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By D. A. Dahlstrom

Application of the cyclone to separation of undesirable -200-mesh clay, silt, and high-ash fractions from coal slurries was found to possess many economic and process advantages. Up to 93.3 pct removal was attained at rates of 113 to 155 gpm per sq ft of cross-sectional area.

Jan 2, 1951

Large equipment for quarrying and for the various stages of crushing and grinding are the trend for new and existing operations. Included are large size haulage units, fast drilling equipment, impact crushers and large mills capable of high tonnage rates for metallic and nonmetallic minerals. In grinding, large-size mills continue as the choice in industries where grinding constitutes a major portion of the processing. Typical is a 10 x 34 ft two-compartment mill in closed circuit with an 18-ft diam air separator for cement. Other cement mill sizes are in the order of 12 x 36 ft, 2500 hp; 10 x 37 ft ball and rod (wet), 1400 hp; 13 x 36 ft, 3000 hp; 13 x 40 ft (wet), 3000 hp. Several installations of combination ball and rod mills have been made, and one of the largest is 12 x 45 ft. In connection with the wet grinding of raw materials, the DSM 270-degree screen has been installed in several cement plants with the intention of producing a material finer than 50 mesh. In ore processing, large autogenous mills (121/2 x 20 ft) are being installed.

Jan 2, 1964

By Joseph Hyde Pratt, Douglas B. Sterrett

Monazite is one of the minerals which, for a long time, was considered somewhat rare in its occurrence, but, upon a commercial demand arising for it, prospectors and engineers soon located large deposits of it in the Carolinas arid Brazil, and the supply has always been able to meet the demand. During 1908 further sources of supply of monazite have been discovered and developed in Idaho. North and South Carolina, however, are the only States that have thus far put any monazite on the market. Monazite is essentially an anhydrous phosphate of the rare-earth metals,ceriunl, lanthanum, and didymium,(Ce,La,Di)PO,. There is nearly always present a varying but small percentage of thoria, Tho2, and silicic acid, SiO2,, which are very probably united in the form of a thorium silicate, ThSiO4. Some mona-zites contain but a fraction of a per cent. of thoria, while others have been recorded that showed the presence of from 18 to 32 per cent.; but the majority contain from 3 to 9 per cent. of this oxide. It is the presence of the thorium oxide that gives the monazite its commercial value. The analysis occasionally shows also the presence of other constituents, as the yttrium and erbium oxides, zirconia, alumina, magnesia, lime, iron oxides, manganese oxide, and titanium oxide. Monazite is light-yellow, honey-yellow, reddish-, brownish-, or greenish-yellop. in color, with a resinous to vitreous luster, and is translucent to subtransparent. It is brittle, with a con-choidal to uneven fracture, and is from 5 to 5.5 in hardness, and from 4.64 to 5.3 in specific gravity. It crystallizes in the monoclinic system, and some crystals have been observed that werc 6 in. in length. The more perfect crystals are,-however,

Jan 1, 1910

Jan 1, 1902

By B. Barlin

Introduction The development of metallurgical practice at lambia Broken Hill is directly related to the change in mineralization of the deposits as mining progressed from the open pits to underground. The ore consists of a mixture of lead and zinc sulphide minerals, together with abundant silicates, carbonates and other oxidized minerals of these metals. The irregularity that characterizes the shape of the orebodies applies equally to their mineral content, which makes ore reserve calculations and the maintenance of a balanced feed to the metallurgical plants, problems of some magnitude. History The Rhodesia Broken Hill Development ,Company was formed in 1904 after an Australian prospector, T. G. Davey, discovered the outcrops in 1902. In the early years zinc ores were calcined for shipment but this proved uneconomic. Cerussite outcrops were then smelted directly in blast furnaces for the production of lead until 1929 when ore above the water level was exhausted.

Jan 1, 1970

By Norman P. Goss

It is generally agreed that cold-working mechanically refines the grains into smaller fragments and with continued working these are oriented with certain crystallographic directions bearing a relation to the direction in which the metal is worked. Some of the energy expended on the metal during plastic deformation appears in the form of heat, but a very small portion remains in the metal as stored energy. The entropy, specific heat capacity, temperature at which recrystallization will just begin, density, ductility, elasticity, tensile strength, and resistance to corrosion are affected. These properties have been studied extensively and some of the changes in the physical properties due to cold-working were attributed to lattice distortion.l-8 The broadening of the Ka lines on the X-ray diffraction diagrams of plastically deformed metals is believed to indicate lattice distortion, and consequently the existence of internal stresses. The evidence supporting this theory rests solely upon the observed experimental fact that the diffraction lines are broadened and the Ka doublets are completely diffused. Elam9 has reviewed the matter of lattice distortion in relationship to the hardening of metals by plastic deformation. The X-ray diagrams of plastically deformed metals differ in general from annealed metals. The hardening of a metal was believed due to lattice distortion.9 The resolution of the doublet is lost when a metal is cold-worked and the Laue spots are elongated. At one time this elongation was thought to indicate the elastic bending of the crystal planes. However, more careful work showed that the asterism was due to new orientations developed within the fragmented grains during plastic deformation. Some theories attributed the hardening to fragmentation of the grains into smaller units. Jeffries and Archer,ll after carefully considering the problem of work-hardening from many angles, came to the conclusion that cold-working mechanically refines the grains into smaller crystal fragments, some of which at least differ in orientation from the parent grain. The increase in

Jan 1, 1940

By Norman P. Goss

It is generally agreed that cold-working mechanically refines the grains into smaller fragments and with continued working these are oriented with certain crystallographic directions bearing a relation to the direction in which the metal is worked. Some of the energy expended on the metal during plastic deformation appears in the form of heat, but a very small portion remains in the metal as stored energy. The entropy, specific heat capacity, temperature at which recrystallization will just begin, density, ductility, elasticity, tensile strength, and resistance to corrosion are affected. These properties have been studied extensively and some of the changes in the physical properties due to cold-working were attributed to lattice distortion.l-8 The broadening of the Ka lines on the X-ray diffraction diagrams of plastically deformed metals is believed to indicate lattice distortion, and consequently the existence of internal stresses. The evidence supporting this theory rests solely upon the observed experimental fact that the diffraction lines are broadened and the Ka doublets are completely diffused. Elam9 has reviewed the matter of lattice distortion in relationship to the hardening of metals by plastic deformation. The X-ray diagrams of plastically deformed metals differ in general from annealed metals. The hardening of a metal was believed due to lattice distortion.9 The resolution of the doublet is lost when a metal is cold-worked and the Laue spots are elongated. At one time this elongation was thought to indicate the elastic bending of the crystal planes. However, more careful work showed that the asterism was due to new orientations developed within the fragmented grains during plastic deformation. Some theories attributed the hardening to fragmentation of the grains into smaller units. Jeffries and Archer,ll after carefully considering the problem of work-hardening from many angles, came to the conclusion that cold-working mechanically refines the grains into smaller crystal fragments, some of which at least differ in orientation from the parent grain. The increase in

Jan 1, 1940

Featured at the 1977 SME-AIME Fall Meeting in St. Louis is a Lead-Zinc Update, organized to complement the 1970 AIME World Symposium on Mining and Metallurgy of Lead and Zinc, also held in St. Louis. The 21 papers comprising the Update are to be presented during four technical sessions at the Fall Meeting; in addition, the papers have been collected in a bound book available at meeting time.

Jan 9, 1977

By Anthony Folger, Howard R. Lowe, J. F. Dougherty, E. G. Trostel, Joffre Meyer

The status of the natural gas industry in Alberta, Canada, is described with particular reference to the current extent of natural gas reserves and possibilities for additional development. Certain major fields are discussed as representative of the types of gas accumulations within various broad geographical divisions of the provinces. The estimation of the future performance of a gas reservoir is discussed as the basis for an estimate of the future availability of natural gas from presently known reserves. The future availability of the provincial reserves and the estimated future demand for gas within the province are described. INTRODUCTION This paper is a condensation of a detailed study of the natural gas reserves and the future availability of pipeline gas in the province of Alberta as prepared for Trans-Canada Pipe Lines Limited and presented in public hearings at Edmonton and Calgary before the Petroleum and Natural Gas Conservation Board of the Province of Alberta. The study began in October, 1950, and resulted in the preparation of five volumes of data at the expenditure of more than 20,000 man-hours. This paper is designed to afford a broad picture with detail limited to a type example of both natural ga-accumulation and future availability of gas supply. The province of Alberta has an area of 255.285 square miles which, for sake of comparison. is 8,359 square miles smaller than the state of Texas. Natural gas was first discovered in 1883 at the now abandoned Alderson well located some 20 miles southeast of the town of Princess. The first gas in commercial quantities was found at Medicine Hat in 1890. During the last 68 years. 187 localities have been discovered which are capable of gas production, and 73 per cent of these have been found since 1945. Sixty fields currently are producing gas, including 22 non-associated gas accumulations. Location of the oil and gas fields and prospects in the province of Alberta is shown in Fig. 1, together with a list of the localities of measurable gas, Fig. 1A. The estimated total provincial gas reserve as of Jan. 1, 1952, for the 104 fields estimated, is 11.7 trillion cu ft proved and probable, and for the 187 known areas capable of production is in excess of 16 trillion cu ft on a total proved, probable, and possible basis. Five fields (Pincher Creek, Leduc-Woodbend, Viking-Kinsella, Cessford and Medicine Hat) are estimated to have recoverable reserves of more than one trillion cu ft each. A sixth field, Turner Valley, was initially in this group, but its reserves have been depleted substantially. Twenty-four fields, of which the above mentioned six fields are a part, have estimated gas reserves (including the possible category) in excess of 100 billion cu ft. These 24 fields account for 79 per cent of the total provincial reserves. Comparative systemic analyses reflect that 56 per cant of Alberta's gas reserves are contained in sediments of Cretaceous age; 30 per cent in sediments of Mississippian age; 10 per cent in sediments of Devonian age; three per cent in sediments of Triassic age; and the remaining one per cent in Jurassic and Permo-Pennsylvanian sediments. It is expected that the relative importance of the Mississippian, Devonian, and Triassic sediments will be increased as exploration progresses. GENERAL GEOLOGY The western Canada basin comprises the sedimentary area between the Canadian Shield and the Rocky Mountain Front Range, the Arctic Ocean, and the International Boundary. The basin has an approximate area of 765,000 square miles and embraces parts of the provinces of Manitoba. Saskatchewan. Alberta, British Columbia and the Northwest Territories. Generalized columnar sections for the Province of Alberta are shown in Fig. 2. Substantially all of Alberta, except its northeast corner, has sedimentary cover. Sediments of all the geologic systems are represented. except those of Silurian age.

Jan 1, 1952

By William Rawles

THIS report is the first of a series planned by The Mineral Inquiry, organized by the American Institute of Mining and Metallurgical Engineers to make factual studies of the world's mineral resources in their political and international relations. The efforts of The Inquiry are directed toward filling certain notable gaps in available information, without duplication of many other investigations touching this field which are being conducted by other organizations, public and private. Much of its work is indirect-suggesting topics for study by other individuals and organizations and aiding in their planning and correlation. The present report is designed to show the nationality of the commercial control of mineral resources, in addition to the geographic distribution of production by nation-in other words, the overlapping of political and commercial control. Detailed accuracy cannot be claimed for the figures presented. For some companies division of ownership by nationality has been very difficult to ascertain, as many companies are reluctant to dis-close the extent of their holdings in other corporations, and the impossi-bility of tracing all stock ownership is obvious. Also there are frequent changes in the distribution of. stock control. The percentages given rep-resent only the participation that has been identified definitely, even though it is known in some cases with fair certainty that larger interests exist, as, for instance, American participation in foreign chromite companies. In bringing together these figures we have had the cordial co-operation of the United States Bureau of Mines, the United States Geologi-cal Survey, the Mineral Division of the Bureau of Foreign and Domestic Commerce, the Brookings Institution, and of many specialists connected with the mineral industries covered. The report does not cover the entire list of minerals. Coal, although it is one of the most important minerals, was omitted because , not more than one or two per cent of the world's production comes from mines that are owned by companies foreign to the countries where the coal is produced. Others, such as gold, are omitted because sufficient data have not yet been accumulated. It is hoped that some of these may be covered in subsequent reports. It is not our purpose here to discuss the significance of the figures sub-mitted, but only to point out the general nature of the problems on which they have a bearing.

Jan 1, 1933

By W. M. Weigal

ECONOMIC deposits of barite occur in Missouri in two main districts. The most important, the Southeastern or Washington County district, is in the southeastern part of the state, mostly in Washington County with a small extension into the northeastern part of St. Francois County. Roughly, it embraces nine townships or about 200,000 acres and accounts for from 80 to 90 per cent. of the state production. The Central district, in the central part of the state, includes most of Morgan and Miller counties, and parts of Camden, Benton, Moniteau and Cole counties. The area embraced is much larger than the Washington County district, but the deposits are more infrequent. The location and general area covered by the two districts is shown in Fig. 1. There is another small area in southern Franklin County but so far its production has been of small consequence. It might be considered as a northward extension of the Washington County field. An area in the central part of Hickory County has also produced a small amount. The outline of the districts as shown indicates the general area in which deposits have been found. The total area covered by deposits of barite is only a small part of this, as, in the Central district especially, there may be miles of supposedly barren areas between ore-bearing areas of an acre or two in extent. The date when barite was first mined in Missouri cannot be definitely stated, but the industry probably dates back to about 1860. The occurrence of barite was known long before this, as it was encountered in the lead mines in Washington County and mentioned by several earlier writers.' Missouri is reported as producing 8000 tons in 1882 so it is evident the industry was well under way in the seventies in order to have arrived at this substantial production. By 1893 Missouri production had increased so that it ranked with that of Virginia, then the largest producer. It increased until in 1914 Missouri accounted for about 65 per cent. of the total United States output. Recent Production of Barite Table 1, compiled from Mineral Resources, published by the United States Geological Survey and Bureau of Mines, gives the production of

Jan 1, 1929

By T. D. Yensen

In the investigation of the magnetic properties of iron-nickel alloys,' it was found necessary in order to make the alloys forgeable, or malleable, to add small quantities of some other element. Iron-nickel alloys have been known for nearly a century, but have been made in commercial quantities only since 1885. Their remarkable mechanical properties were disclosed by Riley in 1889 and from that time on a large amount, of research work has been done both to discover new properties and to correlate the results obtained.2 Lately the Bureau of Standards has collected the published data in a special circular" giving in compact form an account of the properties of the iron-nickel alloys. It also contains a clear historical sketch of the development as well as a selected bibliography. The chief difficulty with the development of iron-nickel alloys was that the "pure" alloys do not forge readily. The addition of small amounts of manganese, however, made the alloys forgeable, and manganese has therefore come to be regarded as a necessary constituent of nickel steels. The present paper shows to what extent manganese is needed for various nickel contents and also what is the effect of other alloying elements on the forgeability. It also touches upon the cause of forgeability but refers to other sources for more exhaustive treatises on the subject. The alloys were prepared by melting electrolytic iron and electrolytic nickel with or without other alloying elements in the desired proportions in a magnesia crucible in a vacuum furnace under a pressure of 1 mm. mercury. The ingots, weighing about 2 kg., were allowed to cool in vacuo. If pipes or blowholes were present, the ingots were cut in such

Jan 1, 1922

By T. D. Yensen

In the investigation of the magnetic properties of iron-nickel alloys,' it was found necessary in order to make the alloys forgeable, or malleable, to add small quantities of some other element. Iron-nickel alloys have been known for nearly a century, but have been made in commercial quantities only since 1885. Their remarkable mechanical properties were disclosed by Riley in 1889 and from that time on a large amount, of research work has been done both to discover new properties and to correlate the results obtained.2 Lately the Bureau of Standards has collected the published data in a special circular" giving in compact form an account of the properties of the iron-nickel alloys. It also contains a clear historical sketch of the development as well as a selected bibliography. The chief difficulty with the development of iron-nickel alloys was that the "pure" alloys do not forge readily. The addition of small amounts of manganese, however, made the alloys forgeable, and manganese has therefore come to be regarded as a necessary constituent of nickel steels. The present paper shows to what extent manganese is needed for various nickel contents and also what is the effect of other alloying elements on the forgeability. It also touches upon the cause of forgeability but refers to other sources for more exhaustive treatises on the subject. The alloys were prepared by melting electrolytic iron and electrolytic nickel with or without other alloying elements in the desired proportions in a magnesia crucible in a vacuum furnace under a pressure of 1 mm. mercury. The ingots, weighing about 2 kg., were allowed to cool in vacuo. If pipes or blowholes were present, the ingots were cut in such

Jan 1, 1922

By Edgar Bain

THE results are presented of an investigation to discover the fundamental atomic conditions existing in Corson's high-copper alloys hardenable by means of silicide solution and reprecipitation. The study attracted the writer because it offered a very convenient example of the general type of hardenable alloys exemplified by duralumin, Sykes' iron-tungsten and iron-molybdenum alloys and the hardenable lead antimony. SUMMARY OF RESULTS AND CONCLUSIONS In brief, the investigation shows that very perfect crystallinity exists in the solid solutions prepared at high temperature to contain as much dissolved silicide as possible. The lattice parameter of copper is altered very little by the amount of cobalt, nickel or chromium, and silicon dissolved. The hardening by drawing at a temperature to initiate precipitation of excess silicon and metal produces a remarkable change in the atomistics of the solid solution. The old perfection of crystallinity in the solid solution is destroyed and the new atomic spacings are of variable magnitude even in one grain, and a condition in a measure resembling that found in martensite is observed. Were no particles whatever precipitated by the drawing action, still ample causes for hardness would be in evidence in the solid solution alone. The lack of plane continuity in the crystal grains would oppose slip in a very effective manner. Complete annealing restores the crystalline perfection in large measure. In these alloys even the most sensitive methods failed to reveal the characteristic pattern of the silicide precipitated by the anneal, but this was largely to be expected as the amount is relatively small.

Jan 1, 1927

By J. G. Thompson

THE methods employed for the determination of oxides and oxygen in ferrous materials may be roughly classed in two groups, "wet" methods and "hot" methods, the first group including the iodine, electrolytic, mercuric chloride, hydrochloric acid, nitric acid, and chlorine methods; the second group including the vacuum-fusion and hydrogen-reduction methods. The wet methods depend upon preferential solubility in a selected medium to separate the metallic portion of the sample from the oxygen-containing constituents. Subsequent analysis of the insoluble residue permits the isolation and separate determination of individual oxides and compounds. The hot methods depend upon the reduction of the oxide constituents of the sample by means of carbon or hydrogen at elevated temperatures. With the exception of the recently developed fractional vacuum-fusion method, the hot methods do not identify individual oxides and compounds but yield only a single value represent-ing the sum of the oxygen contents of several or all of the oxide con-stituents present. With such diversity in the principles and. aims of the different groups, it is not surprising that concordance of results by differ-ent methods has usually been difficult to obtain. The present cooperative attempt to define more rigorously than has been possible heretofore the accuracy and limits of usefulness of the vari-ous methods, originated in correspondence between Dr. John Johnston, Director of Research of the United States Steel Corporation, and other interested metallurgists. The plan was, briefly, to submit identical samples to a number of laboratories for analysis by different methods and to collate the results of these analyses. The project was endorsed by the Iron and Steel Division of the American Institute of Mining and Metal-lurgical Engineers at the annual meeting in February, 1933, and has been conducted under the joint sponsorship of the Iron and Steel Division and the National Bureau of Standards. The latter organization undertook

Jan 1, 1936

By R. R. Sayers

TWO serious hazards from coal dust confront the bituminous-coal miner- -a physical or safety hazard and a physiological or health hazard. The first threatens the miner with loss of life from coal-dint explosions, and the second with loss of health and earning capacity from inhaling large quantities of the dust. Studies by the Bureau of Mines have shown that coal dust, except some grades of anthracite dust, is capable of initiating an explosion when no explosive gas is present and that its property of extending or propagating an explosion has been responsible for nearly all the widespread explosions that have occurred in bituminous mines in the United States in the present century. For years many mining people believed that low-volatile coal dust was not explosive but not only is it explosive but if the source of ignition is intense, it is as explosive as the dust of many high-volatile coals because the war is creating increased pressure for greater coal production and because of the trend toward greater mechanization in mines, explosion and health hazards from coal dust are likely !n increase considerably.

Jan 1, 1943

By Herbert R. Mosley, Paul M. Tyler

STRATEGICALLY situated in almost the heart of the leading fertilizer- consuming area of the United States, Tennessee long has ranked second only to Florida as a phosphate-producing state. Since 1932 its share of the national output of phosphate rock has increased steadily, and in 1937 its production mounted to an all-time record. More significant even than the increase in tonnage are the forward strides in technology. The Tennessee Valley Authority's research program has led to quasicommercial operations using hydroelectric power to manufacture concentrated phosphatic fertilizer that is used to further the farmer education program designed to streamline the fertilizer business and halt the appalling waste of farm land by soil erosion. Even more stimulating to chemically minded imaginations is the production of elemental phosphorus by a private company that not only has succeeded in extracting it from the phosphate rock in electric furnaces but actually has contrived to capture it and to transport it safely in tank cars. New values have been created for low-grade phosphate deposits, and the economic life of reserves has been lengthened while the waste of former years goes back into the mills for recovery of its values by modernized methods. Tennessee's phosphate-mining industry dates from the discovery of blue rock in-lewis County in December 1893. Its known reserves are of the order of 101,500,000 tons, which compares with the production of 825,099 tons in 1937; that is, 21 per cent of the phosphate-rock output of the whole nation. The total output reported from 1894 until July 1, 1938, was approximately 19,000,000 tons. Official estimates of reserves are overly conservative and evidence submitted before a joint Congressional committee in November 1938 places "probable" reserves at more than 6,000,000,000 tons.

Jan 1, 1939

By H. S. Jerabek, Charles S. Barrett, Robert F. Mehl

The precipitation of the nitride Fe4N from the solid solution of nitrogen in a Fe and of the phosphide Fe3P from the solid solution of phosphorus in a Fe both lead to the formation of structures that may be easily identified as Widmanstatten figures, within the meaning of the term as used in this series of papers. A complete solution has been obtained for the figure formed by Fe4N. The structure of Fe3P, however, is not fully known and a complete solution of this figure thus cannot be obtained; nevertheless, a study of this figure has furnished some new information. Precipitation of Fe4N from Alpha Solid Solution of N in Alpha Fe Constitution of System Iron-nitrogen A knowledge of the constitution of the whole of the Fe-N system is unnecessary for this work, though the recent studies by Eisenhut and Kauppl and by Lehrerz have clarified most of the moot points; it is sufficient for our purpose to state that a Fe of high purity dissolves 0.42 per cent of nitrogen in solid solution at the eutectoid temperature, 591' C., and that this solubility decreases at first rapidly and then more slowly until at room temperature the solid solubility amounts to approximately 0.1 per cent nitrogen.3

Jan 1, 1934

By Charles Janin

The first successful bucket-elevator dredge to operate in California was put in comnlisvion wt Oroville in March, 1898. There had been numerous previous attempts at dredging, but noue of the earlier boats proved a success. The gold-miners in California earl3 conceived the idea of a machine to dig gravel from the beds and bars of auriferous streams that were inaccessible by the methods then employed, and it was only a few months after the discovery of gold in California that such a machine was Shipped around Cape Horn from New York to San Francisco. Thij was, however, but the forerunner of many failures in gold-dredging, and was soon at the bottoni of the Sacramento river. During succeeding years many other unsuccessful attempts mere made, and it was not until 1897 that a dredge of the single-lift bucket-elevator type mas floated on the Yuba river. This dredge was built by the Risdon Iron Works for 12. H. Postlethwaite, and would probably have been a success if it had been operated on some of the rich Ororille ground

Jan 1, 1912

By William E. Ford, Edward Salisbury Dana

THIS Appendix contains a series of tables, more or leas complete, of minerals arranged according to chemical composition or to certain prominent crystallograhic or physical characters. These, it is believed, will be of service not only to the student, but ago to the skilled mineralogist. The type used in the printing of the mineral names indicates their relative importance. Table I is a complete list of the species named in this book arranged fist according to the prominent basic elements which they contain and secondly according to their acid radicals. Table II is of Minerals arranged according to their System of Crystallization The other tablets make no claim to completeness, being limited often to common ah important species. For an exhaustive system of Determinative Tables based particularly upon blowpipe and chemical characters, the student is referred to the work of Professors Brush and Pen- field, mentioned on p. 330.

Jan 1, 1922