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By F. Windolph

There are no hard and fast rules for building tailing dams, and each case has to be analyzed individually because of special conditions encountered at each location. Certain criteria are used for building dams at Climax, Colo., where they must be placed in rather steep mountain valleys on foundations that are practically impermeable. The tailing is relatively coarse, and a coarse fraction stays near the berm where it is deposited, while most of the fines flow with the water to the pool. Thirty years experience has led to certain design for toe dams, decanter lines and towers and tailing dams. A new tailing disposal area, started at Climax in 1958, will ultimately have a height of 495 ft and impound about 300 million tons. The following applies to the construction of this new tailing area.

Jan 11, 1961

By William Kent

During the discussions at the Philadelphia meeting in February last;) several speakers expressed their doubts of the general accuracy of chemical analyses of steel made by "iron works chemists," and especially of determinations of manganese. Since the meeting, the discussion of the " practical value of chemical analyses" has been continued at some length in 'the columns of the Iron Age.

Jan 1, 1882

By G. S. Rice

Undoubtedly there is a serious problem through the juxtapostion of gas and oil wells and coal mines, not only at the present time, but possibly of far more serious import for the future.

Jan 1, 1915

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 J. H. Swartz

During 1938 and 1939, an extensive series of geophysical surveys, employing both resistivity and magnetic methods, have been carried on in the Hawaiian Islands by the Section of Geophysics of the United States Geological Survey in cooperation with the Division of Ground-Water of the Survey and the Division of Hydrography of the Territorial Government (see Fig. 1). During this time, surveys have been conducted on the islands of Oahu, Molokai, and Maui. Two distinct types of ground-water occurrence are being investigated: (1) The basal fresh-water lens floating on underlying salt water in obedience to the Ghyben-Herzberg principle (Fig. 2); and (2) perched ground-water (Fig. 3).

Jan 1, 1940

By Barry H. G. Brady

A state of stable equilibrium is required in a mine structure to ensure that small increases in the mined void are accompanied by only small displacements of the rock mass. Methods of determining the stability of equilibrium in a rock mass currently require a geometrically regular stoping layout, and introduce a number of simplifying assumptions. The method reported in this paper models the mine near-field using Finite Elements, and the far-field using Boundary Elements. The stability of equilibrium in the modelled structure can be assessed directly from the value of selected principal minors of the global stiffness matrix.

Jan 1, 1981

By K. I. Savage, L. G. Austin, S. C. Sun

The comminution environment - the physical, chemical, and solid state - was studied for silicon carbide ground wet in a laboratory vibratory mill. The relative importance of these variables on the grinding rate of producing a material 50% passing 5µ from a powder feed of 50% passing 19µ was established.

Jan 1, 1975

By C. F. de Mendonca, T. Kater, R. P. de Souza

Since 1976, Cia Vale do Rio Doce (CVRD) has carried out tests to develop a type of pellet made with an organic binder. Peridur is one binder that showed it could be used in industrial plants. Extensive tests were run in CVRD's pilot plant. The results are presented in this paper. The decision was made to carry out an industrial production of 50 ht (55,000 st) of pellets. The results are shown in this paper. No detrimental effects of the Peridur were observed in either the process or in product quality.

Jan 1, 1985

By C. G. Rhodes

A technique for producing etch pits in uranium monocarbide has been developed. The pits, which are assumed to be associated with dislocations, appear individually and as arrays delineating sub-boundaries, as seen in Fig. 1. The samples used were single crystals prepared by the technique described by Nadler.* Uranium

Jan 1, 1963

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNS, Chairman. PERCY E. BARBOUR, Vice-Chairman A. D. BEERS, Secretary, 55 Wall St., New York, N. Y. C. A. BOHN, Treasurer. JOHN V. N. DORR, LEWIS W. FRANCIS. Boston Meets first Monday of each winter month. W. E. C. EUSTIS, Chairman. R. L. AGASSIZ, Vice-Chairman: E. E. BUGBEE, Secretary-Treasurer, Mass. Inst. of Technology, Boston, Mass. ALBERT SAUVEUR, H. L. SMYTH. Columbia Holds four sessions during year. Annual meeting in September or October. W. H. LINNEY, Chairman. OSCAR LACHMUND, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. STANLY A. EASTON, S. SHEDD.

Jan 2, 1917

By C. M. Wayman, S. R. Rauze

It was recently reported' that the initial transformation in (100) iron whiskers grown in the bcc condition can be nucleated on heating in regions of the whisker which are not necessarily the hottest. Although this behavior was observed1 several times, its sporadic nature precluded any documentation other than occasional visual observations during hot-stage optical-microscope heating experiments. The purpose of this communication is to report how, in one instance, the a-y transformation in such a (100) iron whisker was initiated in a region which was clearly at a lower temperature than an adjacent region which did not transform at all.

Jan 1, 1967

By N. J. Themelis, R. V. Flint

In a four-year period between 1973-76, the Metal Mining Division of Kennecott Copper Corp. conducted a company-wide program of operations improvement which involved line and staff personnel from all company functions. Specialist teams performed detailed studies of all operational aspects at Kennecott's four copper mines and concentrators, four smelters, and two electrore-fineries. The specific recommendations that resulted may transform the Metal Mining Division into the country's lowest cost producer of copper by the mid-1980s. In this article, N. J. Themelis and R. V. Flint describe the mechanics of MMD's integrated approach to operations improvement.

Jan 6, 1979

By T. Imaizumi

Covering the whole scope of the MMIJ activities, i.e. geology and exploration, mining, mineral processing, and metallurgy, the technical innovations and improvements since 1972 were reviewed. Special references were made to the MMIJ Research Committees which were subsidized by the Japan Mining Promotive Foundation, in connection with those activities.

Jan 1, 1976

By R. S. Shoemaker, F. W. McQuiston

CAMPBELL RED LAKE MINES Balmertown, Ontario 1974 Operating Data MINE LOCATION: Balmertown, in Red Lake mining area of Ontario TYPE OF MINE: Underground mine developed by vertical shaft to 4300 feet. Mining active above 3000 ft depth. ORE DESCRIPTION: Gold and minor silver.. Sulfur content about 1.3%. Ar senopyrite , pyrite, pyrrhotite, and stibnite. CAPACITY IN TONS124 HRS: 825 ASSAY: 0.66 oz Au per ton heads MILL PROCESS: Amalgamation, flotation, roasting of concentrate and separate treatment of calcines and flotation tails by cyanide. PLANT BUILDING: Mine mill and service facilities all housed in insulated and heated buildings POWER: Total consumption, mine and mill - 100 Kwh/T WASTE DISPOSAL: Impoundment of tailings. Arsenic to sealed underground storage EMPLOYEES: Total of 300 men on payroll. Housing in Balmertown and nearby communities.

Jan 1, 1975

By Carlos Kovacs-Figueroa

Complying with air pollution regulations created the need to dispose of increased sulfuric acid production by the Morenci smelter. As a result, a two-module leaching plant was constructed to leach Morenci flotation tailings. The leaching plant was equipped to perform the following operations: leach feed pumping, agitated leaching, two-stage countercurrent decantation, neutralization of leached tailings, and copper precipitation. Ancillary facilities were provided for neutralizer and flocculant preparation as well as precipitant handling and recovery of precipitates. Plant control is automatic from a central control panel supervised on a shift schedule by one operator and two helpers. Construction of the first module was initiated in April 1973 and leaching of tailings commenced in November 1974. Construction of the second module began in January 1975 and was completed in November 1975.

Jan 1, 1977

By Chi-shing Wang

Recently the U.S. Bureau of Mines has undertaken a research project to develop the mechanical roof pulling technique as a method for evaluating the effectiveness and the comparative advantages and disadvantages of various roof bolting systems for underground coal mines, based on the characteristic responses of bolted mine roofs to a prescribed external loading system. Two preliminary experiments of the test method were conducted in the Bureau's Safety Research Coal Mine (SRCM) at Bruceton, Pa., and further trials are underway. The fundamental concept of the test method, the design of test rigs, and the experimental results are summarized in this progress report.

Jan 1, 1976

By W. D. Douglas, M. J. Hampshire, G. J. C. Young

This paper describes the replacement of a conventional filtration, clarification, and zinc precipitation plant by a carbon-in-pulp (CIP) electrowinning plant, with the objective of improving the recovery of gold from cyanide leached, acid plant calcines. The discussion covers early laboratory studies to the design and erection of the full-scale plant. Particular emphasis is placed on the problems encountered with commissioning and the strategies employed to solve them.

Jan 1, 1985

By William Kent

DURING the discussions at the Philadelphia meeting in February last, † several speakers expressed their doubts of the general accuracy of chemical analyses of steel made by "iron works chemists," and especially of determinations of manganese. Since the meeting,. the discussion of the "practical value of chemical analyses" has been continued at some length in the columns of the Iron Age. †Transactions, vol. ix, p. 529.

Jan 1, 1882

Technical graduate wanted for metallurgical. work in experimental laboratory of large New England manufacturing concern. A knowledge of metallography of steel is essential. Practical experience is desirable but not required. No. 305. Man familiar with precipitating with the diamond drill core to act as foreman. No. 311. Competent mining man to develop and take charge of mines in Peru. Property to be developed from start and equipped with thoroughly modern appliances to meet the increased production. Applicant must possess considerable mechanical ability and experience. No. 312. Engineers and assistant engineers in forest production for National Defense work for the duration of war. Laboratory work conducted primarily by experimental and research methods, embracing principally investigations of mechanical and physical properties of wood, processes for the preservation of wood against decay and other destructive agents, practical problems of pulp and paper industry, and other industries utilizing wood by chemical means or otherwise. Assistance in this department of Government is urgently required in order to obtain maximum benefits from the investigation. Salary $1860 to $3000 for engineers; $1200 to $1800 for assistant engineers. No. 313.

Jan 6, 1918

By Herbert C. Hoover

While the importance of the superficial alteration of golddeposits is recognized in pure science, it seems often to be singularly disregarded among engineers in practice. Its great practical bearing lies in the exploitation of new regions; and nowhere are the disastrous results of ignoring it more vividly shown than in Western Australia, where the impoverishment of the ores, and their frequent transition from free-milling' to refractory character in depth (things, as a rule, neither anticipated nor ascertained by exploration beforehand), have brought many companies to ruin, or caused the loss of much money squandered on machinery adapted only to temporary conditions.

Jan 1, 1899