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By P. E. Fitzgerald

ACIDIZING, as the terns is used in the petroleum production industry, involves the use of hydrochloric acid in predominantly limestone formations, resulting in the lowering of resistance offered to the flow of oil and gas through the oil-bearing formation, usually with resultant increased production. A number of articles have been written on the chemical treatment of oil and gas wells; a bibliography of these works will appear in Volume 123 of the Institute's TRANSACTIONS (1937), and a few other references are appended to this paper.

Jan 1, 1937

By E. C. Tveter, R. B. Tippin

The separation of minerals by heavy liquids is a standard laboratory technique which goes back at least 50 years, but commercially economic application of this principal to ore concenfration has been prevented by problems of liquid recovery. Recent investigations which demonstrate the different types of liquid-solid systems on various ores using the two major heavy liquids - methylene bromide and tetra-bromoelhane — are discussed in this article. As a result of these studies, over-all liquid recovery, and especially desorption of heavy liquid from the mineral surface, was improved by the use of surfactants as well as both thermal and mechanical energy. The examples given in the article indicate that heavy liquids which should find major commercial use in ore concentration are now available. The sink-float process using a heavy liquid medium has long been recognized as a nearly perfect method of mineral separation based on the differences in density of the minerals. The use of heavy liquid separation (HLS) offers the potential of an ore dressing method that provides the maximum possible natural concentrate grade and high recovery. In addi- tion the process requires no water, causes no waste disposal problems, and is extremely simple — the crushed ore is merely introduced into a liquid whose density is between that of the minerals to be separated. The minerals lighter than the liquid float while those heavier than the liquid sink. As such, HLS has become a standard laboratory tool but major commercial application has been prevented by the requirement for complete recovery of the heavy liquid, imposed by economics and materials handling hazards. Investigations, both in the United States and abroad, have shown that improved liquid stability as well as improved chemical engineering techniques brighten the future for HLS in ore dressing. The available commercial heavy liquids suitable for mineral separation cost from $2.00 to $20.00 per gallon1 and on this basis alone their complete recovery is economically desirable. Possibly of even greater importance is the fact that any residual heavy liquid remaining on the products could create a serious toxicity hazard. Consequently, to make the process commercially attractive requires (1) essentially complete removal of the liquid from the ore products and (2) optimum recovery of the liquid for reuse. Until recently these two stipulations have remained as obstacles but laboratory and pilot plant research now in progress suggests that these may soon be overcome. Various heavy liquid recovery systems have been proposed to meet these requirements and might be classified into one or more of the following three general classes: Solvent Wash (Fig. 1): The dissolution of the heavy liquid from the ore with a less expensive solvent,

Jan 1, 1969

By H. C. Ray

ABOUT the beginning of 1930, coal preparation had reached the stage where the cleaning of coal by liquid or air had become the order of the day. Since that time many new preparation plants have been installed in spite of the years of depression in the coal industry, and this is indicative of a trend wherein the coal producer found it expedient to manufacture a cleaner product in order to compete with other fuels. It was also about 1930 that, because of the difficulties encountered with fine coal in cleaning plants, dust collectors came into use. Both cleaning plants and dust collectors, therefore, were much discussed at the engineering meetings of the early 1930's. During these meetings the many advantages to be gained through the use of dust-collecting systems were pointed out by Hebley,1 Appleyard2 and others. The great possibilities of new markets for this product were emphasized and discussed at the same time; however, the disposal of the collected dust remained a problem. Since the purpose of dust collecting is to improve the preparation and, consequently, the salability of the coal, it seems illogical to return the collected dust to any of the coal being prepared for market use, as is done in preparation plants that include dust-collecting systems. The logical thing is to dispose of the dust in some useful and practical manner outside of the tipple. As a practical matter, this can be done in one or both of two ways; either by consuming the dust at the mine's own power plant or by marketing the dust direct to the consumer. The latter method not only offers the greatest opportunities, but is the most important, because of inequalities that may exist between the quantity of dust collected and the consuming capacity of the mine's power plant. In considering the more important marketing possibilities, we are confronted immediately with the problems connected with the handling and transportation of so fine a material. It is this problem, rather than the problem of finding new markets, that has been responsible for the lack of progress in the matter of dust disposal. It is the purpose of this paper to point out again some of the potential market outlets, and also to describe an existing system of handling and transporting coal dust. To the best of the writer's knowledge, this is the first and only operation in this country that has handled fine-mesh coal in bulk 50-ton lots direct to the consumer. POtential Markets for Fine-mesh Coal Dust In general, the potential market outlets would include any operation of which the pulverization of coal is a necessary part. To be more specific, a few of the better known operations of this type must include: colloidal-fuel plants, briquetting plants, "sea coal" distributing plants, water-purification plants and, obviously, pow-

Jan 1, 1944

By H. C. Ray

ABOUT the beginning of 1930, coal preparation had reached the stage where the cleaning of coal by liquid or air had become the order of the day. Since that time many new preparation plants have been installed in spite of the years of depression in the coal industry, and this is indicative of a trend wherein the coal producer found it expedient to manufacture a cleaner product in order to compete with other fuels. It was also about 1930 that, because of the difficulties encountered with fine coal in cleaning plants, dust collectors came into use. Both cleaning plants and dust collectors, therefore, were much discussed at the engineering meetings of the early 1930's. During these meetings the many advantages to be gained through the use of dust-collecting systems were pointed out by Hebley,1 Appleyard2 and others. The great possibilities of new markets for this product were emphasized and discussed at the same time; however, the disposal of the collected dust remained a problem. Since the purpose of dust collecting is to improve the preparation and, consequently, the salability of the coal, it seems illogical to return the collected dust to any of the coal being prepared for market use, as is done in preparation plants that include dust-collecting systems. The logical thing is to dispose of the dust in some useful and practical manner outside of the tipple. As a practical matter, this can be done in one or both of two ways; either by consuming the dust at the mine's own power plant or by marketing the dust direct to the consumer. The latter method not only offers the greatest opportunities, but is the most important, because of inequalities that may exist between the quantity of dust collected and the consuming capacity of the mine's power plant. In considering the more important marketing possibilities, we are confronted immediately with the problems connected with the handling and transportation of so fine a material. It is this problem, rather than the problem of finding new markets, that has been responsible for the lack of progress in the matter of dust disposal. It is the purpose of this paper to point out again some of the potential market outlets, and also to describe an existing system of handling and transporting coal dust. To the best of the writer's knowledge, this is the first and only operation in this country that has handled fine-mesh coal in bulk 50-ton lots direct to the consumer. POtential Markets for Fine-mesh Coal Dust In general, the potential market outlets would include any operation of which the pulverization of coal is a necessary part. To be more specific, a few of the better known operations of this type must include: colloidal-fuel plants, briquetting plants, "sea coal" distributing plants, water-purification plants and, obviously, pow-

Jan 1, 1944

By Robert E. Thurmond

DISCOVERY of a commercial ore deposit has resulted from a program emphasizing geophysical techniques and concentrating upon exploration of alluvial-covered areas. United Geophysical Co. selected these areas as offering the best possibility of success, for here the surface evidence of ore deposits has been hidden from the eyes of prospector and geologist alike. Pima mining district, Pima County, Arizona, was selected for initial exploration. The project was successful in that a commercial ore deposit was discovered and proved through drilling and extensive underground development. A limited region of activity was chosen and library research was begun on available economic and regional geological publications relating to the mining districts. Field reconnaissance of those districts which seemed to hold exploration possibilities provided a general picture and ascertained the existence of alluvial-covered areas of interest. At the conclusion of the reconnaissance trips all data obtained were compiled, and the district which seemed to present the best exploration possibilities was selected by statistical methods. The statistical summary was based on the following considerations: Geological Factors: 1—type of intrusive, P—presence of favorable host rocks, 3—apparent intensity of mineralization, and 4—presence of favorable structure in covered or unexplored areas. Economic Factors: 1—past production from district or mine; 2—size, shape, grade, and type of ore deposit in the district; 3—ease of acquiring mineral rights; and 4—general development facility. Exploration Favorability Factors: 1—results to be anticipated from geological methods alone; 2—application of geophysical methods, namely, topographic conditions, surface interference, depth-size relation, physical property contrasts as related to ores or controlling structural features; and 3—drilling factors. Admittedly, many of these, factors do not lend themselves to absolute evaluation, but relative evaluation, subject to inaccuracies of personal judgment, is always possible. A relative scale from 1 to 10 was established for every factor, representing varying degrees of favorability. For each district a numerical evaluation of each factor was established and a numerical total determined. The obvious advantage of this scheme is that a more concise summation can be presented by numerical means than can be achieved by descriptive means. After a district had been selected as favorable, the first step was to carry out more detailed geological and economic studies to narrow down the areas of interest. The second step was to compile all available geological data from publications and add to these data by mapping where necessary. Geological interpretation and projection of structural or other control into covered or unexplored areas was made whenever logical. To determine the possibilities of geophysical application and to select a geophysical method, physical property contrasts were related to mineral assemblages and/or structural control. If geophysics seemed applicable, trial profiles were run crossing the area normal to the strike and spaced

Jan 1, 1955

By James Ruddy

THE medical program of the Climax Molybdenum Co. is under the supervision of the department of industrial medicine of the University of Colorado, of which James J. Waring, professor of medicine at the University Medical School, is director. Dr. Waring is consultant and direct supervisor of both the hospital and industrial medical department at Climax. At Climax the program is in charge of the medical director and the associate physician, Dr. Galen M. Hover. The hospital at Climax is completely equipped with all that is necessary for the practice of scientific medicine and surgery. Only graduate registered nurses with experience in industrial medicine are employed. Being only a few hundred yards from the portal of the mine. acci-

Jan 1, 1946

By AIME AIME

THIS year's Chairman of the Institute of Metals Division is a relatively rare phenomenon in the metallurgical profession; he is an expert historian of metallurgy, he is a confirmed collector and student of old works on alchemy, chemistry, and metallurgy-vide: the famous Biringuccio and he is a profound student (with a somewhat idealistic slant) of recent trends in world affairs and in what some incurable optimists call civilization; and at the same time he is still possessed of a sense of humor. Incidentally he is also one of the bestknown nonferrous metallurgists in this country and abroad, and for fifteen years has been a willing worker in A.I.M.E and the Institute of Metals Division.

Jan 1, 1943

By T. D. Tiemann

Extraction of silica from the taconites of the Wisconsin Gogebic range by high temperature digestion in caustic solutions has been described.1,2 The ores consist essentially of hematite, goethite, and microcrystalline quartz, detailed descriptions of which appear in the literature.1,3 It is the purpose of this communication to describe some results obtained from a laboratory investigation of an alternative method, that of sintering the ore with sodium carbonate followed by water extraction of the sodium silicate produced. This is analogous to the Deville-Péchiney4,5 soda ash sinter process for the production of alumina from bauxites in which soluble sodium aluminates are formed. Raw mixes of the desired composition were prepared from 10.0 g minus 200 mesh samples of taconite and sintered in nickel crucibles in a muffle furnace controlled to within ±10°F of the operating temperatures. The resulting sinters were pulverized and then leached in distilled water with continuous agitation for 30 minutes at 95°C. The suspensions were vacuum filtered and the residues dried, ignited and weighed. Iron assays on the ignited samples were made by the standard dichromate procedure after dissolution in hydrochloric acid. The percentage of extraction was calculated from the iron assays by the relation:

Jan 1, 1964

By P. de Vitry, Oliver Bowles

The conventional wire saw, introduced in the slate district of Pennsylvania by the Bureau of Mines in 1927, and used thereafter with remarkable success, consists of a three-strand steel cable having a diameter of 93/16 or 54 in. The equipment, methods used, and accomplishments have been described in previous reports.'-I Similar wire saws have been used extensively in Europe, in quarries and in shaping blocks and slabs. During the period 1932-1937, competition in European marble quarries was keen, prices were declining, and orders were not abundant. When orders were received, there was generally an urgent call for speedy delivery. Because of the diversification of demands, it was impossible to maintain in stock marbles of the color, size, and thickness called for, therefore the material generally had to be fabricated after the order was received. The wire saw enabled stone mills to fill such orders promptly. With skillful handling, 7/8-in. slabs could be cut accurately and rapidly with this equipment. It was found, however, that, as the three-strand wire became worn, the cutting speed dropped rapidly and the cut became less accurate. To overcome these difficulties the junior author of this paper, after much experimentation, developed a new type of wire consisting of a single ribbon-shaped strand, twisted as shown in Fig. I. To ensure straight sawing, the twist of the ribbon is reversed from right to left and vice versa every 25 ft. The reversal of the twist is shown in Fig. 2. This is not a new feature; it has been used to advantage with the three-strand wire both in Europe and America for several years. However, some difficulties arise in splicing the three-strand reverse-twist wire, and the claim is made that cutting is less accurate as the wire becomes worn. To make an endless belt, the ends of the single-strand wire are brazed together with Pyrophyllite is a hydrous aluminum silicate (A1²Si4O10(OH)²)1 that, occurs in both the foliated and the massive forms. The foliated variety resembles talc in that it has a greasy feel, a pearly luster, perfect basal cleavage, and usually is white, although in some deposits apple green, gray, brown, russet, and nearly black specimens may be found. The massive deposits of pyrophyllite yield pearl gray to light tan aggregates, some of which are so friable that they may be crushed with the hands into a fine gritty powder. Frequently specimens of the massive variety are studded with crystals of radial structure. The mineral has a specific gravity of about 2.7 and a hardness of 1 on Mohs' scale.' The chemical composition of commercial pyrophyllite reflects the mineralogy of the deposits, which, according to Stuckey12 contain pyrophyllite and quartz, together with chloritoid, sericite, and a few other minerals of negligible importance. The latter, he says, ('are noticed in but small quantities to the extent they might occur as accessory constituents of an igneous rock or as products of regional metamorphism or weathering. . . . Quartz is abundant everywhere except in the very best grades of pyrophyllite." Analyses of specimens from several deposits are listed in Table 1, showing that the silica content varies from 57 to 73 per cent and the alumina from 22 to 33 per cent. Oxides of iron and the alkaline metals are collectively present, with one exception, to an extent of about 1 to 1.5 per cent. Sources At present, North Carolina is the only commercial source of pyrophyllite, although the mineral has been found in small quantities in many parts of the world. The North Carolina deposits are in the "Carolina Slate Belt," which traverses the center of the state in a southwesterly direction. This belt varies from 8 to 50 miles in width. Two major deposits of pyrophyllite lie along its eastern boundary, in what is known as the Deep

Jan 1, 1942

By P. de Vitry, Oliver Bowles

The conventional wire saw, introduced in the slate district of Pennsylvania by the Bureau of Mines in 1927, and used thereafter with remarkable success, consists of a three-strand steel cable having a diameter of 93/16 or 54 in. The equipment, methods used, and accomplishments have been described in previous reports.'-I Similar wire saws have been used extensively in Europe, in quarries and in shaping blocks and slabs. During the period 1932-1937, competition in European marble quarries was keen, prices were declining, and orders were not abundant. When orders were received, there was generally an urgent call for speedy delivery. Because of the diversification of demands, it was impossible to maintain in stock marbles of the color, size, and thickness called for, therefore the material generally had to be fabricated after the order was received. The wire saw enabled stone mills to fill such orders promptly. With skillful handling, 7/8-in. slabs could be cut accurately and rapidly with this equipment. It was found, however, that, as the three-strand wire became worn, the cutting speed dropped rapidly and the cut became less accurate. To overcome these difficulties the junior author of this paper, after much experimentation, developed a new type of wire consisting of a single ribbon-shaped strand, twisted as shown in Fig. I. To ensure straight sawing, the twist of the ribbon is reversed from right to left and vice versa every 25 ft. The reversal of the twist is shown in Fig. 2. This is not a new feature; it has been used to advantage with the three-strand wire both in Europe and America for several years. However, some difficulties arise in splicing the three-strand reverse-twist wire, and the claim is made that cutting is less accurate as the wire becomes worn. To make an endless belt, the ends of the single-strand wire are brazed together with Pyrophyllite is a hydrous aluminum silicate (A1²Si4O10(OH)²)1 that, occurs in both the foliated and the massive forms. The foliated variety resembles talc in that it has a greasy feel, a pearly luster, perfect basal cleavage, and usually is white, although in some deposits apple green, gray, brown, russet, and nearly black specimens may be found. The massive deposits of pyrophyllite yield pearl gray to light tan aggregates, some of which are so friable that they may be crushed with the hands into a fine gritty powder. Frequently specimens of the massive variety are studded with crystals of radial structure. The mineral has a specific gravity of about 2.7 and a hardness of 1 on Mohs' scale.' The chemical composition of commercial pyrophyllite reflects the mineralogy of the deposits, which, according to Stuckey12 contain pyrophyllite and quartz, together with chloritoid, sericite, and a few other minerals of negligible importance. The latter, he says, ('are noticed in but small quantities to the extent they might occur as accessory constituents of an igneous rock or as products of regional metamorphism or weathering. . . . Quartz is abundant everywhere except in the very best grades of pyrophyllite." Analyses of specimens from several deposits are listed in Table 1, showing that the silica content varies from 57 to 73 per cent and the alumina from 22 to 33 per cent. Oxides of iron and the alkaline metals are collectively present, with one exception, to an extent of about 1 to 1.5 per cent. Sources At present, North Carolina is the only commercial source of pyrophyllite, although the mineral has been found in small quantities in many parts of the world. The North Carolina deposits are in the "Carolina Slate Belt," which traverses the center of the state in a southwesterly direction. This belt varies from 8 to 50 miles in width. Two major deposits of pyrophyllite lie along its eastern boundary, in what is known as the Deep

Jan 1, 1942

By F. S. Sinnatt

This paper is the outcome of an extended investigation carried out in association with Dr. L. Slater. The inquiry had been continued in various directions and a number of results are quoted from an investigation recently completed by S. H. Jenkins. In projecting the work some five years ago, the author had in view a general attack on the problem of the spontaneous combustion of coal from an angle that had received little attention. The basic idea was to obtain a "slow motion study" of the active combustion of coal. This included an examination of the conditions prevailing in a mass of coal at the moment when active combustion ceases. It was thought that, if the factors governing the extinction of combustion in coal could be definitely established, it might offer an explanation of the manner in which the spontaneous combustion of coal originates. The inquiry arose from a detailed study of the properties of fusain that the author began in 1918. Fusain seemed to possess characteristics quite distinct from the coal with which it was associated, for if it were collected into a heap and one portion were heated by a small flame the combustion would traverse the whole mass. This combustion was not accompanied by smoke and passed slowly through the heap of material. Later, it was found that coals, including anthracites, would behave in a similar manner provided they were in the form of powder and that the particles were smaller than a certain size. The limiting size of particles is a definite characteristic of the coals investigated. In view of the fact that fusain exists with coal in a state that enables it to undergo this particular form of combustion, it must be assumed, sometimes, to play a definite part in the spontaneous combustion of coal in the goaf (waste). Tables 1 and 2 contain the analyses of samples of dust collected from a mine and from a dust collector. Some idea of the degree of fineness of the particles of fusain may be obtained from a study of the analyses of the dust from the dust collector; 80 per cent. of the dust would pass through a 200-mesh screen while the fusain was concentrated in the finest dust. The material that passed through a 90-mesh screen contained 54 per cent. of fusain while that between a 30- and a 90-mesh only con-

Jan 1, 1925

By E. P. Jennings

The abundance and value of the tellurium minerals of Colorado is well known, but, as yet, few analyses have been made of them, and I offer these as a small contribution to the chemistry of these valuable ores. 1. Native Tellurium.—The specimens from which the analyses of this mineral were made are from the " John Jay" Mine, Boulder County, Colorado, where it occurs in quite large masses, though mixed with more or less silica and iron pyrites. It is usually a finegrained, tin-white mineral, but sometimes occurs in distorted, hexagonal prisms in cavities in the quartz. Before the blowpipe it gives the reactions for tellurium, sulphur and iron; by cupellation, it yields a small amount of gold. An analysis of a coarsely crystallized specilnen gave the following results : Specific gravity, 5.10.5. Tellurium,.........68.40 Gold, :.........1.36 Iron pyrites,........24 92 Ferric oxide,.....4.37 Silica and silicates,........11.54 Silver, lead, and mercury,... traces. 100.59 Deducting the pyrites, iron oxide and silica, we have for the con]position of the mineral: Tellurium,..........97.78 Gold,.......... 2.27 100.00 Or, considering the gold to be in combination with tellurium to form sylvanite, we have : Nativc tellurium,........96.50 Sylvanite (An, Te3,),........4.50 100.00

Jan 1, 1879

By George H. Jones

NO STRANGER phenomenon exists in the American mining industry today than the so-called bootleg anthracite industry in Pennsylvania which now produces probably close to 15 per cent of the total hard coal out- put of the State. Instead of being what - was first thought to be a temporary condition, countenanced because of the desperate condition of some of the miners at the depth of the depression. it is thriving now as never before. Re- ports of it have penetrated all over the world, as exemplified by inquiries concerning it in Durban, South Africa mentioned by John C. Cosgrove in his article in the July MINING AND META LURGY.

Jan 1, 1939

By W. Robert Power

Dimension stone is considered by many the premium material for beauty and durability in institutional and monumental construction. Nonetheless in the United States it commands an ever decreasing share of the total market. At the beginning of the century dimension stone accounted for more than half the stone produced in the United States, but by 1974 it accounted for little more than 0.2% and the number of producing quarries and finishing plants had greatly reduced. This decrease in use is accounted for in part by competition from cheaper materials, but another factor seems to be the demand by many designers for uniformity and exact repetition of modular units in construction. Even where stone is used in large buildings modem architects want blandness of pattern and uniformity of color in the stone. Because most natural stone contains variations in color and pattern great strain is put on the quarriers to overcome this and produce a uniform product. This results in increased costs, increased waste at the quarries, and consequently increased price in the market. In spite of this, stone is still looked on as the most prestigious of building materials and its aesthetic appeal is born out by the many simulated stone patterns found in synthetic materials. End Use and Specifications The principal uses of dimension stone are in building construction and monuments. Other uses include flagging, curbing, paving, mill-stock slate, roofing slate, laboratory furniture, and refractory brick. Because many of these uses overlap, an orderly classification of dimension stone uses is most difficult. Various classifications have been used by Cumer (1960), Barton (1968), the U.S. Bureau of Mines yearbooks, and the Building Stone Institute (Anon., 1972).

Jan 1, 1975

By Clemens Jones

A FORM of apparatus for volumetric determinations which shall possess the features requisite for the constant use of potassium permanganate, is a very desirable fixture in a well-appointed laboratory. Expedients to economize time and insure accuracy are generously employed for various other reagents, while the permanganate seems to have been consigned to the use of an ordinary burette, and a black bottle of the standardized solution. But the introduction of new, methods dependent on the permanganate, and the urgency of technical requirements where it has long been indispensable, require a revision of practice more scientific and convenient. The apparatus designed by the writer for the laboratory of the Thomas Iron Company at Hokendauqua, Pa., is so simply contrived and works with such entire satisfaction that a description of it may be of use. It may be prefaced that the characteristics of a suitable device offer some mechanical difficulties when combined in a continuous appliance. The burette, B (50 C.C. to 1/10 c.c.), shown in Fig. 1, consists of the graduated tube proper and an arm, E, fused to it below the 50 c.c. mark. At its top are rubber connections with the blast-aspirator, shown in the cut (Fig. 2) of the front view. By means of an extra stopcock, D, connection through E is established with the reservoir F. The burette is clamped Securely to a slide, C, which is counterpoised and moves freely on guides between two parallel sides, L, suitably

Jan 1, 1887

By Smith Bracewell

First evidence of bauxite in Jamaica resulted from an analysis of a soil sample collected at Bull Savannah in 1938 during a systematic local investigation of the island's soil types. Results of subsequent work indicated the possibility of the occurrence of deposits of commercial grade and dimensions, and in 1942, with a view to emergency development of the deposits as a war measure, the Jamaican Government declared all bauxite in the colony to be Crown property.

Jan 10, 1958

By PHILIP N. MOORE

PHILIP NORTH MOORE was born on July 8, 1849, at Connersville, Ind. His father, a civil engineer, was descended from Henry Moore who came from Ireland in 1773 to live in Washington, Pa. Through his mother, Philip Moore was descended from John North, who came to America in 1635 and settled in Connecticut. The story of Mr. Moore's life as told by himself is given on pages 373-386 of T. A. Rickard's "Interviews with Mining Engineers." He studied at Miami University, where he gained the degree of A.B. in 1870, and A.M. in 1873. In 1920 his alma muter conferred on him the honorary degree of LL.D. He, as a special student, was a member of the class of 1872 at the School of Mines of Columbia University.

Jan 1, 1930

By Louise B. Freeman

Kentucky for the first time in its oil history passed the 10 million barrel mark. Of the total 10,019,641 bbl., 8,262,516 bbl. were produced in Western Kentucky, and Union County surpassed all others, with 4,056,142 bbl., or 40 percent of all the production for the state. There were 930 wells known to have been drilled during the year; 510 in Western Kentucky and 221 in the gas-producing area of Eastern Kentucky.

Jan 1, 1946

By Nev A. Gokcen

PUBLISHED data on the solubility of nitrogen in liquid manganese are widely discordant. Ochsenfeldl observed that a Mn-N alloy with 3.6 pct N consisted of solid and liquid phases at 1260°C but at 13 00° to 1340°C the solid phase disappeared and the liquid contained 0.1 to 0.13 pct N. In contrast Saito's measurements at approxhately 1400°C yielded an average value of 0.97 pct N. Sieverts3 volumetric method is not suitable for the determination of gas solubility in manganese because the liquid metal vaporizes readily and condenses in the cooler parts of the apparatus where it can absorb large amounts of nitrogen. The purpose of this investigation was, therefore, to determine the solubility of nitrogen in manganese accurately in the range of 1273" to 1500°C. The experimental method used in this study was as follows. Electrolytic manganese of 99.9 pct purity, and weighing 50 g, was melted in a pure alumina crucible placed in a tubular furnace. Temperature was measured with a Pt-10 pct Rh thermocouple and controlled within ± 5°C. Pure nitrogen was bubbled through the melt for 1 hr at constant temperature and then a sample was taken by sucking the metal into a 2-mm clear silica tube and immediately quenching in water. The sample was broken into small pieces and found to be sound to the naked eye. The entire sample was then dissolved and the resulting solution was analyzed for nitrogen by the well-known solution-distillation method. The experimental results are presented in Fig. 1. All the nitrogen solubility data refer to 1 atm of nitrogen pressure; hence the observed values are slightly corrected by using Sieverts' equation when the atmospheric pressure differed more than 5 mm Hg from 760 mm, and further, in the case of the runs at 1500°C the correction arising from the presence of Mn vapor has been made. (Cf. Eq. [3]). Scattering in the data is within ±5°C in temperature measurement and ±3 pct in total nitrogen analysis. The straight line in Fig. 1, correlating the percentage of dissolved nitrogen, %N, with the inverse temperature in OK-1, can be expressed by:

Jan 1, 1962

By AIME AIME

AN ENGINEER with as varied geographical experience as H. J. Brown does not often specialize on one particular thing all of his professional life. For forty years he has been engaged in gypsum mining, manufacturing, plant design, construction, and operation. Not only is it his work, but he says it is his hobby as well, though membership in three yacht clubs might belie that statement. New England's new representative on the A.I.M.E. Directorate, who was born in New York, Dec. 20, 1879, went to the Lawrence Scientific School at Harvard at the turn of the century. He tried journalism for a year, with the Boston News Bureau and associated financial

Jan 1, 1940