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Jan 1, 1929

Jan 1, 1929

Jan 1, 1914

Jan 1, 1904

By GILBERT E. SEIL

GREAT advances in the preparation of ores for reduction to ferro-alloys have been made, although standard methods of reduction have been continued at most plants. Efficiencies, yields per furnace, and energy requirements per ton are generally better than previously attained. The advantages of sizing and conditioning of ore, fluxing stone, and coke have been realized. Conditioning varies from drying the furnace burden to chemical rearrangements to facilitate reduction reactions and sometimes to furnish some of the energy required for the reaction before the burden reaches the furnace. During the war period it is impossible to discuss in detail many of the advances made. They are subjects for postwar papers. However, the new procedures mentioned in the following paragraphs are indicative of the work already done and in progress.

Jan 1, 1944

By Alfred F. Brainerd

A few months since, Prof. Lawrence C. Johnson, of the U. 8. Survey, discovered in Mississippi large deposits of carbonate iron-ore, geologically located in the Claiborne formation of the Tertiary Epoch. These deposits are not pockets, but continuous layers or beds extending for miles, and can be located with certainty where they have not been removed by erosion. Upon examination, recently made by G. W. West, Birmingham, Ala., the largest deposits and highest grades of ore were found near Enterprise, Lauderdale county, and in Clark county, Miss. These beds measure from 10 to 18 feet in thickness, are superimposed upon a " burr rock," associated with green sand, and dip 30 feet to the mile southeast, at an altitude of 350 feet above sea-level, can be

Jan 1, 1888

Jan 1, 1896

By Rudolph G. Wuerker

With stepped-up work in rock mechanics, more and more data on strength and elastic properties of rocks has become available. Results of measurements of tensile strength, in addition to determinations of compressive strength, allow us to deter- mine, even if only in an approximate way, the third property influencing failure of a brittle material: shear strength. It is fairly generally agreed upon in rock mechanics, in drilling and blasting research, that Mohr's theory provides an acceptable method for explaining the failure of a brittle material. Mohr states that a material may fail either 1) through plastic slip when shearing stress Y in the planes of slips has reached a limiting value (which in general depends on the normal stress, X, acting normal to the surface), or 2) when the largest normal tensile stress has reached a limiting value. The mode of failure depends upon which of the two stresses is the smaller.

Jan 10, 1959

RESOLUTION ADOPTED BY THE BOARD OF DIRECTORS AT ITS MEETING ON APRIL 17,1936 AND AMENDED ON MAY 21, 1947 Recognizing the fact that the problems of the committee named by the Board to prepare the "official ticket" for officers and Directors of the Institute are various and difficult, and desiring to assist this committee by setting forth some of the principles that should guide the committee and some of the qualifications that should be required of candidates, the following instructions are formulated and the Secretary is directed to publish them in MINING AND METALLURGY concurrently with the publication of the names of each newly appointed Nominating Committee and to send a copy to each member of the Committee

Jan 1, 1952

WE the undersigned, being all persons of full age and citizens of the United States, and a majority residents of the State of New York, desiring to form a corporation pursuant to the provisions of the Membership Corporations Law for the purpose of incorporating, as provided in Section 6 of Article I. of said law, the existing unincorporated association known as American Institute of Mining Engineers, do hereby make, acknowledge and 6le this Certificate for that purpose, and do Certify as follows: I. That the American Institute of Mining Engineers is an unincorporated association organized and existing with the object of promoting the arts and sciences connected with the economic production of the useful minerals and metals and the welfare of those employed in these industries by means of meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members and associates the information thus obtained. 11. That the persons duly appointed or designated to manage the affairs of said association are designated by the rules thereof Members of its Council; that the under- signed are all members of said Council as the same was constituted on the 29th day of December, 1904.

Jan 1, 1939

This is a brief account of the history of unit operation in the Salt Creek field, Wyoming, from the time of the agreement to prorate production in March, 1921, to the present. An attempt has been made to evaluate the savings in development and production costs resulting from the unit plans adopted. Summarized, these savings have amounted to $11,650,000. No effort has been made to estimate any increase in ultimate recovery, for it is believed that unit operation can be justified on saving in development and production costs alone. It would require nearly 20,000,000 barrels of additional oil to be produced in order to return the amount saved by not drilling unnecessary wells. Four horizons are affected by unit or near-unit programs, as follows: The principal operator is under contract with six companies to operate 10,400 acres. This includes all of the productive area of the First Wall

Jan 1, 1930

By J. F. Lewis

BELIEVING that one of the essential points in mining, as in all other business, is to know the expense incurred in each particular department, I have carefully kept an account with each department for the past three years; and, as it may be of interest to some of our members, I herewith present it to the Institute, reduced to percentages of the total yearly expense, showing the cost for materials, repairs, expenses, tools, team accounts, powder, oil, and fuel, also for labor under its several heads :

Jan 1, 1878

After a three-year period characterized by inflation, recession, depressed metal prices, lack of demand, enormous world inventories, and rapidly escalating costs, the Canadian mining industry is showing welcome signs of recovery. A rise in world metal prices and particularly strong demand for gold, uranium, and coal have stimulated the industry in early 1979. In this atmosphere of growing optimism, over 3000 mineral industry executives, economists, geologists, and mining and metallurgical engineers convened in Montreal, April 26-29, for Canada's largest mining convention, the Annual General Meeting of the Canadian Institute of Mining and Metallurgy.

Jan 6, 1979

Jan 1, 1947

Jan 1, 1896

Surface mine operators often gamble that the savings gained from elimination of haul-road subbase preparation will offset any potential loss in production due to deteriorating roads. According to the authors of a manual on haul-road construction, this practice yields results that are almost always undesirable. The lack of suitable weight-bearing material under the road surface permits extensive rutting, sinkage, and overall deterioration of the roadway, and a great deal of maintenance work will be needed to keep the road usable. In addition, say Walter W. Kaufman of Skelly and Loy, and James C. Ault, USBM Pittsburgh Mining and Safety Research Center, adverse road conditions pose a serious threat to vehicular controllability and create unsafe haulage road segments.

Jan 3, 1978

By Fred H. Klaer

Water supplies dependent upon induced infiltration can be developed by vertical wells, by infiltration galleries, or by horizontal water collectors. Each method is described and the advantages of water obtained by induced infiltration with respect to cost, chemical quality, and temperature are shown by specific water supplies. THE subject of ground water in industry is assuming increasing importance as new processes and new industries are developed. Industrial specifications of chemical quality and temperature for process water and for cooling purposes are becoming more rigid, and water must now have many properties to meet these requirements. As ground water is usually more constant in quality and temperature, many industries are turning to ground-water supplies to satisfy their growing need. As many published articles have stated during the past several years, the ever increasing demands have caused shortages of water supply in many localities throughout the United States. Although such shortages are generally of a local nature, they have given rise to many attendant problems, such as increased pumping costs, salt water encroachment, and rising ground-water temperatures. One partial solution to the problems of overdevelopment of the ground-water reservoirs in many areas can be accomplished by developing ground-water supplies that are dependent upon induced infiltration and by planning the use of underground reservoirs. These reservoirs can be filled during periods of excess precipitation and stream flow and can be emptied during periods of drought, in a manner similar to the use of surface reservoirs. In this way water that otherwise would be wasted into the oceans is salvaged during periods of excess. The development of water supplies dependent on induced infiltration is a relatively new concept and should be defined. When a well is pumped, the water level around the well is lowered in the shape of an inverted cone or cone of depression. As pumping is continued, the cone of depression will continue to expand, horizontally and vertically, until the quantity of water crossing the perimeter of the cone plus the recharge within the area of the cone is equal to the quantity of water being pumped.

Jan 1, 1954

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's ability to respond to national energy needs?

Jan 12, 1979

By SME

"Comparison of Secondary Fe-Mn Oxides in Fracture Coating and Heavy-Mineral Concentrates as Sampling Media, Silver City Mining Region, New Mexico," a technical paper, appeared in the Aug. 1983 issue of the magazine. In Table 1, page 1182, the correct sequence of the first five metals in column 1 (Elements) should read: Zn, Pb, Cu, Fe, and Mn under "Central District" and Zn, Fe, Pb, Cu, and Mn under "Pinos Altos District." The published table shows the sequences transposed under the opposite districts. All other columns and sequences read correctly.

Jan 1, 1984

By J. H. Frye, D. L. McElroy, E. E. Stansbury

The rates of growth of pearlite in high-purity Fe-C alloys have been measured as a function of the transformation temperature. These and other data have been correlated in terms of a derived rate equation. Activation energies for the growth were found to be 24,200 cal per mol of austenite for the 0.78 pct C alloy and 27,600 cal per mol for the 0.93 pct C alloy. Theoretical implications are discussed. AN excellent review of the the theoretical and experimental studies on the mechanism and kinetics of the eutectoid reaction has been presented recently by Mehl and Dube.' They have pointed out that these investigations have followed two lines of approach: 1—experimental studies and derivations of expressions for the overall transformation characteristics, and 2—derivation of expressions for the nucleation and growth rates in terms of fundamental processes. Investigations of the latter type have been concerned for the most part with the nature of the growth at the austenite-pearlite interface in plain carbon and alloy eutectoid steels. They discuss two theories of the rate of growth of pearlite from aus-tenite—those of Brandt and of Zener. Both derive rate equations which are based on the assumption that carbon diffusion is the controlling mechanism. Mehl and Dube,' Zener,2 and Brandts. " have attempted to calculate growth rates by use of these equations together with thermodynamic and diffusion data. The results are encouraging, but agreement is not so good as to constitute verification of the theories. Furthermore, it Is not clear how these equations are to be used to study the effect of alloying elements which apparently exert little influence on carbon diffusion, but markedly decrease growth rates. It is not clear whether or not the addition to iron of an alloying element which does not diffuse during transformation can alter the rate of growth of body-centered from face-centered cubic iron. That it can greatly decrease the overall transformation rate has

Jan 1, 1954