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By James C. Fisher

Traditional uranium exploration techniques were utilized and comparatively evaluated in the Front Range, Colorado uranium province. Intense surficial leaching and thick colluvial cover render traditional airborne and ground radioactivity reconnaissance prospecting useless. Radon gas emanometry and sulfur gas emanometry were slightly more effective but the long and short term variations In soil gas emanation rates make it extremely difficult to gain useful information from these systems. The technique judged most useful was Track Etch radon prospecting. The excellent definition of the technique, as well as its repeatability, indicate that it is an ideal prospecting tool for narrow vein-type deposits similar to those of the Front Range, Colorado.

Jan 1, 1976

By M. B. Standing, D. L. Katz

Density data are reported on 15 saturated hydrocarbon liquids in the range of 35° to 250°F. and 1000 to 8220 lb. per sq. in. The apparent liquid densities of methane and ethane are shown to vary with the density of the system in which they are present. A method is proposed whereby the densities of liquid hydro- carbon mixtures containing both methane and ethane in solution may be computed at elevated temperature and pressures within the accuracy of usual engineering computations. A method of computing the shrinkage of crude oils based upon the gas-oil ratio, gas analysis, and crude gravity is outlined. Introduction The densities of naturally occurring liquid hydrocarbon mixtures are important in many petroleum engineering computations. Calculation of the shrinkage of a subsurface sample of crude oil as the natural gas is evolved is one example of the use of liquid-density data. Sage, Hicks, and Lacey5 have presented a method of computing the density of hydrocarbon liquid mixtures based on partial molal volumes. Katzl has indicated a method based on the principle of additive

Jan 1, 1942

By Werner Langguth

SINCE the introduction of the improved method of precipitating gold from chlorine solution by SO2 and H2S at the Golden Reward chlorination-works, Deadwood, S. D.,* this modern method has been further adopted in the chlorination-works of the Portland Consolidated Company at Deadwood, and in those of the Black Hills Milling and Smelting Company at Rapid City, S. D. It has proved practically most successful in the handling of large quantities of gold solution, and constitutes up to date, with Mr. John E. Rothwell's most important improvement, namely, barrel-leaching under hydraulic pressure, the principal progress made in gold chlorination. The method of refining the gold sulphides which result from this method of precipitation, was introduced by me in 1890 at the Golden Reward works, and in 1892 at those of the Black Hills Company. It has not suffered any changes during the last three years, and is substantially as described below:

Jan 1, 1895

By L. Moussoulos

Pyrite concentrates produced at the Olympias mines, Northern Greece, show an unusually high gold and silver content (16-20 and 25-40 ppm respectively), associated with the presence of arsenopyrite; their high As content (5-8%) has hindered their utilization so far. In the present paper a simple and environmentally safe method that permits their complete utilization for the production of SO2 gas, As203, and the recovery of Au and Ag is described. According to this method, the pyrites are subjected to a single-stage oxidizing roasting in a fluid bed reactor. The precious metals, and approximately 45% of the contained As, remain with the cinders, while the rest of the As is removed with the SO2 - bearing gases and can be recovered by suitable treatment. The gases, after further cleaning, can be utilized for the production of sulfuric acid.

Jan 1, 1984

By Will B. Jamison

It is a fact that the most serious safety problems encountered in US underground coal mines are related to roof-bolting operations. It is also true that roof bolting is usually the operation which limits coal production from a mine section. There has been a recent focus on activity involving roof bolting research, development, and new ideas as people concerned about mine worker safety and productivity realize that significant progress can be made in these areas, even with equipment presently available.

Jan 7, 1977

By James Fiore

The Nuclear Waste Policy Act of 1982 provides a set of rules for proceeding with the identification and selection of sites for a mined geologic repository as well as for interim storage facilities for high level waste in the event storage facilities are needed. The following paper summarizes the sequence of procedures in site selection, and presents the interaction of governmental agencies, the states, the public, and affected Indian tribes in this process. Several agencies have published regulations assocated with the selection of high level waste sites. These regulations set down a diverse collection of requirements designed to ensure public safety. This paper identifies the organizations working to satisfy these requirements, and outlines the role of the geotechnical community in performing data collection activities to support these same requirements.

Jan 1, 1984

By C. W. Schulties, W. J. Mallio, L. J. Petrovic, J. A. L. Campbell

Roof control comprises about 35% of direct and indirect underground mining costs. In addition, difficulties in estimating roof control costs for new areas lead to the greatest uncertainties when negotiating coal contracts. And obviously, coal cannot be mined if the roof can't be held. Accordingly, there are strong incentives to attack this problem on as many fronts as possible. One successful geological modeling technique for predicting future roof conditions was recently applied at Peabody Coal's Simco mine No. 5, located in Coshocton, Ohio. Benefits derived from it included: - A better identification of areas where poor safety conditions may be encountered. - Improved roof control cost estimates for contract negotiations. - Estimates of time-duration while mining in bad roof areas. - Labor and materials cost predictions in an existing mine. - Productivity increases through prior knowledge of areas to avoid.

Jan 10, 1975

By Desmond De Villiers Oxford, Peter H. Williams

Nchanga Consolidated Copper Mines, Ltd., is one of the four mines operated by the Anglo American Corp. in Northern Rhodesia, now the independent nation of Zambia. Today Nchanga is the second largest single producer of copper in the world, accounting for more than 200,000 long tons of copper annually at a monthly milling rate of 430,000 tons of ore. The average mill-head grade is about 5.20% total copper, of which approximately 60% is copper sulfide. The remainder, referred to as "acid soluble," is copper oxide. Nchanga mines three separate orebodies varying in grade and sulfide-to-oxide ratio. Ore is processed in two separate grinding circuits feeding into three separate flotation circuits. A fourth flotation circuit treats leach plant residue for additional recovery of sulfides.

Jan 1, 1965

By David Firewick, Daniel Stewart, Richard Rein

Panel caving of the Henderson orebody began in August, 1976. Fifty months later, on September 10, 1980, the cave zone appeared on surface as a steep-walled cavity positioned directly above the initial cave area. Although surface survey data revealed the development of a slight depression over the production area, surface inspection by geologists, three days prior to breach- ing, resulted in no evidence of impending glory-hole development. Geologic factors such as rock contacts and alteration-zone boundaries had little influence on the location of the initial glory hole. Since initial breakthrough, the glory-hole shape and growth have not directionally followed caveline advance because of topography and faulting. Based on periodic data, mine production has resulted in immediate growth of the Henderson glory hole.

Jan 1, 1984

By William McCullouch

The method of determining moisture percentages in coal has been defined as purely empirical. The procedure, as defined, has been published in the U.S. Bureau of Lanes technical papers and approved by the American Society of Testing Materials but deviations from this established procedure are common in most commercial and private laboratories. It is not within the scope of this paper to discuss the deviations in common practice but rather to give a detailed account of the method in use in the laboratories of the United Electric Coal Companies. In general, moisture values are presented as surface moisture and, for lack of a better term, inherent moisture. The formula for adding them together to give total moisture is common knowledge. In practice, on high-moisture bituminous coal, it has been found that the line of demarcation between surface and inherent moisture is very indefinite, the inherent moisture being so loosely held that it is released far beyond its natural limits when the prescribed method of the A.S.T.M. for determination of surface moisture is followed. This is shown in Table 1 for two typical washed coals from Illinois.

Jan 1, 1938

By Stephen E. Erickson, Donald G. Oss

The need for instrumentation and automatic control of the various parameters in the heavy media process of iron ore beneficiation has been apparent for some time. Continued demands for higher grade, competitive products from the Mesabi Range have made it necessary to increase the efficiency of the process in every possible way. In a typical heavy media flow scheme for iron ore beneficiation (Fig. 1) a sized, prepared feed (generally about minus 1 ¼ in. to plus ¼ in.) is fed to a heavy media separatory vessel, along with a ferrosilicon slurry. A separation of the feed is made on the basis of specific gravity. Low density particles overflow a tailings discharge weir, while high density ore particles sink to the bottom of the high density pool and are moved away to the concentrate discharge chute.

Jan 5, 1962

By E. D. Gardner

In 1954, the first year the award was conferred, Fred Searles, Jr., remarked, "The earlier years are the easiest." In this, the second year, it was easy to choose the outstanding mining engineer. Our conferee this year has been destined to mine. He comes from pioneer stock, and though a son of the American Revolution he is most proud that all four of his grandparents came to the Jordan River Valley of Utah the "first summer," which all Utahns will recognize as 1847. At the time of discovery of high-grade ore in Bingham, his grandfather, Archibald Gardner, had a crew of men getting out saw timber in the area. The first claim staked in Bingham Canyon was named the Jordan, and Bishop Gardner was the colocator of the claim as well as the man to record it.

Jan 4, 1955

By J. H. Russell

THE great number of wells being drilled in the Gulf Coast creates a great demand for and an opportunity to improve the methods of drilling wells and of producing oil from them. Some improvements have been made, but in the present strenuous drilling campaign at Spindletop, the quickest methods of drilling and completing wells are much too slow. Therefore, not a great deal of thought has been given to any new methods. However, one can not help but compare the method and equipment used in the present-day drilling campaign at Spindletop with those of 1901. The differences in equipment and methods are staggering and the present-day operators can hardly imagine how the old operators ever were able to drill a well. The "Old Timers" explain the reason as being that "Men were men in those days and not much machinery was necessary." Yet the development in 25 years of thought and study has brought about a great improvement in equipment and in methods. I believe there has been a great deal more thought given to the development and improvement of drilling equipment and methods and to the completion of wells than has been given to the actual production operations.

Jan 11, 1926

By Karl Eilers

This process, invented by Messrs. Hanisch and Schroder, of Rosdzin, was patented in 1883. It has attracted considerable attention in Germany, as a very neat and simple method of extracting sulphurous acid from the gases produced by roasting, and of condensing this acid so as to obtain it in the very compact anhydrous liquid form. The special importance which such a process may have at this time in the United States is suggested by the growing inconvenience, amounting to distress, experienced in such localities as Butte, Mont., where the sulphurous gases from large roast-plants have proved not only fatal to vegetation but injurious to human health. It is reported that the authorities of Butte are earnestly considering the enterprise of removing, if practicable, the dense and suffocating cloud which now hangs over that city, and of which sulphurous acid undoubtedly forms the greater and most oppressive, if not the most poisonous, part. May it not be that the solution of this problem is furnished by a

Jan 1, 1892

By Howard W. Jacky

At Weed Heights, Nev., precipitation plays a major role in the plant operation. Almost two-thirds of the present copper production is leach-precipitation plant copper. The entire plant complex processes about 135,000 tons of low grade copper ore per week. Of this tonnage, 49,000 tons of about 0.78% sulfide ore are treated in the concentrator. This is handled in the conventional manner of crushing, grinding, and concentration of the copper sulfide by flotation.

Jan 6, 1967

The library of the above-named Societies is open from 9 A. M. to 10 P. M. except on holidays. It contains about 70,000 volumes and 90,000 pamphlets, including sets of technical periodicals and publications of scientific and technical societies. Members of the Institute, with few exceptions, are forced to spend a portion of their time in localities isolated from sources of information. To these the Library, through its Library Service Bureau, can render valuable service through correspondence; letters requesting information will receive especial attention. The Library is prepared to furnish references and photographic copies of articles on mining and metallurgical subjects; to determine the existence of mining maps, and to furnish general information on the geology and mineral resources of all countries. All communications should be made as definite as possible so that the information received may be what is desired and not include collateral matter which may not be of interest. The time spent in searching for such collateral matter will be saved, and the information will be sent more promptly and in more usable shape.

Jan 12, 1918

By John D. Morgan, Sylvain J. Pirson

AN instantaneous and continuous analysis of a mineral suspension should be of great value in controlling various mineral preparation processes. Described herein is a method of analysis based on the use of high-frequency alternating current, which, under certain restrictive conditions, could be of use. THEORETICAL CONSIDERATIONS In a suspension of conductive minerals, the electrical effect primarily responsible for the variations in electric conductivity is the capacitance. In Fig Ia, let an alternating voltage E be applied across two electrodes F and F', between which are two rows (S and T) of mineral particles, all of approximately the same size, immersed in a fluid. Let the number of rows of particles between the electrodes be R and the number of particles in each row be N. If A is the area of a particle, D is the distance separating two particles, and K is a constant depending on the fluid, the capacity, Co, of the particle system will be given by: [KRA C0 ND] Referring now to Fig Ib, let R, the number of rows, be held constant, but let N, the number of particles in each row (S and T), be increased X-fold. The capacity, C1, of [ ]

Jan 1, 1947

W. N. Triplett (Geology of the Silver-Lead-Zinc Deposits of the Avalos-Providencia District of Mexico, P. 583) was born in Tecumseh, Mich., and attended the University of Michigan and Massachusetts Institute of Technology. From 1912 to 1917 he worked for Moctezuma Copper Co., a Phelps Dodge subsidiary at Nacozari, Sonora, Mex. He served in Army as Second Lieutenant Field Artillery from 1917 to 1918 and from 1919 to 1922 returned to Moctezuma Copper Co. From 1922 to 1952 he has been with Compania Minera de Penoles, S. A., a subsidiary of American Metal Co., Monterrey, N. L., Mexico in Unit Dept. as chief geologist and at present is consulting geologist. Mining geology and operation is of particular interest to Mr. Triplett. He presented a previous paper before with M. W. Hayward entitled, "Occurrence of Lead-Zinc Ores in Dolomitic Limestones in Northern Mexico." Besides being an AIME member, he holds membership in Society of Economic Geologists. Fishing, hunting and photography are his favorite hobbies.

Jan 1, 1952

By A. J. Nicol

Field experience in uranium has shown it is most economical to ram through a drilling program to obtain maximum footage per drill hour. Drift surveys can then determine the course of the holes. Using this method is generally cheaper than paying the additional cost involved in using the drilling technique and equipment necessary to maintain straight holes. Factors Affecting Direction of Bit Travel: In all rotary-drilled holes there is an interplay of forces or conditions affecting the direction of bit travel. Rarely is a straight vertical hole obtained. One of the major factors is weight on a drill string. In looking at a joint of drill stem it is hard to imagine its being quite flexible, but flexing of the steel increases when many joints are made up together, and even a slight weight added to the upper portion causes a buckling or spiraling effect in the hole. The result is that the bit deviates from the vertical.

Jan 1, 1959

By A. G. Crocker

The positions of twin reflections in electron-dijjcraction patterns obtained from thin metal foils may he calculated for any twin in any crystal structure by means of an elementary application of vector algebra, General equations for the four classical orientation relationships are presented using the superscript and subscript notation of the tensor calculus, which is briefly described. As an example of the application of these expressions, the case of twinned rhomhohedral crystals, and hence as a special cased twinned cubic crystals, is examined. CONSIDERABLE interest has recently been shown in the interpretation of electron-diffraction patterns obtained from twinned regions of thin metal foils. In the present paper, it is shown that the necessary information may be obtained directly for all twins in any crystal structure by means of a very elementary application of vector algebra. The equations involved are most conveniently presented by making use of the very powerful superscript and subscript notation of the tensor calculus. The use of this notation will first be described and then applied to the problem of calculating diffraction patterns for any twinned crystal. Finally, as an example of the application of the method, the specific case of twinned rhombohedra1 crystals will be considered.

Jan 1, 1965