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By J. Menashi, D. A. Douglas, A. S. Rappas

A process has been developed for recovering the refractory metals chromium (Cr), vanadium (V), molybdenum (Mo), and tungsten (W) in mixed secondary source materials, such as contaminated grinding wastes. The wastes are calcined with sodium carbonate in air to yield water-insoluble oxides of the base metals iron (Fe), nickel (Ni), cobalt (Co), and copper (Cu) and water-soluble salts of the refractory metals. An aqueous leach separates these two classes of metal values. Cobalt, nickel, and copper can be recovered from the oxidic residue by conventional processing methods. The leach solution is purified and then treated to recover the refractory metals. The process can accommodate a wide range of feed compositions and generates a minimum of aqueous effluents.

Jan 1, 1985

By G. Sachs, S. I. Liu

INTRODUCTION IN a previous investigation on the effects of repeated strains of large magnitude on the aluminum alloy 24ST, it was found that the reduction in ductility by straining in tension was partially restored by a subsequent compression.&apos; As illustrated by the dashed line in, Fig I,§ the ductility (EF) retained after prestraining in tension by a certain amount (EI) and measured in a subsequent tension test is represented by a straight line sloping down under 45°. If a compression of the same magnitude as the first tension is inserted (E2 - EI) between prestraining and final testing in tension, such a "balanced" tension-compression cycle yields a ductility considerably higher than that present after prestraining in tension only. . The results of these tests can be correlated with those of an investigation on the effects of prestraining in compression.2 As also shown in Fig I, the ductility in subsequent tensile tests decreased with compression, at a rate considerably slower than that after prestraining in tension. The above discussed testing conditions can be considered as special cases of a general straining cycle, consisting of first, straining in tension by an amount E1, subsequently straining in compression by an amount E2, and finally determining the retained ductility, Ef, in a tensile test. Prestraining in tension is then represented by E1 > o and E2 = o. Prestraining in compression is given by E1 = o and e2 < o. Balanced cyclic straining is defined. by the condition E1 > o and E2 = -El. In order to obtain further information on the effects of straining cycles consisting of tension and subsequent compression, further tests were made, varying both the tension strain, E1, and the compression strain, E2, within extreme limits; El varied between 0.06 and 0.28 and E2 between -0.008 and -0.60 approximately. Apparently, such tests have not been previously performed. They revealed phenomena which have not been recognized to date. The results of the investigation are herewith reported, without attempting to correlate them with internal processes within the metal structure. However, in order to assist in an analysis of this type, the results have been represented in various manners. In addition, further test data on the effects of prestraining by compression were provided by using specimens of various contours (notched specimens) in the subsequent tensile tests.

Jan 1, 1948

Jan 1, 1929

By Don Simon

In the late 1960s the mining industry was in an apparent slump due to a combination of factors. Enrollment dropped significantly at schools offering mining engineering degrees, resulting in a shortage today of experienced mining graduates to staff middle management positions. How has this limited supply affected salaries? Does the shortage impair the mining industry&apos;s ability to respond to national energy needs?

Jan 12, 1979

By D. L. King

The San Francisco Chemical Co. has been actively interested in phosphate mining since 1908. It was, in fact, the first company to make claims on properties in the western phosphate belt. From the period of 1908 to 1947, the company&apos;s phosphate operations were centered at their Waterloo property, five miles east of Montpelier, Idaho. A small tonnage of phosphate rock was shipped annually from their underground mines in that area. In 1945, the company started the first western open-pit phosphate mine on the slopes of Waterloo Hill. In 1947, they obtained an option and lease on the Beckwith Hills&apos; deposits in southwestern Wyoming, some 25 miles south of Cokeville. While the operations at Montpelier and the Beckwith Hills are both open pit, there are many differences which suggest separate treatment in this paper. Structurally, the Waterloo Hill is the west slope of an anticline. The beddings dip from 20" to 35" to the west. Erosion has caused the footwall exposures (Well&apos;s formation) to appear in the upper areas as a series of apices, giving the outcrops a festooned arrangement. Dip faulting with subsequent erosion has induced gullies normal to the strike and resulted in eroded areas which separate the remnants of the

Jan 1, 1950

CALAMINE is one of the semiminerals that have great similarity to the metals. It is a very heavy mineral earth of a yellowish color. It is found in Germany near the lead mines and in Italy in a mountain between Milan and Como. It is also found, as I have heard, in other places, as at Fosini in the territory of Siena. I believe that it is almost certain that some exists there because there are many other kinds of minerals there- about, although none is mined there in these times. But this does not mean that it could not be mined or that there is not some there that is real. Someone says that he med to melt what he could find with copper [36v]

Jan 1, 1942

By James A. Lewis

It is the purpose of this paper to show the importance of sand characteristics, when combined with other physical data, in evaluating production obtained by secondary recovery operations, and to indicate the benefits to be gained from the application of these principles to primary production.

Jan 1, 1942

By Wayne C. Hazen, James K. Kindig

As the complexity of hydrometallurgical systems increases, it offers new opportunity for applications of solvent extraction. However, the high capital cost of mixer-settlers for large flow rates is a drawback to wide application in base metal recovery. This paper presents information on the use of cyclone separators in place of settlers with attendant significant reduction in capital cost. Various flowsheet possibilities for this development are discussed.

Jan 1, 1972

By G. F. Tagg

EARTH-REISTIVITY measurements are often of service in obtaining information regarding geological formations, particularly when applied to structural problems. In such problems the masses of the various bodies are large, and have a corresponding effect on the average resistivity of the soil. Much work has been done using such measurements, but in general the method of interpretation employed is empirical. Since certain simple cases can be investigated mathematically, it appears to be quite sound to endeavor to apply the mathematical solutions to the practical results, in order to deduce from the latter such unknown quantities as depth. This paper deals with such a method of interpretation for the simple case of a single horizontal stratum. SURFACE Of EARTH In the method described by FIG. 1.-WENNER&apos;S METHOD OT MEASURING Wenner1 for measuring earth resis- EARTH RESISTIVITY. tivity, four stake electrodes are driven into the earth in a straight line as shown in Fig. 1. A current I amperes is passed between the two outer stakes and the potential difference . V volts between the two inner stakes is measured. Then if a is the electrode separation, the specific resistance of the soil, which is assumed to be homogeneous, is given by the formula

Jan 1, 1932

By E. Northcott, I. M. LeBaron

Before describing the electrostatic processing of feldspar, it might be well to review some of the basic definitions and terminology of feldspars. The feldspar minerals constitute a group of alumino-silicates of potassium, sodium, and calcium. Barium feldspar sometimes occurs naturally but is very rare. Hardness varies between 6 and 6.5 and specific gravity between 2.5 and 2.8. Color is generally white or pale shades of red, yellow, or green. The approximate chemical composition of the principal feldspars is given in Table I. The albite (sodium aluminum silicate) and an orthite (calcium aluminum silicate) feldspars are the end members of a series called plagioclase. These two molecules form a complete solid solution series ranging from pure soda feldspar at one end to the pure lime feldspar at the other end. Intermediate solid solutions are known as oligoclase, andesine, labradorite, and bytoconite. The general structure throughout this series is the same. Sodium and calcium may replace each other and silicon and aluminum may replace each other in the structure.

Jan 10, 1958

By J. F. Stiehr, R. L. Sanford, T. L. Myers

This paper summarizes the development of a Directory of Computer Programs Applicable to US Mining Practices and Problems. The directory is funded by the US Bureau of Mines and includes a sampling of computer usage in operating and manufacturing companies, consulting firms, computer companies, research organizations, universities, and various US government agencies. General references to computer applications throughout the mining industry are discussed as well as the availability of programs to interested organizations or individuals.

Jan 9, 1979

By John D. Siddle

Efficient energy utilization in the electrolytic zinc process, relative to other zinc processes, is one of the reasons for its wide adoption in recent years. Designers and operators of electrolytic zinc plants have pioneered process improvements, new equipment, and operating techniques to conserve energy. As energy costs advance still higher in the future, and competitive pressure against the less efficient producers increases, these or alternative energy-saving methods will be looked upon as a necessity for economic survival. Estimated energy savings which may be achieved by various equipment and techniques are included.

Jan 1, 1977

The Institute conducts jointly with the American Society of Civil Engineers, American Society of Mechanical Engineers and American Institute of Electrical Engineers, certain activities as listed below, and is joint owner with them of certain properties. United Engineering Trustees, Inc. When Mr. Carnegie made his gift which made possible a home for the engineering societies, a separate corporation was organized to act as a holding company and to manage the common property. This was long known as the United Engineering Society, but the name has now hen changed to one which more nearly reflects the real function of the corporation. It holds title to the Engineering Societies Building and to various funds placed in its charge and is managed by a Board of Trustees, of which three are chosen by each of the four societies, American Institute of Mining and Metallurgical

Jan 1, 1932

By Erwin Zodrow, De Verle P. Harris

The Smallwood mine, owned and operated by the Iron Ore Co. of Canada, is one of the largest ore producers in Canada, producing about 15 million tons of crude ore per year. Located in the Labrador Trough near, Labrador City, Newfoundland, the open-pit operation has ore consisting chiefly of specular-hematite, with some magnetite. The magnetite content of the ore as a mineral percentage is small, but it is of considerable importance in ore grading because of its effect upon milling. Being harder than specular-hematite, magnetite increases grinding time and milling costs. Specifically, higher grade magnetite (greater than 15%) usually occurs as fine grains in a fine grained siliceous rock matrix (also as larger octahedra in carbonate bands). This tends to increase the overall breaking strength in the crude ore; consequently, the hourly mill rate and the weight recovery decrease. At the same time, because of its relatively high iron content, the magnetite does contribute to the amount of iron in a block of ore. Were the concentration of the magnetite relatively constant, its presence would be of less consequence, for appropriate adjustments could be made in the milling operations. However, the quantity of magnetite present for any run of ore varies considerably; it is the magnetite prediction for a block of ore that constitutes the greatest problem in grading. THE PRESENT ORE GRADING METHOD Ore for the Smallwood mine is graded by a computerized block grading routine (using 50 x 50 x 45-ft blocks) that applies simple weighted (inverse-distance) averaging to ore grades. The results of the block grading program are not reliable with respect to magnetite concentration. Factors responsible for this poor estimation are (1) the structural setting of the deposit, and (2) mineralogical relationships. Neither of these general factors are given adequate consideration by present methods.

Jan 8, 1967

George Otis Smith, Washington, D. C. (communication to the Secretary) : The somewhat exceptional features discussed by Dr. Jenncy in his paper on " The Mineral Crest" mere recognized and described by Mr. Tower in our report on the Tintic district. The general absence of surface-outcrops of important ore-bodies, and their occurrence, when present, at relatively low points, are noticeable characteristics of this district, and the statements made by Dr. Jenncy agree in general with our observations. The approximately horizontal upper limit of the Silver Gem ore-body in the Bullion-Beck mine is figured in this report, and mention made also of the horizontal pipes of ore found in several mines." In only one case," however, was any hypothesis

Jan 1, 1903

Jan 1, 1941

By D. Watson, T. J. N. Grainger-Allan

A technique for studying the mechanism of the froth flotation process in which continuous froth removal does not take place but, instead, an equilibrium is reached between froth and pulp is described. A flotation cell, specially designed to facilitate equilibration, and froth and pulp sampling procedures are described. The main advantage of the technique is that the ability to measure the steady-state froth height allows froth-stability effects to be separated from pulp-process effects. In the flotation of hematite front quartz, linear relationships are found between airflow rate and froth height and between airflow rate and the ratio at equilibrium of mass of values in froth to mass of values in the pulp. A simple mechanistic interpretation of these results is given. It is suggested that froth-stability effects may play a more important role than hitherto allowed. In particular, the way in which concentration and size distribution of gangue particles may affect overall flotation rate is shown.

Jan 1, 1975

By H. O. Hofman, H. L. Norton

Zinc smelters in the central western States have established a very high standard of purity for blende-concentrates, viz., zinc 60, iron less than 3, and lead less than 1 per cent. The very low percentage of iron is made possible by the blende containing less than 0.5 per cent. of isomorphous iron sulphide and by the sparing occurrence of pyritic material in the large blende-deposits of southwestern Missouri and southeastern Kansas. The blende in these districts occurs in sub-carboniferous limestone, and is associated with chert, residual clay, cal-cite, pyrite or marcasite and bitumen. The different minerals are coarse and therefore readily separated by mechanical washing from the blende, with the exception of pyrite and marcasite, as blende has a specific gravity of from 3.9 to 4.1; marcasite, from 4.85 to 4.90; and pyrite, from 4.95 to 5.10. The common procedure of dressing the ores&apos; is to crush in a breaker, size in a trommel with 0.5-in. holes, pass the over-size through roughing-rolls and then jig the ore, now reduced to 0.5 in. maximum size, in roughing multiple-sieve jigs. The products of these are waste-tailings, side-discharge coarse concentrates, side-discharge coarse middlings and bottom-discharge fine middlings. The coarse concentrates are sent to the market. The coarse middlings are crushed in middlings-rolls and brought back into the system by feeding into the main trommel. The fine middlings are cleaned upon finishing-jigs. Any pyrite or marcasite present follows the blende and increases the percent- +1MASSACHUSETTS INSTITUTE OF TECHNOLOGY, BOSTON, MASS.

Jan 1, 1905

By H. W. Young

Development of high-tension outdoor substations during the past few years has been due primarily to economic reasons. The demand for power in small communities could not be met with the conventional and Fig. 1.—33,000-VOLT step-up outdoor air-break switch and substation installation outside of a powerhouse generating at 2300 volts stepping up to 33,000. Twenty-one coal mines are supplied from lines leading from this installation. comparatively expensive indoor types unless the rate for service was materially increased. To prove that the problems lncident to development have been solved successfully, it is only necessary to point to the wide adoption of outdoor substations by utility companies. Passing at once to the question as to whether outdoor substations are applicable to

Jan 1, 1920

By Thomas R. Couzens

This chapter covers certain aspects of open pit production planning based on experience, pointing out approaches to planning that may help produce a realistic picture for evaluation and operation The subjects discussed are roads, preproduction stripping, dump planning, dewatering, the relationship of production planning to equipment selection, and computer methods for the short-range or operational pit planning process Actual determination of ore limits, pit design, and production schedules are covered in other chapters This discussion is somewhat general. Specific problems that occur in mine planning are extremely varied, and it is not possible to cover many of them in a chapter, therefore, only some of the principles that are important in the approach to open pit production planning problems will be discussed.

Jan 1, 1979