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By R. G. O’Meara, M. M. Fine

ONE of the principal activities of the Bureau of Mines connected with the recent war was to help to increase the supply of strategic and critical minerals. Fluorite was one of the most critical of the nonmetallic minerals because of the increased demand for it as a flux in basic open-hearth and electric steel furnaces and as a raw material for the production of artificial cryolite used in the aluminum industry. Wartime developments in the technology of hydrofluoric acid, such as the use of the anhydrous acid as a catalyst in production of high-octane gasoline and the use of organic fluorides as carriers for insecticides, also increased the demand for acid-grade fluorite.[t] In 1943 the consumption of acid-grade fluorite was advancing at a more rapid rate than production, and was only slightly less than production during the latter half of the year.1 The outlook for the postwar market for fluorite is encouraging. Steel production is expected to remain high until the domestic demand for commodities not manufactured during the war is satisfied. The uses for hydrofluoric acid are expected to increase under the impetus of war-initiated research. In consideration of these and other factors some authorities predict a postwar demand for fluorite equal to about 60 to 75 per cent of the wartime production.1,2 Others believe that the postwar fluorite industry will be permanently expanded over its prewar status.3 ACKNOWLEDGMENT This paper is one of many reporting on various aspects of the Bureau of Mines program directed toward the more effective utilization of our mineral resources. The program has been under the general supervision of R. S. Dean, Assistant Director, since July 1942. The scope of the paper falls in the province of the Metallurgical Branch, whose activities embrace the separation of difficultly beneficiated ores, the production of pure metals from domestic deposits, the exploitation of marginal ore reserves, the recovery of secondary metals, and the improvement of present industrial metallurgical practice. The investigation was initiated at the request of Mr. J. H. Steinmesch, vice-president and general manager, Minerva Oil Co., Eldorado, Ill. His hearty cooperation and helpful suggestions, and those of Mr. O. E. Anderson, mill superintendent,

Jan 1, 1946

By Howard Eavenson

THE mines of the United States Coal & Coke Co. are located in the Pocahontas coal field, in McDowell County, West Virginia. Twelve plants have been opened and equipped, of which, by reason of the present business depression, only nine are now in operation. These twelve plants serve eighteen mines; some of the plants having several openings, in either the same seam or in different seams, tributary to the same tipple. Only nine of these mines are now being worked at the plants in operation. Construction work was begun in 1902, and coal from the first three plants started was shipped in December of that year. An additional plant was opened in 1903, two in 1904, two in 1905, two in 1907 and the last two in 1908. On Jan. 1, 1915, the plants have been in operation an average period of 8.8 years. The rules of the company, which have been in operation since work was first begun, are similar to those in use by the H. C. Frick Coke Co. at its mines in Pennsylvania, in which "Safety First" was incorporated as early as 1907; and it has always been the policy of both companies to look carefully after the safety of their employees. Although the field is an extension of the old Pocahontas field, the mines, located upon a new branch railroad, are away by themselves, and, as is usual in such cases, the class of labor attracted at first was temporary in character. The rapid development of the mines required the employment of many new men and officials each year; and, while the accident record from 1904 to 1909 was as good as the average of the field, it was felt to be not as good as it could be made, and a determined campaign was inaugurated for preventing accidents of all kinds. Fig. .1 shows the tonnage of coal produced per fatality, both total and for inside accidents only, at our mines; the tonnage per fatality of all West Virginia mines, and of those in the Pocahontas field.

Jan 2, 1915

By I. N. Knapp

Introduction.—The spccial object of these notes is to describe the mixing, testing, and use of mud-ladened water for rotary drilling in such a way as to make them helpful to the driller, the operator, or the engineer in solving his own special drilling problems. The structures, apparatus and tools used are indicated in a general way. No attempt is made to describe the art of rotary drilling; only such descriptions as are necessary to make plain the use of mud are given. The information is the result of actual experience in drilling in Coastal Plain formations. The materials encountered in the wells drilled were unconsolidated sands, gravels, and clays, in which thin layers of sandstones, shell conglomerates, and shales began to appear at about 1,200 ft, in depth, although one well was drilled to 3,018 ft. without encountering any cemented or indurated materials. Unusual Conditions.—-The general surface of the ground where the drilling was done being hardly a foot above mean tide, and the daily tidal variation being about 15 in., it was found necessary to plank over the sod surface with 3-in. plank to work from. A 30 by 30 ft. planked area was sufficient to carry the derrick with equipment and 2,500 ft. of 4-in. drill pipe stacked in it. The derrick was set up 3 ft. on cribbed blocking arranged to spread the load over the planking. The engine, bailers, and pipe yard were also carried on 3-in. planking. Drilling 0utfit.—This consisted of a derrick, 20 by 20 ft. and 84 ft. high, two 35-h.p., "oil country" boilers, one double 8 1/4 by 10 in. reversible engine, two 10 by 6 by 12 in. duplex mud pumps, one 15-in. rotary, "hoisting works" with chain drive, hoisting block with line, crown block with pulleys, rotary jetting swivels, hose, complement of tools, pipes and connections, and a mud mixer, with engine. Hydraulic Rotary Drilling Method.—This method of drilling is an adaptation of Fauvelle'sl invention made in France in 1833 for drilling

Jan 1, 1915

By O&apos, M. M. Fine, K. G. Meara

One of the principal activities of the Bureau of Mines connected with the recent war was to help to increase the supply of strategic and critical minerals. Fluorite was one of the most critical of the nonmetallic minerals because of the increased demand for it as a flux in basic open-hearth and electric steel furnaces and as a raw material for the production of artificial cryolite used in the aluminum industry. Wartime developments in the technology of hydrofluoric acid, such as the use of the anhydrous acid as a catalyst in production of high-octane gasoline and the use of organic fluorides as carriers for insecticides, also increased the demand for acid-grade fluorite.f In 1943 the consumption of acid-grade fluorite was advancing at a more rapid rate than production, and was only slightly less than production during the latter half of the year.' The outlook for the postwar market for fluorite is encouraging. Steel production is expected to remain high until the domestic demand for commodities not manufactured during the war is satisfied. The uses for hydrofluoric acid are expected to increase under the impetus of war-initiated research. In considerbtion of these and other factors some authorities predict a postwar demand for fluorite equal to about 60 to 75 per cent of the wartime production.1,2 Others believe that the postwar fluorite industry will be permanently expanded over its prewar status.3 Acknowledgment This paper is one of many reporting on various aspects of the Bureau of Mines program directed toward the more effective utilization of our mineral resources. The program has been under the general supervision of R. S. Dean, Assistant Director, since July 1942. The scope of the paper falls in the province of the Metallurgical Branch, whose activities embrace the separation of difficultly beneficiated ores, the production of pure metals from domestic deposits, the exploitation of marginal orc reserves, the recovery of secondary metals, and the improvement of present industrial metallurgical practice. The investigation was initiated at the request of Mr. J. H. Steinmesch, vice-president and general manager, Minerva Oil Co., Eldorado, Ill. His hearty cooperation and helpful suggestions, and those of Mr. 0. E. Anderson, mill superintendent,

Jan 1, 1948

By K. G. Meara, M. M. Fine, O&apos

One of the principal activities of the Bureau of Mines connected with the recent war was to help to increase the supply of strategic and critical minerals. Fluorite was one of the most critical of the nonmetallic minerals because of the increased demand for it as a flux in basic open-hearth and electric steel furnaces and as a raw material for the production of artificial cryolite used in the aluminum industry. Wartime developments in the technology of hydrofluoric acid, such as the use of the anhydrous acid as a catalyst in production of high-octane gasoline and the use of organic fluorides as carriers for insecticides, also increased the demand for acid-grade fluorite.f In 1943 the consumption of acid-grade fluorite was advancing at a more rapid rate than production, and was only slightly less than production during the latter half of the year.' The outlook for the postwar market for fluorite is encouraging. Steel production is expected to remain high until the domestic demand for commodities not manufactured during the war is satisfied. The uses for hydrofluoric acid are expected to increase under the impetus of war-initiated research. In considerbtion of these and other factors some authorities predict a postwar demand for fluorite equal to about 60 to 75 per cent of the wartime production.1,2 Others believe that the postwar fluorite industry will be permanently expanded over its prewar status.3 Acknowledgment This paper is one of many reporting on various aspects of the Bureau of Mines program directed toward the more effective utilization of our mineral resources. The program has been under the general supervision of R. S. Dean, Assistant Director, since July 1942. The scope of the paper falls in the province of the Metallurgical Branch, whose activities embrace the separation of difficultly beneficiated ores, the production of pure metals from domestic deposits, the exploitation of marginal orc reserves, the recovery of secondary metals, and the improvement of present industrial metallurgical practice. The investigation was initiated at the request of Mr. J. H. Steinmesch, vice-president and general manager, Minerva Oil Co., Eldorado, Ill. His hearty cooperation and helpful suggestions, and those of Mr. 0. E. Anderson, mill superintendent,

Jan 1, 1948

ALTHOUGH the open-hearth charge contributes CO, C02, H2, A and water vapor to the combustion gases and absorbs oxygen from them, in the main the thermal effects in the melting charge and molten bath can be considered independently of those in fuel combustion; the latter then is regarded simply as the source of the net heat required to finish a heat of steel. First of all, it should be remembered that a large percentage of the heat supplied to the bath is furnished by oxidation of the various elements in the charge itself. If this charge consisted of 80 to 100 per cent of hot metal and the oxidation were accomplished by blowing in air or oxygen, as in the bessemer converter, the net heat absorption would be negative; that is, the bath would contribute part of the heat required to keep the melting chamber hot, in addition to that contained in the finished steel and slag. In actual open-hearth practices, probably the nearest approach to this is in the duplex furnace, charged with bessemer-blown metal and some hot metal, where very little heat is required to complete the refining and nearly all the heat energy from fuel combustion is used to keep the roof and walls of the melting chamber up to around 2900 to 3000 F (1600 to 1650 C), so that the bath will not cool off during the refining. The other extreme is with all-cold charges containing around 80 per cent steel scrap and 20 per cent cast iron or cold pig iron, in which case a very large proportion of the heat in the bath at tap is supplied from the fuel combustion. THERMAL EFFECTS IN MELTING In a typical heat, the fuel furnishes about four million British thermal units per ton of steel produced. The heat required, for the metallurgical processes is not easily defined in useful manner but it ranges downward from about one million Btu, depending not only on the charge but on the manner of calculation. In, any event, this requirement appears. small in comparison with the

Jan 1, 1964

By Eugene H. Dawson

MICA is a mineral that once was a familiar sight as fireproof windows in stove and furnace doors and as lamp chimneys and shades. Since 1878, the beginning of the electrical age, the use of mica for such purposes has gradually declined and its use in electrical equipment and appliances has developed to such an extent that the known sources of supply are scarcely equal to the demand. With the increasing capacity of electric generating units, the size of mica sheets found in nature was inadequate. However, in 1894, a process was developed whereby thin films or splittings cemented with shellac or other binders could be pressed into large sheets. 18 The introduction of radio in the early 1920s created such a heavy demand for the smaller sizes of mica that on March 22, 1938, mica was included among 23 commodities on the list of strategic materials approved by the United States Army and Navy Munitions Board. To be included in this list, the material must be one whereof the domestic supply is not sufficient to meet the demand. COMPOSITION Mica is a complex mineral composed principally of the silicates of potassium, aluminum, and magnesium. Less prevalent species contain, as essential components, lithium, vanadium, and chromium. Iron usually is present either as an essential component or as an impurity. The mica group comprises some nine different species, five of which, muscovite, phlogopite, vermiculite, lepidolite, and biotite, are widely used in industry. Lepidolite and zinnwaldite (lithium micas) and roscoelite (vanadium mica) are sources of lithium and vanadium. Muscovite, "white mica," is potassium mica. Theoretical formulas H2KAl3(SiO4)3. There are two varieties, distinguished as to color, known in industry as ruby and green. In crystals or "books," the colors each range through varying shades of red and green. However, when split into thin films, all micas, except biotite and phlogopite, are colorless and transparent. Muscovite frequently is stained red or black by thin films of iron oxide between the laminae. The staining usually is derived from magnetite, which sometimes is found as unaltered crystals.

Jan 1, 1949

By Rossiter Raymond

JOHN BIRKINBINE was born Nov. 16, 1844, at Reading, Pa., the eldest son of H. P. M. Birkinbine, widely known as a hydraulic engineer. The family removed subsequently to Philadelphia, where, as a young man he established with his father the office now continued by his sons, after more than 60 years. His education was received at public schools, the Friends' High School in Philadelphia, the Hill School at Pottstown, Pa., and the Polytechnic College of Pennsylvania, where his studies were interrupted in 1863-4 by service in the Union Army, which included participation in the battles at and around Gettysburg. Later, he devoted two years to work in a machine shop; and subsequently he became associated with the late P. L. Weimer, under the firm. name of Weimer & Birkinbine, operating the Weimer Machine Works at Lebanon, Pa. Much of his work was in mining, metallurgy, and blast-furnace construction. As manager for the South Mountain Mining & Iron Co. he carried on experiments with various fuels for iron-ore smelting while maintaining the furnace in constant operation. The carefully recorded results obtained were widely published, and are referred to in text-books by other metallurgists as most complete. From his Philadelphia office he was sent to nearly every State, and to Canada and Mexico, for examinations, reports, constructions or improvements in iron-ore mines, blast furnaces, iron works, water supplies, hydraulic development, irrigation projects, etc., and his engineering knowledge was requisitioned by several European corporations. A number of business trips were made to Mexico, beginning with a visit to the Cerro de Mercado at Durango, before railroads were established in that portion of Mexico, to make a critical examination and report on this "Iron Mountain." Later visits covered other localities and engineering problems, familiarizing him with the major part of the iron industry in Mexico. The late disturbed political conditions in that Republic have retarded the probable enlargement, modernization, and improvement of much of the iron and steel industry of Mexico, upon which he investigated and reported for various capitalists on both continents. One interesting subject included in these reports was a proposed electric furnace, to be operated by energy from water power.

Jan 7, 1915

By Howard A. Meyerhoff, J. Earl Frazier

It is not known when silica sand was first noticed along the north coast of Puerto Rico, but the first mention of its occurrence was made in 1922, by N. L. Britton,1 who described its presence in isolated patches extending from Loiza westward beyond Manati. Further observations were made in 1925 and 1926 by Meyerhoff,2 who extended the known occurrences still farther westward to the low hill belt in the Quebradillas limestone immediately south of Hatillo. The extraordinary purity of the sands, which in most localities exhibit no contamination from the non-siliceous materials surrounding them, was quickly appreciated, and the feasibility of utilizing them for the manufacture of glass was investigated, initially by the Committee on Mineral Resources3 and later (1936) by the Puerto Rico Recon-structionAdministration and by H. C. Ray, mining engineer of the Insular Bureau of Mines. In 1934 samples submitted to the Hazel Atlas Glass Co., of Washington, Pennsylvania, were reported to have the composition as shown in the table on column two. Appreciation of the quality of the sand prompted geological and quantitative studies of the deposits, as well as cornmercial investigations to determine the feasibility of utilizing it locally or on the mainland for the manufacture of glass containers. Distribution of the Sands The quartz sands consistently lie within the outcrop area of the Quebradillas limestone, the youngest of the Miocene formations in the Tertiary coastal plain that fringes the northern coast of the Island. Many of the deposits are closely associated with limestone outcrops, but some appear to be embedded in lagoonal sediments at some distance from rock exposures, and at least one deposit, near Dorado, has been reworked by waves and littoral currents. With this single known exception, the deposits consist of irregular, patternless patches of white sand, which have sharply defined contacts with the surrounding material. Although patches of sand are present in a 90-km. belt that is not more than 5 km. wide, extending from Loiza to Hatillo, they attain maximum size, purity and number in the north central coastal area between Dorado and Barceloneta. Fifty separate deposits have been mapped in Lago Tortuguero and to the south of it, some as small as 50 ft. in diameter but

Jan 1, 1948

By J. Earl Frazier, Howard A. Meyerhoff

It is not known when silica sand was first noticed along the north coast of Puerto Rico, but the first mention of its occurrence was made in 1922, by N. L. Britton,1 who described its presence in isolated patches extending from Loiza westward beyond Manati. Further observations were made in 1925 and 1926 by Meyerhoff,2 who extended the known occurrences still farther westward to the low hill belt in the Quebradillas limestone immediately south of Hatillo. The extraordinary purity of the sands, which in most localities exhibit no contamination from the non-siliceous materials surrounding them, was quickly appreciated, and the feasibility of utilizing them for the manufacture of glass was investigated, initially by the Committee on Mineral Resources3 and later (1936) by the Puerto Rico Recon-structionAdministration and by H. C. Ray, mining engineer of the Insular Bureau of Mines. In 1934 samples submitted to the Hazel Atlas Glass Co., of Washington, Pennsylvania, were reported to have the composition as shown in the table on column two. Appreciation of the quality of the sand prompted geological and quantitative studies of the deposits, as well as cornmercial investigations to determine the feasibility of utilizing it locally or on the mainland for the manufacture of glass containers. Distribution of the Sands The quartz sands consistently lie within the outcrop area of the Quebradillas limestone, the youngest of the Miocene formations in the Tertiary coastal plain that fringes the northern coast of the Island. Many of the deposits are closely associated with limestone outcrops, but some appear to be embedded in lagoonal sediments at some distance from rock exposures, and at least one deposit, near Dorado, has been reworked by waves and littoral currents. With this single known exception, the deposits consist of irregular, patternless patches of white sand, which have sharply defined contacts with the surrounding material. Although patches of sand are present in a 90-km. belt that is not more than 5 km. wide, extending from Loiza to Hatillo, they attain maximum size, purity and number in the north central coastal area between Dorado and Barceloneta. Fifty separate deposits have been mapped in Lago Tortuguero and to the south of it, some as small as 50 ft. in diameter but

Jan 1, 1948

By D. G. Brubaker

IN the history of geophysical exploration by the electromagnetic method many procedures and types of equipment have been used. Source arrangements for surveying on the ground have included long wires grounded at both ends, large loops laid on the ground, small horizontal loops, and vertical loops of moderate to small sizes. Receivers have ranged from simple direction-finding coils to combinations of coils and a bridge circuit to measure quantities related to both amplitude and phase of the received signal. Primary considerations in choosing a survey method are effectiveness, speed, and economy. In work on the ground in which locating and outlining conducting bodies is the objective, methods using a vertical coil and a simple direction-finder have been found the most satisfactory. Mason1 and his associates applied such a method by setting up a vertical source loop, fed with low frequency alternating current by an engine-generator set. With a direction-finding receiver they surveyed lines along the ground in the plane of the loop, taking measurements at each station of the azimuth and inclination of the magnetic field direction. Deviations of this direction from the normal direction, that is, from horizontal and perpendicular to the traverse line, indicated a conducting body. Recent advances in design of light-weight generating equipment have encouraged using this and similar methods. In 1950 W. H. Westphal and the present writer developed a variation of this method and the apparatus for carrying it out. Their ideas were also based on experience with the Boliden Mining Co. method, which uses a small source coil and a vac- uum tube oscillator. The new procedure uses a small vertical source coil, powered by a vacuum tube oscillator, apd a direction-finding receiving coil. Source and receiver are kept a fixed distance apart and move as a unit along the survey lines. At each receiver station only the inclination of the magnetic field created by the source is measured. Source Unit: The source coil and a small vacuum tube oscillator together weigh about 45 lb. The source coil consists of about 60 turns of 10-gage

Jan 1, 1958

By P. Hadzeriga

There are two places in the world where potash, trade name for potassium chloride, is economically recovered from naturally occurring brines by solar evaporation. One is at the Dead Sea and the other at Wendover, Utah. American Potash and Chemical at Trona, Calif. recovers potash from natural brines, but uses fuel to accomplish evaporation. Solar evaporation is always desirable, because of low costs, however artificial evaporation may be economical if a group of very valuable salts are recovered. This is the case for the American Potash operations at Trona. Solar evaporation is limited by low working temperatures, which in most areas of the world is between 18 and 45°C. In many cases the average working temperature is about 25°C. However, solar evaporation will have to accommodate itself to the highs and lows of each 24 hour period, and to the different average temperatures during the months of the year. Therefore, solar evaporation, although more economical than artificial evaporation, has a tem- perature limit which greatly reduces the chances of its application. The feasibility of solar evaporation as a means of recovery of values from a particular brine, may be evaluated by the use of phase diagrams showing the several components present. This paper is restricted to the five component system: C1-, SO4=, Na+, K+, Mg++, and H2O, which correspond to brines found at Wendover, Utah, the Great Salt Lake, and sea water bitterns. THE BONNEVILLE OPERATION AT WENDOVER, UTAH For more than 25 years Bonneville, Ltd., now a division of Standard Magnesium and Chemical Co. (recently acquired by Kaiser Aluminum and Chemical Corp.), has been recovering potassium chloride from the brines found in the desert area just east of Wendover, Utah. Solar evaporation of the brines is possible as a consequence of relatively low precipitations (year average: 4.8 in.), and of dry and hot summer months. The brine, collected by a series of approximately 67 mi. of ditches crossing the desert, is fed into solar evaporation ponds. Evaporation which takes place from around the middle of May to about the end of September, permits the crystallization of approximately 90% of the originally present NaCl on what is called the "General Pond Area". Further evaporation,

Jan 1, 1964

By Merlyn B. Buhle

The value of the earth resistivity method in groundwater studies in Illinois has long been recognized. Owing to the sharp electrical contrasts between sand and gravel deposits and glacial till, alluvial silt or underlying shale, much of the earth resistivity prospecting has been of a relatively elementary nature and has been highly successful. Approximately 90 pct of earth resistivity interpretations by the State Geological Survey have been accurate for practical purposes. Four studies involving fairly simple geologic situations are presented in this paper as typical cases. FOR the past 20 years electrical earth resistivity exploration has been used in Illinois in many phases of study undertaken by the State Geological Survey, chiefly in locating and outlining deposits of water-bearing sand and gravel from which to obtain ground water for municipal and industrial supplies. At least 43 municipalities in the state derive their total water supply from deposits of sand and gravel discovered by resistivity methods. These deposits occur in both Quaternary and preglacial valleys and within much of the glacial drift which covers a large portion of the state. In recent years there has been much demand from rapidly growing municipalities for help from the Illinois Geological Survey to extend existing well fields. Water supplies for many and varied industries constitute a considerable portion of the Survey's studies. The diminishing need of water supplies for railroads has 'been accompanied by an increasing demand by the oil industry for water for secondary recovery programs. The instruments used by the Illinois Geological Survey follow closely the commutated direct current circuits developed by O. H. Gish and W. J. Rooney' using the Wenner2 electrode configuration. More recently replacement of the hand-driven commutator by a synchronous vibrator has led to increased ease of operation and accuracy. Continuing improvement of equipment and technique has led to many changes in the instruments, but the operating theory remains the same. In the field operation at a selected station, four electrodes are set at equal distances in the ground 6 to 10 in. deep, in a straight line. A 16 to 20-cycle current is applied to the two outside steel electrodes

Jan 1, 1954

By Sid T. Killan

The utilization of the reducing power of blast-furnace gas can be estimated by applying two rectifying calculations to the gas analysis. A resulting corrected CO/CO2 ratio varies inversely with furnace production. Directions for calculating the corrected CO/CO2 ratio are given, and a corrected CO/CO2 ratio is compared with actual furnace production. THE inadequacy of the normally accepted CO/CO, ratio as a measure of blast-furnace performance and furnace efficiency was discussed following the presentation of the paper by H. F. Dobscha.' In this outstanding example of careful observation on large scale blast-furnace operation, the changes occurring with beneficiated ores were: 1—A net gain in tonnage of 21.2 pct. 2—A decrease in net coke of 15.3 pct. 3—A decrease of 1.9 pct in the CO/CO, ratio. In this great change in furnace performance, the CO/CO, ratio proved itself worthless. The discussion of the inadequacy of expressing furnace performance and efficiency by the CO/CO, ratio led indirectly to the calculations forming the basis of this paper. At that time Dr. T. L. Joseph said: "We must consider difference in CO, from the stone in the two cases when we talk about the ratios of CO/C02." This statement is used for the second of the two CO/CO, ratio corrections forming the basis of this paper. The research work in attempting to find out why the furnaces could op-erate so differently with practically the same CO/CO, ratio lead not to the answer sought but, after a shift to the gaseous phase in the research work, the proof that the normal CO/ CO, ratio was outmoded and a new corrected ratio should replace it. To be of any value, any new corrected ratio should express approximate furnace efficiency and give an idea of practical furnace performance to be expected. This the normal CO/CO, ratio has failed to do. However, in the absence of anything better, some credence has been attached to the normal CO/CO, ratio. As far as the writer can ascertain, the present paper is the first attempt to change or improve the normally accepted index of

Jan 1, 1952

By E. H. Crabtree, V. W. Winters, T. G. Chapman

IN 1939 one of the authors* described advances in carbon-cyanidation for the period 1932 to 1939 • T. G. Chapman: A Cyanide Process Based on the Simultaneous Dissolution and Adsorption of Gold. Trans. AIME (1939) 134, 207. and included: (1) the dissolution of gold in an ore pulp by cyanide and its simultaneous adsorption by carbon, (2) the stage addition of adsorptive carbon and its movement countercurrent to the flow of the ore pulp, and (3) the recycling of adsorptive carbon. Considerable additional experimental and pilot plant work have been done by the authors since 1939 and the results of such work E. H. CRABTREE, JR., Member AIME, is Director of Milling, Eagle-Picher Mining and Smelting Co., Miami, Okla., V. W. WINTERS is Superintendent, Sahuarita Concentrator, Eagle-Picher Mining and Smelting Co., Tucson, Ariz., and T. G. CHAPMAN, Member AIME, is Dean, College of Mines, University of Arizona, Tucson. AIME Sun Francisco Meeting, February 1949. TP 2744 B. Discussion (2 copies) may be sent to Transactions AIME before March 31, 1950. Manuscript received March 3, 1949. have been sufficiently encouraging to justify a second paper. Developments from 1939 to 1948: In 1941, Verne W. Winters did the first experimental work in eliminating agitation during dissolution and adsorption and thereby demonstrated that the dissolution of gold by cyanide and its simultaneous adsorption by carbon take place essentially to completion in a stagnant pulp. Shortly thereafter, and as a result of the stagnant pulp experimental work, Winters and Chapman demonstrated that soluble gold, in a cyanide ore pulp, would migrate from the ore pulp through a perforated container and be adsorbed by carbon within the container. During the same year, the Eagle-Picher Mining and Smelting Co. erected a 25-ton capacity pilot plant at the Harquahala mine about 9 miles from Salome, Ariz. Experimental work at this plant comprised chiefly the stagnant pulp modification of carbon-cyanidation although considerable work was done in the grinding and activation of carbon, and testing various methods of extracting adsorbed gold from carbon. Soon after the completion of the Harquahala

Jan 1, 1951

By E. H. Crabtree, T. G. Chapman, V. W. Winters

IN 1939 one of the authors* described advances in carbon-cyanidation for the period 1932 to 1939 • T. G. Chapman: A Cyanide Process Based on the Simultaneous Dissolution and Adsorption of Gold. Trans. AIME (1939) 134, 207. and included: (1) the dissolution of gold in an ore pulp by cyanide and its simultaneous adsorption by carbon, (2) the stage addition of adsorptive carbon and its movement countercurrent to the flow of the ore pulp, and (3) the recycling of adsorptive carbon. Considerable additional experimental and pilot plant work have been done by the authors since 1939 and the results of such work E. H. CRABTREE, JR., Member AIME, is Director of Milling, Eagle-Picher Mining and Smelting Co., Miami, Okla., V. W. WINTERS is Superintendent, Sahuarita Concentrator, Eagle-Picher Mining and Smelting Co., Tucson, Ariz., and T. G. CHAPMAN, Member AIME, is Dean, College of Mines, University of Arizona, Tucson. AIME Sun Francisco Meeting, February 1949. TP 2744 B. Discussion (2 copies) may be sent to Transactions AIME before March 31, 1950. Manuscript received March 3, 1949. have been sufficiently encouraging to justify a second paper. Developments from 1939 to 1948: In 1941, Verne W. Winters did the first experimental work in eliminating agitation during dissolution and adsorption and thereby demonstrated that the dissolution of gold by cyanide and its simultaneous adsorption by carbon take place essentially to completion in a stagnant pulp. Shortly thereafter, and as a result of the stagnant pulp experimental work, Winters and Chapman demonstrated that soluble gold, in a cyanide ore pulp, would migrate from the ore pulp through a perforated container and be adsorbed by carbon within the container. During the same year, the Eagle-Picher Mining and Smelting Co. erected a 25-ton capacity pilot plant at the Harquahala mine about 9 miles from Salome, Ariz. Experimental work at this plant comprised chiefly the stagnant pulp modification of carbon-cyanidation although considerable work was done in the grinding and activation of carbon, and testing various methods of extracting adsorbed gold from carbon. Soon after the completion of the Harquahala

Jan 1, 1951

By Percy Hopkins

KIRKLAND LAKE, the second most important gold area in Ontario, is situated in the north¬eastern part of the Province, 392 miles north of Toronto by railway. It is reached by a five-mile macadam road from Swastika, a village on the Temiska-ming & Northern Ontario Railway, 63 miles north of Cobalt. Gold, was first found at Kirkland Lake in 1911 by W. H. Wright. on claim No. 1830, now a part of the Wright-Hargreaves mine. In January, 1912, the metal associated with various tellurides was found by Harry Oakes and George Tough on the Tough-Oakes property 3/4 mile east of the lake. The shipping of hand-sorted, extremely high-grade ore, valued at $350 to $450 in gold per ton, from this property created great interest and resulted in numerous other discoveries. The early developments of the area, however, were much retarded on account of war conditions, labor troubles, and owing to the ore zone being largely under the bed of Kirkland Lake or in drift-covered depressions. It was not until early in 1918, when the Lake Shore Co. found its rich orebody under the bottom of Kirkland Lake, that the various ore deposits were believed to be more or less continuous along one main vein system. From that time most of the work in the area has been done along the "main vein" with gratifying results. Production began late in 1912, and up to the end of March, 1923, the five producing mines have yielded gold, with some silver, valued at $8,379,403. The production in 1922 was $2,162,548; that of 1923 should be over $3,000,000. The same general assemblage of rocks which occurs at. Kirkland Lake extends easterly for many miles to Larder Lake and beyond; hence there is a large area containing formations favorable for gold prospecting. In this general area numerous prospects are being operated, and among the most promising ones, may be mentioned the Argonaut, Crown Reserve and Asso-ciated Goldfields near Larder Lake. A 25-mile branch railway is now being constructed across the mineral area from Swastika to Larder Lake, passing through Kirkland Lake.

Jan 8, 1923

By Thomas R. Cunningham, A. B. Kinzel

Silicon, unfortunately, is not in the same category as some other metals with respect to the absolute value of the highest purity material prepared. Tucker, in England, and Becket, in this country have developed procedures for the purification of silicon, and Becket's process has made industrially available silicon of a purity of 99.8 per cent or better. However, even the term "silicon metal" may be a paradox to some people, although not more so than the term "amorphous" as applied to silicon. These terms come from commerce, and "metal" is used to distinguish industrially high-purity silicon from ferrosilicon, silicon-aluminum, and other high-silicon alloys. Alloys of iron and silicon with 95 per cent Si or less are known as ferrosilicon, with a designation of silicon content where necessary, arid the term "silicon metal" is invariably applied to the grades containing 96 per cent Si and higher. The Becket method of purification was referred to in a monograph on the Alloys of Iron and Silicon, and the Tucker procedure was described in some detail in that publication.' In order to get silicon of still higher purity, a sample, prepared by the Becket method, analyzing 99.84 per cent Si, 0.020 Fe, 0.016 Al, 0.005 Ca, 0.025 C, 0.033 per cent 02, 0.006 H2, 0.006 N2, and 0.001 per cent Mn, was crushed to pass a 100-mesh sieve and further purified by a modification of Tucker's procedure. This modification differs from Tucker's method in that after treatment the 100-mesh alloy was centrifuged to remove the last traces of acid. Our directly determined analysis of this purified sample shows: Si, 99.952 per cent; Fe, 0.009; Al, 0.012; Ca, 0.003; C, 0.006; or 99.982 per cent. Silicon by difference equals 99.97 per cent. The variation between silicon by difference and silicon as directly determined is important. Although Tucker mentions the amount of insoluble matter in commercial silicon both before and after his treatment, he does not mention the existence of carbon in the alloy; nevertheless, he reports silicon by difference. Any final figure as to purity obviously results from agreement between direct determination and

Jan 1, 1940

By A. B. Kinzel, Thomas R. Cunningham

Silicon, unfortunately, is not in the same category as some other metals with respect to the absolute value of the highest purity material prepared. Tucker, in England, and Becket, in this country have developed procedures for the purification of silicon, and Becket's process has made industrially available silicon of a purity of 99.8 per cent or better. However, even the term "silicon metal" may be a paradox to some people, although not more so than the term "amorphous" as applied to silicon. These terms come from commerce, and "metal" is used to distinguish industrially high-purity silicon from ferrosilicon, silicon-aluminum, and other high-silicon alloys. Alloys of iron and silicon with 95 per cent Si or less are known as ferrosilicon, with a designation of silicon content where necessary, arid the term "silicon metal" is invariably applied to the grades containing 96 per cent Si and higher. The Becket method of purification was referred to in a monograph on the Alloys of Iron and Silicon, and the Tucker procedure was described in some detail in that publication.' In order to get silicon of still higher purity, a sample, prepared by the Becket method, analyzing 99.84 per cent Si, 0.020 Fe, 0.016 Al, 0.005 Ca, 0.025 C, 0.033 per cent 02, 0.006 H2, 0.006 N2, and 0.001 per cent Mn, was crushed to pass a 100-mesh sieve and further purified by a modification of Tucker's procedure. This modification differs from Tucker's method in that after treatment the 100-mesh alloy was centrifuged to remove the last traces of acid. Our directly determined analysis of this purified sample shows: Si, 99.952 per cent; Fe, 0.009; Al, 0.012; Ca, 0.003; C, 0.006; or 99.982 per cent. Silicon by difference equals 99.97 per cent. The variation between silicon by difference and silicon as directly determined is important. Although Tucker mentions the amount of insoluble matter in commercial silicon both before and after his treatment, he does not mention the existence of carbon in the alloy; nevertheless, he reports silicon by difference. Any final figure as to purity obviously results from agreement between direct determination and

Jan 1, 1940

By George C. Stone

The stack gases from regenerative furnaces lare very seldom utilized for the production of steam. If the temperature of the gases is not higher than 300" C. (572" F.) there is no economy in their use for this purpose, as the amount of available heat is very small and the temperature is so little above that of the steam that the interchange is too slow. With higher temperatures of the waste gases, however, good results can be obtained. At the plant of the New Jersey Zinc Co. (of Pa.) at Palmerton there are a number of return tubular boilers, each 6 ft. in diameter and 20 ft. long, with 96 3.5-in. tubes, which are heated by the waste gases from the spelter furnaces. These furnaces have continuous regenerators heating the air only and the stack gases reach the boilers at a temperature of about 450". The gas producers for one of these furnaces require 14 tons of anthracite (a mixture of Nos. 2 and 3 buckwheat), and the waste heat from the furnace gives a little more than 42 h.p. in steam. The boilers are not well adapted for the purpose, as they are much too large for the amount of heat going to them and the area of the tubes is not sufficient to take the gas from two furnaces without causing an objectionable amount of back pressure. The plant was built without any idea of using waste-heat boilers, and it was impossible to place the latter as close to the furnaces as they should be. Furnace and boiler are connected by an underground brick flue in which the temperature of the gas drops about 100°, losing 40 per cent. of its available heat. If the boilers were close to the furnaces the horse power of each would be 70 instead of 42. Even under these unfavorable conditions the boilers have been very advantageous, as one boiler easily supplies the steam necessary for two batteries of producers. With such low gas temperatures the heating surface of the boilers is, of course, not as efficient and the flue areas need to be considerably larger than for coal firing.

Jan 1, 1914