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The fate of generations yet unborn lies in man's hands. Shall it be prosperity, a high standard of living, and the development of spiritual values; or ruin, misery, and a reversion to jungle law? World affairs move in high gear, at high tension, in many directions. Each nation fears the other fellow- races, crosses the white line on curves, skids, takes its half in the center; and the devil take the hindmost. For one, the United States is on the horns of dilemma; it must insure a flow of raw materials of industry and world-wide markets in order that the American people may maintain high standards of living, but the commitments of the United States cannot be fulfilled without trimming present standards of comfort and convenience back to the level of perhaps a quarter of a century ago. A way must be found to retreat without anarchy at home as well as abroad. Everything is relative and all things change, and change is the essence of civilization. It is now clear that man has not kept pace with changes of all kinds, some of them overnight, during the past 50 years. Conventionality has led to stagnation; man now seeks learning of all kinds at an accelerated pace, but men should not be educated beyond their native intelligence for they must be able to apply their education. There must be a resolute action now on 10 great challenges in regard to conservation of human and ma-

Jan 1, 1950

By Charles D. Russell, L. H. Jenks, W. J. Leas

A detailed description is given of an experimental method for determining relative permeability of porous media to gas. Results are presented for natural and synthetic cores. The experimental data for two and three phase systems are compared. The reproduci-bility of the equilibrium gas saturation ii demonstrated and the effects due to a variation in rate of gas flow are discussed. An attempt is made to correlate total permeability and rock textural factors with relative permeability to gas. Capillary pressure curves obtained simultaneously with the relative permeability curves are shown to be equivalent to those obtained in conventional displacement cells. INTRODUCTION The advances in petroleum reservoir technology during the past decade have made increasingly apparent the desirability of a simple, rapid, reliable metliod for obtaining relative permeability data on small cores. Such data are needed in order to study fluid mechanics in porous media and for the more refined reservoir behavior prediction calculations now under development. The early experimental work in this field was done by Wyckoff and Botset1 who measured relative permeabilities for gas-liquid mixtures flowing through

Jan 1, 1950

By O. W. Ellis

Introduction During the month of September, 1928 enough money had. been promised by private individuals and corporations to comply with the Research ?Foundation Act 1928 (Chapter 57, 18 George V) of the Province of Ontario. The Ontario Research Foundation (referred to below as O.R.F.) may be said to 1iave come into being at that time. Under the terms of this Act, the Treasurer of the Province was empowered to match dollar for dollar of the sums subscribed by private .corporations and individuals up to a limit of $1,000,000. However, the response to the appeal for this by the Premier of the Province, the Honourable Mr. G. Howard Ferg uson, was so exceptional that the Act was amended in 1929 so as to empower the Treasurer to increase the maximum contribution on the part of the Province to $2,500,000. In March, 1933, the Chairman of the Foundation, Sir Joseph Flaville, Bart., was able to report that, in the interval between the Premier's appeal and December 1st, 1932, private enterprise had paid ?into the treasury of the Foundation $1,670,050, and that the Provincial Treasurer had assumed responsibility for a like sum. The endownment Fund of the Foundation was, therefore. $3,340,100. This sum was ?invested a lm~ s t entirely in Government securities, in securities guar. anteed by the Government, and in 1mmicipal securities. Sir Joseph Flavelle remarked at that time that "The payment of $1,670,050 to the Endowment of the Foundation by private persons and corporations is a somewhat remarkable performance when it is remembered that for three of the five years the business of the country has been suffering from a severe depression". Since that time it has been the consistent policy of O.R.F. to live within the income derived (1) from the investment of its Endowment Fund and (2) from fees collected for services rendered.

Jan 1, 1950

By Robert W. Geehan

The Bureau of Mines has been developing deposits of critical and essential minerals in the United States since 1939. A preliminary examination of the Union lead mine was made in November 1944 and January 1945 by W. T. Benson, a Bureau of Mines engineer, who recommended development by diamond drilling. The Bureau conducted a drilling project at the mine from February 12 to May 16, 1947. The property is in sec.12, T. 17'N., R. 19 E., Mount Diablo Base and Meridian, in. southern Washoe County, Nev., about 15 miles south of Reno. The Union lead mane, also known 4s the Commonwealth mine, has been an intermittent producer of zinc-lead-silver ore since 1860. During World War II, ore was shipped to smelter& near: salt Lake City, Utah. The Bureau drilled 21 diamond-drill holes having a total length of 1,549 feet and 20 long percussion-drill holes with a total length of 359 feet. The program was designed to test for horizontal and vertical extensions of the ore body and to prospect for parallel ore bodies. As a result of this program, extensions of the ore zone were established, but no parallel ore-bearing structures were found. The areas drilled were limited by drill sites available.

Jan 1, 1950

By Heath B. Fowler

The surface mining operations of the Simplot Fertilizer Co. are on the Fort Hall Indian Reservation approximately 16 miles east of Fort Hall, Idaho (Fig 1). The Phosphoria formation outcrops in sec. 2, 3, 11, 14, 15, 22 and 27, T 4 S, R 37 E, Boise Meridian. The ownership of these phosphate-bearing lands is divided between individual Indians and the Bannock-Shoshone Tribe, and the royalties are paid to the respective owners on a tonnage basis, as the rock is mined. The geology and mineral resources of the Fort Hall Reservation were studied by the U. S. Geological Survey in 1913 and reported on in 1920. † However, it was not until the winter of 1945 that exploratory work was undertaken by private enterprise. Diamond drilling was begun by the Simplot Fertilizer Co. in April 1946, and stripping operations were started in June. A camp was established near

Jan 1, 1950

By G. E. Johnson

The problem of efficient reclamation of zinc base die cast scrap became interesting early in 1930. Die Cast Metal, as referred to in this paper, is a zinc base alloy with various proportions of aluminum, copper, magnesium, antimony and tin. Many attempts were made to work out some means of reclaiming the discarded die cast metal for re-use as new die cast metal. Difficulties in such reclamation were attributable to contamination by lead and tin from solder, chromium and nickel from electroplated coatings, and iron from iron inserts. This paper relates the experiments that led to the development of a specialized muffle furnace for the treatment of zinc base die cast scrap for the production of zinc oxide and zinc, and describes the development of the muffle furnace and the equipment now used commercially for these purposes. The Eagle-Picher Co. acquired all patent rights' for these developments from the International Smelting and Refining Co. in connection with their purchase of the East Chicago Plant. Zinc Base Serap Situation About 1935, the die cast scrap situation became increasingly acute for scrap dealers. This scrap was accumulating from dismantling automobiles and household appliances which contained die cast parts. Efforts to find an outlet for this type of scrap were intensified. The International Smelting and Refining Co. began to study the possibilities of a commercial process for the recovery of values from die cast scrap. At that time most of the die cast metal reclaimed was melted down in small kettles of from one to five tons capacity, the iron inserts being removed by skimming. The dross was skimmed off and disposed of as a zinc dross. The drossed metal was cast into slabs and was given the trade name "die cast slabs.". Distribution of the products produced by melting die cast scrap in kettles is shown in Table 1. American Process Experiments A method considered for the production of zinc oxide from die cast scrap was an adaption of the standard American Process of zinc oxide manufacture. Thus some die cast scrap was mixed with oxidized zinc materials and charged to Wetherill grates. The zinc oxidized to zinc oxide but, while the aluminum and copper largely remained in the residue, the color of the zinc oxide produced was impaired by copper contamination. As the proportion of die cast scrap was increased, liquation took place; that is, the metal trickled through the charge then solidified in the openings of the grates. French Process Experiments Several hundred tons of die cast scrap were purchased for test purposes and converted into die cast slabs. These slabs were charged into a French Process (horizontal retort) zinc oxide furnace with some electrolytic zinc. A satisfactory grade of zinc oxide was not produced. Distillation in Belgian Retorts It was then decided that, rather than attempt to use scrap die cast metal or scrap zinc for the production of zinc oxide, it would be advisable to redistill the die cast slab metal in a Belgian retort furnace. The opportunity to do so was provided by the closing of the zinc smelter of the Illinois Zinc Co. at Peru, Ill. Arrangements were made for the operation of a Belgian retort furnace for such redistillation purposes. The results of this experiment are summarized in Table 2.

Jan 1, 1950

By S. J. Swainson

"It appears to me that the chief progress in milling operations in America have been made in the steady improvement of existing practice through both higher extractions and increased efficiencies of operations rather than by the development of new processes. The recent rapid development of sink-float, or heavy-medium separation, however, is an exception, and is becoming increasingly used to permit the economic treatment of certain low-grade ores that otherwise could not profitably be mined. The use of spirals and of small cyclones, both of which employ the principle of centrifugal force, show promise of increasing adoption through their application and efficiency in special cases." So did our distinguished colleague, O. A. E. Jackson, consulting metallurgist for the Union Corporation and president of the Chemical, Metallurgical and Mining Society of South Africa, summarize his impressions of a recent tour which he made of various metallurgical and milling plants in North America. I believe that all mineral dressers will agree with Dr. Jackson's concise conclusions.

Jan 1, 1950

By G. W. Jones

In the course of experiments on the stabilization of acetylene gas by addition of other gases, notably hydrocarbons such as methane, propane, and butane, it was observed that large quantities of carbon black are produced during the explosion of acetylene or mixtures of acetylene with the, above hydrocarbons, the added hydrocarbon being essentially decomposed into hydrogen and carbon. It is known that in the complete absence of air acetylene explodes upon application of an intense ignition source at pressure above 5.9 p.s.i. gage. The same is true of mixtures of hydrocarbons and acetylene. However, the pressures necessary for explosion are considerably higher in the case of these mixtures and depend on the amount of added hydrocarbon. The present report contains data on gaseous products and the physical characteristics of the carbon black formed by explosion at elevated pressures of various mixtures of acetylene and hydrocarbons as well as other gases, such as hydrogen, helium, nitrogen, and carbon dioxide.

Jan 1, 1950

By H. W. St. Clair

This study of the rate of evaporation of zinc was undertaken as a part, of a general investigation on refining mixtures of metals resulting from melting reclaimed scrap. One of the methods by which the more volatile metals, such as zinc, magnesium, and cadmium, may be separated is by distillation. Distillation may be carried out at lower temperatures if it is done in an evacuated enclosure. The immediate purpose of the present investigation was to determine accurately the effect of temperature, pressure, and other factors on the rate of evaporation of zinc.

Jan 1, 1950

Thus far virtually the sole theme of the conservationist has been the preservation of natural resources. Little thought has been devoted to the conservation of America's most significant asset-her people. True, considerable effort has been devoted to conserving man's physical strength by the invention and application of labor-saving machinery. Notable progress has been made also in the conservation of man's health through important discoveries in medicine. However, little if any positive success has been achieved in the conservation of the most valuable attributes of man-intellect, skills, manpower. Human resources are interrelated and interdependent. There is no monopoly on knowledge or skills' or human energy. No one must sell them short. All the knowledge and all the skills and all the energy possessed by all men are required to render all the services needed by all men. One of the major sources of wasted manpower is found in the nation's schools, with an educational system based on the outmoded theory of uniform education for all. Actually, if democracy means free initiative for the individual, and unlimited progress at the maximum rate of speed of which the individual is capable, then our public schools are not democratic in-

Jan 1, 1950

By J. S. Westwater

The Mather mine of The Negaunee Mine Co. embraces nearly all of Sections 1 and 2, T47N, R27W, within the limits of the cities of Negaunee and Ishpeming on the Marquette iron range of Michigan's Upper Peninsula. Operations of the Negaunee Mine Co., the stock of which is jointly owned by Bethlehem Steel Co. and The Cleve-land-Cliffs Iron Co., are under the direction of the latter company. The opening of the Mather mine was described by C. W. Al1en.† Mather " A " shaft was completed to an initial depth of 2352 ft in early 1943. The shaft capacity of over one million tons yearly is in prospect of being realized by orderly development and mining, and sinking of the second or "B" shaft then started in accordance with previous planning. Mather "B," also a vertical shaft, was designed as a twin to Mather "A" shaft and the sinking technique developed at Mather "A" was utilized in "B" shaft operation. Shaft Sinking General Plan An average depth of 16 ft of sand overburden at the shaft site was cleared away by bulldozer, and the shaft approximately 15 by 20 ft in rock opening put down to an initial depth of 87 ft. Mucking of the broken rock to this depth was accomplished by an Insley excavator equipped with a 1/2 yard ca-pacity Owens clamshell bucket. Addition of 200 lb weight to each lip of the clam bucket provided adequate "bite" to dig the broken diorite and jasper rock. Temporary heavy wood bearers were placed across the shaft mouth to support the steel shaft sets which were hung in this initial 87 ft depth, aligned accurately and concreted in place from the lowest set upwards. The permanent steel headframe foundations and three service tunnel openings to the shaft were also concreted in the upper section to the shaft collar. A temporary wood headframe was then erected over the shaft mouth, and initial hoisting machinery assembled consisting of a Lake Shore 12 ft diam single drum grooved for a 1 3/8 in. rope and powered by two 400 hp motors to attain hoisting speed of 1100 fpm. Compressed air was obtained from a Nordberg 2 stage tandem horizontal type with a capacity of 1500 cfm. An enclosed landing platform at the shaft collar was equipped with a rotary dump and pocket for discharge of the rock into a Euclid 15 ton truck. On completing assembly of this equipment and installation of a special cage in the shaft, sinking was resumed on a three shift, six days per week

Jan 1, 1950

By Morris Muskat, James M. McDowell

A report is given of electrical analog experiments on the effect of casing perforation completions on well productivity for ideal uniform reservoirs under steady state homogeneous fluid flow conditions. Graphical results are presented for the effect of perforations of different densities and various degrees of penetration into the formation surrounding the casing or cement sheath. The latter range from perforations which terminate flush with the casing to those which extend into the formation a distance equal to the casing diameter. For the special case where the perforations terminate immediately beyond the casing with semi-spherical protrusions the electrical analog results correct and supersede previously reported theoretical calculations. It is found that the penetration of the perforations into the surrounding productive section may so increase the resultant productivity as to approach or even exceed that for open hole completions. INTRODUCTION A theoretical analysis of the effect of casing perforation on well completion, without additional penetration of the formation, was reported several years ago.' In this treatment the perforations were represented by mathematical sinks and no explicit account was taken of the imperviousness to flow of the casing in which the perforations were made. This procedure was justified by consideration of the mutual interference between the sinks, which seemed to indicate that the analytical method automatically eliminated flow across the casing radius between the perforations. However, both further theoretical investigation and the electrical analog measurements described below showed that this assumption in the previously developed theory was not valid and that the calculated well capacities would considerably exceed the correct values. § Even if this simplifying assumption were retained the generalization of the theory to situations where the perforations extend into the producing formation would be extremely difficult. On the other hand, the electrolytic model analog of this type of steady-state homogenous fluid system is, in principle, so simple that it has not been worthwhile to attempt to develop the exact analysis even for the more limited case of strict casing perforation. The whole problem has therefore been studied anew by electrical models to cover the range from holes in the casing which terminate flush with the casing surface to such as extend into the surrounding rock to a depth equal to the casing diameter. It is to be expected that the productivity of a well completed with casing radius* rw, perforated with holes of radius Tp, and extending to depths d into the surrounding rock, would depend primarily on the dimensionless geometrical parameters Te Tw TP d of the system, such as —, —, — , and —, where re is the Tw, a a rw external boundary radius and a is the mean vertical separation between the perforations. It will also depend, of course, on the number of perforation lines or total perforation density. While such parameters automatically control analytical treatments, it would require a very extensive series of model experiments to fully disclose their functional effect on the well productivity. For practical purposes, however, a rather limited range of the variables suffices to give the effects of interest. Accordingly, in the experimental study reported here the casing diameter has been kept fixed? at six in., the perforation diameter has been taken as either one-fourth in. or one-half in., their density has been varied from one to eight per ft, and their penetration into the formation has ranged from zero to six in., with a primary scaling factor of one to six. EXPERIMENTAL METHOD AND RESEARCH Although electrolytic model experiments have been made for years, there still seems to be some question as to what set of conditions will give the best results. For this reason a number of electrode materials and electrolytes were tried. Those chosen for the final experiments were copper electrodes and a weak copper sulphate solution as the electrolyte. This 'Assuming that the casing has been cemented with a uniform and impermeable cement sheath, the effective casing radius is to be interpreted as the external radius of the cement annulus. It is also assumed here that the casing is set through the complete producing section that it is perforated throughout with a uniform density and that tie formation has a a and isotropic permeability. As noted later, however, a uniform scale change permits reinterpreting the primary measurements to correspond to a casing diameter of 12 in.

Jan 1, 1950

Jan 1, 1950

By N. A. Eilertsen

Mining operations were in progress at the Shawangunk mine near Summitville, Sullivan County, N. Y. as early as 1843 and again as late as 1918. Difficulty in effecting mechanical separation of sphalerite and galena was the primary reason for abandonment by various operators. The Bureau of Mines investigated this mine by diamond drilling, sampling, and performing beneficiation tests. The investigation included the construction of 1.25 miles of access road and the completion of 6,526 feet of core drilling in 24 holes. In addition, 151 samples were taken in the mine. The investigation proved an extension of ore contiguous to the old mine workings and resulted in the discovery of another ore shoot at depth. The ore occurs as fissure filling in a fault zone and contains concentrations of zinc and lead sulfides with minor dissemination of chalcopyrite in a quartz gangue. Metallurgical tests indicate that the ore can be concentrated by selective flotation.

Jan 1, 1950

By E. W. Newman

The Bureau of Mines, in cooperation with the U. S. Geological Survey, developed the property of the Tungsten Metals Corp. by surface trenching and diamond drilling from November 1940 to June 1941 and from August 1943 to December 1943. The purpose of the work was to determine possible reserves of tungsten in the downward extension and lateral eastern extension of three major tungsten-bearing quartz veins. The property is 50 miles south of Ely, White Pine County, Nev., in the Minerva Mining District. Tungsten ore was discovered in the district in 1915, and mining started in 1916. The tungsten ore bodies occur as shoots in quartz veins that occur along faults in limestone. With the exception of a small-scale leasing operation in 1932, the property was idle from 1919 until 1936, when Tungsten Metals Corp. was organized to acquire the mines. Production ceased in May 1945, and the mines were idle until leased in 1947. Development by the Bureau of Mines during 1940 and 1941 consisted of surface trenching, sampling, and diamond drilling 37 holes for a total of 6,959 feet. Subsequent drilling of eight holes, totaling 3,067 feet, in 1943 disclosed additional reserves. This report sets forth in considerable detail the exploration work completed by the Bureau and briefly describes the mining and milling methods employed. Diamond-drill halo logs and sample analyses are shown graphically in the illustrations that accompany the report.

Jan 1, 1950

By C. C. Miller, C. A. Hutchinson, A. B. Dyes

This paper presents a simple and practical method for the estimation of effective permeability and reservoir pressures from the rise in bottom hole pressure when a well is shut in. The equations on which the method is based consider a stabilized well producing from a uniform formation when flow is shut off at the sand face followed by the unsteady state flow of a compressible liquid from regions far from a well to points closer in during the build-up period. An approximation for extending the method for two-phase flow in the reservoir is also presented. In order to compare the effects of extremes in the conditions existing at the external boundary of the reservoir, two general equations defining the build-up characteristics of the reservoir are shown: first, for a reservoir with constant pressure maintained at the radius of drainage, and second, for a reservoir with no influx over the radius of drainage. These equations define the build-up characteristics for the shut-in well as functions of time, the permeability and porosity of the drainage area, the viscosity and compressibility of the fluid flowing, the production rate prior to shut-in, and the radius of drainage of the well. When a well is shut in at the surface, rather than at the sand face, flow will continue into the well bore after shut-in due to the compressibility of the fluids in the bore. The effect upon the build-up characteristics of this flow into the well after shut-in has been studied by means of the electrical analyzer. From the basic relationships and consideration of the limitations due to continued flow after shut-in, methods have been developed for the estimation of the effective permeability of an area from the plot of the build-up characteristics of the well producing that area. Likewise, equations are presented for the estimation of the reservoir pressure from an early portion of the build-up curve. By means of the electrical analyzer, studies have been made concerning the variations in the build-up characteristics resulting from damaged or improved permeability in the immediate vicinity of the well bore. These studies show that the permeability estimated from the build-up curves represents the average effective permeability of the majority of the drainage area and that the permeability in the immediate vicinity of the well does not affect this estimate. Since the major portion of the drawdown is in the immediate vicinity of the well, variations in the permeability of this area greatly affect the productivity of the well as expressed by the productivity index. From pressure build-up and productivity index tests the ratio of the permeability of some arbitrarily specified area immediately surrounding the well and the effective permeability in the majority of the drainage area can be computed. This ratio is a measure of any damage to the well incurred in drilling or reworking and likewise any benefits as a result of remedial measures. In build-up tests and many other tests that are made on a producing well it is at least desirable, if not absolutely necessary, that the well be stabilized prior to testing. A method is presented here for relating the time required to stabilize a well and the reservoir and fluid properties. An equation is also presented for approximation of the length of shut-in time required to obtain sufficient build-up data for the estimation of permeability and reservoir pressure.

Jan 1, 1950

By M. M., Fine

In a laboratory study of grinding and classification' of silica sand, a satisfactory means of producing the medium-fine specification sand desired by producers of flint-glass containers was developed. The best procedure consisted of ball-mill grinding and double classification, which gave a properly sized sand containing less iron than the feed.

Jan 1, 1950

By J. S. Brown, A. G. Guy

With the exception of the work of Tammann and Hartmann,1 no published information has been found on the structural changes produced in eutectic structures as the result of heating following plastic deformation. In part this lack of information may be due to the fact that many eutectic structures contain an intermetallic compound as a prominent phase, and as a consequence have been considered to be unworkable. For example, Tammann and Hartmann were able to obtain useful data only on those alloys that they could greatly reduce in thickness by cold rolling. This restriction placed on the investigation of alloys containing intermetallic compounds has been largely removed by the work of Savitskii2 which showed that large deformations of such alloys can be produced by relatively slow compression at temperatures near the melting range. It was possible, therefore, to carry out the present work on a range of binary eutectics including one composed of two intermetallic compounds. The essential results obtained on the alloy systems studied are illustrated by the Pb-Mg eutectic containing 33.2 pct Mg, Fig 1. The cast structure, Fig la, was obtained by melting together magnesium of 99.8 pct purity and chemically pure test lead, casting into a heated, small steel mold, and furnace cooling in the mold from about the eutectic temperature. The fairly coarse eutectic structure thus obtained was too brittle to work at room temperature without cracking. Fig 16 shows the worked structure obtained by compressing a 1/2-in. cube 70 pct in about 15 sec at 550°F and then water quenching. The pronounced changes in the distribution of the two phases produced by heating the worked alloy at 850°F for 1 hr are shown in Fig lc. Recrystallization of both phases appears to have taken place, and the mechanical properties of the cast alloy must have been significantly changed by the working and heat treatment. Similar results were obtained with the Mg-59.5 pet Bi, Mg-36.4 pet Sn, Mg-65.4 pet Cu, and Bi-40 pet Cd eutectics, only the last of which could be worked at room temperature. Tammann and Hartmann reported a thickening and shortening of the needles of the eutectics which they heated about 10°C below the melting range for 1 hr after drastic cold rolling. They found the following eutectics, given the indicated amounts of reduc- tion, to have a granular structure after heat treatment: Sn-9 pet Zn (98 pet); Cd-82.5 pet Pb (60 pet); and Bi-43.5 pet Pb (90 pet). On the other hand the alloy Al-11.7 pet Si (60 pet) showed no change after heating. Tammann and Hartmann observed a distinct shrinking of the needles in unworked eutectics subjected to heat-treatment. In the present work inappreciable change in the eutectic structure was found on heating undeformed alloys. In summary, it appears that eutectic structures can be recrystallized into a "spheroidized" condition by heating near the eutectic temperature after severe deformation. If the eutectic contains one or more brittle phases the necessary deformation can be accomplished by pressing at high temperatures. It is reasonable to expect that this tendency towards equiaxed grains from the plate- or needle-like eutectic structure should be general since the energy relations and mode of growth in recrystallization are so different from those that hold for eutectic crystallization. References 1. G. Tammann and H. Hartmann: Ztsch. Melallkunde (1937) 29, 141-144. 2. E. M. Savitskii: Doklady Akad. Nauk S.S.S.R. (1940) 62, 349-351. Abstr. in Melal Prog. (July, 1949) 56, 126, 128.

Jan 1, 1950

By Hennessy F. L

It is generally recognised that slags are active participants in pyrometallurgical processes, and not merely inert liquids which must be produced. to effect separation of gangue material in smelting, or of impurities in refining. The importance attached to slag-metal reactions in steelmaking is shown by the numerous investigations in this field. However, there are still many important reactions of slags which require explanation. In this paper some new aspects of the reactions of slags will be discussed, as far as possible quantitatively.FREE AND COMBINED OXIDESMetallurgical experience indicates that variations in the composition of slags produce changes in the chemical behaviour of the various components. These variations have been generally ascribed to changes in the proportions of free and combined oxides, i.e., compounds have been assumed to be present in the liquid slag.Considerable support for this view has been adduced from the existence of compounds such as metallic silicates, phosphates, etc., in the solIdified slag. However, this does not imply that such compounds necessarily exist in the molten slag.The most direct evidence as to the nature of molten slag is to be obtained from a study of the liquid state. In...

Jan 1, 1950

By E. G. Kearnery

Introduction It is believed that the present paper will be of some interest, not because of any outstanding features of Renabie milling practice but because Renabie is the first gold mining property in a newly explored area - in Leeson and Rennie townships, Sudbury district, Ontario - to reach the production stage. The Renabie mill was originally designed by the General Engineering Company (Canada), Limited, as a 300-ton plant and went into operation in June, 1947, treating an average of only 128 tons a day for the balance of that year. Toward the end of 1948 the capacity of the plant was expanded to 450 tons a day, and the tonnage treated was gradually increased from the 1947 figure to the point where 420 tons a day was averaged for the first nine months of 1949. Description of Ore In general, the outstanding gangue component of Renabie ore is white quartz, which comprises at least 80 per cent of its total bulk and in some sections considerably more. Virtually all the gold occurs in very finely divided state; only very rarely has free gold coarser than 325 mesh been observed. The ore has a very low sulphide content, ranging from about 0.50 to 1.00 per cent by weight. The gold occurs both free in the gangue and ? locked in sulphides, the proportion of one to the other varying considerably from one orebody to the other. Pyrite is by far the most abundant sulphide, followed by galena, which, however, appears to be entirely absent in some of the orebodies. Minor amounts of pyrrhotite, chalcopyrite, chalcocite, and sphalerite have been noted. The ore appears to be entirely free, or almost so, of minerals containing arsenic, antimony, or molybdenum, and in general it could be described as free milling. The various hindrances to extraction of the gold which have been met with are believed to be due largely to the very finely divided state of the metal and to its intimate association with the sulphides and gangue. The ore contains silver, with the gold-silver ratio about 3:1.

Jan 1, 1950