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By Heinrich A. Kortmann

Specifications on the chemical, physical and metallurgical properties of the blast furnace burden are steadily becoming more stringent, especially in those countries where higher raw material and energy costs can be overcome only by improved technology. This paper describes the test methods for the relative predetermination of the criteria where the effects of temperature, gas composition and physical load in the blast furnace are duly considered. Data are presented to show the correlations between burden material tests and blast furnace results. Possible test methods for the direct reduction process are also discussed.

Jan 1, 1977

By R. E. Tate, F. W. Schonfeld

In 1899, Lebeau1 reported the preparation of the compound Lis As through reduction of lithium arse-nate with carbon. Brauer and zint12 have described the preparation of Li3 As by combining the elements in liquefied ammonia and by melting the elements in a zirconia crucible coated with lithium fluoride. In 1953, at the Los Alamos Scientific Laboratory, LisAs and a previously unreported compound, LiAs, were prepared by the reaction of the elements. PREPARATION OF THE COMPOUNDS Attempts to form lithium-arsenic compounds by

Jan 1, 1960

By Ronald D. Irving

The object of the present paper is to give an outline account of the mineral resources of the State of Wisconsin, so far as they are now known, including both metallic ores and non-metallic useful mineral substances. Tl~e only previous publication making ally attempt at such an account is one of a popular nature, prepared by the writer for Snyder and Van Vechten7s Historicccl Atlas of Wisconsin, which was published at Milwaukee in 1878. The data upon which the statements of the following pages are based are chiefly from the

Jan 1, 1880

The Murray Plant of the American Smelting & Refining Company is situated seven miles south of Salt Lake City, and has a fine view of the Salt Lake Valley with its fertile farms and orchards. It is located on the Los Angeles & Salt Lake and Denver & Rio Grande Western Railroads, and has a fine electric car service, cars running every 15 minutes. The beautiful and majestic Wasatch range lies about five miles to the east and the Oquirrh Range to the west, and from these mountains a large proportion of the ores treated are obtained.

Jan 1, 1925

THE Institute Committee on Industrial Relations, of which Robert Linton is chairman, held a meeting on Feb. 21, listed as one of the technical sessions of the annual meeting, at which reports of the sub-committees were presented. Following are abstracts of these reports. The Institute can furnish mimeo-graphed copies of the complete reports on Safety, Employment, Illness, Mental Factors, and Cripples in Industry. The supply of the other reports has been exhausted. A paper by George F. Kunz, which was presented at the same meeting, is printed here in full.

Jan 6, 1922

By W. L. Remick

WHEN the senior author of this paper presented an article on Fine Coal Cleaning by the Hydrotator Process,1 at the February, 1927, meeting, that process had been developed in the anthracite region only to clean what is known as "slush" or "silt." This size constitutes all of the material passing the finest screen used at any particular colliery. Some use a 3/32 -in. round-hole screen and others use a 1/16 -in. round hole. Practice varies throughout the anthracite region, but the tendency seems to be toward the finer screen.

Jan 1, 1929

Briefly, an open stope is one in which the ore is taken out and no filling is put in; the only support for the walls may be posts or pillars of ore. Such a method is limited to orebodies with strong walls and ore strong enough to stand unsupported over the back of the stope. Details vary and depend on the dip of the vein, mode of breaking ground, method of handling broken ore, and so forth. The examples given are the Beat-son, Birmingham district, Mineville district, and Cornucopia.

Jan 1, 1925

Henry LOUIS, London, England (communication to the Secretary) : Prof. Richards's paper has impressed me as highly valuable. Without entering upon any discussion of it as careful and thorough as it deserves, I venture to mention one or two points which a perusal of it has recalled to my mind in connection with my own study and practice of ore-dressing. I always mentally divide jigging into two phases: 1. A particle at rest on the jig-bed is lifted and carried upwards by the rising current of water, at an increasing velocity, which tends to a maximum. When the upward current is stopped, the particle continues to rise with rapidly diminishing velocity until it comes to rest. This completes the first phase. 2. In the second phase, the particle falls from its position of rest with an increasing velocity which tends again to a maximum, and continues to fall until the rising current of water has reduced its velocity to zero. This completes the second phase. The second phase will evidently be greatly modified by the effect of suction, as Prof. Richards shows; but I do not see that his experiments very clearly imitate the action of the second phase. And the brief intervals at the end of each phase, when the mineral particle, by reason of its acquired velocity, is still moving, though in opposition to the water-current, yet remain to be investigated. I feel especially, in Prof. Richards's paper, a difficulty which I have felt with regard to all similar previous investigations, namely, that the experiments deal with particles falling a long distance, when the velocity becomes uniform. I question whether this uniform maximum velocity is attained in actual jigging-practice. If so, it is certainly for a comparatively very small proportion only of each stroke. It seems to me that an investigation like that of Prof. Richards, but confined to the first 6 or 8 inches of fall only, and carried out with suitably delicate recording-apparatus, is what we

Jan 1, 1895

By R. J. Evans

THE Combined Metals Reduction Co.'s plant is at Bauer, Utah. It was built primarily to treat ore from the Combined Metals mine at Pioche, Nevada. Shortly after its completion, the company acquired the old Honerine mine, and ores from this mine, as well as custom ores from widely scattered districts, are now being treated at the Bauer plant. PIOCHE ORE The Pioche ore, which comprises about 50 per cent. of the mill feed, occurs as a replacement of an impure thin-bedded limestone. The lime beddings are separated by thin layers of micaceous shale containing appreciable quantities of sericite and graphite. The ore is an exceptionally fine-grained, dense mixture of minerals and gangue, assaying approximately 0.03 oz. gold, 7.2 oz. silver, 7 per cent. lead, 15 per cent. zinc, 16 per cent. iron, 29 per cent. insoluble and 1.5 per cent. lime. Of the total lead 7 per cent. is in the form of sulfate and carbonate. Approximately 10 per cent. of the ore consists of chert nodules impregnated with barren pyrite; the nodules average 0.8 mm. in size, and are extremely hard, compared with the other constituents of the ore. Microscopic examination of Pioche ore ground to 80 per cent. minus 150 mesh shows pyrite, sphalerite and galena still attached. EARLY ATTEMPTS AT ORE DRESSING Metallurgists, both professional and those working for private companies, have been more or less familiar with the Pioche ore since 1913; in fact, a total of 35 commercial and plant laboratories experimented with the ore between 1913 and 1921. The work during this period was decidedly negative, it being seemingly impossible to effect a satisfactory separation of the valuable minerals into marketable products. In 1913, it was recognized that fine grinding-that is, about minus 200 mesh-was required to liberate the minerals from one another, and from the gangue, but such fine grinding was not considered practicable at this time.

Jan 1, 1928

By R. J. Evans

The Combined Metals Reduction Co.'s plant is at Bauer, Utah. It was built primarily to treat ore from the Combined Metals mine at Pioche, Nevada. Shortly after its completion, the company acquired the old Honerine mine, and ores from this mine, as well as custom ores from widely scattered districts, are now being treated at the Bauer plant. Pioche Ore The Pioche ore, which comprises about 50 per cent. of the mill feed, occurs as a replacement of an impure thin-bedded limestone. The lime beddings are separated by thin layers of micaceous shale containing appreciable quantities of sericitc and graphite. The ore is an exeeptionally fine-grained, dense mixture of minerals and gangue, assaying approximately 0.03 oz. gold, 7.2 oz. silver, 7 per cent. lead, 15 per cent. zinc, 16 per cent. iron, 29 per cent. insoluble and 1.5 per cent,. lime. Of the total lead 7 per cent. is in the form of sulfate and carbonate. Approximately 10 per cent,. of the ore consists of chert nodules impregnated with barren pyrite; the nodules average 0.8 mm. in size, and ire extrcmely hard, compared with the other constituents of the ore. Microscopic examination of Pioche ore ground to 80 per cent . minus 150 nicsh shows pyrite, sphalerite and galena still attached. Early Attempts at Ore Dressing Metallurgists, both professional and those working for private companies, have been more or less familiar with the Pioche ore sinee. 1913; in fact, a total of 35 commercial and plant laboratories expenmented with the ore between 1913 and 1921. The work during this period was decidedly negative, it being seemingly impossible to effeet a satisfactory separation of the valuable minerals into marketable products. In 1913, it was recognized that fine grinding-—that is, about minus. : 200 mesh—-was required to liberate the minerals from one another, and from the gangue, but such fine grinding was not considertd practicable at this time.

Jan 1, 1928

By A. L. Sweetser

EXPERIENCE has shown how difficult it is to obtain information regarding laboratory-tests in connection with the chlorination-process for the extraction of gold from its ores, and I therefore present the following method, somewhat in detail, for the benefit of those who may desire to pursue research work in this field. The ore chosen was a partly-decomposed porphyry, extremely siliceous and comparatively soft, and of an average value per ton of from $25 to $26 in gold and $0.68 in silver. The chemical analysis gave : Fe2O3, 3.35; FeS, 1.5; MnO2, 0.75; ZnCO3, 4; Al2O3, 3.20; H2O, 0.7; SiO2 and insol., 83.50 per cent. The ore, first crushed to pass a 5-mesh screen, was coned and quartered until a 45-lb. sample was obtained. Samples for assay and analysis, taken from this lot by means of riffles, were crushed to pass a 100-mesh screen. The original sample was divided into 10-lb. lots, of which one was crushed to pass a 10-mesh screen; another through a 12-; the third through a 20-, .and the last through a 30-mesh screen. Because of the production of an excessive quantity of fine material it was deemed inexpedient to crush finer than 30-mesh size-a decision the wisdom of which is proved by the data in Table I., showing the increasing ratio of slimes, in proportion as the ore is crushed finer. In order to determine the percentage of fines in the sizes of mesh selected, a weighed sample of ore was taken from each mesh, and a sample from the 10-mesh lot was passed successively through 20-, 40- and 100-mesh screens, and the percentage remaining on each screen determined. This process was repeated with the 12-, 20- and 30-mesh lots, with the results given in Table I.

Sep 1, 1907

By C. E. Barnett, G. R. Durland

LUMINESCENT materials have been used in an increasing variety of ways in recent years. Such uses range from the screens on which the picture or image is presented in television and other cathode ray tubes to fluorescent lamps, fluorescent effects in decorative, theatrical, and display lighting, and the many applications of phosphorescence in paints, textiles, paper, and plastics. During the war the screens for a radar set or the "night-seeing" devices were not fundamentally different from those in other cathode ray tubes, but nevertheless they presented special problems for the phosphor manufacturer. It was essential that the "pips" on a radar screen continue to glow after the exciting beam had swept on, but this afterglow would be ruinous to a television screen. In the image tube used for seeing at night with infrared instead of visible light, electrons emitted by an infrared-sensitive receiving surface were amplified and converted to visible light after striking a fluorescent screen. The small size of the screen caused special problems in reducing the grain size of the phosphor to obtain adequate resolution. Other devices used phosphor surfaces which could be stimulated directly by infrared radiation to emit visible light. Energy was stored in the phosphors by prior excitation with short-wave-length radiation, and the stored energy released on subsequent exposure to infrared radiation. Maps, navigational charts, bombing manuals, and computers of various sorts were printed on fluorescent paper or lettered with fluorescent inks. Fluorescent markings excited by small ultraviolet lamps were used on airplane instrument dials. A large amount of research was done to determine the best color for the emitted light and other properties for the fluorescent materials, and on the best methods for their fabrication into the items listed above. Phosphorescent materials found wide use during blackout restrictions to mark safe passageways, to delineate traffic hazards, to identify packages, and to mark tools and other items of equipment.

Jan 1, 1948

By Carl Scholz

Discussion of the paper of Carl Scholz, published in Bi-monthly Bulletin, No. 22, July, 1908, pp. 551 to 559. HOWARD N. EAVENSON, Gary, W. Va. (communication to the Secretary*) :-For some time before the publication of Mr. Scholz's paper, I had been collecting data bearing upon its subject, and I now take pleasure in presenting my results to the Institute in the form of a discussion. It has long been a matter of common opinion among mining-men that mice-explosions are, more frequent during the colder, or winter months, than during the warmer ones, and it is a matter of common knowledge among them that the air-ways and road-ways in most mines are much drier and are more in¬clined to be dusty during the winter than during the summer. In many mines, places which are wet and sloppy in the summer are dry and sometimes dusty during the winter. These changes, of course, can only be due to atmospheric conditions, and are caused by differences in temperature and humidity. Until recently, however, very little attention has been paid to the part that atmospheric conditions may play in mine-explosions, or, rather, to the effect they may have in rendering mine-conditions peculiarly dangerous, and in spreading and rendering more disastrous the effects of what would otherwise probably have been .small explosions. To show the difference in mine-conditions during sunnier .and winter months, I have tabulated in Table I. the results of 24 observations of hygrometric conditions in several different mines at different times of the year. Mines Nos. 1, 2, and 6 are located in the Pocahontas.coal -region, in McDowell couuty, W.Va., the first one being a shaft-mine shaft mine and the others drift. Mines 1A and 2A are drift-mines located in Logan county, W. Va. All of these are mines of fair size, but none of them has been in operation more than six years,

Jun 1, 1909

By Willard P. Ward

SOME TIME in the year 1874 or 1875, I conceived the idea that spiegeleisen might be made -in a blast furnace from ores that were not carbonates, and which did not contain both manganese and iron in the same ore. Up to this time, such ores had formed the basis of all the spiegel that had been produced; and all the ferromanganese that was on the market before 1875 was made in crucibles, and cost about 00 per ton, for 80 per cent. Mn. I consulted the great steel metallurgist of the day, Alexander Holley, who listened attentively to what I had to say, and told me he did not think my plan was practical, so I abandoned it for the time being. But I was so stubborn that I could not get the notion out of my head. It seemed to me that a good metallurgist should be able to work the thing out in some way. I had already had some experience in smelting refractory lead ores in Utah, and was young and not lacking in self confidence, so after waiting a bit, I got Anton Eilers, the best all-around metallurgist I knew, and J. H. Bramwell, the best iron blast-furnace man I knew, both intimate friends of -mine, to come to my place in Bartow County, Georgia, and look over things. They remained for several days, and made all the examination they thought necessary; and they also advised me to give up the project, and either to keep the furnace running on car-wheel iron or to blow it out. After my talk with Holley, I improved my plant in several ways. I closed the top of the furnace, put in a hot-blast stove, a steam boiler and a Weimer blowing-engine which gave me blast enough, at a pressure high enough for all the requirements of, the furnace, and which I could bring up to a temperature of 600° to 700° F.

Jan 1, 1921

Reno, Nevada. J A Fulton, Director For publications of either the Mackay School of Mines or the State Bureau of Mines, address the School of Mines at the given address. Except where the contrary is indicated in the following list, available publications are sent free From the Mackay School of Mines. Bulletin 1, The identification of Nevada's common minerals, 50 cents; 3, Notes on the ore deposits of Cave Valley mining district, Lincoln County, 4, A preliminary survey of the Scossa mining district, Pershing County, 5, Ore deposits of the Gold Circle mining district, Elko County, 6, Bedded deposits of manganese oxides near Las Vegas, 7, Spruce Mountain district, Elko County, and Cherry Creek (Egan Canyon) district, White Pine County From the State Bureau of Mines: Bulletin 1, Mineral resources of southern Nevada One volume: Mining districts and mineral resources of Nevada, by F C. Lincoln (1923), $1.50.

Jan 1, 1933

Under the joint auspices of the Illuminating Engineering Society and the University of Pennsylvania there will be given about 20 lectures covering the general principles of illumination and the aspects of lighting practice. They will be held at the University of Pennsylvania in Philadelphia, from Sept. 21 to 28, 1916, inclusive. The subject of illumination of mines will be included in this series, which will be delivered by men selected on account of their qualifications to deal authoritatively with the several phases of the subject. In connection with the lectures there will be an exhibition of the latest developments in illuminating appliances, including lamps, accessories, photometers, together with novel applications of light. There will also be an inspection tour which will include visits to manufacturing establishments, laboratories, lighting companies and notable lighting installations. For further particulars apply to the Illuminating Engineering Society, 29 West 39th Street, New York City.

Jan 6, 1916

The Sub-committee on Safety of the Industrial Organization Com-mittee of the Institute has been asked to cooperate with the National Safety Council, and has made certain recommendations to the Board of Directors of the Institute regarding ways and means of bringing about this cooperation. The National Safety Council has been in existence seven years. Its inception was at a meeting of the American Iron and Steel Electrical Engineers held in Milwaukee in 1912. The first annual congress was held in New York City in October, 1913, at which time the Council was definitely organized. Its membership now consists of nearly four thousand members, representing industrial plants, railroads, public utility companies, insurance companies, state labor commissions, Chambers of Commerce, manufacturers' organizations, etc. These members are in all states of the Union and in eleven foreign countries, and through them the National Safety Council reaches more than six million workers.

Jan 7, 1919

INTERNATIONAL ENGINEERING CONGRESS This Congress will be held under the auspices of five National Engineering Societies, of whi h the Institute is one. The sessions will be held in 11 sections and the proceedings will be published in 10 volumes of 500 pages each, of which Volume 8 will contain the papers and proceedings on Mining Engineering and Metallurgy. The membership fee of $5 will entitle the holder to the volume of General Proceedings and Index, and, in addition thereto, any other single volume chosen. Other volumes may be subscribed for according to a sliding scale depending upon the number of volumes taken. The Institute will have a meeting in San Francisco during 1915, and it is desirable for our members to join the International Engineering Congress at in early date in order that their support of the enterprise may be given in its early stages, when it is most needed.

Jan 2, 1914

By M. J. Coolbaugh

Standard Metals Corp.'s mining and milling operation at Silverton, Colo., has found that it can justify the use of a large computer system entirely on the basis of cost savings, and at the same time receive the benefits of speed, greater accuracy, and valuable data otherwise unobtainable at a reasonable cost. The Silverton operation consists of the historic Sunnyside mine and Mayflower mill, about 300 miles southwest of Denver, which produce about 700 tpd of a complex lead-zinc ore. This operation has not yet tried to use its computer for large, involved programs such as optimizing the efficiency of an operation, linear programming, or determining economic ore limits, although these are certainly within the capability of the equipment. However, there have been enough money-saving applications in the everyday routine to justify the use of this computer system, even before branching out into the more unusual or complex problems.

Jan 8, 1968

By D. W. Fuerstenau

The United States is rapidly approaching an acute shortage of minerals. According to some observers, this situation may even be more severe than the energy crisis because the US consumes nearly 30% of the world's mineral production. With the mounting competition for world mineral supplies, we can no longer take for granted that foreign mineral products will be available to the US as abundantly as in the past. In 1973, US consumption of mineral raw materials was $35 billion. Of this, $7 billion consisted of imports. Without a drastic reorientation towards the mining of domestic mineral resources, the 1973 $7 billion deficit might mushroom to $100 billion by the year 2000. Thus, a return to domestic sources of raw materials will become absolutely necessary-and will be bucking the trend of the past 25 years, characterized by capital investment for growth in multinational overseas mining operations.

Jan 11, 1975