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By Amos Bowman

In the last two years I have had an opportunity to study the conditions of gold-mining in the far northwest of the Pacific coast —in Cariboo district, British Columbia. That country joins Alaska

Jan 1, 1887

By J. C. Jr. Vaughan

ALTHOUGH a considerable amount of practical importance attaches to systems involving gases and molten metals, little is known regarding the effects of alloy elements upon the solubility of gases in liquid iron. The solubilities of hydrogen1 and nitrogen2,3 in pure liquid iron are known and it has been shown that small amounts of silicon and aluminum3 exert only a small effect upon the solubility of nitrogen but greatly increase its rate of solution. This paper presents the results of a study of the Solubility Of nitrogen, at pressures approximately one atmosphere, in molten iron containing up to 1.5.5 per cent silicon.

Jan 1, 1939

By Helmar Schubert

The tensile strength of moist agglomerates consisting of granular materials is demonstrated with the aid of models. The applicability of these models is proved by experiments. An explanation of the different values of strength of imbibed and drained agglomerates is given and it is shown that the maximum tensile strength occurs at the so-called entry suction. The entry suction, which can be considered as the characteristic capillary pressure of the agglomerates, is described in terms of its parameters by a dimensional analysis. The influence of porosity is determined experimentally by means of regressional analysis and is compared with known model equations.

Jan 1, 1977

Jan 1, 1895

By I. Iwasaki, K. A. Smith

A chlorination process for treating metal sulfide flotation concentrates is described. The process involves low temperature chlorination combined with sulfur chloride conversion and selective oxidation to produce nonferrous metal chlorides, elemental sulfur, and ferric oxide in a three-stage fluidized bed reactor. The nonferrous metal chlorides may then be water leached, separated, purified, and electrolyzed to recover copper and nickel metals and to regenerate chlorine for recycling.

Jan 1, 1986

By W. F. Mullen

WITH few exceptions, unit operations in the Pennsylvania slate industry in 1950 did not differ appreciably from production methods described by Behre1 and Bowles 2-4 several decades ago. Many traditionally picturesque but relatively inefficient hand operations continued to contribute to high operating costs in an industry in which the margin of profit, for various reasons, was admittedly low. As part of a general program in which the Pennsylvania State College has been assisting the slate industry to solve some of its problems, time and method studies were used in an effort to determine the bottlenecks of production flow. The results are as applicable to other stone industries as they are to slate.

Jan 12, 1951

By Charles J. Speake, Dennis R. Haley, Thomas E. Finch

As there exists a strong trend to computer assisted mine design, this twofold presentation will emphasize an examination of the parameters wed to create a mine design computer program. The program results are a first-order engineering design and evaluation of methods wed to handle the parting or inner burden found in thick-seam western surface coal mines. The alternative selections are draglines, backhoes, scrapers, front-end loaders, shovels, and bucket wheel excavators used in direct stow or haul-back techniques. The computer program wed in the design selection will be explained and typical input and output information shown.

Jan 1, 1980

By V. Rajaram, I. P. Nielsen, H. D. Raymond

The Parachute Creek member of the Green River formation in the Piceance Basin, Colorado, contains vast reserves of oil shale, nahcolite, dawsonite, and other accessory minerals. The dry alkali process of sulfur dioxide removal using nahcolite (naturally occurring sodium bicarbonate) has great potential. A room and pillar mining scheme has been designed to extract a nahcolite zone occurring at a depth of 472 m, from the lease application area of the Yankee Gulch joint venture. Geotechnical parameters affecting mine design will be discussed. A preliminary development plan for mining at the rate of 1000 t/d will be described in detail.

Jan 12, 1979

By Ernest Wiltsee

The Half-Moon mine, situated three miles west of the town of Pioche, exhibits geological features which are peculiar and interesting. The general formation in the vicinity of Pioche consists of a quartzite, usually covered with an overlying limestone containing strata of shale. In the camp itself, where the original mines are situated, the quartzite has been denuded, and the principal veins outcrop in this formation; to the west, the quartzite is again covered with limestone, containing thin strata of shale.

Jan 1, 1893

By L. P. Teas

Although 1927 in the Arkansas-Louisiana territory will probably pass into history as a year of small profits and little new production, nevcrtheless during this period two large gas fields were developed; two new oil fields were discovered, and two new oil horizons, hitherto of minor annual production Fig. 1.—Production of North louisiana and ARkansas by fields, for 1926 and 1927. (Upper blocks represent 1926 production; lower blocks, 1927 production ) importance, were developed. In spite of the "hard times" some of the leading supply houses did more business this year in this district than in any year since 1920.

Jan 1, 1928

By L. F. Mashburn, T. J. Ferree

A Reichert cone concentrator was installed in an aggregate plant circuit to recover the extremely fine "flour gold" known to exist in the deposit. The gold content of the bank- run gravels averages about 0.1 g/t-about $1.29/t, based upon $12.86/g ($400 per oz) gold. The fineness of the gold averages between 950 and 960. The Reichert cone, in conjunction with a conventional shaking table, recovers in excess of 85% of the gold. A screen analysis of the gold particles shows 44.1 % is - 74pm (-200 mesh) in size. The plant operates with a two-man crew.

Jan 1, 1983

By L. Eaton, A. W. Last, J. L. Stevens

COPPER ore from Kennecott Copper's Ray mine, about 60 miles southeast of Phoenix, Ariz., is concentrated at the company's mill at Hayden, some 18 miles south of the mine. The Hayden mill is currently treating 16,000 tons of ore per day by flotation, using raconite, a crude butyl xanthate, as a collector for the sulfide copper minerals and lime as a pyrite depressant.1 The ore contains significant amounts of nonsulfide copper minerals, but recovery of these values has been low. The Hayden mill is now being modified to provide for treatment of future ores by leach- precipitation-flotation (L-P-F). This modification, costing about $5 million, is expected to reduce the loss of nonsulfide copper values and improve overall copper recovery by an additional 2 lb per ton of ore.

Jan 11, 1957

By Thomas M. Drown

IN a communication to this Institute at the Baltimore meeting, February, 1879,* on the "Determination of Silicon in Pig Iron and Steel," the method recommended was the treatment of the metal with nitric acid until action had ceased, and then evaporating with sulphuric acid until the nitric acid was nearly or quite driven off After filtration of the siliceous and carbonaceous residue, and washing with hot water and hydrochloric acid, a silica was obtained, on ignition, which was quite pure. Since this paper was read before the Institute, we have had large experience with the method, and * Transactions, vol. vii, p. 346.

Jan 1, 1880

By K. H. Nimerick, G. P. Laflin

Laboratory data and field tests indicate that substantial losses of valuable coal can be caused by wind erosion. Wind tunnel tests show the effects of wind velocity and particle sizing on the amount of coal lost while in transit. Different coals were evaluated to determine the variables associated with wind erosion. The erosion losses can be substantially reduced by using a binder, or crusting agent, to consolidate the surfaces of the coal into a solid mass which resists erosion. This not only reduces economic loss but minimizes pollution.

Jan 8, 1979

By Tony B. Szwilski

A short study has been made of the underground mining potential in the Plains region, the Province of Alberta, Canada. Particular reference is made to the possible application of longwall mining: Presently underground mining is limited to small scale room-and- pillar methods. The problems anticipated with large scale mining at shallow depths (30 m) are examined. Production factors based upon longwall retreat mining utilizing shield supports are also considered.

Jan 1, 1981

By H. L. Armstrong

SOLID-STATE diffusion is an important technique in certain aspects of metallurgy, and especially the metallurgy of semi-conductors and semi-conductor devices. If the diffusion is carried out under constant conditions for a time, t, the concentration, C, of the diffusant at a depth, x, below the surface from which the diffusion is carried out is given by an expression of the form. C = Cof(x,Dt) [I] Co being a constant, and D the diffusion constant of the diffusant in the material and at the temperature

Jan 1, 1959

By Dominique François-Bongarçon

A new method for open-pit design has been devised by G. MATHERON and the writers: it replaces the search for an optimum contour by the determination of a parametrizing function. The isovalue curves of this function give the optimum pit design corresponding to varying economic parameters; The method is described and indications are given about the corresponding program. Simulated data have been processed by the program and by a standard program using LERCES-GROSSMAN graphical method: the comparative results are described.

Jan 1, 1977

By Thomas V. Falkie

The use of operation research and computer techniques in the mineral industries continued to gain acceptance during 1966. There are generally at least five sources of information for researchers and practitioners in the field: (1) Technical periodicals like MINING ENGINEER- ING, Mining Congress Journal, etc. (2) Proceedings of the Symposium and Short Course on Computers and Operations Re- search in Mineral Industries, held last year at Penn. State University and jointly sponsored by the University of Arizona, Stanford University, Colorado School of Mines, Penn. State University and the Society of Mining Engineers of AIME. (3) Various local conferences, such as the 1966 Rocky Mountain Minerals Conference held in Denver. (4) United States Bureau of Mines publications. (5) The AIME annual meeting in New York and the SME Fall Meeting in Tampa.

Jan 2, 1967

By C. V. O. Hughes

DIATOMACEOUS earth is probably the most widely used, and certainly the least well publicized, of the important non-metallics of the United States. The very multiplicity of the names by which this whitish earthy sediment is described has served to confuse its identity, and to dissipate a realization of its full importance.

Jan 3, 1953

By E. P. Pfleider, O. Rellensmann

In the May 1959 issue of [=] the authors reported on the gyrotheodolite as used for determining azimuths in surface and underground work. Further research has led to the development of a new type of gyro instrument, the band-suspended gyro attachment, which is essentially an upset gyro attached to the top of a theodolite. The new gyro attachment is light enough to be mounted on any angle-measuring instrument if the design of the telescope standard permits. Gyrotheodolite units have been used to transfer meridian lines underground in the Coeur d'Alene mining district, although they have not been used extensively in the U.S. In other parts of the world, however, they have been adopted as the standard surveying instrument by mining engineers.

Jan 3, 1968