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By W. G. Fischer

This paper attempts to close the gap between extensive rock testing with field measurements and the mine operator's need for safe mine layouts and alternatives. It was found that many of the variables that influence mine geometry and worker safety are relatively unimportant while others are critical. The development of empirical relationships that tie the critical variables to the safe useful life of a trona mine layout and observations made in 140 production areas where the variables were researched over a 15-year period are discussed. The concepts presented may have applicability in mine design for other bedded deposits.

Jan 1, 1986

By R. E. Collom

VARIOUS chapters already written in the history of development of the North Dome of Kettleman Hills are monotonously identical in the one underlying theme of conservation of oil and gas. Discovered on Oct. 4, 1928, by Milham Exploration Co. with its wildcat Elliot No. 1, the field has been subjected to practically every modern form of produc-tion restraint in the name of conservation. The record thus far developed shows that conservation was had for a time, at a price; and that unitiza-tion must he blessed by single ownership or 100 per cent participation to be effective. In fact, incomplete unitization places a heavy handicap upon its participants in the competitive development that follows.

Jan 1, 1937

[Queensland :-(Continued.) petrography of the Mount Morgan mine, LV, 263. Queensland tin mine and mill, Santa Barbara, Guanajuato, Mex., XXXVI, 227. Quenner disintegrator, XLI, 801; XLII, 15011. Quenstedt, F.: petroleum deposits, Suabia, XLVIII, 14881. Queretaro, Mex., silver mines, XXXIX, 360. Quicksilver: mining and reduction, LI, 110. Oceanic mine, Cambria, Cal., LI, 110. Quicksilver and iron decompose silver sulphide, XL, 872. Quicksilver deposits: China, -XL111, 49. Pacific slope, XXXVI, 1311.. Siberia, Vhdivostok district, XLIV, 16001.]

Jan 1, 1918

By I. Milton LeBaron

Operation of the phosphate flotation plant at the Peace valley mine of the International Minerals and Chemical Corporation, Florida, began in the summer of 1942. Since that time several changes have been made in the flowsheet, with resultant increases in metallurgical results. Three flowsheets, together with the comparative plant results, are given in this paper, together with a discussion of the desliming circuit used for preliminary washing of the flotation feed. Fig. I lists the essential units in the original flowsheet at the Peace Valley plant. The figures for tonnage and grade are average for a period of two months. Mineral Separation Airflow cells are used for both the fatty acid and the amine float. Three immediate difficulties presented themselves in the use of this flow sheet: I. Floating a maximum amount of phosphate in the rougher section to give good recovery sent a low-grade concentrate to the silica float, resulting in high costs for amine reagent in that section.

Jan 1, 1947

By I. Milton LeBaron

Operation of the phosphate flotation plant at the Peace valley mine of the International Minerals and Chemical Corporation, Florida, began in the summer of 1942. Since that time several changes have been made in the flowsheet, with resultant increases in metallurgical results. Three flowsheets, together with the comparative plant results, are given in this paper, together with a discussion of the desliming circuit used for preliminary washing of the flotation feed. Fig. I lists the essential units in the original flowsheet at the Peace Valley plant. The figures for tonnage and grade are average for a period of two months. Mineral Separation Airflow cells are used for both the fatty acid and the amine float. Three immediate difficulties presented themselves in the use of this flow sheet: I. Floating a maximum amount of phosphate in the rougher section to give good recovery sent a low-grade concentrate to the silica float, resulting in high costs for amine reagent in that section.

Jan 1, 1947

By A. W. Mitchell

Barite occurs as bedded and vein-type deposits in Nevada along a north-northeast trending zone that Parallels the Antler orogenic belt. The Nevada bedded deposits presently supply 85% of domestic barite production, used primarily as a weighting agent in the petroleum drilling industry. The ore bodies are controlled structurally and stratigraphically along regional and local structural breaks in siliceous eugeosynclinal rocks of lower to middle Paleozoic age. Evidence for the origin of the barite includes sedimentary and hydrothermal features, indicating that localization probably took place along fractures in the sea floor.

Jan 1, 1982

By Stephen R. Holsinger

During 1972, Asarco's Silver Bell Unit embarked upon a project to test a digital computer-controlled grinding circuit against the performance of its other five grinding lines. The planning, implementation, and subsequent outcome of that project has been previously reported in a paper by Pitts 1, et al. This paper will describe the solutions to major problems incurred during the implementation of this control strategy on the remaining five primary grinding lines. Changes made in operating philosophy and methods during the expansion will also be discussed.

Jan 12, 1978

By Stephen R. Holsinger

During 1972, Asarco's Silver Bell Unit embarked upon a project to test a digital computer-controlled grinding circuit against the performance of its other five grinding lines. The planning, implementation, and subsequent outcome of that project has been previously reported in a paper by Pittsl, et al. This paper will describe the solutions to major problems incurred during the implementation of this control strategy on the remaining five primary grinding lines. Changes made in operating philosophy and methods during the expansion will also be discussed.

Jan 1, 1979

Preliminary plans of this meeting, together with a most interesting series of papers that have been received or promised, were published in the May Bulletin. The plans are being carried out enthusiastically and hospitably by the Colorado members and all indications point to an interesting and valuable meeting.

Jan 6, 1918

By Thiann R. Yu, William J. Quesnel

At Kidd Creek, the annual production of 4.5 million tonnes of ore has been achieved primarily with sublevel blasthole stoping. This mining method has allowed underground operations to meet the designed production capacity while maintaining an outstanding safety record. To achieve this goal, rock mechanics principles have been integrated into each facet of mining in the planning stage, in the production stage, and in various stages of ground support. This paper evaluates the two adopted mining sequences based on ground stress patterns, blasting control, ground reinforcement, backfill support, and numerical modelling for stope stability at the mines.

Jan 1, 1984

By J. A. Herbst, J. L. Sepulveda, J. D. Miller

Effective bismuth removal from flue dust residues has been accomplished for flue dusts from both zinc and copper smelters. Selective dissolution of bismuth, with respect to silver and lead, can be achieved by the proper manipulation of temperature, sulfuric acid addition and sodium chloride addition. Optimum levels of these variables were determined using a response surface technique to maximize the objective function: Y = %Bi/(1 + %Ag). In the case of the flue dust residue from a zinc smelter, which contains bismuth as an impurity (0.05%), 86% bismuth removal can be realized with less than 1% combined silver and lead dissolution. Similarly, in the case of flue dust from a copper smelter, which contains bismuth as a primary constituent (3.3%), 93% bismuth removal was obtained with little dissolution of silver and lead values.

Jan 1, 1977

SEC. 1. The membership of the 'Institute shall comprise six classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Members; 6, Rocky Mountain Members. All shall be equally entitled to the privileges of membership, excepting that no member of any class whose residence shall be outside of the United States of America, except those residing in Mexico and Canada, shall be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the class of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain members.

Jan 1, 1932

By H. R. Hardy

The study of the mechanical properties of geologic materials was initiated in the Mining Research Section of the Fuels and Mining Practice Division in 1951 as part of a fundamental study of ground stress in Canadian coal mines.1 Early in the investigation of the mechanical properties of geologic materials, however, it was realized that the test results are influenced by the rate and the duration of loading. For this reason, laboratory investigations2,3 were undertaken to study the effect of long-period uniaxial stress on the deformation and failure properties of these materials. A literature survey indicated that work on the time-dependent properties of geologic materials had been very limited in the past.

Jan 1, 1965

By R. W. Raymond

The relations of Eckley B. Coxe to the Institute, as one of its founders and early Presidents, and, throughout its history, an enthusiastic supporter and a valued contributor, would alone

Jan 1, 1896

By T. H. Miller

THE CHAIRMAN.-This session has to do largely with the question of specifications and conservation as regards secondary metals produced from scrap. We are all familiar with the many varieties of scrap metals and the astonishing number of secondary metals of various specifications produced from the treatment of those scraps. The impact. of the war on this industry has required a great many changes in the types of secondary metals produced from scrap, and in their utilization. In the short period available we cannot cover very much of this field, but we do hope to give you through the various papers a brief introduction to some of the principal problems. Mr. James S. Earle will present the first paper. Mr. Earle:

Jan 1, 1943

By D. M. Wyslouzil

Standard testing methods are described that are presently used for the selection of grinding equipment. Correlation between laboratory batch grinding tests and pilot plant continuous tests are established by means of particle size distributions and flotation results. Conventional and autogenous grinding circuits are discussed showing the relationships of the controllable circuit parameters.

Jan 1, 1982

Sec. 1. The membership of the Institute shall comprise six classes, namely: 1. Members; 2. Honorary Members; 3. Senior Members; 4. Associates; 5. Junior Members; 6. Rocky Mountain Members. All shall be equally entitled to the privileges of membership, excepting that no member of any class whom residence shall be outside of the United States of America, except those residing in Mexico and Canada, shall be entitled to vote. SEC. 2. Members: A person to be eligible for election or transfer into the claw of Member must be at least 27 years of age and must have had at least six years' employment in the practice of engineering, mining, geology, metallurgy, or chemistry, during at least three years of which he must have held positions of responsibility in one or more of these fields. This shall not apply to Rocky Mountain members.

Jan 1, 1934

By C. E. Birchenall, C L. McCabe

IN attempting to extend vapor pressure measurements of the type previously reported by Schadel and Birchenall1 for silver and by Schadel, Derge, and Birchenall' for silver-silicon to other systems, it was observed that the materials melted at indicated temperatures 10" to 15" below their accepted melting points. Further investigation revealed that the thermocouple readings were in error due to appreciable conduction losses along the reference thermocouple wires. If the wire diameter of the reference couple inserted into the Knudsen cell was reduced, the correction for the indicating couple changed in a manner tending to explain the melting behavior. When extrapolated to zero wire diameter from measurements with several reference thermocouples of different wire thickness, the melting point of silver then agreed with the indicated temperature at which silver chips were observed to coalesce into a sphere. Approximately the same calibration was given by observing the melting of small wires of silver or gold in the Knudsen cell connected in series with an ammeter, where the leads into the cell were very fine in order to minimize heat conduction. Unfortunately neither of these methods seemed to yield a sufficiently precise temperature calibration to match the apparent precision of the other aspects of the vapor pressure measurement. It was decided. therefore, to redetermine the vapor pressure of silver in another setup under conditions permitting precise temperature measurement. The vapor pressure of pure silver could then be used as an internal calibration of temperature in the older unit in making runs on alloys. This has been done; the present report is a correction to ref. 1. Experimental Procedure The apparatus, shown in Fig. 1, was very similar to that employed by Harteck,3 except that the orifice sizes were smaller and the residual pressure in the vacuum system was probably much lower. A small, sharp-edged hole, nearly circular in shape, was ground into the rounded end of a quartz tube. The orifice area was then measured by tracing the image at known magnification on graph paper and counting the squares enclosed. The silver specimen was sealed into the tube to make a Knudsen cell. A tantalum jacket surrounding the cell served to increase the uniformity of temperature. This assembly was placed in the bottom of a long quartz tube with an inside diameter of about 1 in., which was connected to the vacuum system through a ground joint sealed with picein wax well removed from the furnace. A thermocouple tube inserted through the top of the vacuum line reached into the tantalum jacket so that the thermocouple junction was immediately adjacent to the Knudsen cell except for the protection tube wall. A resistance furnace could be raised to cover the end of the quartz tube containing the cell in such a way that the cell was in the uniform temperature zone 13 in. from the end of the furnace. An ionization gage was included in the vacuum system in the cold lines of wide diameter, immediately beyond the ground joint. The vacuum system consisted of a mercury one-stage diffusion pump, backed by a Welch duo-seal mechanical pump. The pumps were separated from the reactor chamber by a dry ice trap. The ionization gage always read less than 10-5 mm Hg after initial outgassing and before each run was started. Each newly filled Knudsen cell was evacuated at high temperature overnight before the first weighing was made. The cell was returned to the system, heated for a measured time at constant temperature, cooled, and reweighed. The heating and cooling times were quite short since the hot furnace was raised to receive the reactor at the beginning of the run and removed again at the end. The tube heated or cooled quickly. The total mass loss was attributed entirely to effusion of silver vapor from the quartz cell, since empty quartz cells maintained constant mass through similar heating cycles. The vaporized silver condensed on the cold walls of the quartz tube extending above the furnace. Earlier studies in the induction heated unit had shown that the same vapor pressure was found for silver, whether the silver was in contact with the tantalum metal cell or with porcelain or quartz liners. The Pt-Pt-10 pct Rh thermocouple was calibrated against a secondary standard of the same material and found to agree with the published tables. Always operating in air at temperatures below 100O°C,

Jan 1, 1954

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 David D. Rabb

Under the auspices of the Atomic Energy Commission, the Lawrence Radiation Laboratory of the University of California analyzed an experiment to provide information as to whether the chimney of broken rock produced by a deeply buried nuclear explosive could be "drawn" by conventional techniques. Since many low-grade disseminated ore-bodies occur in a granite media, the experiment took place in a granodiorite-quartz monzonite intrusive porphyry in the Nevada Test Site as a follow-up to the Department of Defense's Hardhat detonation in February 1962. For emplacement of the nuclear device, a 12 ¼ - in. pilot hole was reamed to a diameter of 44 in. and a depth of 950 ft in one pass using a Hughes multiple-cluster rotary bit. It was then cased to 36 in. ID. The center of the explosive device was located 938.85 ft below the collar. The yield of the device was predicted to be 5 kilotons, or an equivalent of 5000 tons of TNT; the yield was later confirmed by chemical means to be 5.4 kilotons.

Jan 3, 1964