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By Walter E. Lewis, Robert L. Marovelli

Underground support has a long history as evidenced by Agricola's general description in Dc Re Metallica:1 "The timbering of these openings is done as follows: stulls are set at intervals into hitches in the hanging and footwall, and upon them smooth poles are laid continuously; and that they may be able to bear the weight, the stulls are generally a foot and a half thick. After the ore has been taken out and the mining of the vein is being done elsewhere, the rock then broken, especially if it cannot be taken away without great difficulty, is thrown into these openings among the timbers, and the carriers of the ore are saved toil, and the owners save half the expense. This, then, generally speaking, is the method by which everything related to the timbering of shafts, tunnels, and drifts is carried out."

Jan 1, 1971

By Z. M. Zavodni

The stability of waste dumps depends to a great extent on the physical properties of the underlying foundation. These physical properties are evaluated through surface geotechnical surveys, subsurface exploration, and field and laboratory testing. Sufficient information must be obtained to define and assess the strength, consolidation, distribution, topographic and hydrogeologic properties for these materials. Important foundation data collected in the field include: surface infiltration rates, downhole hydraulic conductivities, ground water levels, bedrock structural parameters, soil types and soil thickness. Laboratory testing should identify the classification, strength, moisture content, hydraulic conductivity, attenuation and consolidation characteristics. Summarized in this paper are procedures and typical results of porphyry copper leach dump foundation investigations. Laboratory properties and design recommendations for potenia1 foundation liner materials are described. Back analysis and laboratory foundation strengths are compared. The topographic effect of the foundation on dump behavior is discussed and a foundation pore pressure monitoring experiment at the toe of an active waste dump is described.

Jan 1, 1985

By O. W. Walvoord

Mill design of the past will not necessarily dictate mill design of the future. There have been many advances and changes in the last few decades, many of which have been extensive and remarkable. Almost certainly, there will be still greater changes in the near future. Minerals beneficiation, for example, as it relates to future mill design, is likely to experience the greatest progress. Gravity separation, though one of the older arts, is in a continuous state of refinement. Flotation, having celebrated its 50th anniversary in 1961, has yet to be surpassed in its contribution to the art of mineral dressing. Ion-exchange, too, will flourish.

Jan 1, 1971

By H. Foster Bain

The recent admirable paper on the general subject of coalcutting machines presented to the Institute by Mr. E. W. Parker* leaves but little to be desired so far as the well-proven and widely-used machines are concerned. The general character of the machines in use and the range of their adaptabilities have been very well stated. It will be noted that in all cases these machines are being used in room-and-pillar work, and indeed (though attention was not directed especially by Mr. Parker to that point) they are practically confined to that work. It is probable that neither the chain breast- nor the pick-machine is, or can be, used to any great advantage in long-wall work.

Jan 1, 1900

By George W. Goetz

As is well known, the general use of natural gas in Pittsburgh and vicinity for domestic and industrial purposes has shown the great advantages and benefits to be derived by the use of a gaseous fuel. In order to ascertain and bring together all the facts relating to a large and economical production, purification, distribution, and consumption of fuel-gas made out of coal, the Fuel-Gas and Electric Engineering Company, Ltd., was organized, under the presidency of George westinghouse, Jr.

Jan 1, 1890

By Roderick K. Davey

Introduction in any business, it is essential that we select those alternatives which are not only technically feasible, but will be the most profitable to the business m terms of corporate objectives Some of the studies and activities requiring support of financial analysis to select the alternatives which most closely satisfy the management objectives and technical considerations are as follows 1 ) Cutoff grade determination. 2) Ore reserve estimation. 3) Production forecasts (long- and short-term) for an operating mine, development of a new mine, or expansion of an existing mine. 4) Evaluation of haulage alternatives. 5) Evaluation of equipment.

Jan 1, 1979

[¦Abad, Leopoldo F., College of Min., Univ. of California Berkeley, Cal. '23 ¦Abarquez, Ramon F., Met., Bureau of Science Manila, P. 1. '24 ¦Abbey, Robert Graham, Student, Case School of Applied Science Cleveland, Ohio. '21 Abbott, A. N., Mines Supt., Mazapil Copper Co., Ltd ...Concepcion del Oro, Zacatecas, Mexico. '23 Abbott, Clarence B., Gen'l Supt., Iron Mines Div., Tenn. Coal, Iron & R. R. Co., 1405 Minnesota Ave., Bessemer, Ala.' '04] [ ]

Jan 1, 1925

By C. A. Allen

FOR over three years we have been endeavoring to reduce the number of fatalities and minor accidents in Utah. The physical condition of the o? Represents the average of 4 States mentioned excluding the catastrophes indicated. FIG. 1.-NUMBER KILLED PER MILLION SHORT TONS OF COAL PRODUCED IN COLO¬RADO, NEW MEXICO, UTAH, WYOMING, AND BITUMINOUS MINES OF THE UNITED STATES, 1914 TO 1920. mines, concentrators, and smelters is good, yet the number of accidents,

Jan 5, 1922

Aamot, Olav Crone, (M'29) Chem. Engr., Elektro¬kcmisk, Raadhusgt. 32, Oslo. Norway. . Aase. Glenn D., (J'40) Jr. Met., American Smelt. & Refin. Co., Selby, Calif. Abadie, Henry G., (J'43) Petr. Engrg., Avenal, Calif. Abadilla, Quirico A., (M'38) Min. Engr., Dir., Bureau of Mines, Manila, P. I. Abbott, Agatin Townsend, (J'40) Jr. Engr., Phelps Dodge Corp., Morenci Branch. Morenci. Ariz. Abbott, Clarence E., (M'04) Civ. Engr. V.P., Tennessee Coal Iron & R.R. Co., 1542. Brown Mars Bldg. Birmingham. Ala. Abel, Raymond L.. (M'23) Chem. Engr., Com¬manding Officer, Pittsburgh Chem. Warfare urement Dist., American Bank Bldg.. Pittsburgh. Pa. Abel, Walter D., (M'32) Min. Engr., Supvr. Engr.. R.F.C., Los Angeles, Calif. Abele, Louis T., (M'31) 423 3rd Ave., Decatur. Ga. Abell, Leo M.: (M'31) Mill Supt. & Met.. Em¬ peror Gold Min. Co., Ltd., Vatukoula. Fiji Islands. Abernathy, G. E., (M'38) Geol., Kansas State Geol. Survey, Pittsburg, Fan. Abernathy, Jack H., (M'40) Cons. Petr. Engr., First National Bldg.. Oklahoma City, Okla.

Jan 1, 1943

By J. B. Novak

The program describes preventive maintenance practices and controls applicable in situations where maintenance actions are triggered primarily by breakdown or part failure and specification and documentation of detailed maintenance practices are minimal or nonexistent. The presentation describes requirements of organization structure, program administration, implementation and operation, type of benefits expected, and actual benefits derived in selected areas. The principle objectives of the program are to provide quick, inexpensive, and effective controls over maintenance practices and requirements and to establish a nucleus of controls that subsequently can be expanded to cover all maintenance activities.

Jan 1, 1973

By D. J. Blickwede

WHEN iron is dipped in molten zinc at temperatures in the range 840" to 930°F, the two metals react to form layers of Fe-Zn compounds which adhere to the iron. At the galvanizing tem- perature, the successive layers are:' y (Fe5Zn21), 61 (FeZn;), and 5 (FeZn13), in conformity with the Fe-Zn constitution diagram. There is no quantitative information in the literature on the rates of growth of the individual alloy layers over the temperature range 840° to 930°F. Rather all the past experiments have studied the loss in weight of iron as a function of galvanizing

Jan 1, 1954

By R. V. Ramani, C. J. Bise

The potential of deep-mineable coal reserves in the western United States for meeting future energy needs has been recognized for quite some time. However, two of the major constraints tending to limit the development of these underground reserves are the great thicknesses of the coal seams encountered and their high pitch. Although new mining methods may need to be developed to recover these reserves, at least in the short-term the industry has to incorporate presently available equipment not originally designed for thick-seam mining. The purpose of this paper is to present an analysis of the various equipment in use today and their possible application to thick-seam mining. The paper also addresses various ground control and safety considerations unique to thick-seam extraction.

Jan 1, 1984

By John B. Mitchell

Approximately 90% of all potash produced is employed as a fertilizer, either directly or with nitrogen and phosphorus. The remaining 10% is utilized in the manufacture of other chemical products. The original source of potassium was wood ash, however, today the term potash refers to all commercially important salts of potassium. The world's first potash mining operation commenced in Strassfurt, Germany, circa 1860, and since that time the industry has grown steadily to its present annual output of about 30 million tons of potassium chloride products or 18 million tons of Kg0 equivalent, potassium chloride or "muriate of potash" being equivalent to 63.1 % pure KPO.

Jan 5, 1972

By J. H. Polhems, R. B. Brackin, D. B. Grove

P. L. Jones (Sink and Float Corp., New York)—The comparisons between galena and ferrosilicon medium should be applied only to the specific sink-float process used at Mascot since no evidence is presented that allows the comparison to be extended generally to galena medium as now used in other forms of sink-float. It is stated that flotation recovery of galena medium was tried but was unsuccessful and therefore the elaborate gravity system of medium recovery was applied. The expense of the gravity system at Mascot was one of the reasons for changing to ferrosilicon. However two important sink-float plants treating a combined total of over 13,000 tons of ore per day are using flotation to clean galena medium most successfully and are obtaining medium recoveries comparable with those reported in the paper for ferrosilicon. Slightly increased zinc recovery is claimed due to the change-over but it is to be noted that at the time of the change a decreased density differential was obtained in the separator. With galena a differential

Jan 1, 1952

By F. C. Blickensderfer

DURING 1914 and 1915 extensive experiments were conducted at the concentrator of The Detroit Copper Mining Co. of Arizona, at Morenci, Ariz., in order to test the relative grinding efficiencies of the Marathon, the Chilean and the Hardinge Mills. The Marathon mill used in the experiments was the first one ever built by the manufacturers; and since this was the first time that it was given a thorough tryout, with such remarkable results, the data have been, assembled in the following paper and submitted in the interests of the milling profession.

Jan 8, 1916

Abbey, Robert Graham, District Mgr.. The W. W. Sly Mfg. Co., 50 Church St.. New York, N. Y. '21 Abbott, A. N., Mines Supt., Mazapil Copper Co., Ltd Concepcion del Oro, Zac., Mexico. '28 Abbott, Argyle Campbell, Dev. Dept., E. I. du Pont de Nemours & Co., Wilmington, Del. '29 Abbott, Clarence E., V.P., Charge of Raw Materials, Tenn. Coal, Iron & R. R. Co., 1242 Brown-Marx Bldg.. Birmingham, Ala. '04 Abbott, Louis Benjamin, Chief Engr., Elkhorn Div., Consolidation Coal Co., Jenkins, Ky. '16 Abeel, George H., Jr., Cons. Min. Engr Box 427, Santa Monica, Cal. '18 Abel, Albert E., Asst. to Pres., Valley Mould & Iron Corp Hubbard, Ohio. '19 Abel, Raymond L., Asst. Prof., Dept. of Pet. Refin., Univ. of Pittsburgh Pittsburgh. Pa. '28 Abeel, Leo M., Research Engr., Sullivan Concentrator Chapman Camp, B. C., Canada. '31

Jan 1, 1932

By W. R. Hibbard Jr., T. Michalak

THAT the amount of deformation and annealing time influences the recrystallization temperature of cold-rolled copper has been well established. Evidence that the recrystallization temperature can be affected by the deformation texture has been reported by Brick and Williamson,% ho found that copper straight-cold-rolled to 99 pct reduction to produce one deformation texture and copper cross-cold-rolled to 99 pct reduction to produce a second and different deformation texture correspondingly recrystallized at different temperatures to different textures. The purpose of the present work was to study more thoroughly the effect of the deformation texture on the recrystallization of cold-rolled copper. Experimental Procedure The copper used in this investigation was commercial OFHC copper (nominally 99.985 pct Cu) in the form of 0.500-in. plate. Qualitative spectro-graphic analysis showed only a slight trace of iron and a trace of silver. No analysis was performed to determine the exact content of the iron and silver,

Jan 1, 1958

WE the undersigned, being all persons of full age and citizens of the United States, and a majority residents of the State of New York, desiring to form a corporation pursuant to the provisions of the Membership Corporations Law for the purpose of incorporating, as provided in Section 5 of Article I. of said law, the existing unincorporated association known as American Institute of Mining Engineers, do hereby make, acknowledge and file this Certificate for that purpose, and do Certify as follows I. That the American Institute of Mining Engineers is an unincorporated association organized and existing with the object of promoting the arts and sciences connected with the economic production of the useful minerals and metals and the welfare of those employed in these industries by means of meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members and associates the information thus obtained.

Jan 1, 1917

By W. A. Longacre

IN the geophysical exploration program of the Cleveland-Cliffs Iron Co. on the Marquette Range of Northern Michigan, the vertical intensity magnetometer has been used to obtain magnetic anomaly maps of large areas. A network of magnetic base stations has been established and the relative vertical intensity at each station measured carefully with respect to a prime base. In the search for the relatively nonmagnetic soft red hematite ore, the magnetic exploration is indirect, involving the study of dikes, faults, contacts, and other structural features. It was found that the, magnetometer, adjusted to a scale value of approximately 40 y per scale division, was satisfactory for this type of exploration, although many magnetic anomalies were encountered that required the use of auxiliary magnets.

Jan 10, 1951

By R. H. Heinen

Introduction Drilling is the initial operating step In open pit mining. It goes hand-in-hand with the blasting operations to ensure adequately broken material for the excavation equipment employed. The drilling effectiveness is highly dependent on the quality of the drill evaluation. This discussion will center on the parameters that are needed to evaluate drill requirements for a new mine The procedure that is generated can, however, be used to evaluate whether to expand existing operations and replace existing equipment. Methods of breaking ground, other than blasthole drilling and blasting, such as ripping, will not be discussed. The importance of correct drill evaluation extends to the other facets of open pit mining. Inadequate fragmentation, the direct result of poor drilling and blasting techniques, results in oversized, hard digging for the excavating equipment. The result is higher secondary blasting costs, reduced excavation efficiencies, higher excavation costs, higher road repair costs, and higher haulage equipment costs. The main objective of evaluating drill fleet requirements, therefore, is to determine the equipment needed to minimize the operational constraints, caused by blasthole drilling, on other facets of open pit mining at the lowest cash flow costs.

Jan 1, 1979