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By Frank M. Brooks

Endeavoring to meet the requirements of more oil created by the war effort, the oil industry of Kansas in 1944 maintained a level of exploratory and development work well above the average of previous years. During the year, 1866 test wells were drilled, of which 838 were completed as new oil wells, 89 as new gas wells and 939 as dry holes. These figures compare with 895 new oil wells, 32 new gas wells and 834 dry holes for a total of 1761 tests in 1943. Thus, there was a marked decrease in the number of new oil wells, and an increase in the new gas wells and dry holes. The total daily initial potential of production discovered by the successful wells amounted to 494,689 bbl. of oil as compared with 736,297 bbl. in 1943. The increase in unsuccessful tests and decrease in the daily initial potential of production has caused considerable comment and speculation among the oil operators of the state. This tends to confirm the fact that each year it is becoming harder to find the remaining oil fields. The total number of wildcats drilled in Kansas was 651 in 1944, including the so-called "extension wildcats" (more than 1/2 to I mile from known production). Of this number, 410 are classified as "rank wildcats," being more than one mile from production. The total of 651 compares with the total of 577 for 1943, showing an increase in wildcat drilling of 74 test wells: Of these tests, 81 were successful in finding new oil fields or substafitially extending known areas of production, and 20 either found new gas pools or extended old ones. The ratio of dry holes to producing wells among the "rank" wildcats was approximately 10 to I (372 dry and 38 successful). This compares with a ratio of 10 to I in 1943, 11 to I in 1942, and 6 to I in 1941. A compilation of the results obtained by 34 active companies, including all of the major companies, reveals that their efforts accounted for 286 rank wildcat wells, of which-37 found oil or gas, making a dry-hole percentage of 87. Approximately 55 per cent of all, tests (pool and wildcat) were failures. Thc Kansas Nomenclature Committee of the Kansas Geological Society named and classified 43 new oil fields and 8 new gas fields during the year. The discovery wells of the new oil fields had a total initial potential of 18,358 bbl. for a per well average or' 427 bbl. The average initial potential per well in 1942 and 1943 was 894 and 419 bbl., respectively. With nearly all wells producing at their economic capacity, the total production for Kansas during 1944 totaled 101,896,704 bbl., which compares with total runs of 107,709,679 bbl. in 1943. Production of natural gas during 1944 reached a new high record of 135 billion cubic feet. This compares with 122 billion cubic feet for 1943, and 98 1/2 billion cubic feet for 1942. The large Hugoton field of Southwestern Kansas accounted for about half of the total gas produced. Highlights OF the Year Although 51 new fields were found in the state during 1944, it is apparent that the

Jan 1, 1945

By William E. Newman

Lead mining has been carried on in several localities of the Province of Ontario in a desultory fashion for the past 60 years, but up to 1916 the results have not been of much commercial importance. The most ambitious attempt was made by an English company which built a lead smelter at Kingston, Ont., in 1880 to treat the concentrates from the Frontenac mines. After 2 years' operation, the mines and smelter were abandoned. Up to the present there has not been a sufficient tonnage of concentrates to support an efficient blast-furnace plant and as most of the small properties could not stand the heavy freight and duty charges into the United States, development work has not been carried on in a systematic manner. As a result the industry has languished. At Galetta, in southeastern Ontario, considerable prospecting and development work has been carried on in the last few years and very promising deposits of galena have been found in the Chats Island group by the James Robertson Co., Ltd., of Montreal. The chief deposit is that of the Galetta or Kingdon lead mine, located on Chats Island in the Ottawa River about 5 miles east of the town of Arnprior. The rocks1 in the vicinity of the mines consist of an interbedded series of crystalline limestone and biotite gneisses of pre-Cambrian age. This part of the Ottawa River basin has been severely faulted and the overlying Paleozoic limestones may be seen in normal fault cantact with the pre-Cambrian. The vein filling is of a very well-marked fault fissure type and although the amount of displacement is not determined at this point, similar faults to the east show a displacement of from 1,500 to 1,800 ft. which would indicate mineralized fault fissures of considerable depth. The ore occurs in a highly crystalline calcite with some barite and fluorite, and the galena occurs more or less richly disseminated in clusters and crystal aggregates. In some cases these masses weigh several hundred pounds. Small amounts of sphalerite are occasionally encountered.

Jan 1, 1918

By Cecil J. May

The importance of a knowledge of the physical laws involved in the production of oil from a reservoir has come to be generally realized in recent years and it is therefore unnecessary to elaborate on the many problems which still await complete solution. Among them the vertical flow of mixtures of oil and gas has attracted considerable attention and a number of papers have appeared in the literature from time to time. The complete solution of the problem would cover such aspects of oil-field technology as the calculation of bottom-hole pressures from purely surface data; the estimation of natural flowing lives; the design of gas-lifts and the selection of tubing for natural flow, and so on. It is still true, however, that the results so far published have not been particularly consistent and there are no generally accepted data available of universal applicability. It is, in fact, by no means easy to obtain a sufficiently wide range of variables under the operator's control to determine the laws of flow without ambiguity and much of the published research has been directed towards the solution of the specific problems of individual fields representing only a partial treatment of the whole subject. It was with a similar object that work was commenced on the Masjid-i-Sulairnan field of the Anglo-Persian Oil Co. towards the end of 1930 and has since continued as opportunity offered. Of course, the results obtained cannot necessarily be applied elsewhere without modification and, in some cases, considerable extension. At the same time conditions in this field are somewhat unusual in allowing certain aspects of the problem to be isolated and examined without the disturbing effects of a large number of independent or partially independent variables. For example, since the field is under unit control, it is possible to maintain steady conditions on any particular well over long periods. Moreover, the structure of the limestone reservoir is such that the gas-oil ratio for a given well is sensibly constant over very wide ranges of production rates, and in many cases the bottom-hole differential pres-

Jan 1, 1935

By Raymond B. Ladoo

The Paley report made little attempt to project future production and consumption for any industrial mineral except fluorspar and only about a dozen minerals were mentioned by name. Except for fluorspar the treatment consisted mainly of statistics of production, consumption, imports, and sometimes reserves up to 1950. FLUORSPAR In 1954 the author had occasion to evaluate the Paley fluorspar estimates. At that time a fairly detailed study of the world picture was made and bases for the Paley estimates were studied. Data for later years confirm, in the main, the conclusions reached in this earlier report and it will be drawn upon here.

Jan 11, 1959

By F. M. Hamilton, H. F. Ameen

Results of a laboratory investigation of some sintering variables are presented. The effect on physical properties of mix component variation and rate of cooling of the sinter is illustrated by crush and tumbler test results and data of reducibility tests and microscopic examination of sinters are shown. The results of using solid additions in the mix to improve bed permeability are given. SOME of the variables encountered in the sintering of iron ores and their effect on sinter properties have been investigated at the Jones and Laughlin Ore Research Laboratory in Michigan. Ores requiring agglomeration before blast furnace utilization may be classed as coarse, intermediate or fine. Coarse iron ore is considered similar to a — 1/4-in. Mesabi wash ore containing some 95 pct of its particles between 94 in. and 100-mesh. Intermediate iron ore is considered similar to our New York State magnetic concentrates in which all the particles are — 20-mesh and about 60 pct are +100-mesh. Fine ores are considered as being at least 100 pct —100-mesh. This paper will deal only with the two coarser classifications. Most of the work has been done in a small experimental batch unit previously described in an AIME1 paper. Results being obtained form a basis for present and future trials in production sinter plants. It is expected that new production units that may be added in the future will benefit from laboratory studies. In general, the results reported here are obtained by laboratory study, but it is Experimental Sinter Machine: The laboratory sinter machine employed in the work consists of a chamber with 1 sq ft of grate area. It is mounted on

Jan 1, 1951

By H. F. Ameen, F. M. Hamilton

Results of a laboratory investigation of some sintering variables are presented. The effect on physical properties of mix component variation and rate of cooling of the sinter is illustrated by crush and tumbler test results and data of reducibility tests and microscopic examination of sinters are shown. The results of using solid additions in the mix to improve bed permeability are given. SOME of the variables encountered in the sintering of iron ores and their effect on sinter properties have been investigated at the Jones and Laughlin Ore Research Laboratory in Michigan. Ores requiring agglomeration before blast furnace utilization may be classed as coarse, intermediate or fine. Coarse iron ore is considered similar to a — 1/4-in. Mesabi wash ore containing some 95 pct of its particles between 94 in. and 100-mesh. Intermediate iron ore is considered similar to our New York State magnetic concentrates in which all the particles are — 20-mesh and about 60 pct are +100-mesh. Fine ores are considered as being at least 100 pct —100-mesh. This paper will deal only with the two coarser classifications. Most of the work has been done in a small experimental batch unit previously described in an AIME1 paper. Results being obtained form a basis for present and future trials in production sinter plants. It is expected that new production units that may be added in the future will benefit from laboratory studies. In general, the results reported here are obtained by laboratory study, but it is Experimental Sinter Machine: The laboratory sinter machine employed in the work consists of a chamber with 1 sq ft of grate area. It is mounted on

Jan 1, 1951

By R. I. Jaffee, C. T. Sims, C. M. Craighead

The fabrication of rhenium metal by powder metallurgy techniques is discussed. The following physical and mechanical properties have been measured and are reported: lattice constants, melting point, electrical resistivity, thermal expansion, spectral emissivity, modulus of elasticity, tensile properties and ductility at room and elevated temperatures, work hardening, recrystallization, grain growth, and oxidation resistance. IT is only occasionally that a metal reaches present-day technology with as little known about its properties as element No. 75, rhenium. Relatively scarce to date, it has been studied only infrequently and used less. Previous work on rhenium has been carried out primarily by European scientists. However, realization that rhenium occurs in commercial quantities in the United States recently has focused attention on this metal. Rhenium is a very dense high melting hexagonal-close-packed metal. Like tungsten and molybdenum, its highest oxide is volatile. However, when protected by reducing or inert atmospheres, its strength at high temperatures is greater than that of tungsten. Rhenium work hardens more than any other known pure metal, but, on annealing, becomes quite soft and ductile. Its vapor pressure is approximately that of tantalum, but it does not enter into the so-called "water cycle" nearly as readily as does tungsten. (The water cycle is a deleterious phenomenon causing blackening of lamp bulbs and vacuum tubes with subsequent failure of the filaments.) These and other properties, some already known and some found as a result of the current researches, have indicated that rhenium has many potential uses, primarily of an electrical or electronic nature. Rhenium or its alloys soon may be found in service as electron-tube filaments, cathodic emitters, or as electrical contact materials. In addition, rhenium or its alloys have potential use in such devices as high temperature thermocouples, and high wear-resistant parts such as precision instrument points. Rhenium, in the form of potassium perrhenate, was made available for this study by the Kennecott Copper Corp. The potassium perrhenate was reduced to rhenium metal in two stages, accompanied by leaching to remove potassium in the form of hydroxide. This impure metal was then oxidized to rhenium heptoxide and dissolved in water. The solution was neutralized with ammonium hydroxide to produce highly purified ammonium perrhenate, a typical analysis of which is shown in Table I. The ammonium perrhenate was ground to —325 mesh in a rubber-lined ball mill with Burundum balls. This operation caused a certain amount of impurity pickup, as reflected in the rhenium analysis shown in Table I. The fine ammonium perrhenate was reduced to metal with hydrogen. Particle size of the powder ranged from 1 to 25 microns, as illustrated by Fig. 1.

Jan 1, 1956

By A. Eilers

THE telluride of gold and silver, the " Tellurgold-silver" of Hausmann, and " Petzite" of other mineralogists, has been found in so few localities, that a late discovery of the mineral in a new locality may not be uninteresting. So far this mineral has been found in Europe only in a few mines in Transylvania, and in Hungary ; and in the United States in the Stanislaus Mine, in Calaveras County, California, in the Golden Rule Mine, Tuolumne County, California, and in a mine in Montana, the precise locality of which I have forgotten. The new locality referred to is at the Red Cloud Mine, Gold Hill District, Boulder County, Colorado.

Jan 1, 1873

By Arthur Tauber, Horst Kedesdy

FERRITES are sintered metallic oxides of the spinel structure type1 and belong to the class of soft ferromagnetic materials. Similar to a ceramic, they can be formed and fired to a dense body, exhibiting a high electrical volume resistivity ranging from 102to 107 ohm-cm as compared with 10-6 ohm-cm for some of the metallic magnetic materials. This high resistivity, with resulting low eddy current losses, finds special application at high frequencies. The dispersive susceptibility of ferrites at microwave frequencies has also led to many applications in this field. Ferrites are used in low frequency applications where high resistivity with high permeability is desirable. During the last few years ferrites exhibiting rectangular hysteresis loops have been developed for computer and magnetic memory systems. The general formula for ferrites is MeFe2O4 where Me is a divalent metal ion such as Ni, Zn, Mg, Mn, Cu, Cd, and Fe. Only two of these ferrites are nonferromagnetic, namely, those with Zn and Cd. Solid solutions can be formed between different ferrites, and it is of interest to note that solid solutions of a ferromagnetic ferrite with a nonferromagnetic ferrite yield much better magnetic materials than the basic ferrite body. In general, it can be said that the solid solution formation between ferrites has widened the field of ferrite synthesis and has led to methods of preparing materials with a large variety of magnetic properties. During the last two decades the synthesis of ferromagnetic oxides has been the object of extensive research, but commercial production has been started only within the last ten years. Along with more fundamental studies, there remains the never- ending task of developing ways to realize the optimum characteristics of materials in large-scale production. Ordinarily, to produce a ferrite material it is necessary for the constituent oxides to be mixed intimately, pressed, and then fired at temperatures above 1000°C. Ferrite Synthesis: Formation of a basic ferrite by solid state reaction from Fe2O3 and a monoxide such as NiO, under normal atmospheric conditions, is governed by a progressive diffusion of cations between adjacent particles of the constituents. Firing temperature, furnace atmosphere, and cooling can vary the magnetic properties, however. If, for example, a dioxide, a sesquioxide, or an oxide of the Me3O4 type is substituted for the monoxide, the reaction mechanism becomes more complex and extremely dependent on atmospheric conditions and firing cycles. For this reason reproduction often

Jan 1, 1958

By P. P. Scott, George C. Howard

A field remedial procedure utilizing a kerosene-cement slurry as a water plug-off agent in fractured formations was evaluated both in the laboratory and in the field. This procedure has proved to be capable of effectively shutting off water without causing permanent impairment of the oil production. Success was attributed to the fact that an immobile cement slurry, when placed in a water-producing strata, will set and form an impermeable barrier; whereas when placed in an oil-producing section the cement will retain a relatively high permeability and may be removed by acidizing. INTRODUCTION One of the most perplexing problems facing the oil industry is the selective exclusion of water production from oil or gas-producing wells. This problem has been studied by many investigators in an attempt to develop a material that is not only capable of reducing water production but is also capable of being selective in that it will not impair oil production in either fractured or intergranular type reservoirs. A study of these two types of formations indicated that two distinct types of materials for controlling water production might be required — a completely liquid plugging agent for intergranular formations and a semi-liquid or slurry type plugging agent for fractured formations. This paper is limited to the control of water production from fractured formations. A common source of water in the vicinity of oil bearing rock reservoirs is water which previously has entered and, because of its higher density, generally lies near the bottom of the formation. When the deepest point of penetration of a well into such an oil and water-bearing formation is above the level of the water, and the dynamical gradients due to the flow of oil overbalance the difference in densities between oil and water, water production becomes a problem. Then the water level rises in the shape of a cone and is produced from the lower depths. Other investigators1,2,3,4 have developed theories which define the pressure gradients and contours of this cone in a homogeneous formation and have shown that the placement of a plug in the bottom of a well is only slightly effective in temporarily reducing the flow of water. Assuming that the manner of flow of bottom water from fractured formations to a well is generally similar to the flow in homogeneous formations, then it would be expected that some form of coning, perhaps of less symmetry, would also occur. Then, because of the similarity of the manner of flow of water, placement of a vertical plug in a fractured formation would also probably be ineffectual for controlling water production. However, as has been shown by electric model flow study,' the placing of a plug in a well and an impermeable horizontal streak in the formation might prove to be a means for materially reducing or even eliminating water production in a fractured formation. An indication of the difference in effectiveness between horizontal and vertical plugs based on theory developed from study of the flow of water and oil in rock reservoirs is depicted in Fig. 1. These curves show the expected

Jan 1, 1955

By F. A. Howard, R. T. Haslam

In a broad sense automotive fuel is simply fuel in general and includes coal, coke, wood, charcoal and gas, in addition to the full range of liquid combustibles. All of these are actually used, or have been used, commercially to some extent as fuel for automotive vehicles. The steam lorry burning coal and coke is a common sight on the roads of England. The fact that these coal-fired steam lorries have a distinct advantage in taxes over the conventional gasoline-driven lorry probably explains the survival of this vehicle. The omnibus, or charabanc, operated by city gas carried in a balloon container on the roof, was also at one time a common sight in England, although not as common as the ubiquitous steam lorry. These gas-operated vehicles have, however, disappeared from the streets in recent years, and probably owed their existence entirely to war conditions. In France one of the largest motor vehicle manufacturers had last year more than 30 trucks equipped with regular gasoline engines in service in the Parisian area operating on producer gas obtained from a small gas producer mounted on the running board of the truck. Both wood and charcoal have been used in these gas producers. The authors were interested enough in this unique commercial development to spend some time examining the apparatus used and inquiring into the success which it had met. The picture is by no means an impossible one purely from the standpoint of practicability, but there is no doubt of the soundness of the conclusion that this is not a development which has any present important significance. Powdered carbonaceous matter, coal, coke or lignite, has been used experimentally in special forms of internal combustion engines, but so far as is known, these have never been applied to automotive practice. Range of Liquid Combustibles In the field of liquid combustibles the full range has been exploited to some extent. Heavy residual fuel oils from petroleum have been

Jan 1, 1928

By Charles Weaver

DURING the past few years there has been considerable activity in prospecting for oil and gas in several parts of western Washington. From time to time seepages of oil or emanations of gas have been reported from various places. Several companies have been organized for the purpose of drilling, but only a part of these have actually begun operations. In certain localities very small seepages of oil occur, but up to the present time no oil or gas in commercial quantities has been obtained. In order to determine the conditions which may be favorable or unfavorable 'to the occurrence of petroleum it becomes necessary to know the character and extent of the geological formations in which such deposits might occur. In other regions where producing wells have been developed it is possible to know what formations contain the oil mind what structural conditions influence its concentration in reservoirs or zones. It is usually possible to determine those strata which contained the a materials from which the petroleum may have been derived and also the position and distribution of the more porous sandstone belts into which it may have collected. Detailed stratigraphic surveys, may even determine the depth at, which a certain known oil-bearing zone may be tapped at any particular place. It is also possible to recognize those formations which are presumably barren of oil, as well as those which are absolutely so.

Jan 7, 1915

By R. C. Ellman

In the United States, the consumption of lignite and subbituminous coals is increasing. A variety of energy-oriented companies have leased large blocks of reserves, new large power plants are in operation and being constructed, and new producing mines are being developed. The Bureau of Mines has maintained an active interest in the utilization of low-rank coals for many years. In 1951, with the completion of the Bureau's Grand Forks Coal Research Laboratory, an organizational unit was established for studies in lignite preparation. Since that time, numerous investigations have been completed. This research has dealt almost exclusively with lignite, but since subbituminous coals have many similar characteristics, the findings can often be applied to both types of coal.

Jan 1, 1970

Discussion of the paper of E. J. Hall and C. W. Drury, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 78, June, 1913, pp. 1059 to 1066. A. M. SMOOT,* New York, N. Y. (communication to the Secretary +) :-The nails method is given in many text books on assaying as a standard method for gold or for gold and silver in ores. It appears to be taught in the laboratories of technical and scientific schools as a standard method, and to some extent it is used by assayers in actual practice, although the class of ores to which it may be applied is limited to those free from reducible metallic compounds, the metals of which would enter the lead button. The experiments of Messrs. Hall and Drury show the inaccuracy of this rnethod for silver, in heavy sulphides, but not so clearly the short-comings with regard to gold. It seems certain that low silver is caused by the solubility of silver in iron-alkali sulphide as compared with its solubility in molten lead; that is, silver is distributed between iron-alkali sulphide and metal in the charge in proportion to solubility at the particular temperature of the fusion. Lead is a fixed quantity in these assay charges, but iron-alkali sulphide increases with increased sulphur, so the more sulphur in the charge, the lower the silver results.

Jan 11, 1913

By John Boardman

THE Anaconda company has never indulged in any employee activities at Butte which might be termed paternalistic, but it has exerted a vast amount of effort in care of its employees during working hours. The reason for this policy is not lack of interest or that the company does not feel the effect of employees' activities while they are "off the job"; it is that the company and the city of Butte have grown up together and, each has been adequate in its own sphere, the company in providing employment at the highest possible wage and the city in providing housing, sanitation, commercial services, medical services, schools, churches, amusements and entertainments. The one exception to this independence between the company and the community is the Butte Water Co., which is a wholly owned sub-sidiary of the Anaconda Copper Mining Co. Mention of this relationship is made here because the water supply of such a city as Butte is one of the principal factors in determining the health of the people. Very early in the development of the Anaconda company an adequate and dependable water supply for the operations became necessary, therefore the company took over this important community function. So well has this activity worked out that during the whole period of time covered, in which the company has expanded to become practically the sole mine operator and the community has grown from a small mining camp to the status of a modern city, there has been no shortage of water or any outbreak of water-borne, epidemic disease.

Jan 1, 1938

By F. E. Marcy

IT is not my purpose to write a lengthy article or to attempt the solotion of the problem I am presenting, but to call attention to what I believe an important issue, hoping that it may arouse in some one, or in some company, a sense of responsibility. I am referring particularly to modern up-to-date milling plants discharging tailings which under existing conditions cannot be further treated or from which a recovery cannot be made at a profit, but where a quantitative and qualitative analysis shows that a portion of these tailings might profitably bee treated, at some future time when our metallurgical knowledge has advanced, when we have cheaper power, chemicals, labor or other advantageous conditions. Early Methods In our early milling methods very little attention was given to the care of tailings. It was thought that if the mill could be located by a stream or a river where the final disposal of the tailings could be forever lost sight of, it was highly desirable. We can now see acid estimate what was lost in these rich tailings, not recoverable from the streams and the great rivers. Fortunately for many, the depositing of tailings in these streams and rivers was objected to by the farmers and finally prohibited by the State Legislatures. In looking back over our past milling methods, it seems that, the first endeavor was to make the maximum amount of money for a particular period, or year, regardless of the future, the depletion of the mine, or the conservation of the total mineral content. The dumping and sluicing of 3,000 tons per day, for a period of many years, of a copper tailing carrying

Jan 8, 1917

By L. S. Deitz

This part of the symposium deals with the problems encountered by the consumer of nonferrous scrap, that is, the smelter and refiner who melts the selected scrap items and produces foundry ingots of specified compositions or billets for rolling or extrusion in nonferrous mills. The fundamental problems are quite similar for all secondary' nonferrous metals. However, these remarks will be confined to the copper-base alloys since in the sorting, melting and refining of these alloys probably all the usual types of problems are encountered; in addition, papers are being presented later on secondary lead, zinc and aluminum. While metallurgical

Jan 1, 1943

By C. E. Shoenfelt

The discovery of oil in the Powder Wash stricture in northwestern Colorado late in the fall of 1936 is the most important development in Colorado since oil was first discovered in the Moffat dome in the same county in 1923. The Powder Wash structure gives promise of developing into an oil and gas field of major proportions and is of particular interest because the oil was found in Tertiary rocks of Eocene age, which heretofore had been productive in the Rocky Mountain region of gas only, and very few of the many structures of this kind have been tested because it was believed that oil production probably would be confined to rocks of Cretaceous age only, and these were, in most instances, at excessive drilling depths. Powder Wash is one of a series of small domes in the belt of folds and faults on the south side of the large but shallow depression known as

Jan 1, 1937

By C. G. Maier

COMMERCIAL processes of lead softening directly involve the behavior on fusion of mixtures of the oxides of antimony and lead, and the vapor pressures of these materials. Practically no quantitative data have been available for the discussion of lead softening from the point of view of the fundamental metallurgy of the process. The Pacific Experiment Station -of the United States Bureau of Mines, in cooperation with the University of California, in the course of its program of study of the fundamental properties of oxides and sulfides, recently made vapor pressure measurements upon the various forms of pure antimony trioxide.1 When these measurements were considered in connection with the softening and "fuming" furnaces which are often used for lead purification, an unexpectedly anomalous condition appeared. In brief, this anomaly consisted in the fact that in certain softening furnaces, where lead bullion of approximately 1 per cent antimony content was being treated at a temperature of approximately 1300° F., no appreciable volatilization of antimony occurred, there being produced only a "skim" containing from 15 to 20 per cent Sb, 65 to 60 per cent Pb, as mixed oxides. In the "fuming furnaces," where the temperature was only about 1400° F. and where an accumulation of "skims" from the primary softener was being treated with certain other antimony-containing materials, a considerable volatilization of antimony as oxide occurred; an "impure" skim of some 60 to 65 per cent Sb and 10 per cent Pb was also produced as mixed oxides. The latter material cannot be suitably treated in hearth-type or softener furnaces. The essential chemical difference between the first and second step is the customary use of some reducing material (such as petroleum coke) in the later operation. An obvious interpretation of the effect of coke in facilitating the fuming of the antimony is the supposition that the antimony may be reduced to metal, and volatilized as such. This supposition is improbable, however, when it is realized that a slight extrapolation of the vapor-

Jan 1, 1932

Although grinding mill liner life has been the subject of extensive studies, evaluation of the effect of liner design a power consumption, a far more significant part of total grinding costs, has been less comprehensive. The factors that effect ball mill energy efficiency are reviewed, and attention is then focused on the mechanism of grinding. The trajectory of the outer row of balls, with different lifting face angles, is derived. Basic recommendations for mill speed and liner configuration are also presented

Jan 1, 1984