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Jan 1, 1887

Jan 1, 1942

By Harold N. Underhill

Larger equipment, more attention to maintenance, new types of bits, radio communication, and advances in jet piercing highlight an active year.

Jan 3, 1951

INTRODUCTION The mineral sample is the fundamental unit upon which the mineral appraisal is built. Values derived from the sample are the most important quantitative measurements made in the total evaluation process. The sample value

Jan 1, 1980

Jan 1, 1905

By J. R. Sturgul

Two problems which are common to nearly every branch of applied physics, including geophysics, are the ‘Dirichlet Problem’ and the ‘Poisson Problem.’ A numerical method for their solution is derived and a problem of heat flow in a plate is solved using a high-speed digital computer. The solution to this problem is presented in a form which illustrates the versatility of computer output.

Jan 1, 1969

Coal Division Industrial Minerals Division Minerals Beneficiation Division Mining, Geology and Geophysics Division OFFICERS AND COMMITTEES S D Michaelson, President J W Woomer, President-elect Elmer A Jones, Past President C E Lawall, Eastern Regional Vice-President G Donald Emigh, Central Regional Vice-President J D Forrester, Western Regional Vice-president R B Ladoo, Treasurer John Cameron Fox, Secretary

Jan 1, 1958

By William P. Blake

A recent paper by Prof. George P. Merrill, Curator of the Department of Geology of the U. S. National Museum, Wash-

Jan 1, 1897

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 Ross C. Anderson, William I. Weisman

THE manufacture of anhydrous sodium sulphate or salt cake from natural deposits in the United States has been in general somewhat of a marginal undertaking. Competition from foreign sources and from large quantities of byproduct sodium sulphate produced domestically in the manufacture of hydro-chloric acid and other chemicals has existed and continues.

Jan 7, 1953

By Victor Phillips

Cyclone thickeners have emerged from the development stage and now can be accepted as useful tools for the recovery of fine coal from a preparation plant circulating water. As primary thickeners in a closed water circuit operation, their advantages over conventional thickening methods are twofold-the lower initial investment and reduced area requirements.

Jan 8, 1951

By Roswell Johnson

THE prevailing system of wells on a rectangular basis, as shown in Fig. 1-A, has developed because of the exigencies of offsetting at boundary lines. When, however, a very large tract is, being drilled, it is often possible to abandon this inferior method for the superior arrangement C- PROPER STAGGERING FIG. 1.-THREE SYSTEMS OF SPACING WELLS. known as "staggering," which is illustrated in Fig. 1, B and C. The advantages of the triangular over the rectangular method are evident from Fig. 2, computed on the basis of one well to 10 acres (4 ha.). With the triangular system, no land is more than 409.4 ft. (124.8 m.) from a

Jan 8, 1918

By L. Alan Weakly

Abstract-The Bureau of Mines has pursued a program of research on mine illumination that has defined the coal miner's illumination needs. St. Joe Minerals Corporation, recognizing the need for improving the illumination of the working places in their mines, entered into a cooperative research agreement with the Bureau of Mines to utilize the Bureau's expertise in this field. Some similarity in the environment, in which coal and hard rock miners work, has allowed the application of developed coal mine illumination technology and equipment to be utilized in hard rock, room and pillar mines.

Jan 6, 1978

By J. R. Eickmeier

Jan 1, 1914

By C. C. Bailey

THE vendor seeking outside capital for his project has the following potential sources which may be approached; 1--private sources, 2-institutional funds, 3--government agencies, 4--established mining concerns, and 5-public financing.

Jan 7, 1953

By Tayler H. Bingham

Personal consumption expenditures represent roughly two-thirds of total of GNP. While these expenditures directly account for only a small portion of total natural resource consumption, they account for a significant proportion indirectly. The reason is that all economic activity can be shown to be interrelated and that the intermediate production sectors, which are the primary users of natural resources, represent the interindustry transactions necessary to produce all final goods, including consumer goods. This paper provides a discussion of the methodology and quantitative estimates in physical units of the interrelationships between 15 major nonenergy resources and 6 energy resources and 477 personal consumption expenditure items.

Jan 1, 1977

Executive SIDNEY J. JENNINGS, Chairman GEORGE D. BARRON J. E. JOHNSON, JR. EDWIN LUDLOW ROBERT-M. RAYMOND Membership LEWIS W. FRANCIS KARL EILERS, Chairman J. E. JOHNSON, JR. LOUIS D. HUNTOON ARTHUR L. WALKER Finance GEORGE D. BARRON, Chairman CHARLES F. RAND BENJAMIN B. THAYER Library E. GYBBON SPILSBURY.1 Chairman. ALEX C. HUMPHREYS3 GEORGE C. STONE2 J. H. JANEWAY4 BRADLEY STOUGHTON Papers and Publications BRADLEY STOUGHTON, Chairman

Jan 2, 1919

By Adrian Brown

Over the last decade, a number of large slopes have been excavated in rock which contains families of joints or faults which dip steeply into the cut slope. Despite the absence of "adverse" structures, these slopes have exhibited alarming movement rates at very modest heights (as little as 100 meters) and slope angles (as little as 20º). Classical stability analysis suggests that such slopes should be unconditionally stable. This paper describes the toppling mechanism which has been found to be the cause of the observed movements and develops a general method for analysis of it. Simple cases are analyzed in order to provide charts which allow quick evaluation of the likelihood of this phenomenon occurring. The safety implications of such movements in slopes are also examined.

Jan 1, 1982

By M. J. Coolbaugh

Standard Metals Corp.'s mining and milling operation at Silverton, Colo., has found that it can justify the use of a large computer system entirely on the basis of cost savings, and at the same time receive the benefits of speed, greater accuracy, and valuable data otherwise unobtainable at a reasonable cost. The Silverton operation consists of the historic Sunnyside mine and Mayflower mill, about 300 miles southwest of Denver, which produce about 700 tpd of a complex lead-zinc ore. This operation has not yet tried to use its computer for large, involved programs such as optimizing the efficiency of an operation, linear programming, or determining economic ore limits, although these are certainly within the capability of the equipment. However, there have been enough money-saving applications in the everyday routine to justify the use of this computer system, even before branching out into the more unusual or complex problems.

Jan 8, 1968