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Jan 1, 1944

Jan 1, 1964

Jan 1, 1944

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Jan 1, 1949

Jan 1, 1957

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Jan 1, 1944

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Jan 1, 1952

By R. S. Shoemaker, F. W. McQuiston

Ore Classification / Mine Where Used / Treatment Method Table page

Jan 1, 1975

Jan 1, 1957

By W. A. Goodyear

It is safe to assert that in cities generally, the fuel of the future for all domestic, as well as for most manufacturing and metallurgical purposes, will be gaseous fuel. The immense advantages which gas possesses in facility and cheapness of distribution, cleanliness, and economy of manipulation, and the facilities which it offers for utilizing in almost all cases a much higher percentage of the total quantity of heat produced, than it is possible to do with any kind of solid fuel, are facts which will vastly more than compensate for the comparatively small loss of heating power, which will be found necessary in the turning of the solid fuel into gas upon a large scale, and which, in the bpinion of the writer, will, at no distant day, command attention, and will ultimately result in a revolution in our use of fuel. The employment of gaseous fuel upon a scale of any considerable magnitude, has hitherto been almost entirely confined to the utilization of the waste gases of the iron smelting furnace for heating the blast, and the rapidly increasing use, for certain metallurgical pur-

Jan 1, 1883

Forty-three years ago a record for low cost was made at the Spanish mine, in Nevada county, California. In 22 days of September, 1887, there was mined 2796 tons of ore at a cost of 37.5 cents per ton, of which 32.4 cents was for labor and 5.1 cents for supplies. The mill treated this ore for 23 cents per ton, of which 12.3 cents was for labor and 10.7 cents for supplies. Thus the total operating cost was 60.5 cents per ton. The yield was $1.16 in gold per ton, leaving a profit of 56 cents per ton, or 48 per cent of the yield. The mine was an open-cut in a schist formation on a hillside and the work was done by Chinese laborers that were paid $1.40 per shift. The ore was soft, and could be ground effectively in four Hunting- ton mills, supplemented by silvered amalgamating plates.* The engineer in charge was F. W. Bradley, a student from the University of California. As has been indicated, the conditions were unusually favorable in respect of softness of ore, accessibility to the mill, metallurgic simplicity, with cheap labor and power, but even at that the results were so remark- able as to attract general attention, which, as might be expected, was magnified, for advertising purposes, by the manufacturers of the Huntington mill, the firm of Parke & Lacy, at San Francisco. The record made at the Spanish mine therefore found its way into many textbooks on mining published at that time. The editor of the 'Mining and Scientific Press'† (at that date, Charles G. Yale) evidently took a warm interest in. the

Jan 1, 1932

By Shun-ichi Satoh

A NEW method of treating steel by ammonia has recently been intro¬duced into the metallurgical industry, by means of which piston cylinders of internal combustion engines, shafts and other similar steel products can be made more resistant to wear than formerly. In 1929 the writer' published the historical notes and some experiments upon nitrification. He believes that the corrosion of nitrified steel is a matter of importance and worth studying; and as there have been few studies thereof, he has conducted experiments in this respect. L. Guillet,2 in 1927, reported corrosion tests made on nitrified and cemented steels with acid and salt solutions. In 1928, 0. Hengstenberg3 reported the high resistance of nitrified steel to water vapor and air. V. 0. Homerberg4 stated that nitrified steel has high resistance to water, air and salt solution; and G. Hagg5 studied nitrified layers of iron by means of the X-ray. Though F. Hanaman6 in 1913, measured the single potential difference of steel treated with ammonia at above 650° C., no one, it seems, has ever measured the single potential difference of the so-called nitrified steels having extraordinary hardness. The writer measured the single potential differences of nitrified special steels in various solutions with the object of studying the corrosion problem and, if possible, of knowing whether any new physical property would be caused by nitrification.

Jan 1, 1932

Jan 1, 1965

By Walter E. Duncan

The ores treated at the concentrating plant of the Mahoning Mining Co. at Rosiclare, III., come largely from the blanket replacement deposits of the northeastern part of Hardin County, Illinois, and consist of complex mixtures of galena, sphalerite and fluorspar in a gangue of quartz, limestone and sandstone. The several minerals are so intimately inter-grown that they are not liberated at the sizes usually treated by gravity concentration in the usual fluorspar plant. For this reason, an all-flotation method of concentration was developed in cooperation with the station of the U. S. Bureau of Mines at Rolla, Mo.1 This flotation separation made possible the commercial production of four concentrates: (I) lead, (2) zinc, (3) acid-grade fluorspar and (4) metallurgical-grade fluorspar.2,3 Although fluorspar had been floated in Canada in 1921 and a plant at Rosiclare had been floating fluorspar since March 1929, fluorspar flotation was given considerable impetus by the Mahoning developments, since some features of the separation were quickly adopted by other fluorspar companies. The Bureau of Mines6 reports that in the 10 years preceding 1938 only 50,552 tons of fluorspar flotation concentrates were produced in the United States. The rise from this almost nominal figure to 153,750 tons (largely acid grade) in one year (1944)6 is indicative of the activity in fluorspar flotation occasioned by the war. The industry thus proved to be in a position to expand and keep up reasonably well with the requirements imposed upon it by such developments as occurred in high octane aviation gasoline alkylation, in the use of Freon as a refrigerant and as carrier in the Aerosol "bug bomb," and in the atomic bomb project as well as in the expansion of other activities requiring hydrofluoric acid; for example, the aluminum industry. Despite the fact that the greater portion of acid-grade fluorspar produced in the last few years went directly into war uses, the future of the acid-grade field still appears bright. As a result of the activity in fluorine chemistry during the war, it seems likely that in the relatively near future almost every phase of human endeavor will find some fluorine compound involved. The other three concentrates produced deserve some attention in these introductory remarks. The lead concentrates first produced contained both zinc and fluorspar but these did not interfere with their marketing. As will be pointed out later, the quality has steadily improved until today it is a relatively high-grade product. Although some zinc smelters accept concentrates containing limited quantities of fluorspar, it is a very objectionable impurity. Since flotation methods fail in the complete removal of the fluorspar, chemical methods were developed for

Jan 1, 1947

By Walter E. Duncan

The ores treated at the concentrating plant of the Mahoning Mining Co. at Rosiclare, III., come largely from the blanket replacement deposits of the northeastern part of Hardin County, Illinois, and consist of complex mixtures of galena, sphalerite and fluorspar in a gangue of quartz, limestone and sandstone. The several minerals are so intimately inter-grown that they are not liberated at the sizes usually treated by gravity concentration in the usual fluorspar plant. For this reason, an all-flotation method of concentration was developed in cooperation with the station of the U. S. Bureau of Mines at Rolla, Mo.1 This flotation separation made possible the commercial production of four concentrates: (I) lead, (2) zinc, (3) acid-grade fluorspar and (4) metallurgical-grade fluorspar.2,3 Although fluorspar had been floated in Canada in 1921 and a plant at Rosiclare had been floating fluorspar since March 1929, fluorspar flotation was given considerable impetus by the Mahoning developments, since some features of the separation were quickly adopted by other fluorspar companies. The Bureau of Mines6 reports that in the 10 years preceding 1938 only 50,552 tons of fluorspar flotation concentrates were produced in the United States. The rise from this almost nominal figure to 153,750 tons (largely acid grade) in one year (1944)6 is indicative of the activity in fluorspar flotation occasioned by the war. The industry thus proved to be in a position to expand and keep up reasonably well with the requirements imposed upon it by such developments as occurred in high octane aviation gasoline alkylation, in the use of Freon as a refrigerant and as carrier in the Aerosol "bug bomb," and in the atomic bomb project as well as in the expansion of other activities requiring hydrofluoric acid; for example, the aluminum industry. Despite the fact that the greater portion of acid-grade fluorspar produced in the last few years went directly into war uses, the future of the acid-grade field still appears bright. As a result of the activity in fluorine chemistry during the war, it seems likely that in the relatively near future almost every phase of human endeavor will find some fluorine compound involved. The other three concentrates produced deserve some attention in these introductory remarks. The lead concentrates first produced contained both zinc and fluorspar but these did not interfere with their marketing. As will be pointed out later, the quality has steadily improved until today it is a relatively high-grade product. Although some zinc smelters accept concentrates containing limited quantities of fluorspar, it is a very objectionable impurity. Since flotation methods fail in the complete removal of the fluorspar, chemical methods were developed for

Jan 1, 1947

Jan 1, 1943

Jan 1, 1942