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By Burton H. Boyum

Greater depth of exploration drill holes and increasing cost of drilling have been principal factors in reviving interest on the Mar-quette Iron Range in controlled directional drill-hole deflection. This deflection is obtained by the application of the Hall-Row wedging technique. Modifications were made in the technique and equipment in the effort to simplify and strengthen the procedure. The practice is similar in many respects to the oil well type of deflection with a whipstock. Introduction The deflection of diamond drill holes by wedging was a widespread practice in Canada, South Africa and the Lake Superior District as early as 1907 to 1920. Several basic schemes were used, with local variations.' The deflecting wedge assembly was the idea of Mr. Welldon and Mr. Payne-Gallwey operating under the supervision of Mr. William Gallagher of Johannesburg, South Africa. All schemes employed some means of plugging the old hole. A footpiece of various styles was placed in the hole on the plug. In some methods, the orientation of this piece was determined before placing the deflecting wedge. Some techniques permitted continuing the hole the same size after wedging, while others necessitated a size reduction. Interest in wedging diamond drill holes in the Lake Superior District waned after 1920. The Hall-Row patented system for deflecting holes was developed in Canada about 1918.2 Interest centers on the wedging process for the following applications: 1. Maintaining a given course and inclination of the drill hole. 2. By passing an obstruction in a drill hole. 3. Resampling an ore body. 4. Exploring an area overlain by surface conditions not favorable to drilling. During the period of 1913 to 1920, The Cleveland-Cliffs Iron Co. used the wedging technique under a variety of conditions. In general, the practice was not applicable again until 1946. Meanwhile the Hall-Row system of drill-hole deflection survived years of application as the best technique available. In the intervening years, our depth of exploration has increased as well as the overall cost of drilling. As exploration becomes deeper, there is the possible economy of cutting the ore body at a moderate distance from the parent hole without redrilling from surface. Thus a branch hole started near the mid-point of a deep hole can reach the ore horizon at a considerable offset from the parent hole. This permits a greater interval between surface drill holes as drilling becomes deeper. Our interest revived in the subject and a wedging program was initiated. General Description Results The maximum theoretical angular deflection possible, based on the deflecting

Jan 1, 1949

By Burton H. Boyum

Greater depth of exploration drill holes and increasing cost of drilling have been principal factors in reviving interest on the Mar-quette Iron Range in controlled directional drill-hole deflection. This deflection is obtained by the application of the Hall-Row wedging technique. Modifications were made in the technique and equipment in the effort to simplify and strengthen the procedure. The practice is similar in many respects to the oil well type of deflection with a whipstock. Introduction The deflection of diamond drill holes by wedging was a widespread practice in Canada, South Africa and the Lake Superior District as early as 1907 to 1920. Several basic schemes were used, with local variations.' The deflecting wedge assembly was the idea of Mr. Welldon and Mr. Payne-Gallwey operating under the supervision of Mr. William Gallagher of Johannesburg, South Africa. All schemes employed some means of plugging the old hole. A footpiece of various styles was placed in the hole on the plug. In some methods, the orientation of this piece was determined before placing the deflecting wedge. Some techniques permitted continuing the hole the same size after wedging, while others necessitated a size reduction. Interest in wedging diamond drill holes in the Lake Superior District waned after 1920. The Hall-Row patented system for deflecting holes was developed in Canada about 1918.2 Interest centers on the wedging process for the following applications: 1. Maintaining a given course and inclination of the drill hole. 2. By passing an obstruction in a drill hole. 3. Resampling an ore body. 4. Exploring an area overlain by surface conditions not favorable to drilling. During the period of 1913 to 1920, The Cleveland-Cliffs Iron Co. used the wedging technique under a variety of conditions. In general, the practice was not applicable again until 1946. Meanwhile the Hall-Row system of drill-hole deflection survived years of application as the best technique available. In the intervening years, our depth of exploration has increased as well as the overall cost of drilling. As exploration becomes deeper, there is the possible economy of cutting the ore body at a moderate distance from the parent hole without redrilling from surface. Thus a branch hole started near the mid-point of a deep hole can reach the ore horizon at a considerable offset from the parent hole. This permits a greater interval between surface drill holes as drilling becomes deeper. Our interest revived in the subject and a wedging program was initiated. General Description Results The maximum theoretical angular deflection possible, based on the deflecting

Jan 1, 1949

By William J. Craig, Harold L. Walker

INDUSTRY has for many years recognized the dependence of certain mechanical and physical properties, as well as workability, upon grain size variations in brass. Although the dependence of properties upon grain size has been recognized there are not many instances where a planned program of testing has been conducted and where the only intentional variable has been grain size. In particular the literature is limited with respect to the effect of grain- size on the endurance limit, though there are many industrial applications where the brasses are subjected to cycles of repetitive stresses. LITERATURE A number of the physical and mechanical properties of a given brass sheet, in the annealed condition, will depend upon: (I) The ready-to-finish grain size before final rolling, (2) the percentage deformation by cold working, and (3) the time and temperature of annealing, The first and second variables affect the recrystallized grain size, and the third variable affects the coalesced grain size. Gibbs1 has shown the effect of two different ready-to-finish grain sizes upon the tensile strength and hardness of deep drawing brass strip after a definite amount of cold rolling. The smaller the ready-to-finish grain size, the higher the tensile strength and hardness, but with lowered ductility, Gibbs also demonstrated, for a given time and temperature of anneal, that the tensile strength, hardness, and elastic limit are higher for the smaller ready-to-finish grain size, but the elongation is lowered, Townsend and Greenall2 have reported data which show that cold working increases the tensile strength, hardness, and load carrying ability of deep drawing brass sheet under reversed stress. Greenall and Gohn3 have reported data which show that the smaller grain sizes have higher tensile strength and hardness properties, and the data also show that increased cold working increases the tensile strength and hardness properties of deep drawing brass sheet. Kommers4 has reported data for tests of brass of known ready-to-finish grain size, a specific amount of cold reduction, and annealed at different temperatures above and below the recrystallization temperature. Kommers' results indicate that annealing below the recrystallization temperature does not change the tensile strength and hardness properties, but the endurance limit may be increased from 22,000 to 28,000 psi. The increased endurance limit is explained as resulting from the reduction of internal stresses by a stress-relief anneal. Burghoff5 and associates have reported data on creep tests, over

Jan 1, 1948

By R. J. Miller, W. A. Bates

ALTHOUGH cresylic acids have been standard frothers in flotation for many years, there has been little discussion of their nature in the metallurgical literature. Aside from references in the patent literature, the paper by Landolt, Hill, and Lowy1 in 1930, which presented a study of the frothing and collecting properties of some of the constituents of crude cresylic acids, represents the only contribution of this type. The close froth control required in the delicate selective separations of present-day flotation operations have required the flotation metallurgist to choose his frothers with care, and have caused him to require of the manufacturer a closely controlled, uniform product. A background of knowledge of the chemical composition and physical and chemical properties of the frothers, by which their action may be correlated, should aid in selecting frothers for particular flotation requirements. Further, the recent almost complete replacement in flotation of coal-tar cresylic acids by those derived from petroleum makes it especially desirable to review the flotation behavior of the acids from the old and the new sources. In view of these facts the Milling Methods Committee of the A.I.M.E. suggested to the Oronite Chemical Co. of San Francisco the preparation of a paper on the subject, and this paper has accordingly been prepared as a contribution by the California Research Corporation, the research affiliate of the Oronite Chemical Co. The discussion is from the following aspects: (I) constitution and properties; (2) sources; (3) comparison of coal-tar and petroleum cresylic acids ; (4) characteristics as frothers, with particular reference to the effect of the substitution of petroleum acids for coal-tar acids. CONSTITUTION AND PROPERTIES Cresylic acids are commonly regarded as mixtures of orthocresol, metacresol and paracresol. This was, indeed, the former meaning of the term, but in recent years it has been loosely applied to any mixture of alkyl phenols boiling above 190°C.; that is, excluding only phenol itself. This means that cresylic acids, as they are known today, may consist of mixtures, not only of the three isomeric cresols, but of six xylenols and of a variety of higher boiling homologues. Generically the constituents of cresylic acids are alkyl phenols, and they are often so designated in the literature to avoid the more indefinite term, "cresylic acids." They form an homologous series starting with phenol, which has the familiar benzene ring, with an hydroxyl group in place of one of the hydrogen atoms. The series of alkyl phenols is formed by the substitution of alkyl side chains, such as methyl, ethyl, propyl, butyl, etc., for hydrogen

Jan 1, 1946

By Arthur L. Christenson, Clarence E. Jackson

IN the establishment of the relationship between weldability and hardenability, two methods have been employed in correcting for the grain growth produced in the heat-affected zone: first, the hardenability calculated from chemical composition1 may be corrected to the grain size observed in an actual weld,2 or, second, a hardenability test may be made on the steel quenched from a temperature high enough to produce a grain size comparable to that found in the heat-affected zone.3 In order to obtain grain sizes in the end-quench hardenability bar comparable to those resulting in the base metal from the welding cycle, a quenching temperature of 2100°F. has been used. In studies of the end-quench hardenability specimen quenched from 2100°F. instead of from a lower temperature of 1700°F., it is important to ascertain the relative cooling rates for various distances along the bar. It is a question as to whether the cooling occurs at the same rate or whether there is any significant difference from the standard cooling-rate curve published by Jominy and confirmed by others.4,5 This paper reports experimental evidence concerning the effect of quenching temperature on the cooling rates in the end-quench hardenability test. The effect of quenching temperatures on cooling rates has been studied by a number of investigators.6,7 French has considered this effect from both theoretical and experimental aspects. In French's studies on complete quenching of spheres and rounds, an increase in the quenching temperature caused an increase in the cooling rate at 720°C. at the center of the specimen. The center cooling velocity also has been shown to be dependent upon the surface per unit volume for the type of specimens studied; the velocity of cooling increases with an increase in the surface per unit volume. Three methods of indicating the rapidity of cooling of a body of metal during a quenching operation have been proposed: I. The time it takes for the metal to cool from the quenching temperature to a temperature halfway between the quenching. temperature and the temperature of the quenching medium (half-temperature time): Grossmann, Asimow and Urban7 justify the use of this criterion by the fact that the half-temperature time includes the temperature and time of incubation as well as the zone of formation of pearlite and, further, the data so derived accord very closely with experimental values. 2. The time interval the metal remains in a given temperature range; for example,

Jan 1, 1943

By Leonard D. Jaffe, Donald C. Buffum

THE importance of temper brittleness in alloy steels has long been realized in Europe, In the United States recognition of its importance has developed within the last several years. Many brittle failures encountered in parts made of alloy steel are undoubtedly attributable, wholly or in part, to temper brittleness. These failures have occurred particularly at low temperatures, under shock loading, and in the presence of notches, restraints and combined stresses. It has been almost universally accepted that plain carbon steels are not susceptible to temper brittleness. As a result, considerable effort has been expended in attempts to discover the manner in which alloying elements introduce temper brittleness. It is desired to raise the possibility that plain carbon steels are not only susceptible to temper brittleness, but are much more susceptible than alloy steels, in the sense that they embrittle much more rapidly. It is suggested that previous views, (that plain carbon steels are not susceptible), are based upon an erroneous interpretation of the experimental results. INTERPRETATION OF PREVIOUS DATA For many years the standard criterion for susceptibility of a steel to temper brittleness consisted of comparison of the energy absorption, in a notched-bar impact test at room temperature, of specimens that had received two heat treatments.1 One specimen (or group of specimens) was quenched, tempered, and quenched from the temper. The other specimen (or group) differed only in having received an embrittlement treatment, which might consist of a slow cool from the tempering temperature, or of an isothermal hold in the range 450-550°C subsequent to quenching from the temper. If the energy absorption of the specimen receiving the embrittlement treatment was lower than that of the specimen not given this treatment, it was said that the steel was susceptible to temper brittleness, If the energy absorptions were the same, it was said that the steel was not susceptible. Several investigators2,3 found that plain carbon steels showed negligible difference in energy absorption in such tests (at least when their manganese content was below 0.60 pct), and concluded that plain carbon steels are not susceptible to temper brittleness. Recently the deficiencies of the criterion mentioned above have been pointed out.4-6 The criterion now generally used for susceptibility to temper brittleness retains the heat treatments used in the earlier scheme, but instead of the notched-bar impact tests being made only at room temperature, they are made over a range of temperatures, covering the transition from ductile to brittle fracture, If the transition temperature of the specimens receiving the embrittlement treatment is higher than those

Jan 1, 1948

By Howard N. Eavenson

One who has been trained in belief in the law of supply and demand and its effect upon prices finds it difficult to adjust himself to the minute regulations imposed by the New Deal, and also to the bewildering changes of government policy as expressed within a short period of time between the antitrust laws and the N.R.A., and later by the Bituminous Coal Conservation Act of 1935. A survey of the coal industry since the World War, both in this country and Great Britain, however, shows that regulation of some sort is needed if any stabilization is to be achieved and if the wage structure and economic welfare of the many communities dependent solely upon coal are to be maintained. Let us look at what has happened to the industry since 1920, which can be considered as the end of the period affected by the war influence. This discussion will be confined solely to bituminous coal, although many of the general conditions are equally applicable to anthracite, the position of which now is at least as bad as that of the softer variety. Since 1920—to the end of 1934—the production of coal has decreased from 568.7 million to 358.4 million tons, or 37 per cent; the number of mines from 14,766 to 6,258, or 58 per cent; the average annual production per mine has changed from 38,512 to 57,425 tons, or 50 per cent. The number of large mines has increased considerably, and the number of men employed has decreased from 639,547 to 458,011, a reduction of 28 per cent, while the average output per employee has changed from 4.0 to 4.4 tons, or an increase of 10 per cent. The average price per ton of coal at the mine has varied from $3.75 to $1.75. During that time wages decreased largely until 1933 and since that time have increased, until now the rates paid are considerably above those in other occupations, although the actual yearly earnings are low, because of part-time work. From 1920 to the signing of the Jacksonville wage agreement in 1924, about two-thirds of the men were union members and practically all of the nonunion mines were south of the Ohio River; with the fixing of the high wage scale of that agreement, which soon proved to be an uneconomic one, many of the mines found that they could not retain their business, so gradually changed to nonunion. By 1928 the proportion

Jan 1, 1936

By John Guillermo Bartram

The oil industry continued relatively quiet in Wyoming in 1935, although production increased about 8 per cent over the previous year; 55 oil wells were completed in 1935, compared to 34 in 1934, and at the end of the year 44 wells were drilling, 33 in proven fields and 11 in wildcat locations. The total drilling a year ago was only 30. In the year 1935 Wyoming produced a total of 13,451,000 bbl. of oil, a gain of 912,000 bbl. over the 1934 figure of 12,539,000 bbl. Approxi-mately two-thirds of the increase, or 630,000 bbl., was from black oil fields and one-third, or 285,000 bbl., from light oil pools. Salt Creek, with production of 6,357,000 bbl., is still many times the largest field in Wyoming but in 1935 it made less than 50 per cent of the state's total, after producing more than all other fields in the state for 24 years; however, its decline was only 3.8 per cent from the previous year. Oregon Basin, a black oil field, held second place again with production of 1,163,-000 bbl., a good increase over 1934. Grass Creek, with increases in both its light and black oil, jumped into third place; and Lance Creek, with its new Sundance light oil production, was in fourth place in the amount of production. Frannie, which was in third place in 1934, dropped far back on the list because of lack of market. Byron and Garland, two other black oil fields in the Big Horn Basin, increased considerably. Big Muddy, a prominent light-oil field, was down with a natural decline; and Elk Basin, also light oil, produced less because of market conditions. During 1934 only three gas wells were drilled in Wyoming and 29 dry holes, 13 in proven fields and 16 at wildcat locations. Of the latter, 5 were on wildcat structures of considerable interest. Of the 55 wells completed during the year, 53 were in proven fields and of these 17 were small ones in the shallow Osage field and 10 were light-oil wells good for 1500 to 3000 bbl. each in the Lance Creek field. Discoveries Two of the oil wells were discoveries at Medicine Bow and Sheep Creek. Medicine Bow is a very large anticline with more than 3500 ft. of closure and is located in Carbon County in the south-central part of the state. In 1923 it showed some oil in the Upper Cretaceous Frontier

Jan 1, 1936

By Wilson D. Michell

The Magma copper vein trends east-west, dips 70" south, and cuts through a 6000-ft thickness of limestones, quartzites,. shale, diabase, and schist. The vein is itself a fault with a horizontal offset of 500 ft on the formation contacts in the two walls. There are two principal faults of large displacement and numerous smaller steep and flat faults that complicate the prediction of ore occurrence. A study of the geology, its systematic recording to facitliate ready reference, and graphic methods of interpretation of mineralization have aided the exploration, development, 2nd mining of the ore. In making predictions of the distribution of mineable ore bodies and their shape in critical areas, studies are made of "mineralization contours" and "mineralization trends," which are developed on a longitudinal section of the vein from variations in the concentration of the combined base metal content as shown by assays of available openings in the mine. Introduction This paper describes an example of geological work applied directly to mining and exploration problems in a deep vein deposit, and it is presented as being of interest especially to those engaged in working more or less similar veins. In 1944 to 1945 the writer spent a year as assistant to J. K. Gustafson in a thorough geological examination of the Magma mine. Much of the writer's subsequent independent work described in the present paper had its inception in ideas originated by Gustafson during that examination. Objectives of Geological Work at Magma Mine The objectives of geological work at Magma, as at operating vein mines of a similar nature, can be summarized as follows: 1. Direct assistance to the mining department by means of predictions as to the size, shape, grade, and location of ore bodies; by solution of fault problems and irregularities in the veins; by prepara-?ion of detailed ore-reserve estimates in specific areas; by keeping a complete record of the geology and assay results in the mine; and by guiding development work. In short, geology can aid in the realization of the prime purpose of the mining department, which is that of producing the greatest amount of ore in the most economical and expeditious manner possible. 2. Guidance for exploration, especially diamond drilling, in undeveloped areas of the mine. 3. Contributions to the understanding of the general geology of the deposit and its regional setting, including ore genesis, structure, and mineral relationships. Magma Ore Deposit The east-west trending Magma vein, dipping about 70" south, cuts through a 6000-ft thickness of concordant limestones, quartzites, shale, diabase, and schist, named in descending order. These

Jan 1, 1949

By John Guillermo Bartram

The oil industry continued relatively quiet in Wyoming in 1935, although production increased about 8 per cent over the previous year; 55 oil wells were completed in 1935, compared to 34 in 1934, and at the end of the year 44 wells were drilling, 33 in proven fields and 11 in wildcat locations. The total drilling a year ago was only 30. In the year 1935 Wyoming produced a total of 13,451,000 bbl. of oil, a gain of 912,000 bbl. over the 1934 figure of 12,539,000 bbl. Approxi-mately two-thirds of the increase, or 630,000 bbl., was from black oil fields and one-third, or 285,000 bbl., from light oil pools. Salt Creek, with production of 6,357,000 bbl., is still many times the largest field in Wyoming but in 1935 it made less than 50 per cent of the state's total, after producing more than all other fields in the state for 24 years; however, its decline was only 3.8 per cent from the previous year. Oregon Basin, a black oil field, held second place again with production of 1,163,-000 bbl., a good increase over 1934. Grass Creek, with increases in both its light and black oil, jumped into third place; and Lance Creek, with its new Sundance light oil production, was in fourth place in the amount of production. Frannie, which was in third place in 1934, dropped far back on the list because of lack of market. Byron and Garland, two other black oil fields in the Big Horn Basin, increased considerably. Big Muddy, a prominent light-oil field, was down with a natural decline; and Elk Basin, also light oil, produced less because of market conditions. During 1934 only three gas wells were drilled in Wyoming and 29 dry holes, 13 in proven fields and 16 at wildcat locations. Of the latter, 5 were on wildcat structures of considerable interest. Of the 55 wells completed during the year, 53 were in proven fields and of these 17 were small ones in the shallow Osage field and 10 were light-oil wells good for 1500 to 3000 bbl. each in the Lance Creek field. Discoveries Two of the oil wells were discoveries at Medicine Bow and Sheep Creek. Medicine Bow is a very large anticline with more than 3500 ft. of closure and is located in Carbon County in the south-central part of the state. In 1923 it showed some oil in the Upper Cretaceous Frontier

Jan 1, 1936

By Wilson D. Michell

The Magma copper vein trends east-west, dips 70" south, and cuts through a 6000-ft thickness of limestones, quartzites,. shale, diabase, and schist. The vein is itself a fault with a horizontal offset of 500 ft on the formation contacts in the two walls. There are two principal faults of large displacement and numerous smaller steep and flat faults that complicate the prediction of ore occurrence. A study of the geology, its systematic recording to facitliate ready reference, and graphic methods of interpretation of mineralization have aided the exploration, development, 2nd mining of the ore. In making predictions of the distribution of mineable ore bodies and their shape in critical areas, studies are made of "mineralization contours" and "mineralization trends," which are developed on a longitudinal section of the vein from variations in the concentration of the combined base metal content as shown by assays of available openings in the mine. Introduction This paper describes an example of geological work applied directly to mining and exploration problems in a deep vein deposit, and it is presented as being of interest especially to those engaged in working more or less similar veins. In 1944 to 1945 the writer spent a year as assistant to J. K. Gustafson in a thorough geological examination of the Magma mine. Much of the writer's subsequent independent work described in the present paper had its inception in ideas originated by Gustafson during that examination. Objectives of Geological Work at Magma Mine The objectives of geological work at Magma, as at operating vein mines of a similar nature, can be summarized as follows: 1. Direct assistance to the mining department by means of predictions as to the size, shape, grade, and location of ore bodies; by solution of fault problems and irregularities in the veins; by prepara-?ion of detailed ore-reserve estimates in specific areas; by keeping a complete record of the geology and assay results in the mine; and by guiding development work. In short, geology can aid in the realization of the prime purpose of the mining department, which is that of producing the greatest amount of ore in the most economical and expeditious manner possible. 2. Guidance for exploration, especially diamond drilling, in undeveloped areas of the mine. 3. Contributions to the understanding of the general geology of the deposit and its regional setting, including ore genesis, structure, and mineral relationships. Magma Ore Deposit The east-west trending Magma vein, dipping about 70" south, cuts through a 6000-ft thickness of concordant limestones, quartzites, shale, diabase, and schist, named in descending order. These

Jan 1, 1949

By E. S. Wheeler

THE conversion plant of the Climax Molybdenum Co. is at Langeloth, Washington County, Pennsylvania, approximately 30 miles west of Pittsburgh. The molybdenite concentrates converted originate in the company's mine and mill at Climax, Colorado.1 They are delivered to the Langeloth plant by rail packed in 175-lb. bags. War production of concentrates at the mill started in 1918 but it was not until about 1920 that any peacetime uses of the metal began to develop. Early conversion of Climax concentrates was mainly into ferromolybden um, produced for the company by a custom smelter. CHRONOLOGY OF PLANT DEVELOPMENT In 1924 a small hand-rabbled roaster was built at Langeloth, the roasted concentrates being used principally in the production of calcium molybdate by a conventional wet method. The size of the original plant is indicated by the fact that during 1925 about 400,000 lb. of molybdenum was converted. In 1925-1926, a multiple-hearth roaster was erected (12-ft. o.d. 8-hearth Nichols-Herreshoff); also the first experimental ferromolybdenum was produced at Langeloth. At this time calcium molybdate was produced in the furnace by a process to be described. With continued interest in and increased use of molybdenum, it was necessary to arrange for enlargement of plant facilities. Although only one 12-hearth 16-ft. o.d. roaster was erected at this time (1929), plans were prepared for a duplicate unit, which was completed in 1935, giving a potential roasting capacity of some 16,000 lb. Mo per day under the then prevailing roasting practice. Shortly after this second unit had gone into production, increased demand overtaxed the plant, and as a result two 12-hearth 18-ft. o.d. roasters were placed in operation in 1936 and 1937. This gave the plant a potential roasting capacity of 40,000 to 50,000 lb. Mo per day, and necessitated major changes in auxiliary handling equipment as well as improved facilities for producing ferromolybdenum. Following the introduction (1938) of a new product-molybdic oxide briquets and because of the constantly growing demand for molybdenum, plant facilities were again enlarged in 1940 and 1941 by the erection of two 16-hearth 18-ft. o.d. roasters. These two new units, along with a change in roasting practice, brought the potential roasting capacity to 150,000 to 190,000 lb. Mo per day, based on about 15 lb. per sq. ft. of hearth area. Other departments of the plant have necessarily grown, until today the plant is modern throughout and completely mechanized, with equipment geared to produce marketable products as follows:

Jan 1, 1944

By Howard N. Eavenson

One who has been trained in belief in the law of supply and demand and its effect upon prices finds it difficult to adjust himself to the minute regulations imposed by the New Deal, and also to the bewildering changes of government policy as expressed within a short period of time between the antitrust laws and the N.R.A., and later by the Bituminous Coal Conservation Act of 1935. A survey of the coal industry since the World War, both in this country and Great Britain, however, shows that regulation of some sort is needed if any stabilization is to be achieved and if the wage structure and economic welfare of the many communities dependent solely upon coal are to be maintained. Let us look at what has happened to the industry since 1920, which can be considered as the end of the period affected by the war influence. This discussion will be confined solely to bituminous coal, although many of the general conditions are equally applicable to anthracite, the position of which now is at least as bad as that of the softer variety. Since 1920—to the end of 1934—the production of coal has decreased from 568.7 million to 358.4 million tons, or 37 per cent; the number of mines from 14,766 to 6,258, or 58 per cent; the average annual production per mine has changed from 38,512 to 57,425 tons, or 50 per cent. The number of large mines has increased considerably, and the number of men employed has decreased from 639,547 to 458,011, a reduction of 28 per cent, while the average output per employee has changed from 4.0 to 4.4 tons, or an increase of 10 per cent. The average price per ton of coal at the mine has varied from $3.75 to $1.75. During that time wages decreased largely until 1933 and since that time have increased, until now the rates paid are considerably above those in other occupations, although the actual yearly earnings are low, because of part-time work. From 1920 to the signing of the Jacksonville wage agreement in 1924, about two-thirds of the men were union members and practically all of the nonunion mines were south of the Ohio River; with the fixing of the high wage scale of that agreement, which soon proved to be an uneconomic one, many of the mines found that they could not retain their business, so gradually changed to nonunion. By 1928 the proportion

Jan 1, 1936

By A. T. Beckwith

THE Lehigh Navigation Coal Company Inc. operates steep-pitch, relatively deep mines in the Panther Creek Valley, at the eastern end of the southern anthracite coal field. Commercially minable coal beds are the Mammoth,† Primrose, Orchard, and Buck Mountain,‡ their respective thicknesses average 50, 15, 1o and 12 ft. Sand slates immediately overlie and underlie these beds, though in some locations sandstone or conglomerate beds occur. Underground operations extend to a depth of 1200 ft. below the surface, and comprise a bulk of virgin work on the lower levels, and a small amount of remining on the upper levels. With increase in depth, ventilation has become a more important factor. DEVELOPMENT In early days slopes or drifts were driven in the outcropping coal on the hillsides. Subsequent development was by water-level tunnels, with portals above high water in Panther Creek. These tunnels have been maintained because they intercept and drain much water that enters the mined-out portion of the bed and otherwise would follow down to the deep workings. Below these tunnels, the coal was customarily developed by slopes. Muleways, which are zigzag chutes easy to travel, were also driven to connect lower openings with the water levels. When it became necessary to go still deeper, the slopes were abandoned, and vertical multicompartment shafts were sunk from the surface. Levels have been at vertical intervals of from 195 to 250 ft. Recent practice has been toward the latter spacing; splitting the total lift, however, by starting to mine from chutes extending halfway up to the level above. Chutes customarily are spaced at 50, 60 or 70-ft. centers along the gangways. At some mines, additional shafts have been sunk from the surface to the level containing the main pumping station, and these carry the discharge lines from the pumps. As the mines are ventilated by the exhausting system, both the hoisting and so-called water shafts serve as intakes. The main fan is always on the surface, and is connected with the return airways from the various levels by an air hole or a vertical shaft. For economy, when the present deepest levels were developed, main return-air shafts or air holes were not extended to the new level, but connections were made from the new level to that above by two or more holes. It is doubtful that this method will be continued, as complications in the system, increased resistance to flow, and other difficulties undoubtedly will counterbalance any economies this provision may afford.

Jan 1, 1942

By Carl F. Floe, Michael B. Bever

THE possibility that carbon may be soluble in copper to a limited extent has been recognized for over a century. The quantitative investigation of this problem, however, requires more sensitive techniques than have formerly been available. Three recent developments have made possible more accurate determinations: the vacuum-fusion method of analysis, the production of copper of high purity and the availability of high-purity refractories, particularly graphite. In addition to its obvious theoretical interest, the problem of carbon solubility in copper is of practical importance. In the production of copper and of high-copper alloys, carbonaceous covers are frequently used. If even minute amounts of carbon are dissolved, insoluble carbon oxide gases will be formed when such metals are poured under oxidizing conditions. A mechanism of this kind could well be one of the principal causes of gas porosity in casting copper-base products. REVIEW OF LITERATURE In 1823 Vivian1 raised the question as to whether copper by overpoling becomes "combined with a minute portion of carbon." Karsten2 asserted, in 1832, that carbon reduces the high-temperature strength of pure copper, so that when the carbon content has reached 0.2 per cent the metal will be brittle at a dark red heat. According to Karsten, carbon contents of o.05 per cent make it difficult to hot-work copper. He also reported that the specific gravity of copper is 8.8969 and that it increases to 8.92 58 if the copper is cemented with carbon and then melted. He emphasized the difficulty of determining analytically the small amounts of carbon present in copper. The metal was removed by wet methods and the residue considered as carbon. At Percy's request, Dick,3 in 1856, carried out various working tests on copper that had been in prolonged contact with carbon, and found that the working properties of the metal had not been affected. He also attempted to determine the presence of carbon analytically. In one experiment the copper was dissolved and the residue was fused with litharge, and in another essentially a combustion analysis was made on a copper sample. In a final experiment, a sample was dissolved and the residue subsequently subjected to a combustion analysis. Indications of as much as o.005 per cent carbon were found, but Dick considered his work inconclusive largely because of the possible interference of sulphur. Percy4 concluded, from Dick's experiments and from some experimental work of his own, that the solubility of carbon in copper had not been established with

Jan 1, 1945

By Michael B. Bever, Carl F. Floe

he possibility that carbon may be soluble in copper to a limited extent has bten recognized for over a century. The quantitative investigation of this problem, however, requires more sensitive techniques than have formerly been available. Three recent developments have made possible more accurate determinations: the vacuum-fusion method of analysis, the production of copper of high purity and the availability of high-purity refractories, particularly graphite. In addition to its obvious theoretical interest, the problem of carbon solubility in copper is of practical importance. In the production of copper and of high-copper alloys, carbonaceous covers are freauerltlv used. If even minute amounts of carbon are dissolved, insoluble carbon oxide gases will be formed when such metals are poured under oxidizing conditions. A mechanism of this kind could well be one of the principal causes of gas porosity in casting copper-base products. Review of Literature In 1823 Vivian1 raised the question as to whether copper by overpoling becomes "combined with a minute portion of carbon." Karsten2 asserted, in 1832, that carbon reduces the high-temperature strength of pure copper, so that when the carbon content has reached 0.2 per cent the metal will be brittle at a dark red heat. According to Karsten, carbon contents of 0.05 per cent make it difficult to hot-work copper. He also reported that the specific gravity of copper is 8.8969 and that it increases to 8.9258 if the copper is cemented with carbon and then melted. He emphasized the difficulty of determining analytically the small amounts of carbon present in copper. The metal was removed by wet methods and the residue considered as carbon. At Percy's request, Dick,3 in 1856, carried out various working tests on copper that had been ill prolonged contact with carbon, and found that the working properties of the metal had not been affected. He also attempted to determine the presence of carbon analytically. In one experiment the copper was dissolved and the residue was fused with litharge, and in another essentially a combustion analysis was made on a copper sample. In a final experiment, a sample was dissolved and the residue subsequently subjected to a combustion analysis. Indications of as much as 0.005 per cent carbon were found, but Dick considered his work inconclusive largely because of the possible interference of sulphur. Percy4 concluded, from Dick's experiments and from some experimental work of his own, that the solubility of carbon in copper had not been established with

Jan 1, 1946

By Jasper L. Stuckey

It is not known when kaolin mining was first begun in North carolina, Evidence, in the form of excavations and primitive tools, indicates that some of the deposits were worked in prehistoric times. It has been suggested that the prehistoric mining was for mica, but the workings were all in altered or partly altered pegmatite material and the dumps do not represent the amount of material removed. some of the early openings may have been made in search of kaolin or semi-kaolinized feldspar which was sold to English1 traders along the coast and used in some Of the early English porcelains. In 1744,2 an application was made for an English patent to produce porcelain from an earthy mixture obtained from the Cherokee Nation in North America. It is well established, however, that the occurrence of kaolin in western North Carolina was known in England by 1767. In that year, Josiah Wedgewood sent T. Griffiths3,4 to what is now Macon County, North Carolina, to secure a supply Of kaolin for use in England. Griffiths diary, now in Etruria Museum, Stokes-on-Trent, contains a most interesting account of his experience. Kaolin was discovered at St. Austell, England, shortly after the voyage Of Griffiths, which probably accounts for the lack of further interest in American kaolin. Between 1767 and 1888, there are no records of kaolin mining in North Carolina. In the latter year, however, mining was begun near Webster, Jackson County, and, in the intervening period, has become an important industry. 'Or some 20 years, kaolin mining was carried On chiefly in Jackson, Macon, and Swain Counties. About 1904, it was begun in the Spruce Pine district and for the past 20 Yea's most of the kaolin mined in the State has come from Avery, Mitchell, and Yancey Counties. Distribution The kaolins of North Carolina are limited in occurrence to the Piedmont Plateau and Appalachian Mountain area of the State. While kaolins are widespread in the Piedmont Plateau, having been prospected for in Rutherford, Cleveland, Gaston, Granville, Lincoln, Catawba, Ire-dell, Richmond, Moore, Randolph, and Montgomery Counties, the production from that area has never been important. The known deposits of commercial importance are limited entirely to the mountain area of the State. While kaolins occur widely distributed throughout the mountain area and have been prospected for in many counties of that area, commercial production has come chiefly from two districts. One of these includes Jackson, Macon, Swain, and Haywood Counties. The other includes Avery, Mitchell, and Yancey Counties. Geology With few exceptions, all the known kaolin deposits in North Carolina contain

Jan 1, 1948

By Jasper L. Stuckey

It is not known when kaolin mining was first begun in North carolina, Evidence, in the form of excavations and primitive tools, indicates that some of the deposits were worked in prehistoric times. It has been suggested that the prehistoric mining was for mica, but the workings were all in altered or partly altered pegmatite material and the dumps do not represent the amount of material removed. some of the early openings may have been made in search of kaolin or semi-kaolinized feldspar which was sold to English1 traders along the coast and used in some Of the early English porcelains. In 1744,2 an application was made for an English patent to produce porcelain from an earthy mixture obtained from the Cherokee Nation in North America. It is well established, however, that the occurrence of kaolin in western North Carolina was known in England by 1767. In that year, Josiah Wedgewood sent T. Griffiths3,4 to what is now Macon County, North Carolina, to secure a supply Of kaolin for use in England. Griffiths diary, now in Etruria Museum, Stokes-on-Trent, contains a most interesting account of his experience. Kaolin was discovered at St. Austell, England, shortly after the voyage Of Griffiths, which probably accounts for the lack of further interest in American kaolin. Between 1767 and 1888, there are no records of kaolin mining in North Carolina. In the latter year, however, mining was begun near Webster, Jackson County, and, in the intervening period, has become an important industry. 'Or some 20 years, kaolin mining was carried On chiefly in Jackson, Macon, and Swain Counties. About 1904, it was begun in the Spruce Pine district and for the past 20 Yea's most of the kaolin mined in the State has come from Avery, Mitchell, and Yancey Counties. Distribution The kaolins of North Carolina are limited in occurrence to the Piedmont Plateau and Appalachian Mountain area of the State. While kaolins are widespread in the Piedmont Plateau, having been prospected for in Rutherford, Cleveland, Gaston, Granville, Lincoln, Catawba, Ire-dell, Richmond, Moore, Randolph, and Montgomery Counties, the production from that area has never been important. The known deposits of commercial importance are limited entirely to the mountain area of the State. While kaolins occur widely distributed throughout the mountain area and have been prospected for in many counties of that area, commercial production has come chiefly from two districts. One of these includes Jackson, Macon, Swain, and Haywood Counties. The other includes Avery, Mitchell, and Yancey Counties. Geology With few exceptions, all the known kaolin deposits in North Carolina contain

Jan 1, 1948

By Carl F. Floe, Michael B. Bever

he possibility that carbon may be soluble in copper to a limited extent has bten recognized for over a century. The quantitative investigation of this problem, however, requires more sensitive techniques than have formerly been available. Three recent developments have made possible more accurate determinations: the vacuum-fusion method of analysis, the production of copper of high purity and the availability of high-purity refractories, particularly graphite. In addition to its obvious theoretical interest, the problem of carbon solubility in copper is of practical importance. In the production of copper and of high-copper alloys, carbonaceous covers are freauerltlv used. If even minute amounts of carbon are dissolved, insoluble carbon oxide gases will be formed when such metals are poured under oxidizing conditions. A mechanism of this kind could well be one of the principal causes of gas porosity in casting copper-base products. Review of Literature In 1823 Vivian1 raised the question as to whether copper by overpoling becomes "combined with a minute portion of carbon." Karsten2 asserted, in 1832, that carbon reduces the high-temperature strength of pure copper, so that when the carbon content has reached 0.2 per cent the metal will be brittle at a dark red heat. According to Karsten, carbon contents of 0.05 per cent make it difficult to hot-work copper. He also reported that the specific gravity of copper is 8.8969 and that it increases to 8.9258 if the copper is cemented with carbon and then melted. He emphasized the difficulty of determining analytically the small amounts of carbon present in copper. The metal was removed by wet methods and the residue considered as carbon. At Percy's request, Dick,3 in 1856, carried out various working tests on copper that had been ill prolonged contact with carbon, and found that the working properties of the metal had not been affected. He also attempted to determine the presence of carbon analytically. In one experiment the copper was dissolved and the residue was fused with litharge, and in another essentially a combustion analysis was made on a copper sample. In a final experiment, a sample was dissolved and the residue subsequently subjected to a combustion analysis. Indications of as much as 0.005 per cent carbon were found, but Dick considered his work inconclusive largely because of the possible interference of sulphur. Percy4 concluded, from Dick's experiments and from some experimental work of his own, that the solubility of carbon in copper had not been established with

Jan 1, 1946

By John L. Lamont, Walter Crafts

AN investigation has been made of the multiplying factors for some of the more common alloying and deoxidizing elements for use in calculating hardenability of steel according to Grossmann's method.1 The factors for manganese, silicon, and aluminum that were reported in an earlier communication2 have been confirmed by microscopic determination of the half-martensite structure rather than on the basis of an empirically determined hardness corresponding to a half-martensite structure. Measurement of ideal critical diameter by microscopic examination was found to he necessary for other alloying elements, and multiplying factors for nickel, chromium, molybdenum, zirconium, vanadium, titanium, and boron have been determined. The nature and order of magnitude of the multiplying factors reflect the effect of the alloying elements on the structural character of the steel. Except for nickel and vanadium, the multiplying factors agree fairly well with previously published results. Good correlation between actual and calculated ideal critical diameters has been found in developing the multiplying factors and in checking the results against fairly simple steels. However, some discrepancies have suggested the need for a more thorough study of low-carbon and complex steels. TESTING PROCEDURE The investigation was conducted principally on steels made at the Union Carbide and Carbon Research Laboratories, Inc., in high-frequency induction furnaces using Armco iron and standard alloying materials. However, a few open-hearth steels were used in establishing the effect of nickel, and the hardenability factor for boron was based primarily on open-hearth steels. All bars were normalized prior to the machining of Jominy hardenability specimens. The Jominy test was carried out under conditions standard for the test.3 Austenitizing temperatures judged to-be-appropriate for the composi¬tions of the steels were used., Chemical analysis was determined on a sample taken adjacent to the Jominy specimen. Residual amounts of phosphorus, sulphur, nickel, chromium, molybdenum, and copper were determined on only one heat of each group made with the same materials during the same period. "Acid-soluble" aluminum and zirconium rather than total amounts were determined, as it is considered probable that the acid-soluble amount is more representative of the effective alloy. As tin was present to the extent of only 0.002 per cent, its effect was neglected. The method used to determine boron in the steels shown in Table 9* was developed by Galen Porter, Vincent Napoleon, and Thomas R. Cunningham,of the Union Carbide and Carbon Research Laboratories, Inc., and is. a modification of J. Naftel's procedure for boron in soils

Jan 1, 1944