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By W. Petruk, R. S. Boorman, R. Gilders

Approximately 33% of the silver in the Zn-Pb-Cu-Ag ore of Brunswick Mining and Smelting Corporation Limited is lost to the tailings and an additional 11% to the zinc concentrate for which no payment is received. 38% to 44% of this lost silver is carried by tetrahedrite, 28% by galena and 28% to 34% by a third silver carrier. The silver minerals acanthite and pyrargyrite have been identified in mill products and hence these are suggested as the principal third silver carrier(s) accounting for 13 to 20% of the silver in Brunswick ore. About 24% of this third silver carrier assemblage is lost to the zinc concentrate and 52% to concentrator tailings.

Jan 1, 1984

By O. P. Hood

None of the methods now in use for the transportation of materials underground is entirely free from more or less serious objection.

Jan 1, 1915

By Willard S. Morse

The ores of the district are treated at this mill by the lixiviation process, consisting of drying, crushing, chloridizing-roasting and lixiviation by hyposulphite and Russell solutions. Gas is used as fuel for both drying and roasting, The gas-plant consists of two- Taylor revolving-bottom gas-producers, one 6 feet in diameter for the ore-dryers, the other 7 feet in diameter for the Stetefeldt furnace. The producers were made by Messrs. R. D. Wood & Co., Philadelphia, who also furnished the

Jan 1, 1893

By T. A. Rickard

The mountains of the picturesque Dauphine, in southeastern France, have long been known to collectors as the source of many minerals of rare occurrence; but. they contain also several mines, which, though less known, date from the time of the Saracens, many centuries back, to that of the graduate from the Ecole des Mines. In the department of the Isere, upon the cliffs of Villard Ey-

Jan 1, 1893

By George Hunt

THE first practical treatment of wood to prevent decay was devised early in the 19th century. At that time the oaken navy of England, when the nation was fighting for its very existence, seemed doomed to annihilation by the swift ravages of decay. The acute situation inspired a desperate search for preventive measures and resulted in the development of the Burnett, Bethel and Kyan processes for impregnating wood with zinc chloride, coal-tar creosote and mercuric chloride, respectively. In the century that has elapsed, their use has spread throughout the world and the three original preservatives are used today in enormous quantities. Meanwhile, improved processes have been developed, new preservatives discovered, and the practice of impregnating wood to make it last longer has attained a position of major importance in the field of structural materials. USE OF PRESERVATIVES BY THE RAILROADS In the application of wood preservatives in the United States the railroads have been the leaders for the past 50 years or more. Having found that decay is the chief cause of the early destruction of wood and that preservative treatment is the remedy, they have treated their ties and timber in increasing amounts(1)?-in 1925 about 220;000,000 cubic feet. By preservative treatment the Santa Fe Railroad saves annually 1,500,000 ties in its 18,000 miles of track, and many other railroads effect similar savings. (2) In like manner the life of wooden bridges and trestles,(3) poles, marine piling, water tanks and other wooden railroad structures has been greatly increased, reducing the amount of timber required annually to maintain them.(5),(7)

Jan 1, 1927

By A. L. Engel

IN the treatment of complex ores by flotation, one of the most important steps is conditioning the feed. Conditioning primarily consists of the addition, in the grinding circuit, of an alkaline reagent, for example sodium carbonate, which neutralizes any acidity of ore and mill water, counteracts the effect of 'harmful soluble salts, disperses colloids, and provides the necessary alkalinity for the best metallurgical results. The several minerals of the ore should be put in such condition that they may be floated or rejected as desired, through the action of further reagents thereafter used.

Jan 1, 1932

By J. A. Rajala, R. W. Smith

The effect of increasing ionic strength, via monovalent and divalent ions, on alkyl sulfate flotation of hematite and quartz war investigated. The effects of collector chain length and pretreatment on this flotation were also studied. Sodium hexadecyl sulfate was shown to be a superior flotation collector to sodium dodecyl sulfate for recovery of hematite when there was no salt addition. Similar observation were made when sodium sulfate or sodium chloride was used to control ionic strength. Sodium dodecyl sulfate floated hematite better than its longer chutited counterpart under conditions of low pretreatment temperature and increasing calcium chloride concentration. The flotation recovery for all salt containing pulps was almost always improved after preboiling. Most of the results obtained when the pretreatment temperature was raised were attributed to increased solubility of the collector.

Jan 1, 1984

By Richard D. Dick

The Los Alamos National Laboratory was involved in an oil shale fragmentation research program in cooperation with a Consortium of industrial companies to investigate the feasibility of using modified in-situ (MIS) recovery of oil from oil shale. Field tests were conducted at the Anvil Points Mine, Colorado, in the thick oil shale beds of the Green River formation. Part of the program included obtaining data about fragmentation by instrumenting the tests with accelerometers, velocity gauges, and the CORRTEX technique (Continuous Reflectometry for Radius versus Time Experiments). Some of the rock motion data from accelerometer and velocity gauges is presented, along with some conclusions. In addition, the signal recording system is briefly explained. The CORRTEX technique is discussed, and some results on explosive performance and stem behavior using the method are discussed.

Jan 1, 1984

By George Frederick Kunz

The garnet-district of Bohemia is situated about 60 kilometers northwest of Prague, and is bounded on the north by Meronitz and Trebnice, 12 miles apart, and by Decany and Skan on the south. This region is covered with alluvium resting on the diluvium, which

Jan 1, 1893

By G. Broughton

For the past few years a great amount of work has been done on the viscosity characteristics and gelation of clay suspensions, much of which has been reported in papers published by the Institute.7,12,18,19,24 Impor-tant reviews have been made elsewhere by Evans and Reid,10 Marshall20 and Clews, Macey and Rigby,8 the last two on the general properties of clay. It is unnecessary, therefore, to recapitulate past work beyond recalling that three explanations for the high viscosity and gelation of clay suspensions have been put forward. For lack of more exact nomencla-ture, these may be called the water hull,16 mechanical interference" and attraction-repulsion" theories. The first pictures the clay particles as surrounded by relatively rigid water envelopes, which increase effective volume; the second emphasizes the mechanical interference of platy particles or their agglomerates; while in the third the particles are assumed to be held relatively rigidly at a distance from each other determined by the balance between the attractive (van der Waal's) forces and the elec-trical repulsions of the charges. 13,14 This article presents fresh data on clay suspensions, particularly on the influence of previous flow history of the suspensions, specific contra-ions, temperature, solvation and particle size, in an attempt to contribute to the solution of the problem.

Jan 1, 1938

By Waldemar F. Dietrich

Mineral fillers are relatively inert chemically under the conditions of use but have physical properties* that modify those of the materials in which they are incorporated. The mineral fillers considered in this article are asbestos, barite, clays, diatomite, crushed limestone, limestone whiting and lime, mica, silica, talc and soapstone, and pyrophyllite. Slate and stone, other than limestone and its derivatives, are excluded because, even though used in large quantities, they are exceptionally low-cost materials generally produced close to the area where they are used.

Jan 8, 1959

By R. M. Stewart, C. W. MacQueen

Anaconda's Berkeley pit at Butte produces 34,000 tpd of ore averaging 0.8 pct copper. Two-and-one-half tons of waste is stripped per ton of ore, approximately 40,000 tpd by the company and an added 45,000 tons by the F&S Contracting Co. The company truck fleet consists of 24 Euclid and 18 Mack 34-ton, rear-dump diesel trucks.

Jan 7, 1961

The production of petroleum in India (including Burma) increased from 334,811,624 gal.' ill 1936 to 350,322,222 gal. in 1937, the highest figure in the history of the industry. The increase in 1937 was clue to an increase of some 20 million gallons from Singu, 51/2 million gallons from Attack, 11/4 million gallons from Thayetmyo, and 1 mi1lien gallons from Digboi, accompanied by decrcases of 91/2 million gallons from Yenan-gyaung and 2 million gallons from Yenangyat,. The amount of gasoline produced from natural gas during the year was 10,616,313 gal. in Burma and 456,780 gal. in the Punjab. Yenangyaung Field.—The Yenangyaung field maintained its reputation of being one of the most wonderful oil fields in the world. The total production during 1937 was less than in the previous year but the resources of the field as a whole are sufficient to ensure an adequate supply of oil for many years. At the end of 1037 there were 2910 wells producing in the field. Besides a large number of ells drilled to shallow sands, this total includes 180 hand-dug wells, whose continued existenice is one of the interesting features of the field. During the year the deep drilling activities of 1936 in the southern part of the field died down, owing to the disappointing results obtained. On the eastern flank the limit of present economic extension of the oil sands was approximately demareated. Satisfactory results continue to be obtained from gas drives in the leased blocks; gas is also injected for repressuring and storage. Casing policies continue to be carefully designed to protect the oil sands against the danger of flooding by water and, in general, production methods throughout the field are characterized by a realization of the importance of the conservation of oil and gas and the prevention of waste, whether simple or underground. Singu Field.—-In 1937 the increase in the output from the Singu field was continued. This increased production was due not only to the rapid development of the valuable area in the southern part of the field but also to the successful results obtained from the first wells to produce from behind the practically completed river training wall of the Burmah Oil

Jan 1, 1939

The production of petroleum in India (including Burma) increased from 334,811,624 gal.' ill 1936 to 350,322,222 gal. in 1937, the highest figure in the history of the industry. The increase in 1937 was clue to an increase of some 20 million gallons from Singu, 51/2 million gallons from Attack, 11/4 million gallons from Thayetmyo, and 1 mi1lien gallons from Digboi, accompanied by decrcases of 91/2 million gallons from Yenan-gyaung and 2 million gallons from Yenangyat,. The amount of gasoline produced from natural gas during the year was 10,616,313 gal. in Burma and 456,780 gal. in the Punjab. Yenangyaung Field.—The Yenangyaung field maintained its reputation of being one of the most wonderful oil fields in the world. The total production during 1937 was less than in the previous year but the resources of the field as a whole are sufficient to ensure an adequate supply of oil for many years. At the end of 1037 there were 2910 wells producing in the field. Besides a large number of ells drilled to shallow sands, this total includes 180 hand-dug wells, whose continued existenice is one of the interesting features of the field. During the year the deep drilling activities of 1936 in the southern part of the field died down, owing to the disappointing results obtained. On the eastern flank the limit of present economic extension of the oil sands was approximately demareated. Satisfactory results continue to be obtained from gas drives in the leased blocks; gas is also injected for repressuring and storage. Casing policies continue to be carefully designed to protect the oil sands against the danger of flooding by water and, in general, production methods throughout the field are characterized by a realization of the importance of the conservation of oil and gas and the prevention of waste, whether simple or underground. Singu Field.—-In 1937 the increase in the output from the Singu field was continued. This increased production was due not only to the rapid development of the valuable area in the southern part of the field but also to the successful results obtained from the first wells to produce from behind the practically completed river training wall of the Burmah Oil

Jan 1, 1939

By J. C. Norman

Jan 1, 1985

By Frank Foote, V. H. Nordstrom, Eric R. Jette, Bernard Queneau

The nickel-chromium alloys form the base for many industrial heating alloys, so that this system is of considerable practical importance. The literature on these alloys, however, contains much conflicting evidence, not only regarding the solubility limits of the terminal solid solutions at different temperatures but even regarding the number of phases existing in the system. Part of the difficulty undoubtedly arises from the fact that chromium of sufficiently high purity has been available only during the last few years. A second and possibly even more important difficulty arises from the ease with which chromium reacts with silicon and carbon compounds and the atmosphere to form silicides, carbides, nitrides and oxides. Pilling and Kihlgrenl in 1929 reviewed the existing scanty information. They did not consider the diagram by which they summarized the various bits of information to be entirely satisfactory. Matsunaga2 investigated the system by thermal analysis, microscopic examination and other means. Electrolytic nickel of 99.9 per cent purity and thermit chromium containing 0.30 per cent Al, 0.40 per cent Fe, 0.25 per cent Si and 0.04 per cent C were used. A Tammann furnace with hydrogen flowing through it was used for melting. Sekito and Matsunaga3 reported an X-ray investigation, presumably on these same alloys, which, as far as can be judged from the abstract, essentially confirmed the thermal and microscopic results. Nishigori and Hamasumi4 found compositions for the terminal solid solutions in equilibrium at the eutectic temperature which agreed fairly

Jan 1, 1934

By Michael Tenenbaum

RECENT researches on the reduction of iron ores have stimulated interest in the effect of increased pressures within the iron blast furnace. From a physicochemical viewpoint, it seems logical to suppose that the increased pressure would increase the rate of reduction of the iron ore within the furnace. This increased reaction velocity would in turn be reflected in an increase in the output of the blast furnace. Any sub-stantial effect of elevated blast-furnace pressures should accordingly be of both technical and economic interest to the operator. It is doubtful whether it is possible to increase the pressure in the stack of the blast furnace beyond two or three atmospheres without incurring severe mechanical difficulties. The benefits to be procured by elevations in pressure must therefore be restricted to pressures below two, or at the most, three atmospheres. Within this range it would seem both economically and mechanically feasible to modify the present design of the upper portion of the blast furnace to accommodate these more stringent operating conditions. This investigation was undertaken to study the effect of moderate pressures on the rate of reduction of iron ore with hydrogen. The use of carbon monoxide is contemplated for later work. Although any results that are obtained in the laboratory cannot be interpreted directly in terms of large-scale commercial operations, it is possible, through such an investigation, to ascertain the order of magnitude of the effects of higher pressure. A more quantitative conception of the effects that would result from the use of increased pressures in the modern blast furnace is needed.

Jan 1, 1939

By Jock A. Campbell

Oil-impregnated rocks are known to occur in 22 of the 50 states. The largest known petroleum resources of this type are in Utah, with over 95% of the inventoried total, The Utah deposits are estimated to contain over 25 million bbl (42 gal per bbl) of oil in place.' All major Utah tar sand deposits crop out and can be mined partially by open pit methods, but in-situ techniques will have to be employed to recover oil from the deeper parts of the deposits. No significant development of Utah tar sands deposits for their petroleum content has occurred to date, although a mine and extraction plant are anticipated this year at Asphalt Ridge. The barriers to development have been mainly economic, but technological and legal problems will also have to be overcome.

Jan 5, 1975

By H. C. Meister

The zinc-smelting industry of the United States has grown very rapidly in recent years and bids fair to outrival that of all other countries in the future. On account of the geographical situation of the chief ore-supplies, the industry may be divided into two main groups, the eastern and the western. The eastern and older group includes the works of Penn-

Jan 1, 1905

THE bellows are important and necessary agents in most melting processes. In addition to seeing that these have sufficient soft cloth, extend far and wide, and are of good design, including good valves and good long tubes, and that they cannot break and lose the air received, it is very important to give attention to their installation so that they may easily effect their purpose. Therefore I now wish to proceed by noting some common devices for moving them, both with water and with man power, so that you may make use of them as the need arises.

Jan 1, 1942