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By Howland Bancroft

THE writer has observed that some confusion is experienced by many mining engineers in making vertical sections of ore deposits in mining properties which they have examined. Having much examination work calling for the correct interpretation of vein structure and the subsequent platting of the same on sections, it has occurred to the writer that the accompanying diagram may be of use to others who at times may be called upon to prepare numerous sections. For example, a great mass of data on-strike and dip of ore bodies is collected underground in separate

Jan 7, 1914

By J. S. Mitchell

Cobalt recovery from arsenical concentrates by pressure leaching and reduction involves special methods and operating problems. Principal steps in the process are auto-oxidation acid leaching under pressure, filtration of the tailings, purification of the solution, hydrogen reduction of the ammoniacal solution, and electrical furnacing for sulfur removal and granulating the metal. Extracting cobalt metal from arsenical ores has presented a major metallurgical problem for many years. In acquiring the Blackbird mine near Salmon City, Idaho in 1943 Calera Mining Co. accepted the challenge to solve this problem.

Nov 1, 1956

By J. J. Scott, L. Adler3

L. Adler (Assoc. Professor, Department of Mining Engineering, Virginia Polytechnic Institute, Blacks-burg, Va.) - Dr. Scott is to be commended for undertaking the arduous and specialized task of applying three-dimensional photoelastic techniques to a mining problem. However, 1 feel his analysis suffers seriously from a lack of clarification on one important matter, among several others; and that the paper as a whole lacks balance and thus tends to confuse the reader. 1) The major technical criticism refers to the fact that nowhere are the boundary conditions for his mod-

Jan 1, 1964

By Merlyn B. Buhle

FOR the past 20 years electrical earth resistivity exploration has been used in Illinois in many phases of study undertaken by the State Geological Survey, chiefly in locating and outlining deposits of water-bearing sand and gravel from which to obtain ground water for municipal and industrial supplies. At least 43 municipalities in the state derive their total water supply from deposits of sand and gravel discovered by resistivity methods. These deposits occur in both Quaternary and preglacial valleys and within much of the glacial drift which covers .a large portion of the state

Jan 4, 1953

By J. S. Li, J. C. Edwards

A prediction is made of the airflow at the Bureau of Mines Lake Lynn Laboratory with a ventilation computer program that accounts for fan-driven forced ventilation and temperature-induced natural ventilation. There was substantial agreement between measured and predicted airflow rates. The capability of the program is demonstrated as a planning aid for ventilation under emergency conditions in a multilevel coal mine. Smoke spread in a multilevel mine is analyzed following the occurrence of two events, the failure of the main exhaust fan and the development of a fuel-rich fire in a passageway.

Jan 1, 1983

By O. Skiredj, J. F. Elliott

It has been necessary to collate the available data on the solubility of graphite in Fe-Si-Mn alloys for a study of slag-metal equilibria in ferromanganese production. That study will be reported later; the collation is reported here. The carbon content of graphite-saturated liquid iron above 1153ºC by Chipman and co-workers1 is: %C= 1.34 + 2.54 x 10~3t(°C) [l] For graphite-saturated manganese above 1322ºC it is: %C = 2.68 + 3.52 x 1CT3 t(°C) [2]

Jan 1, 1963

By D. E. Munson, P. R. Dawson

An empirical model is developed that predicts accurately the transient response of salt creep to incremental and decremental changes in stress and temperature. Even though the model is empirical, it is derived from a firm theoretical framework for the micromechanical deformation processes of both steady-state and transient creep. In the model, the transient creep functions modify the steady-state creep behavior, which in turn is based upon creep mechanisms and the def ormation-mechanism map. The model is applied successfully to experimental stress-drop results obtained for salt.

Jan 1, 1982

By W. S. Hungerford

As several papers on the subject of mining in soft ore-bodies have recently appeared in the Transactions and in the Engineering and Mining Journal, the following brief account of the method introduced by the writer at Low Moor, Va., may be of interest. It is in some respects similar to the system at Longdale, Va., referred to in Mr. Rothwell's paper, though differing in many of its details. That system has been employed by the Longdale Iron Company for many years, and to that company the writer is indebted for many

Jan 1, 1889

By Dennis Z. Mraz

An engineering procedure for designing the minimum separation between solution mined caverns in bedded salt deposit is described. The procedure is based on data obtained by in-situ and laboratory test methods. The formulae utilize the concept that salt rock under high pressure in a deep salt rock deposit would behave as a perfectly plastic substance, and that the active opening surrounding a typical cavern could be described by a circular ellipsoid. The paper describes the calculations required for the safe design of a solution mined salt cavern field.

Jan 1, 1984

By C. G. Fink, G. L. Putnam

The dissolution of gold by cyanide solutions was studied by determining the time required for the solvents to dissolve gold leaf. Minute traces, even 0.5 ppm, of sulphide ion retard the dissolution of gold, and this behavior cannot be accounted for by the presently accepted hypotheses involving oxygen-depletion or thiocyanate formation. On the other hand, traces of the salts of lead, bismuth, mercury, and thallium considerably accelerate the dissolution. The beneficial effect of lead is dependent upon the pH and cyanide ion concentration of the solution.

Jan 9, 1950

By Robert C. Bates

Published information on costs of radon daughter control in uranium mines was analyzed to develop estimates of the cost per ton for any level of radiation exposure control. All data were converted to 1967 cost of living index to provide a common analysis base. Re- of the analysis show that the cost per ton increases exponentially as the radiation level is lowered. A linear relationship with the cost of living index is assumed, and equations and graphs are provided to estimate control cost per ton for any exposure control level and cost of living index.

Jan 1, 1982

By William E. Messner

California’s Monterey Peninsula, noted for its beaches, resort hotels, and beautiful homes, also harbors a pioneering beneficiation operation. Here for more than 35 years the Del Monte Properties Co. has provided sand products from large dunes, some over 300 ft high, located in the Del Monte Forest. Raw material-the dunes derived by wave action from Santa Lucia granite of Jurassic age-has unusually consistent chemical and physical composition. Coarse crystalline feldspar is the principal constituent, followed in abundance by quartz, with some biotite, ilmenite, garnet, zircon, and monazite.

Jan 2, 1955

By Peter J. Huck, Madan M. Singh

IIT Research Institute has investigated the potential of high pressure water jets for rapid rock excavation. During this study, an attempt was made to correlate the extent of breakage effected to the mechanical properties of rocks. Six rock types were used in these experiments and nine properties were determined for each rock variety. A regression equation using the two most significant rock properties and one jet parameter (pressure) was established. Although tests were conducted to specific pressures of 35, no minimum in the specific energy consumption was noted.

Jan 1, 1971

By W. R. Boehme

The laboratory test work compares various 6 x 16 mesh activated coconut carbons using a gold standard solution of 4 ppm dissolved in sodium cyanide. The carbon adsorption rate and maximum loading are measured for different feed solution ionic contaminates: silver, copper, thiocyanate, and ferrocyanide. Conclusions are drawn that among the activated coconut carbons tested, maximum loading and the effects of specific ions varied significantly. The work presented can be applied to 6 x 16 mesh carbon selection tests and specific ion monitoring for industrial carbon adsorption systems.

Jan 1, 1984

By L. G. Austin, P. T. Luckie

The Bond Work Index has been used for many years to estimate the power requirement of a material with known work index. The index is determined by a completely empirical test and no logical base for its use has been formulated. However, consideration of grinding as a unit operation which can be mathematically treated offers the prospect of considerably more accurate design and mill power estimation when sufficient data on large-scale mills becomes available. The interrelation of the Bond type with the unit operation approach is discussed.

Jan 1, 1973

W. O. OWEN,* Washington, D. C. (written discussion?). Few people appear to realize that the time to reach the crippled soldier is when he is first hurt. In my own judgment, the best time to reach him is before he is hurt, by showing him what other cripples have themselves clone of their own initiative, without Government-support, rendering themselves self-supporting, able to bear a little bit more than their own weight, so that they may lay aside a little bit for a rainy clay and some for a little fun in

Jan 5, 1918

By E. L. Brack

ASARCO's copper smelter at Hayden, Arizona has been upgraded to meet the increasing Environmental Protection Agency (EPA) and Occupational Safety and Health Administration (OSHA) environmental standards. Fortunately, means were found to accomplish these standards and provide for more efficient operations. With the adaptation of oxygen flash smelting and other related operations at Hayden, ASARCO has turned to the use of minicomputers and microprocessors for inter-plant communications and local area process control. The applications of distributive and computer controls to the plant operations at the Hayden smelter are discussed in this paper.

Jan 1, 1984

By John A. Ruppert, John E. Conley

Shortages of cinders, largely resulting from industrial plants converting to fuel-oil, together with an enhanced building activity, have seriously affected the cinder block and lightweight concrete manufacturers. In the search for other sources of lightweight aggregate, various clays, shales, slates and natural occurring lightweight rocks such as pumice, scoria, volcanic ash and the like have received special attention. Methods and equipment for producing suitable lightweight aggregates have been considered. In addition to an expanded use of the rotary kiln, the traveling-grate and continuous-sintering machines are being installed in many localities.

Jan 4, 1950

By Howland Bancroft

The writer has observed that some confusion is experienced by many mining engineers in making vertical sections of ore deposits in mining properties which they have examined. Having much examination work calling for the correct interpretation of vein structure and the subsequent platting of the same on sections, it has occurred to the writer that the accompanying diagram may be of use to others who at times may be called upon to prepare numerous sections. For example, a great mass of data on strike and dip of ore bodies is collected underground in separate

Jan 1, 1915

By D. T. Van Zandt

IN the late 1920's rotary drills began to replace the churn drills in the petroleum industry, but until the middle 1940's the churn drill was the only widely accepted means of drilling large-diameter blastholes for quarry operations. The Calcite plant of the Michigan Limestone Div., U. S. Steel Corp., was one of the first to experiment with rotary drills for quarry blasthole drilling, and the first to employ compressed air on a fully rotary rig to cool the bit and raise the cuttings to the collar of the blasthole.

Jan 8, 1954