Search Documents

By K. S. Benson

DEPLETION is a subject of vital importance to the mining industry. Yet, in spite of its importance, its significance is not generally understood. The purpose of this discussion is to clarify the main aspects of the subject from the viewpoint of a metal mine taxpayer.

Jan 7, 1951

By Kefton H. Teague

Attempts to locate domestic supplies of sillimanite have been un- successful until recently. This paper describes recent discoveries of sillimanite-bearing schists in the Southeastern States, with emphasis on geology of the deposits, mineral composition, origin, and reserves. Statements concerning possible methods of mining, milling, and utilization of sillimanite are given. Results from refractory tests on a laboratory scale are summarized.

Jan 7, 1950

By Lewis Stockett

During the year 1903, a building having machinery corresponding to ail anthracite-coal breaker was erected at the town of Stockett, Cascade county, Mont., for the purpose of breaking-up and cleaning bituminous coal. The coal is mined from a vein of the Kootenai group of the Lower Cretaceous measures having the following section: The vein is nearly horizontal in position, and each bench differs in quality as shown in Table I.

Jan 1, 1905

By Ed Ramsay

The Kerr Addison process involves the cyanidation, flotation, and roasting of graphitic gold ore. The grinding and treatment section of the present mill has at the present time a capacity of 1400 stpd and the precipitation section has a capacity of 6000 stpd. The grind is maintained at 80%, -200 mesh, and a gold recovery of 92% is obtained in the cyanidation circuit. With flotation and roasting, the overall gold recovery is increased to 98%.

Jan 1, 1978

By E. J. Haug, M. M. Fine

For several years work has been carried on by the U.S. Bureau of Mines at Rolla, Mo., to develop improved methods of concentrating the oxidized ores of lead and zinc. Various samples have been investigated, and results on some have been published. Details of the progress to date are given in a mineral dressing study now being conducted for an extensive oxidized lead-bearing tract in southeast Missouri, property of St. Joseph Lead Co. These oxidized ores present problems typical of many encountered in modern mineral dressing research in that recovery of very fine particles is of

Jan 4, 1955

By R. D. Coleman, A. E. McIlhinney, C. E. Capes

Problems of unstable operation in continuous balling circuits may be traced to the random generation of seed agglomerates. This has been verified during the continuous operation of a laboratory balling drum with internal recycle described previously by the authors. The cyclical behavior of a balling circuit was also investigated using a simple numerical computer model. Changes are suggested in the design of balling equipment to improve stability.

Jan 1, 1976

John Edward Stead, a past-president of the British Iron and Steel Institute, and an Honorary Member of this Institute since 1906, died at his home at Redcar, Yorkshire, on Oct. 31, 1923, after a long illness. For many years, Mr. Stead had been recognized as a leading authority in chemical and metallurgical matters, particularly those relating to iron; he gave freely of his experience by the contribution of papers to the twenty-eight technical societies in which he retained his membership as recently as 1920. He had been honored with the Doctor's degree by three English universities, and was elected a Fellow of the Royal Society 1219

Jan 1, 1924

By W. H. Hoffman

At the Glen Summit meeting (Trans., xx., 605) I described in a general way the grinding-machine known as the Sturtevant mill, built by the Sturtevant Mill Co., of Boston, Mass. My first experiments in granulating magnetic. iron-ores with this machine were made five years ago in the northern portion of New York State.

Jan 1, 1893

By A. Blake Caldwell

The continental margins and ocean basins represent by far the largest unexplored frontier for discovery and development of mineral values. In April 1971, Deepsea Ventures, Inc., at a press conference in its Gloucester Point, Va. headquarters, announced what may become the first commercial deepsea venture--15,000 ft below the ocean surface. During the presentation, Deepsea's president, John E. Flipse, announced that studies made by company personnel had proven the feasibility of mining, transporting, and milling L million tpy of manganese nodules taken from the ocean floor, and that, based on current conditions and prevailing construction costs, a venture of this magnitude would cost about $200 million split evenly between mining and processing facilities. A subsidiary of Tenneco, Deepsea has tentatively reserved 1976 as the year in which it plans to mine, process and market the nodules.

Jan 1, 1971

By C. A. Wert, K. C. Hsieh

Measurement has been made of the organic sulfur concentration in coal macerals using microanalytical techniques in the transmission electron microscope. This technique utilizes measurements of x-rays emitted by the sulfur atoms embedded in the hydrocarbon constituents and the bremsstrahlung x-rays generated in the matrix. It is a simple technique for thin specimens and yields reliable results. Although it can be used to measure the average organic sulfur content of coal, it is most useful in determining organic sulfur in extremely small volumes of material. Variations in organic sulfur content can be measured at a scale unimagined earlier. This TEM technique also has application for determination of organic chlorine, phosphorous, potassium and other elements often found distributed through the hydrocarbon constituent of fuels.

Jan 1, 1985

By R. B. Berg

Chlorite veins in the Silver Star district were of little interest to those who were mining gold and silver in the late 19th century. In 1975 unusually pure magnesian chlorite of the variety clinochlore was identified from a "talc" claim in this district. In 1977 tests by Cyprus Industrial Minerals showed that this chlorite was suitable for use in ceramics. Mining begun in that year continues. These replacement veins of chlorite in Precambrian quartzofeldspathic gneiss differ from nearby metalliferous veins to the northwest in both attitude and mineralogy.

Jan 1, 1984

Executive SIDNEY J. JENNINGS, Chairman GEORGE D. BARRON J. E. JOHNSON, JR. EDWIN LUDLOW ROBERT M. RAYMOND Membership KARL EILERS, Chairman LEWIS W. FRANCIS J. E. JOHNSON, JR. LOUIS D. HUNTOON ARTHUR L. WALKER Finance GEORGE D. BARRON, Chairman CHARLES F. RAND BENJAMIN B. THAYER Library E. GYBBON SPILSBURY,1 Chairman ALEX C. HUMPHREYS3 GEORGE C.' STONE2 J. H. JANEWAY4 BRADLEY, STOUGHTON Papers and Publications BRADLEY STOUGHTON, Chairman

Jan 7, 1918

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

Jan 1, 1965

By J. C. Smock

The magnetic and polaric properties of magnetite, or magnetic iron ore: are fundamental facts in magnetism. The disturbing erect of this mineral upon the magnettic needle in land surveying must have been very early observed. The difficulties arising from this source are still almost insurmountable in making accurate surveys in districts where this ore occurs to any extent, either as a rock

By Daniel T. Hegyan, Thomas B. Zugates

Continuous vacuum disk filters are increasingly being used to filter refuse from the fine-coal washing circuits as it becomes important to close the water circuits and eliminate sludge holding ponds. This paper discusses our past experience filtering refuse, effects of solids concentration in the filter feed, use of polymer flocculation aids, effect of flocculation devices, and effects of particle size and ash content on the filtration rate. Detailed tests were performed on existing installations utilizing coal refuse filters to determine optimum flocculant dosage, solids concentration, and disk rotation speed to form a dischargeable cake. Information was also obtained showing effect of flocculant addition on the moisture of the filter cake.

Jan 1, 1977

By Edwin T. Wood

THE term blending as used herein refers to the mixing of ores assaying more than 0.20 pct U3O8 with low grade material assaying less than 0.20 pct U3O8. Such blending when properly understood and controlled will produce more total dollars of profit from many mining ventures. The question whether or not to blend is particularly vexing when an orebody is surrounded by an envelope of low grade material or separate tonnages of low grade exist which could be extracted coincident with the higher grade ores. Should any, all or part of this low grade be mined? If so, in what proportion and what is the limiting assay of the low grade material?

Jan 7, 1958

Robert Campbell Gemmell, assistant managing director of the Jackling allied porphyry mining properties in Utah, New Mexico, Arizona and Nevada, died suddenly on Oct. 25, of heart trouble, while traveling from Hurley, N. M., to Los Angeles. To shape justly even an outline of the brilliant career and uniquely charming personality of Mr; Gemmell is well-nigh impossible, and any effort so to do can but demonstrate the inadequacy of language to sound the depths of soul-stirring sentiments. To touch upon his more important work, and afford even a limited conception of his general worth and character, is all I can hope to do.

Jan 1, 1923

By L. J. Cabri

The calculation of metallurgical balances for precious metals is very dependent on a precise mineralogical understanding of the distribution of each element. Determination whether the precious metals occur as dilute solid solutions in major minerals is not always easy because of the relatively high levels of detection (9200-500 ppm) of the precious metals by the most common methods of in-situ analysis (e.g. electron microprobe). Particle Induced X-ray Emission (PIXE) analysis of sulfides from Izok Lake, N.W.T., Canada and from the Hilton mine, Mount Isa, Australia with a proton beam (proton microprobe) confirms solid solution of Ag in chalcopyrite from both deposits. In addition, chalcopyrite and sphalerite from Izok Lake both contain indium.

Jan 1, 1984

By Tuncel M. Yegulalp

This article summarizes the preliminary results of continuing research at the Henry Krumb School of Mines. Columbia University, which is directed towards improving the production efficiency of mining operations. The purpose of the particular

Jan 1, 1979