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By A. R. Denison

This field in 1933 continued as in 1932, although to a much less extent, to dominate the drilling and production situation throughout the oil business. The 2466 producers completed in this field during the year are 28 per cent of such wells completed in the United States. The 2556 completions reported in the five counties within which the East Texas field lies are 21 per cent of all such wells reported in the United States. It follows that with such a command of the development situation, every other factor with regard to this field has an important bearing on the entire oil business. As a consequence, the important developments in the East Texas field are the important developments of the year. Very little new productive territory was added to the already known limits of this enormous field. On the other hand, drilling has shown that with a few very minor exceptions this field is a continuous productive area, with a regular outline and no "dry spots" other than that of a single well surrounded by producing wells. Drilling was confined to the already proven limits of the field. This consisted essentially of more adequate coverage of leases by wells, the meeting of required offsets and the drilling of a large number of small tracts which developed from subdivision of larger leases due to court action and other causes. The allowable throughout the year was, with minor variable factors, on a per-well basis. With the steady decline in per-well allowable after May, every operator was faced with declining

Jan 1, 1934

By Adrian E. Ross

DRILLING through caving formations in diamond drill holes at depths greater than 2000 ft has long been a serious problem. These caving formations are normally passed only by casing the hole or by cementing the hole. Casing the hole is possible only when a resulting smaller hole is acceptable. In as much as only a limited number of reductions are economically practical, cementing is frequently considered the only method suitable for solving these problems. Cementing either by pumping a slurry into the hole or by dropping cylinders containing cement has proved satisfactory on holes under 2000 ft. In holes substantially deeper than 2000 ft these methods are not satisfactory, since during the pumping process cement separates out, whereas cylinders usually break before the bottom of the hole is reached. A new procedure, the injector method, apparently solves these problems.* With this method, cement is lowered in the hole in a cylinder, the cement being

Jan 1, 1952

Jan 1, 1934

By George W. King

The yield strength of a dispersion-hardened W-3.8 vol pct Tho,alloy, in both the recovered and recrys-tallized condition, was investigated and cornpared with that ofrecrystallized pure tungsten over the temperature range of 325" to 2400°C. It is deduced that the Orowan mechanism is obeyed in the recrystallized alloy. In the recovered alloy, a further enhancement of the yield strength results from the retained substructure which is stable up to temperatures in excess of 2700°C. Temperature and strain rate cycling tests were also performed, and the apparent activation energy for the deformation process was derived. This activation energy, - 3 ev, for the recovered and also the recrystallized alloy was about the same as that for re crystallized pure tungsten. However, the activation volume of the recovered alloy, -10-2 cu cm, was about an order of magnitude lower than that of the recrystallized alloy or pure tungsten. This fact accounts for an enhancement oj- the temperature dependence of the yield stress of the recovered alloy. A dislocation velocity exponent of about 4 to 13 was deduced frorn the strain rate cycling tests , which is in good agreement with values reported for tungsten single crystals. VARIOUS theories have been developed to explain the enhanced yield strength of a metal containing a dispersed second phase of small hard particles. These theories are thoroughly reviewed by Kelly and Nicholson.' The theoretical models can be separated into two types. The first type assumes direct interactions between moving dislocations and dispersoids. One of the most widely investigated models for this mechanism is the bowing out of dislocations between the dis-persoids and their subsequent pinching off in order to bypass the obstacles. This is the well-known Orowan mechanism.' The second type is an indirect effect of the dispersion because of its ability to stabilize to high temperatures the substructure introduced by cold working. In this instance, the increment in the yield strength is expected to be inversely proportional to the square root of the subgrain diameter. In the present work, a quantitative study was made of the strengthening effect caused by a thoria dispersion in a recrystallized W-3.8 vol pct Thoz alloy over the temperature range 325" to 2400°C. The results are compared with the increment predicted for the Orowan mechanism based on the calculations by ~shb~.~ In addition, the alloy was tested in the recovered state so that any additional strengthening resulting from the substructure produced during fabrication could be measured. The respective contributions can be separated in this manner, provided that the particle size distribution of the dispersion remains the same in both the work-hardened and the recrystallized state. Particle size distribution measurements showed that this condition was met in the present work. I) EXPERIMENTAL PROCEDURES A) Material Production and Fabrication. The alloy investigated is essentially the same as that reported much earlier by ~effries,~ who also found the strength of tungsten to be improved by the thoria dispersion. The procedure for producing the alloy consisted of mechanically blending a thorium nitrate solution in proper concentration with tungsten oxide (WO3) powder, followed by hydrogen reduction to metal powder. After reduction, the dispersed second phase is present as thoria (Thoz). The pure tungsten powder used for comparison was produced in the same manner except that the thoria doping step was omitted. The powders were consolidated by cold pressing and self-resistance sintering in hydrogen. The resulting ingot had a cross section about 0.6 sq in. and a density about 93 pct of theoretical. The ingot was swaged to 0.174-in.-diam rod at temperatures varying from 1650°C initially to -1200°C near final rod sizes. Two intermediate recrystallization anneals were employed during fabrication. Analysis of the swaged rods is reported in Table I. B) Electron Microscopy Techniques. Carbon extraction rrPxcas prepared by a technique reported by ~00' were used to quantitatively evaluate the thoria particle size and distribution. Electron nlicrographs of extraction replicas were taken at 20,000 times but were then enlarged two to three times in printing. The areas photographed were randomly selected. A Zeiss Particle Size Analyzer (Model TGZ3) was used to count and measure the sizes of all particles present on the print. About three thousand particles were counted in determining a distribution curve. Electron transmission microscopy was used to determine the effect of annealing on the substructures of the materials. Thin foils were produced by a two-stage thinning process. The rods were first ground on emery paper to ribbons about 10 mils thick and then a jet of 5 pct KOH was used to electrolytically reduce a portion of the cross section of the ribbon. Final perforation was achieved by immersing the specimen in a 5 pct KOH solution and electrolytically polishing at a current density of about 0.3 amp cm-'. The foils were examined with a Hitachi HU-11A electron microscope. C) Tensile Testing. Tensile testing was performed in an Instron Testing Machine equipped with a radiation-type vacuum furnace which operates at about 1O"S torr at temperatures as high as 2400 °C. The same furnace was used for annealing the tensile specimens.

Jan 1, 1970

By R. B. Adair, J. S. Browning

The Bureau of Mines conducted laboratory research to determine the applicability of heavy liquid separation to the evaluation of certain mica ores and plant products. After careful standardization of the particular mica ores and associated gangue, accurate analysis of muscovite content could be obtained from results of heavy liquid separation. Where applicable, the method should be particularly suited to the analysis of ores and control of plant operations wherein savings in time would be of considerable advantage. Specifically, there are many instances where a quick plant control method should enable the production of a more uniform grade of mica concentrate. The laboratory use of various heavy liquids for separating minerals of different specific gravities has been recognized for many years.1-8 Sink-float procedures have proven their utility as a rapid and moderately accurate means for determining the mineral content of ores, test products, and plant products in certain nonmetallic concentrating operations. A standard method of analysis for mica in ore samples has not been published or generally accepted by the mica industry. Recently, the U.S. Bureau of Mines investigated methods for analyzing mica by heavy liquid separation. This report has been prepared to make the methods available to others who may need simple, relatively rapid methods of determining the mica content of ores and plant products. The heavy liquid method of mica determination has recently been adopted by one of the major mica producers for evaluating exploration and mill control samples. DESCRIPTION OF THE ORES AND HEAVY LlQLllD The weathered mica pegmatite ores used in the investigation were obtained from commercial mica op erations in Alabama, Georgia, and North Carolina. The major mineral constituents of the ores were muscovite, quartz, kaolin, and minerals of the feldspar group. The ores also contained minor quantities of biotite, limonite, and tourmaline. A comparison of the specific gravities of the major constituents of the ores (muscovite 2.76 +, quartz 2.65, kaolin 2.61, and feldspar 2.57), indicates that an effective separation of muscovite from the other minerals can be made in heavy liquids at a specific

Jan 1, 1968

By E. A. Anderson

THE copper-zinc phase equilibrium diagram has been the sub-ject of many investigations. Until recently, however, the boundary of the terminal solid solution of copper in zinc (eta) has not been thoroughly investigated. This paper reports determinations of the solid solubility of copper in zinc at temperatures from 100° to 400° C., the course of the liquidus and solidus for the eta solid solution and determinations of the peritectic temperature and peritectic point for the reaction between epsilon and the melt to form eta. The liquidus of the eta phase was determined by thermal analysis and the solidus by the microscopical examination of specimens quenched from temperatures above and below the solidus. The temperature of the peritectic horizontal was obtained by thermal analysis and the com-position at the peritectic point was determined by extrapolation of the solid solubility boundary of the eta phase to the peritectic horizontal. The solid solubility boundary of the eta solid solution was investigated very carefully. Particular care was used to achieve equilibrium in the alloys at each temperature selected. The X-ray, electrical con-ductivity and microscopical methods were used in determining the solid solubility limits. The X-ray method measures the changes in the solvent lattice with increasing solute content and in this manner locates the composition of the alloy at which no further change in the solvent lattice takes place, the limit of solid solubility. The method of electrical conductivity measures the conductivity of the alloys of a graded series of compositions, whereby the solubility limit is indicated by a discontinuity in the conductivity-

Jan 1, 1934

By Charles H. Thurman

THE data given herein were first included in a paper read before San Francisco Section, A.I.M.E., in October 1940, and are applicable to conditions existing until the gold-dredging industry was temporarily suspended by Order L-208 of the War Production Board in the fall of 1942. There is no doubt that gold dredging will be resumed at some future time, and on a scale equivalent to that of the recent past, but the cost data given herein will be affected to some extent by conditions existing at that time, and by labor rates and prices for materials then prevailing. DRAGLINE VS. BUCKET-LINE Dragline dredges should not be considered for mining large areas of low-grade placer gravel. In such deposits a dragline operator with a 5-cu. yd. dragline would be doing well to maintain an operating cost of 6¢ per cu. yd., while a bucket-line dredge with buckets no smaller than 7 cu. ft. each could be operated for less than 4¢ per cu. yd. By operating costs, I mean only field charges such as direct operating and overhead, which includes pay roll, power or fuel, repairs and maintenance, insurance, land clearing and general expenses, but not including such items as prospecting, depletion, depreciation of equipment, State Franchise Tax, or Federal Income Tax. It is not to be inferred that a dragline dredge cannot make a profit in small low-grade deposits, where the extent of a given property is too small to justify the use of the more costly bucket-line dredge. Consider small deposits of 10¢ gravel. It is obvious that a deposit of 5,000,000 cu. yd. of such gravel could not be mined profitably with a new, 7-cu. ft. bucket-line dredge, costing upward of $250,000, and with operation costs at 4¢ per cu. yd., paying for land or royalties out of earnings; nor could a new combination 5-cu. yd. dragline and washing plant, worth upward of $125,000 and working at 6¢ per cu. yd., make a profit. These comparisons are made because the hourly capacity of both types of dredges is nearly the same. The bucket-line dredge averages 93 per cent operating time in 24 hr., as against about 80 per cent or less for the dragline dredge. These percentages of operating time are important factors in making a comparison of this kind. The bucket-line dredge has greater efficiency in cleaning soft bedrock, usually characteristic of dredging deposits, and a 7-cu. ft. bucket-line dredge can be efficient to a total digging depth of 80 ft. (65 ft. below water, 15 ft. above). A 5-cu. yd. dragline dredge is limited to about 30 ft. of efficient digging depth, 5 ft. of which could be above water. In small areas of gravel not over 30 ft. deep, a 5-cu. yd. dragline dredge could make a profit where a bucket-line dredge could not do so. As an example: compare the dredging of 3,000,000 cu. yd. of 10¢ gravel 28 ft. deep with bucket line, costing 4¢ per cu. yd., and with a 5-cu. yd. dragline dredge operating at 6¢ per cu. yd. Because of small yardage, new equipment is not warranted, therefore we can assume that the dredges of both types are used equipment, fully depreciated. Dismantling, mov-

Jan 1, 1945

By Thomas S. Carnahan

UNION MINIERE D HAUT-KATAIGA operates a group of mines and metallurgical works in the Katanga province of the Belgian Congo. It is especially prominent as a copper producer, but its output of accessory metals, such as cobalt, radium, silver, tin and gold have been considerable. The Belgian Congo covers 920,000 sq. mi. of central Africa, with a native population of about 8,500,000. In addition, Belgium controls by mandate the districts of Ruanda-Urundi (formerly a part of German East Africa) with an area of some 20,000 sq. mi. and a population of about 3,500,000 natives. Most of the native population of the Belgian Congo is found on the wide fertile plains of the great rivers, living under primitive conditions in a tropical climate, where it has survived throughout the centuries in spite of tropical diseases and intertribal wars. In more recent times, especially during the last two centuries, 'the natives have been subjected to frequent raids by the slave traders, which made their existence even more precarious, and if continued much longer would probably have resulted in their complete extermination.

Jan 1, 1932

By L. F. Mondolfo, B. E. Sundquist

The undercooling associated with the nucleation of the secondary phase from the liquid by the solid primary phase was studied in sixty binary alloys by means of a hot-stage microscope. It was found that in a system of a and ß, a usually nucleates ß at low undercoolings, but ß does not nucleate a, except possibly at undercoolings approaching homogeneous nucleation. This behavior can be explained in terms of relative interfacial energies and shows that crystallographic disregistry is only a minor factor in heterogeneous nucleation from metallic liquids. PREVIOUS experimental work1-6 on nucleation of solids from liquids has shown that normally nucleation is heterogeneous, and that small solid particles present in the liquid are responsible for the nucleation. These experiments and the theory that has evolved from them have made apparent that there is a "characteristic undercooling" associated with the nucleation of the solid from a given liquid by a given impurity. Little is known, however, about the chemical and structural relationships between the nucleating agent and nucleated solid that control the effectiveness of the nucleating agent in catalyzing the nucleation, as measured by the required undercooling. A review of the literature has yielded seventeen undercoolingsL-6 for the nucleation of solid from liquid metals by "known" nucleating agents. All values come from experiments in which the metal studied was divided into a number of particles (10 to 300 pin diam.) much larger than the number of extraneous impurity particles so as to obtain a large number of particles free of foreign nucleating catalysts. Known nucleating agents are then introduced by coating the droplets with particles or a thin film of the catalyst. Six of the seventeen undercooling values referred to cases where, for various reasons, the identity of the nucleating species was not at all certain. Another six cases involved nucleating agents with a crystal structure that was not known. Four other cases involved undercoolings listed as greater than or equal to undercoolings which were very likely those for homogeneous nucleation. One investigation3 involved adding to droplets powdered oxides, carbides, and so forth that were doubtlessly covered with adsorbed oxide or nitride films. The highly variable nature of these films resulted in highly variable undercooling (as was also found in preliminary work in this investigation). It is apparent that the information on heterogeneous nucleation in liquid metals is too limited to give rise to any definite conclusions on the nature of the catalytic process. With these problems in mind a new method was

Jan 1, 1962

By Samuel H. Dolbear

THE value of a mine is basically dependent on its capacity to yield profits. Since the ore must be mined, treated, and sold, some of it in various future years, there is a risk involved as to future costs, selling price, and working conditions. It cannot be expected that the economic condition existing at the time of valuation will continue unchanged for long periods in the future.

Jan 9, 1953

By J. Menashi, D. A. Douglas, A. S. Rappas

A process has been developed for recovering the refractory metals chromium (Cr), vanadium (V), molybdenum (Mo), and tungsten (W) in mixed secondary source materials, such as contaminated grinding wastes. The wastes are calcined with sodium carbonate in air to yield water-insoluble oxides of the base metals iron (Fe), nickel (Ni), cobalt (Co), and copper (Cu) and water-soluble salts of the refractory metals. An aqueous leach separates these two classes of metal values. Cobalt, nickel, and copper can be recovered from the oxidic residue by conventional processing methods. The leach solution is purified and then treated to recover the refractory metals. The process can accommodate a wide range of feed compositions and generates a minimum of aqueous effluents.

Jan 1, 1985

By Alec M. Crowell, C. H. Thigpen

Continuing the increase in production of crude oil and condensate started in 1937, the oil fields of South Arkansas reached a 13-year peak with 26,570,704 bbl. for the year 1942. The stability of the production branch of the industry in the area is demonstrated by Fig. I, which reflects the fact that although the number of producing wells in the state has declined from 3280 in 1931 to 2957 at the end of 1942, total production has continuously increased since the beginning of 1937. This is because all fields discovered since Jan. I, 1937, have observed spacing patterns up to one well to each 160 surface acres, the dual completion of wells where there is more than one producing horizon Eight new pools were brought into production in South Arkansas during 1942 (Fig. 2) They increased the state's crude oil and condensate reserve by 121,000,000 bbl., bringing the total recoverable reserve figure to 450,000,000 bbl. (Table 3) as of Jan. I, 1943. Abandonment of wells in the stripper areas of the state increased by 32 per cent over the preceding year, there having been 142 wells permanently abandoned in 1942. For economic reasons 279 wells were temporarily shut down as of Dec. 31, 1942. A price increase may start these wells to pumping again and also be the incentive toward the commencing of several secondary recovery projects in the fields discovered between 1922 and 1937. There were 149 wells brought into production in 1942 as against 119 for the

Jan 1, 1943

By C. H. Thigpen, Alec M. Crowell

Continuing the increase in production of crude oil and condensate started in 1937, the oil fields of South Arkansas reached a 13-year peak with 26,570,704 bbl. for the year 1942. The stability of the production branch of the industry in the area is demonstrated by Fig. I, which reflects the fact that although the number of producing wells in the state has declined from 3280 in 1931 to 2957 at the end of 1942, total production has continuously increased since the beginning of 1937. This is because all fields discovered since Jan. I, 1937, have observed spacing patterns up to one well to each 160 surface acres, the dual completion of wells where there is more than one producing horizon Eight new pools were brought into production in South Arkansas during 1942 (Fig. 2) They increased the state's crude oil and condensate reserve by 121,000,000 bbl., bringing the total recoverable reserve figure to 450,000,000 bbl. (Table 3) as of Jan. I, 1943. Abandonment of wells in the stripper areas of the state increased by 32 per cent over the preceding year, there having been 142 wells permanently abandoned in 1942. For economic reasons 279 wells were temporarily shut down as of Dec. 31, 1942. A price increase may start these wells to pumping again and also be the incentive toward the commencing of several secondary recovery projects in the fields discovered between 1922 and 1937. There were 149 wells brought into production in 1942 as against 119 for the

Jan 1, 1943

By Carl Lemke

SOME of the principal metallurgical difficulties en-countered in the differential flotation of lead-zinc-iron sulfide ores arise from the following causes: The oxidized, or partly-oxidized, condition of one or more of the minerals ; impurities in the minerals them-selves; composition and character of the gangue miner-als; soluble salts in the ore; and unfavorable metal ratios. In many of the ores received at a custom mill there are present appreciable amounts of oxidized' or partly-oxidized minerals, although the ores may be substantially sulfides. Often the ores are not oxidized at all when received but on account of operating condi-tions at the mill it is necessary to stock them for several months before they can be milled, and considerable oxi-dation takes place while they are lying in stock. In most ores received at Midvale, when oxidation is pres-ent, the lead and iron sulfides have been more affected than the zinc sulfide, but with some ores the zinc mineral has also become partly oxidized. Some ores, such as those taken from old mine-dumps or from old stopes, may show very little total oxidation, but the greater part of the valuable minerals has been sufficiently acted upon by oxidation to make the minerals very difficult to float. Ores of this character are among the most difficult the flotation operator has to contend with, be-cause the galena, sphalerite, and pyrite are all sluggish in their behavior in the flotation cells. Only a part of the lead mineral will float in the lead circuit. The re-mainder will lag badly and tend to come up with the zinc or, if badly oxidized, will go -through all the flota-tion circuits into the tailing. The zinc mineral, if it has also been affected by oxidation, will act in a man-ner similar to the lead mineral. A hard pull will be required to float a reasonable percentage of it, and this is likely to bring up so much pyrite that it will be difficult to make a zinc concentrate of commercial grade. If it happens that the zinc mineral has not been no-ticeably affected by oxidation it will tend to float in the lead circuit because a hard pull is also required in that circuit in order to bring up the sluggish galena. When only a fraction of the sulfide minerals has become partly altered, or completely oxidized mineral is present in relatively small quantity, it is usually possible to make reasonably clean concentrates of all three sulfides, that is, lead, zinc and iron concentrates. Most of the oxi-dized and semi-oxidized minerals will go into the tailing and the losses will be proportional to the oxidation.

Jan 4, 1927

ROBERT VAN ARSDALE NORRIS, who died at his home at Wilkes-Barre, Pa., on April 20, 1928, was born at Newark, N. J., on May 2, 1864, of parents who were direct descendants of such sterling New Eng-landers as Governor William Bradford, John Alden and Timothy Dwight. He went to the Collegiate School in New York and then to the Colum-bia School of Mines where he graduated with the class of 1885, having among class-mates A. S. Dwight, E. N. En-gelhardt, H. L. Hollis, G. B. Lee, Richard Moldenke, Wil-bur Sanders, Joseph Struth-ers, E. A. Wiltsee, and I. H. Woolson. His marked ability even among so many men of unusual ability caused him to be chosen as assistant to Pro- fessor Munroe in the summer school of mining and survey-ing immediately after gradua-tion, and he shortly after was also inspector of dredging operations on the Maurice River improvement work, Millville, N. J. The follow- ing year he worked in the chemical laboratory of Herman Behr in Brooklyn, and toward the end of 1886 he joined the staff of the Pennsylvania R. R. Coal Co. and the Susquehanna Coal Co. as assistant engineer. Six years later he was made principal assistant en- gineer and in 1900 he was made chief engineer of these companies. In 1904, he withdrew from them and estab- lished an office as a consulting engineer at Wilkes- Barre, later taking his son, Robert V., Jr., into partner- ship with him. They acted as consulting engineers for the coal department of the Delaware, Lackawanna & Western R. R. Co., the Lehigh Valley Coal Co., Coke Bros. & Go., Inc., the coal department of the Pennsyl- vania R. R. Co., the Wilkes-Barre & Hazelton R. R. Co., the Sterling Salt Co., and others, specializing in ex- amination and appraisal of coal properties, and also matters of Federal taxation.

Jan 5, 1928

By A. B. Young

THERE were produced in this country in 1923 probably in the neighborhood of 12,000 or 13,000 tons of refined and crude arsenic, by far the greater portion coming as a by product of smelting operations. Early this year copper smelters were producing arsenic at the rate of about 425 tons per month and lead smelters at the rate of 7;0 tons per month. During the entire eighteen years prior to 1919, there were produced in the United States only 47,000 tons of arsenic, which amounts to only 25 per cent. of the present output. The great increased demand has come about through the augmented use of arsenates as insecticides and arsenates as weed killers. In an extract from "Mineral Resources of the United States" on "Arsenic in 1922," Messrs. Heikes and Loughlin say, "The minimum possible demand for arsenic in 1923 was estimated at the end of 1922 to be about 13,000 tons, including 2000 tons for plate glass manufacturers, 3000 tons for lead arsenate, 3500 tons for calcium arsenate, 1500 tons for weed killers, 1200 tons for Paris green, 1000 tons for sheep dips and 750 tons for proprietary mixtures. More recent information, however, indicates twice as great a demand for calcium arsenate." The latter has found great use in the last three or four years as a weapon to combat the boll weevil pest of the southern cotton belt. ~t the present writing refined white arsenic is being quoted on the New York market at from 13)d c. to 1455 c. per Ib., while the average price during the eighteen-year period just mentioned was 4.8 c.

Jan 1, 1924

By A. F. Baker, E. R. Palowitch, A. W. Deurbrouck

As air-pollution regulations become increasingly more stringent, increased significance is being placed on the amount of sulfur present in coals used for steam generation. These regulations are aimed at minimizing the pollution of the atmosphere with noxious gases such as the sulfur oxides that are formed and emitted when coal is burned. Two meet these future requirements, a definite need exists to reduce the sulfur content of some of the coals used for steam generation. Reducing pyritic sulfur involves liberating the pyrite from the coal and then removing it. The specific gravity of pyrite is high (5.0) compared to that of coal (about 1.2, mineral-free), and standard coal-washing devices, such as wet concentrating tables, will efficiently remove pyrite particles larger than about 100 mesh. Particles below this size will be entrained in the table water and will be carried into the clean coal product. Techniques such as froth flotation are of little benefit for pyrite reduction because the flotation characteristics of pyrite are similar to those of coal.

Jan 6, 1966

By James F. Kemp

Discussion of the paper of D. Foster Hewett, Bulletin To. 27, March, 1909, pp. 291 to 310. JAMES F. KEMP, New York, N. Y.:-Mr. Hewett's paper is one of exceptional interest, because it not only adds an important contribution regarding one of the rarer, valuable elements, but also because it introduces compounds hitherto unknown and in associations no less novel. While we have occasionally dis¬covered and recorded asphaltite in metalliferous deposits, for example in the Joplin and Granby districts, we have not seen a metallic ore in a deposit essentially asphaltite. The source and method of introduction afford a subject well worth serious reflection. Vanadium was first discovered and recognized as a distinct element in the slags obtained in smelting the titaniferous magnetites at Taberg, Sweden. For a long time, therefore, we looked upon the titaniferous magnetites as its hone. Analyses proved, years ago, that it was present in the ores of this type in New Jersey and in the Adirondacks. It was quite rarely determined, but when looked for it was, I think, invariably found, although the Amount seldom exceeded 0.5 per cent. of V,05., In just what combination it exists in the titaniferous ores is uncertain. One might imagine V2O3 replacing some of the Fe2O3 of magnetite; or, since in the lead series vanadates and phosphates are closely akin, one might wonder if a lime-vanadate could take the place of apatite. Yet no lime-vanadate has been found in nature, and apatite itself is usually rare in the titaniferous ores. When percentage-curves are plotted for a series of analyses of the ores, the line of vanadic oxide shows a curious sympathetic behavior with the line of chromic oxide;' but the data are somewhat limited, and no compound has sug¬gested itself which throws light on the matter. Dr. W. F. Hillebrand has discussed the occurrence and dis-

Oct 1, 1909

By James A. L. White

Of the natural elemental surfur deposits of the world, volcanic deposits are not only the most spectacular, but probably the most widely distributed. As defined for the purposes of this paper, volcanic sulfur deposits include those associated with all phases of volcanic activity, including eruptive flows, and fumarolic and hot spring deposits. The line of demarcation between the latter and sedimentary deposits is not always clearly defined. Although volcanic sulfur has played an important role for centuries, serving as essentially the only source of sulfur, currently it is considered as purely marginal material. Volcanic deposits were relegated to this position by the advent of Frasch sulfur into world markets, which established sulfur prices and annual production levels with which volcanic sulfur cannot compete, Since early in the 20th century commercial interest in volcanic deposits of sulfur has been high only when premium markets are available. This occurred in the early 1950s and is the case at present. Considerable effort is currently being expended to establish new producers of volcanic sulfur, and to expand current operations or reactivate previous ones.

Jan 6, 1968

Papers in Classes A-Metal Mining, B-Milling and Concentration, H-Industrial Minerals, and I-Mining Geology are distributed in MINING TECHNOLOGY, which is issued every Other month. Papers in Classes C-Iron and Steel Division, D-Nonferrous Metallurgy and E-Institute Of Metals Division are distributed in METALS TECHNOLOGY, which is issued twice quarterly. Papers in Class G-Petroleum Division are distributed in PETROLEUM TECHNOLOGY, which is issued every Other month. TECHNICAL PUBLICATIONS in Classes F-Coal Division, J-Mineral Industry Education Division, K-Mining Administration, and L-Geophysics, are issued as separate pamphlets. Contributions are papers that when printed Or mimeographed are available, but Only On request. All the TECHNICAL PUBLICATIONS Of the F, J, K Or L classes, the TECHNOLOGYS and the CONTRIBUTIONS issued in 1945 are available at Institute headquarters, unless Otherwise noted. They are also On file in many public, university and technical libraries and, when so indicated in the list, the papers may be found in the TRANSACTIONS. An Institute member is entitled to One copy Of any TECHNOLOGY, TECHNICAL PUBLICATION Of the F, J, K Or L classes, Or printed Or mimeographed CONTRIBUTION. Copies Of TECHNOLOGYS and TECHNICAL PUBLICATIONS Of the F, J, K Or L classes listed have been mailed to members Of the Institute according to their registration by classes. CONTRIBUTIONS will he sent upon request. A member may purchase an additional copy Of a TECHNICAL PUBLICATION Of the F, J, K Or L classes, a paper in a TECHNOLOGY, Or a CONTRIBUTION at One cent a page; minimum charge, 25¢.

Jan 1, 1946