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By Kent A. Pease

Design methods for foundation anchors and sockets constructed in rock are based largely on empirical correlations which yield a reasonable estimate for initial capacity, but do not address the general concerns of failure mode and load-displacement behavior. This paper focuses on the behavior of foundation-rock interfaces and shows that interface behavior under increasing load results in a progression from an elastic response to secondary behavior, in which interface failure occurs, and finally to a residual stage at large deformations. Procedures to follow this progression are outlined to provide a more fundamental understanding of the problem.

Jan 1, 1984

By Michael A. Arkoosh, E. A. Peretti

ANALYTICAL results have previously been presented for the diffusion-controlled solution of a second phase in a finite medium for planar, cylindrical, and spherical geometries.' These results were obtained by numerical methods using digital computer techniques and are applicable not only to the stage of the problem where the unstable phase shrinks to zero size, but also the subsequent stage where the concentration gradients in the matrix phase become negligible (essentially complete homogenization). It is anticipated that the results of such an analysis may be of use to those workers who are interested in the processes

Jan 1, 1970

"IRON for iron" may soon be the primary concept of Mexico's mining industry. If reports that President Adolfo Ruiz Cortines intends to extend federal control over mining are true, Mexico will export iron ore to the U. S. only in return for machinery. Actual exporter will be the Federal Government, with negotiations through the Bank of Mexico. Shipments of iron ore, under this kind of arrangement, can be tightly controlled, assuring that machinery and heavy equipment instead of dollars are the means of payment. Expansion of this policy in the next few years can be expected according to reports.

Jan 6, 1953

By J. D. Vincent, Paul A. Weyler

Climax Molybdenum's plan for the Henderson 30,000 tpd molybdenite plant didn't just happen. It slowly evolved over a period of 3% years. Many plants cannot afford similar delays, but the Henderson project will take about 10 years to complete from the time the orebody was first discovered until production begins. Pilot plant testing results with both the single stage and two-stage semi-autogenous grinding circuits were highly favorable in terms of operating costs reduction-so much so, that the Amax subsidiary made the decision to go with semi-autogenous grinding for the Henderson mill.

Jan 5, 1972

By R. C. Dorward

DIFFUSION considerations are necessary to describe many technologically important metallurgical and physical processes. Since most commercially important alloys are comprised of more than two components, diffusion calculations applicable to binary systems are often unjustified. However, in many instances the more general equations valid for three-component systems may be employed. The phenom-enological description of ternary diffusion is now well-established,1-4 and the theory has been applied with some success to a few practical situations.5"7 The flux equations for the solutes (components 1 and 2) of a ternary solution may be expressed by:

Jan 1, 1969

No. 576.-Graduate mining engineer, married, 32 years of age. Have had 10 years' experience in mining from position of mucker to that of general superintendent. For past four years have been in Copper River District of Alaska as mining engineer, and superintendent of gold and copper mines. Desire position in U. S. Best of reference. No. 577.-Member, technical, age 27, married. Open for engagement. Past year in war mineral field work, operation and production. Ten years thorough experience in both subordinate and executive positions, gold, silver and copper in the U. S., Mexico and South America. Devel-

Jan 5, 1919

By N. Brown, J. Washburn, E. R. Parker

MOST previous quantitative work on creep of single crystals has been concerned primarily with developing empirical equations for the creep curve. Although the equations used by Cottrell and Aytekin¹ and Tyndall² represented the data quite well, it was often necessary to use different values of the constants for different specimens even though they were apparently tested under identical conditions. In the course of previous work on the effect of surface coatings on creep of zinc single crystals," it was found that equal resolved shear stress frequently did not produce equal creep rates in different specimens. The work of Chalmers' in the very

Jan 1, 1954

By Sam Rosenblum

The anomaly ratio is obtained by dividing the analyzed value of an element by the anomaly threshold value of the element. The sum of anomaly ratios for all anomaly elements in a sample may be compared with similar sums for other samples, so that samples having the greatest anomaly- ratio totals can be recognized easily. In partial or full suites of ore elements the we of anomaly ratios is more meaningful than use of analyzed value because the ratios quickly indicate how use of analyzed values because the ratios quickly indicate how anomalous some elements are, and call attention to samples and

Jan 1, 1982

By G. P. White, J. M. Jones

Introduction Computer simulation is a technique that has been around for many years. Its applications include designing steel mills, planning space shots, or even developing ways to beat the casinos in Las Vegas. However, the use of computer simulation in surface coal mining is fairly recent. To promote its use, several government agencies, including the US Bureau of Mines, Forest Service, and Department of Energy, contracted with universities and private companies to develop computer simulation programs for surface coal mining. Some of these developers include McDonnell-Douglas Electronics Co., Pennsylvania State University, Montana State University, Fluor Mining and

Jan 1, 1985

By E. J. Haug, M. M. Fine

For several years work has been carried on by the U.S. Bureau of Mines at Rolla, Mo., to develop improved methods of concentrating the oxidized ores of lead and zinc. Various samples have been investigated, and results on some have been published. Details of the progress to date are given in a mineral dressing study now being conducted for an extensive oxidized lead-bearing tract in southeast Missouri, property of St. Joseph Lead Co. These oxidized ores present problems typical of many encountered in modern mineral dressing research in that recovery of very fine particles is of

Jan 4, 1955

By Ronald J. Roman

All mining and milling complexes can, within limits, operate at a variety of production rates. Factors of economic importance that are affected by production rates are costs per unit production, recovery, and product grade. Once the relationship between the production rate and cost is established, dynamic-programming techniques can define the optimum production schedule (i.e., the production schedule that maximizes the present worth of the operation) for the life of the deposit. In general, the optimum production rate is not constant for the life of the deposit, but declines gradually as the deposit is being exhausted.

Jan 1, 1972

By L. W. Saperstein

Public Law (PL) 95-87 contains explicit demands for land use planning in its reclamation and designation sections. Both sections require recognition of local land use plans; however, they are not well integrated. Accommodation to these planning requirements affords an opportunity to create better links among local land use planners, the state's permitting authority and designation office, and mine designers. Mining companies should take a more positive interest in local land use plans and in resource inventories. States should coder handing down to local government the responsibility for accepting mine permit applications and designation of unsuitability petitions.

Jan 1, 1984

By John H. Bassarear

By 1968, Cyprus Pima was milling 34.5 kt /d (38,000 tpd) of copper ore using a conventional flowsheet consisting of three stages of crushing, rod milk and ball, mills. A 13.6 kt /d (15,000 tpd) expansion was put onstream late in 1971 using primary crushing, semiautogenous milk, and ball mills. Identical ore is treated in both concentrators. This paper shows the weight and life of each liner for each crusher and each mill over a four year period from 1974-1977. Media consumption is shown for the same period and a comparison is made between the two reduction methods.

Jan 1, 1983

By Carl R. Davis

The cost of mining during the past history of these mines has been excessive, principally by reason of the inefficiency of labor under the wage-system. The amount of labor performed per man was unsatisfactory; and Mr. Edmund B. Kirby, the general manager, decided to adopt the contract-system as a remedy. For this purpose the method now in use was devised by the writer (then and now the superintendent), as best adapted to the local conditions. On March 12, 1900, this system was presented to the miners of the War Eagle and the Center Star. The issue remained unsettled for several weeks,

Jan 1, 1902

By Thomas A. Earl

Much of the strip mining in the Appalachian coalfields was done prior to backfilling and regrading requirements, resulting in many devastated areas which also have serious acid mine drainage problems. Economic incentive or justification for reclaiming these thousands of acres of land does not exist unless some value can be attached to the open cuts and weathered overburden piles. In Pennsylvania many of these old strip mine cuts are being successfully used for sanitary landfills and sludge disposal sites, and multiple benefits are realized. Given proper regulatory control, this technique could be beneficially applied to many other areas in the east.

Jan 1, 1977

By John Dasher

Chemical processing is descended from alchemy, which developed our major lixivants. The profession might have done more if it had been less preoccupied with turning base metals into gold-a process that still hasn't been developed. Georg Agricola, over 400 years ago, gave us ten recipes for "aqua valens" to part gold and silver, and described cementation of gold and silver on base metals. His text stood for 200 years, by which time heap roasting, leaching and cementation were winning copper from pyrites at Rio Tinto and the Barba furnace was distilling mercury from the ores of Almaden.

Jan 1, 1971

By L. S. Deitz

This part of the symposium deals with the problems encountered by the consumer of nonferrous scrap, that is, the smelter and refiner who melts the selected scrap items and produces foundry ingots of specified compositions or billets for rolling or extrusion in nonferrous mills. The fundamental problems are quite similar for all secondary' nonferrous metals. However, these remarks will be confined to the copper-base alloys since in the sorting, melting and refining of these alloys probably all the usual types of problems are encountered; in addition, papers are being presented later on secondary lead, zinc and aluminum. While metallurgical

Jan 1, 1943

What has been billed as the underground drilling technology of the 1980's got a dramatic head start when Boliden engineers at Stekenjokk decided to go with all hydraulic drilling for primary ore production and mine development. This application represents a major first in meeting the needs of high productivity, better energy utilization, and an improved drilling environment. At Stekenjokk, engineers chose three Atlas Copco Boomer H132 two-boom electro-hydraulic drill rigs with the COP 1038 rock drills. An additional single-boom Boomer H131 was also selected with the COP 1038 HD for roof bolting functions.

Jan 12, 1977

By T. Kusakawa

In Japan, natural gypsum is rarely mined for industrial use and almost all gypsum is synthetic, that is desulphogypsum, produced from waste sulphur dioxide gas from metal smelters and power plants and other industrial waste sources. The amount of synthetic gypsum production (1979) reached more than 6 Mt/a (6.6 million stpy). Major uses are for cement and building materials. Other uses include soil conditioner, investment casting molds, and organic composite materials. Sulphur recovery by gypsum decomposition is being examined. This paper summarizes present Japanese production and uses of synthetic gypsum produced from industrial wastes.

Jan 1, 1984

By E. J. Haug, M. M. Fine

FOR several years work has been carried on by the U.S. Bureau of Mines at Rolla, Mo., to develop improved methods of concentrating the oxidized ores of lead and zinc. Various samples have been investigated, and results on some have been published 1,2 lished.l, 2 Details of the progress to date are given in a mineral dressing study now being conducted for an extensive oxidized lead-bearing tract in southeast Missouri, property of St. Joseph Lead Co. These oxidized ores present problems typical of many encountered in modern mineral dressing research in that recovery of very fine particles is of

Jan 1, 1956