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By E. A. Moulder

The mining industry is continually faced with problems involving dewatering, pollution, water supply, leaching and hydrochemical mining and prospecting. Greater application of the principles of ground-water hydrology to solution of these problems promises improved operating efficiency, increased safety and better public relations. Estimating the magnitude of dewatering for a proposed mine may be a major factor in determining the feasibility of proceeding with mine development. Diverting the source of ground water to an abandoned mine may save costly treatment of acid-mine drainage. Development of a large ground-water supply near an ore deposit may enhance the possibilities of a leaching operation. Detection of certain dissolved minerals in water from springs or wells may lead to hitherto unknown mineral deposits. Current efforts of industry, educational institutions and government are making these kind of events more commonplace. Dewatering of Mines The magnitude of dewatering problems was dramatized by a flooding that occurred last year in a gold mine in South Africa. During drilling operations at the West Driefortein mine, a major fracture was encountered from which large volumes of water issued necessitating evacuation of 1350 men from the mine. Dewatering required an increase in pumping of more than 80 million gpd. Models of ground-water systems are being used to test alternate plans for dewatering mines. Using the models in conjunction with computer optimization programs may lead to minimizing costs of operation. In addition to computer simulation of aquifers associated with phosphate deposits in North Carolina mentioned in last year's report, two USGS employees developed a model to estimate the amount of pumping required to dewater a mine site in Colorado.

Jan 1, 1970

By Harold H. Haman

In view of Twentieth Century advances in mineral dressing technology, most modern metallurgists would be inclined to class jigging as an early, somewhat primitive, representation of their art. The practice of metallic sulfide concentration by jigging is becoming rare. This is so, in part, because the type of ore amenable to the process is becoming rare. It is appropriate, however, that this symposium recognize that a significant contribution of domestic zinc remains dependent upon coarse preconcentration by jigging, and that the state of the art be described even though the theory and applications are already well delineated in technical literature. One of the few areas still using jigging as a major concentrating process is The Upper Mississippi Valley. AREA HISTORY AND JIGGING The Upper Mississippi Valley (UMV) has produced one billion dollars worth of zinc and lead at current prices. The district includes the southwest part of Wisconsin, the northwest corner of Illinois and an adjoining narrow strip of Iowa. Within a total area of 4,000 square miles, important sub-districts cover about 400 square miles. As is widely known, early mining in this district involved shallow lead---crevice deposits of galena that were very selectively mined, hand sorted and cleaned, and then smelted at or near the site. The district has produced almost a million short tons of metallic lead, a very large part of this during the fifty- year period following 1830. Zinc mining began at the end of the civil war, but at a very low rate until about 1905.

Jan 1, 1970

By P. A. Farrar, M. D. Silver, K. L. Komarek

Thermodynamic properties of Hf-0 alloys have been determined from 0 to 25 at. pct 0 between 1000" and 1200°K by equilibrating specimens with alkaline metal oxide-metal vapor combinations. Partial molar-free energies, enthalpies, and entropies of oxygen have been obtained and are conzpared with similar results for the Ti-0 and ZY-0 In continuation of a thermodynamic investigation of the Ti-O and Zr-O systems1 activities of oxygen and lattice parameters of Hf-0 alloys have been deter- system. The positional entropy in all three systems corresponds to an ideal random interstitial solution with one interstitial site per one metal atom. The lattice parameters of hafnium and Hf-O solid solutions have been determined in the range 0 to 20 at. pct O from measurements of Debye powder patterns. mined. All three metals dissolve large quantities of oxygen to form interstitial solid solutions. The phase diagram of the Hf-O system is shown in Fig. 1.' The maximum solubility of oxygen in the cph a phase is considerable (up to 25 at. pct O). The solubility in the high-temperature phase is much smaller. The only stable compound in the solid state is HfO2 which may exist with a certain oxygen deficiency. The low partial pressure of oxygen of Hf-0 alloys required the application of an indirect method. As the most suitable procedure a method, first applied by Kubaschewski to the V-O system,3 was combined with a principle developed by Herasymenko for the

Jan 1, 1963

ALKALINE LEACHING; SODIUM HYDROXIDE U.S. 4,091,071 -In the alkaline digestion of bauxite containing goethite, boehmite and/or diaspore, the process is accelerated by adding to the digestion mass an optimum proportion of calcium oxide and divalent manganese ions, advantageously in the form of a calcium carbonate-containing manganese oxide ore, whereby goethite is transformed into hematite, the alumina yield increased, and loss of caustic soda values minimized. J. Boros, assigned to Femipari Kutato Intezet, Aluterv Alumiumipari Tervezo Vallalat and Almasfuzitoi Timfoldgyar. May 23, 1978. 7 pp. Filed: 12-23-75 (643,670). Priority: Hungary, 12-24-74 (AU 330). Same: British 1,528,146, dated Oct. 11, 1978.

Jan 1, 1979

Jan 1, 1896

By Daniel T. O’Brian

Exploration targets and results in the mining industry are commonly summarized in terms of tonnage and grade. Business appraisals require, as additional information, the expected profit or loss implied by the physical summary. The early incorporation of knowledge gained through financial analysis computations can provide a means for economically resolving many common exploration and development problems. Examples of such applications from the activities of exploration planning, reconnaissance, land acquisition, and development planning are presented in this paper.

Jan 1, 1969

By Dale K. Fields

With today's technological advances in mineral processing equipment, there is an increasing demand for accurate system control. This can only come about through representative sampling. The purpose of this paper is to guide in the selection of sampling equipment and outline design parameters for the cutters used in dry and wet sampling without adding redundant mathematical probability formulas. Special attention will also be given to the equipment used in conjunction with samplers and sampling system, such as feeders, crushers, chutes, launders, and controls.

Jan 10, 1979

By M. F. Werneke, J. A. Jones

Abstract- The use of a unique class of sulfhydryl collectors, the monoalkyldithiocarbamate salts ([RNHCS]) as direct collectors for malachite and azurite is presented. Microflotation and laboratory scale flotation tests were performed to define the collector properties of these reagents under a variety of flotation conditions. On the basis of the results, it is proposed that some property of the amine-hydrogen atom in the reagent has a significant influence on the unusual activity of these collectors for oxide copper minerals.

Jan 1, 1978

By Ronald D. Hill, Roger C. Wilmoth

The neutralization of acid mine drainage is becoming a common practice in the eastern United States. Over 200 plants are now in operation. Lime is the neutralizing agent utilized in most treatment plants; however, limestone may have an economic and practical advantage. Current research efforts of the Federal Water Quality Administration, both inhouse and through grants, to develop and demonstrate the use of limestone are reported. In essence, a state-of-the-art review is presented.

Jan 1, 1972

By Merrill F. McCarty, Robert S. Olson

New organic flocculants of high-molecular weight are replacing lime, glue, and starch in liquid- solid separation. Of these synthetic materials, polyacrylamides are outstanding. Polyacrylamides form a class of compounds varying widely in composition and activity. Separan 2610H, one of the first of these flocculants' released to the mining industry in 1954, is described' as a high- molecular weight polymer of acrylamide with or without a copolymer material and with some replacement of amide by carboxylic groups.

Jan 1, 1959

By Bryan Denby

The curvilinear nature of shear strength envelopes for rock discontinuities may be simply and precisely represented by a power curve. The development of shear strength criteria applicable to rock discontinuities is reviewed and related to a theoretical basis for curvilinearity. An approach is reported to enable the quantification of the two power curve indices using a nomogram based on empirical studies. Using a knowledge of discontinuity basic friction angle and peak dilation angle the relevant indices ranges may be predicted for mine slope studies.

Jan 1, 1984

Perhaps, after years of concerted effort at a mineral prospect, your company has reached the stage of feasibility study. Detailed target investigations, drilling, bulk sampling, land acquisition, and engineering analyses are complete, and the deposit still remains an attractive investment possibility. Your company, after long study, decides to begin mine development-now, how do you convince lending institutions that your proposed operation will return their borrowed funds, plus interest, over the term of the loan?

Jan 12, 1978

By S. E. Craig

Jen Inc., operator of the Cord mine, in the Big Indian district of San Juan County, Utah, has a contract with a milling company that provides a small bonus for proper grading and preparation of uranium ores shipped. To obtain maximum returns on this contract very close grading is required with settlements made on individual lots, which vary from 250 to 300 tons. Another feature of the contract, and one that is rather unique in this country, is that the ore is sold over truck scales at the mine. Grade is determined at the buyer's sample plant. It is necessary to take a moisture sample of each truckload shipped for ac- curate weighing and this is done by the representative of the buyer, using facilities supplied by Jen Inc. The sample is hardly more than a grab sample and includes only the finer and smaller pieces of the ore shipped.

Jan 10, 1958

F. G. SMITH.-Probably someone will ask whether I discovered why the bottoms of the large shells broke out. I did not, as a result of this investigation. An experiment was made along the lines indicated in this paper, to determine whether abnormal grains greatly affected the physical properties of brass. Two ordinary test bars were annealed for 1/2 hr. at 750° C. and physical properties determined on one. The other was covered with indentations made with a peen hammer and then reannealed. for 5 hr. at 750° C. It was found in the tensile test to be made up of large grains 1/4 to 1/2 in. in diameter. The physical properties, however, differed from those of the first bar only as much as might be expected after a 5 hr. anneal under normal conditions. It appears then that the large grains produced in this manner do not ruin the physical qualities of the brass.

Jan 12, 1919

By A. A. Archer

Marine mining is here defined as the commercial recovery of minerals other than oil and natural gas from the surface of, or below, the seabed by operations connected only indirectly with the land. The number of operations falling within this definition and the number of countries involved are remarkably limited in view of the widespread interest shown in marine mining prospects during the last few years. Marine mining is still restricted to continental shelves, where the only superficial minerals currently being mined are sand and gravel, calcium carbonate in different forms, and tin and iron sands.

Jan 12, 1973

Michigan State Department of Conservation, Lansing, Mich The Department of Conservation has two divisions issuing publications which should be listed in this directory. Geological Survey Division. R. A Smith, State Geologist Land Economic Survey Division L R Schoenmann, Head. A price list of publications of either division will be sent upon request to that division Geological Survey Division.-Citizens of Michigan may obtain publications of this Division on payment of forwarding charges Prices to others for available publications are given below: Vol 5 (1881-1884): Pt 1, Geological report of the Upper Peninsula of Michigan, by L L Hubbard, pt 2, Geology of Lower Michigan with reference to deep borings, by A C Lane, $125. Annual Report for 1908. Pt b, Geological section of Michigan, by A C. Lane and A E Seaman, 50 cents. Publication No 5, The Late Glacial and Post Glacial Uplift of the Michigan Basin, and earthquakes in Michigan, by W. H

Jan 1, 1933

By M. Dubrovsky, J. W. Evans

A laboratory scale cell (approximately 50 amps current) equipped with a fluidized bed cathode was used in a study of the electrodeposition of cobalt from acidified aqueous sulfate solutions The effect of current density (in the range 0.1 to 1 amp/cm2 of diaphragm), cobalt concentration (4 8 to 100 glliter) and catholyte pH (1 35 to 6 2) on current efficiency and energy consumption were determined. Generally the current efficiency increased with increasing current density and cobalt concentration Current efficiencies were comparable to those reported in the literature for conventional electrowinning

Jan 1, 1981

By D. J. Mack, J. A. Mullendore

MUCH work has been reported in the literature on the separation of individual phases in steels, particularly carbides, for the purpose of structural and chemical analysis. The methods usually involve separation of the particles from the matrix by chemical or electrochemical methods. Another .group of alloys ideally suited for selective removal of one phase is the commercial aluminum bronzes. Al-

Jan 1, 1959

By Fred Prime

To an association like the one before which I read this paper, few questions can be more important and constantly recurring than the following, viz.: "What economy can be effected in the manufacture of American iron ?" And it is the one with which I purpose to deal in this paper; premising, however, that my object is merely to indicate the direction in which an answer should be sought for, rather than to give it myself. This subject may be divided into two parts; " Economy in the production of pig-iron," and " Economy in the manufacture of wrought-iron;" but it is to the former alone that I shall confine myself this evening.

Jan 1, 1873

By W. Julian Parton

General Crushed Stone Co. operates a dozen quarries in such rock types as gabbro, basalt, granite and limestone. Drilling characteristics and problems vary from one operation to another so that a variety of equipment and methods must be employed. In addition, it has been found that equipment improvements make it advisable to continuously look for and experiment with new machines and accessories. This article discusses drilling progress at some of the Company's more interesting operations.

Jan 1, 1963