graphed average costs of $800,000 T0.6 for underground mine/mill projects and $400,000 T 0.6 for low-grade open-pit mine/mill projects.High mine project costs and high operating costs are characteristic of open-pit mines with high stripping ratios, underground mines with thin orebodies, mills with complex metallurgy, and projects located in isolated regions with severe climate, mountainous topography, and lacking access to existing roads, towns and electric power. When none of these adverse conditions prevailed, the mine project cost was typically much less than the graphed average cost. Virtually all the conditions likely to cause high capital and operating costs are known from knowledge of the local topography, climate or accessibility, or can be assessed by tests on core samples, as soon as the orebody has been outlined by drilling .A more accurate estimate of over-all project capital cost and operating cost can be made from a summation of items of cost after judging the effect of specific local conditions on each item of capital and operating cost. This paper offers guides in judging the effect of local conditions on the sizing and 1978 cost of specific items of capital cost and operating cost and operating cost of mine projects. When the specific items of capital cost and operating cost are totaled and measured against expected net revenue and taxes over the life of the mine using the net-present-value or discount-cash-flow methods, the result should show whether the mine project development is clearly feasible, doubtfully feasible or clearly uneconomic. If the development of the mine project is clearly feasible, or probably feasible, a detailed feasibility study by experienced consulting engineers should be commissioned before any financial commitments are made; but if project development appears to be uneconomic, the time and cost of a detailed feasibility study is not warranted."

Jan 1, 1980

By Robert Anderson Cook

AS the margin of profit in the manufacture of iron continues to decrease, attention is called more and more to economies in every department. Beginning at the bottom, in the preparation of the ore at the mine, me notice a general tendency is towards the shipment of richer ores, securing to the mine-owner a better price per ton, which the purchaser is glad to pay by reason of the saving in freight of iron, and in the cost of reduction, which depends so largely upon the amount of fuel and flux, and the productive capacity of the plant. In other words, the difference in value between rich and poor ores is much greater than their relative percentages of iron indicates; because the barren material in a lean ore is not merely worthless, it is a positive source of expense, requiring transportation, handling, fluxing, smelting, and its due share of general expenses; in return for which it yields nothing and decreases the available capacity of a given plant and capital for profitable work. The enriching of the ore is done in most places by hand-picking, and in a few by wet concentration; but the managers of several magnetite mines in Sweden have been practically successful in doing it by machinery. The only magnetic separating machine which has actually taken the place of hand-picking was designed and patented by Mr. Jonas Wenström of Örebrö, Sweden. In this machine, which is illustrated in Figs. 1 and 2, Mr. Wenström has taken advantage of the property of soft iron to become magnetized by induction. The machine consists of a barrel made up of soft iron bars and some non-conducting material (usually wood), which is rotated around a stationary shaft by means of a cog-wheel. Inside of this barrel, on the shaft, is placed eccentrically a cylindrical electro-magnet, provided with a number of manges (N, S, Fig. I), between which wire is wound in such a manner that the flanges are of negative and positive polarity, being energized by a current passing through the wire coils from a small dynamo. As will be seen in Fig. 1, the flanges, N, S, are circular, and follow the internal contour of the barrel on the front side, while on the opposite side they are cut down to the line B, B' in Fig. 2. Hence the bars of the revolving barrel on the front side of the machine are mag-

Jan 1, 1889

By H. C. Vacher

THE limiting concentrations of carbon and oxygen which may co-exist at equilibrium in liquid iron are important in determining the degree to which liquid steel may be refined before it is deoxidized. Most refining processes depend upon the oxidation of a highly carburized iron which invariably results in contaminating the steel with oxygen. The oxygen .thus introduced presents many problems to the refiner, who in turn has attempted to rid the steel of this impurity by deoxidation with elements such as manganese, silicon and aluminum. The importance of the limiting concentrations of carbon and oxygen is accentuated in view of a number of recent researches which have indicated in many instances the existence of relations between oxide inclusions and dissolved oxygen and physical properties and chemical behavior of steel. The determination of the equilibrium concentrations of carbon and oxygen existing in iron under steelmaking conditions is obviously of fundamental importance. It has been generally assumed that the product of the equilibrium concentrations of carbon and oxygen in liquid iron is a constant and that this product is directly proportional to the carbon monoxide pressure in equilibrium with the liquid iron. Herty1,2 has computed values for this product based on open-hearth data which are all in the neighborhood of 0.01 to 0.03 (per cent. FeO X per cent. C) for temperatures in the vicinity of 1550° to 1600 C. and one atmosphere pressure. Kinzel and Egan3 have attempted to determine the value of this product by exposing liquid iron to carbon monoxide at one atmosphere pressure. The value reported by them was 0.0005 at 1550°. C. In. order to apply certain equations to the rate of carbon elimination in the open-hearth process, Feild4 found it necessary to assume. a value of 0.0102 at 1580° C. for this

Jan 1, 1931

By A. M. Gaudin

The study that is presented here was undertaken in order to condense information concerning comminution, and covering a great variety of conditions, into one or several rules which would be of use in the development of a systematic theory as well as in many directly practical ways. As the result of this work, the following conclusions appear justified: 1. Rocks may be classified, from the point of view of comminution, into two general classes which are (a) structurally homogeneous, and (b) structurally heterogenous. Structurally homogeneous rocks are those in which fracture takes place through grains and grain boundaries alike; heterogeneous rocks are those in which fracture passes in preference through grain boundaries. 2. If a sized product composed of structurally homogeneous rock grains is crushed, a product results in which the relation between the percentage weight of grains of various sizes and these sizes themselves follows a definite law. This is not true of structurally heterogeneous rocks. 3. Ball milling with structurally homogeneous rocks, and under certain conditions, presents exceptions to this rule. 4. In ball milling with structurally homogeneous rocks, there exists a critical ratio of size of feed to size of balls, above which the machine operates essentially by surface wear, and below which it operates essentially by breaking across the body of the particle. 5. In ball milling, with structurally homogeneous rocks, and when the size of feed grains exceeds the critical size, the particles worn off are of a substantially definite size which depends upon the ball size. 6. In the case of a typical heterogeneous rock, such as Manhattan schist, particles are crushed in such a way that there is a greater proportion of grains of the size that is the average grain-size of the rock than there would be in that range of size with a structurally homogeneous rock. This has been found to be true with all the crushers tested. 7. Different methods of crushing produce grains of different shapes. 8. The importance of sizing the — 200-mesh portion of a crushed product, in crushing-efficiency investigations, has been greatly under-

Jan 1, 1926

By J. Torma-Krajewski, M. Lehman

In 2005, NIOSH and Badger Mining Corporation entered a partnership to implement ergonomic interventions, including a systematic process, to address exposures to risk factors that may result in musculoskeletal disorders or other types of injuries/illnesses. As a result of this partnership, an ergonomics process was integrated with the existing safety and health program to promote an on-going application of ergonomic principles, and over 40 task-specific interventions were implemented during the first year of the process. This paper presents details of the process integration, and several examples of task-specific interventions that reduced exposures to risk factors.

Jan 1, 2007

By C. Richard Tinsley

SUMMARY A detailed analysis of nickel, copper, and cobalt recovery from manganese nodules shows simple rates of return of 9-15% in 1985. A sulfur dioxide roast process yields a slightly better return than an ammonia leach technique. Nodule tonnage predictions tend to be over-optimistic and more conservative forecasts show that market penetrations are only significant for cobalt and manganese. However, cobalt prices are unlikely to fall to the level of nickel. Between now and 1985, cobalt is expected to be in balanced to tight availability. INTRODUCTION Deep-ocean manganese nodules are one- to two-inch concretions which cover 2040% of large areas of the ocean bottom. Commercial targets far these black, potato-like nodules are located in the North Pacific at water depths of 5,000-6,000 m. in a belt roughly midway between Hawaii and Mexico. However, good grade nodules are not solely limited to this belt as areas southwest and northwest of Hawaii, as well as in the Indian Ocean, contain concentrations of acceptable grade manganese nodules. Some 90% of the nodules are found half-buried on the deep ocean bottom. A siliceous-ooze host soil combined with low sedimentation rates, certain ocean currents, and possible geo- thermal effects are favorable factors far nodule formation. The viewpoints and analyses in this paper are the author's own and should not be attributed in any way to Amoco Minerals Co.

Jan 1, 1976

By Giovanni B. Barla, Stefan H. Boshkov

The block caving method is examined in this paper on the basis of experimental results and observations in the field, and through the use of numerical modeling by the Finite Element Method. The Grace Mine, developed by a panel caving method, served as a reference case. However, the results obtained and the simulation techniques which have been developed may find useful application in more general conditions as encountered in other mining operations by block caving. Following a brief description of the Grace Mine and of the mining method, the problems associated with the behavior of underground drifts at the production levels, during undercutting and caving, are addressed. The most important results obtained through monitoring of strains and loads in the supports of a runway are discussed, while giving relevance to the sequence of mining operations in the immediate vicinity. The most important geomechanical data, as provided for subsequent modeling, are described with reference to: (a) rock mass characterization and (b) in situ state of stress. Then, the numerical modeling procedures, developed by the Finite Element Method in order to predict the caving phenomena and the behavior of underground openings during undercutting, are discussed. Finally, an attempt is made to compare the pre- dictions of the numerical analyses with, the measurements carried out at the instrumented site. Suggestions as to how to improve the results both qualitatively and quantitatively are also given.

Jan 1, 1984

By E. Yalçin, A. Ünal

In transitional mineralization, the sill of the underlying variogram is relatively easily estimated, but the estimation of the nugget effect may be more difficult. This study aims to determine for massive copper deposits just how sensitive the estimations of ore reserve, economic copper content, total net value, and ultimate pit limits are to the errors of estimation in the nugget effect of the spherical variogram model. A massive copper deposit which has a log-normal distribution and a spherical variogram was simulated on a rectangular grid using the turning bands method. By using the three dimensional random kriging method, the mean block grades were estimated at four different sampling densities. The ultimate pit-limits were determined by using the two-dimensional dynamic programming algorithm. To calculate the estimation errors, the values obtained by using the actual nugget effect and structured component values were deducted from the estimations obtained using the incorrect nugget effect and structured component values. For isotropic massive copper deposits, it was found that the ratio of the nugget effect to the structured component of the spherical variogram has no significant effect on either the block grades estimated by the kriging method or on the ultimate pit limits.

Jan 1, 1992

By Andrew R. Swanson

An experimental study of the process parameters controlling the selective agglomeration of raw coal slurries is described. Particular attention has been paid to the influence of input variables on agglomerate size and process kinetics. These factors were considered to be of paramount importance as they determine the selection and sizing of the process equipment. The variables studied include oil addition, pulp density, agitation rate and particle size of the feed. The results have been qualitatively interpreted in terms of a classical reaction kinetic model.

Jan 1, 1977

By L. A. Norman

ANOTHER chapter in the history of Mother Lode mining is being written by operations in the Old Eureka mine near Sutter Creek, Amador County, California. During a two-year period (1938-1939), 85,517 tons of ore averaging 0.62 oz. gold per ton were mined and milled, as compared to the production of approximately 210,000 tons of 0.315-oz. gold ore during the preceding seven years. This is a repetition of mining history in the Mother Lode, where a period of prosperity has followed a long period of lean production. The location of this new ore in the hitherto unproductive hanging-wall greenstones and its mining and geological developments are most interesting. HISTORY OF THE OLD EUREKA MINE The Old Eureka mine, also known as the Hayward, Eureka, Hetty Green and Amador Consolidated, is in the most productive 10-mile length of the 120-mile long Mother Lode of California. The mine was first opened in 1852 with operations more or less continuous for the next 30 years. Production during this period amounted to $12,000,000 from an ore shoot 500 ft. long, which bottomed 1700 ft. below the surface. The shaft was continued as a prospect to 2065 ft. on the incline, where work was stopped in 1881. The mine was sold in 1916 by Hetty Green and the shaft deepened to the 3500-ft. level (3212 ft. vertically) by the new owners. Drifts were run on the 1700, 2100, 3000 and 3500-ft. levels, together with approximately 1500 ft. of crosscuts. No ore was found and work was abandoned in 1921. The present owners, the Central Eureka Mining Co., purchased the mine in 1924 after threatened litigation over rights to the rich ore shoot being mined from the lower levels of the Central Eureka mine on the south. Rehabilitation of the shaft commenced in 1926 and in 1930 mining on the old 2100-ft. level was started. While efforts of the previous owners had been directed for the most part toward the area south of the Old Eureka shaft and adjacent to the productive Central Eureka mine, the present owners started drifting northward on the old 2100-ft. level. On the 2000-ft., 2100 and 2300-ft. levels, drifts were run in part along the

Jan 1, 1939

By K. Biswas, F. C. Felipe

Paste backfill, because of its colloidal or water-holding properties, does not produce run-off water when placed underground. Paste backfill is generally, prepared from relatively low water content, full mill tailings with a certain proportion of ultra-fine particles and mixed with cement, thus producing early and better strength. Mill plant discharge tailings and other materials available at or near the mine site such as sand, aggregates or waste rock are used as blending materials in the mix design. This study investigates the influence of the above-mentioned blending materials on the mechanical characteristics of paste backfill, as well as the grading, shape, specific surface area, mineralogy and workability of the different mix design.

Jan 1, 2000

By T. E. Leontis, R. S. Busk

WORK was initiated several years ago at The Dow Chemical Company to determine the applicability of powder metallurgy processes to magnesium and its alloys. Although it was found possible to apply the normal techniques of compacting and sintering, it was discovered early that the technique of extrusion offered special promise. This technique and the alloys produced were therefore studied extensively, and the present paper is a partial report of those studies. It is expected that a second paper will discuss more extensively some of the alloy systems simply mentioned here. Although the literature on powder metallurgy is very extensive, there are only two articles dealing with magnesium13,14 and there is no reference to the direct extrusion of the powder of any metal without the preliminary step of compacting. Furthermore, no mention has been made of the possibility of designing alloys by the technique of powder extrusion, particularly alloys that cannot be made in any other way. Sauerwaldl3 discusses the extrusion of magnesium and aluminum powder to produce alloys containing nonequilibrium phases, but again he emphasizes the importance of pre-compacting before extrusion. There seems to be general agreement that some form of hot-pressing is essential to obtain in a compact the full theoretical density of the metal used.'-" The nearest approach to the technique of direct powder extrusion is that of extrusion of pre-sintered compacts,'-" for which the best review through 1944 is that by Kieffer and Hotop.11 Ensign* discussed a specialized technique of "extruding" already compacted and sintered gears for the purpose of sizing. Sauerwa1d13 discussed the compacting and extrusion of magnesium and magnesium-aluminum alloy band-saw chips. The properties of the extruded compacts were found to be comparable with those of extrusions prepared from solid billets. He also extruded a compacted mixture of magnesium and aluminum powder and found the properties to be somewhat different from those obtained on an extrusion made from a cast billet of the same composition. The second reference dealing specifically with the powder metallurgy of magnesium is Stern's patent," in which is described the extrusion of scrap chips and turnings following a hot-pressing and sintering step. Considerable emphasis in most of these articles is placed on the necessity of atmospheric protection to minimize the danger of oxidation. Experimental Procedure The first experiments were made with the small extrusion press shown in fig. 1. With this press, billets of about 1/2 in. diam are used to produce wire

Jan 1, 1951