Search Documents

By Will Mitchell

There are in this country some 20 or 30 societies for engineers and engineering scientists. Most of these organizations are autonomous, and there is little or no cooperation among them. Many do not touch the lives of our Institute members. However, during the course of the years several societies closely associated with the AIME have banded together to handle specific situations where cooperation was necessary. It is believed by many engineers that the functions of these cooperative societies should be analyzed and a plan set up to unify the engineering profession into an organization similar to the American Medical Association and the American Bar Association. The preliminary study of the AIME Committee for Inter-Engineering Society Cooperation has indicated that the following organizations bear upon the professional lives of our members. Some of these are federated groups, such as EJC and ECPD; others are individual-member participation groups, such as the Founder Societies and NSPE.

Jan 10, 1960

By Arvid Holst Mortensen

The rational exploitation of deposits for cement manufacture requires evaluation of the material, the planning of the quarrying and the right choice of quarry machinery. By using a computer for all evaluations and planning work the optimal recovery of material is arrived at and a quarry layout - and machinery is decided upon. The result will be uniform production throughout the lift of the deposits using a rationally chosen quarry equipment.

Jan 1, 1977

By U. K. Custred

To the layman, the term "strip mining" usually applies to the appearance of mined-over land after an operation is completed, not to the technique. This attitude, however, is becoming pass6 in the central Florida pebble phosphate field as eight mining companies in the area pursue a mutual program of land reclamation. The Florida phosphate industry is fortunate in this respect because it occupies an area favorable to reclamation. The terrain is flat; overburden is sand and clay which will support vegetation fairly readily; a high ground water table naturally converts mine pits into lakes. Too, this is water which readily supports marine life, not the acidic water so frequently found in the coal industry.

Jan 4, 1963

By M. Allingham

This paper examines the contribution which econometric methods may be expected to make to the specification of commodity agreements, and how in turn computer methods may help in this. Starting from the specification of a model, the paper examines four activities: estimation of the unknown parameters; analysis of the properties of the model; simulation experiments with the model; and control of the model. In each of these activities the basic methodology is outlined, and the contribution of computer methods assessed.

Jan 1, 1977

New York Meets first Wednesday after first Tuesday of each month. J. E. JOHNSON, JR., Chairman EDGAR RICKARD, Vice-Chairman D. MI. LIDDELL, Secretary, 7 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. R. L. AGASSIZ, Chairman JAMES G. CARLETON, Vice-Chairman E. E. BUGBEE Secretary-Treasurer, Mass. Inst. of Technology. Cambridge, Mass. W. E. C. EUSTIS G. A. PACKARD 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 8, 1917

By Donald W. Jenkinson

Many types of gravity concentration equipment have been employed throughout the years since beneficiation of materials has been practiced. These include jigs, concentrating tables, vanners, sluice boxes, heavy media cyclones, and static heavy media separators or sink-float separators. In the beneficiation of coarse aggregate for concrete mixes, static heavy media separation employs the same principles of gravity concentration involved in separating lead-zinc ore, dolomite, limestone, diamonds, manganese, iron, and many other minerals. In aggregate beneficiation, as in most metallurgical operations, sink or heavy fraction is the product. The undesirable portion of coarse gravel is usually much lighter than the desirable particles, allowing most aggregates to be amenable to gravity concentration methods.

Jan 7, 1960

W. O. OWEN,* Washington, D. C. (written discussion?). Few people appear to realize that the time to reach the crippled soldier is when he is first hurt. In my own judgment, the best time to reach him is before he is hurt, by showing him what other cripples have themselves clone of their own initiative, without Government-support, rendering themselves self-supporting, able to bear a little bit more than their own weight, so that they may lay aside a little bit for a rainy clay and some for a little fun in

Jan 5, 1918

By F. H. McDowell

About a year ago Dr. Raymond, as engineer of Messrs. Cooper, Hewitt & Co., together with Mr. Rothwell, was considering the removal of the ore-floors and pillars from the Peters Mine at Ringwood, N. J., where the limit of profitable working by the old method of mining had been very nearly reached. Mr. Ferdinand Ruttmann was engaged to make the survey which forms the basis of the accompanying diagrams. At first it was thought that some method of mining and filling might be introduced with advantage; but after a careful study of the operations at the Tilly Foster it was decided to adopt the system of stripping.

Jan 1, 1890

Jan 1, 1937

By Robert B. Hill

A history of gravity classification shows the development of many types of equipment with several prominent types continuing in use today. Part of the development and evolution is the spiral classifier. Data will be presented showing characteristic size separations in a closed circuit grinding operation. Comparisons with hydro- cyclone operation will be shown including operating cost comparisons. Effects of variables will be shown in spiral classifier operation. Finally, other uses for spiral classifiers will be described.

Jan 1, 1982

By W. N. Marchant, P. T. Brooks, P. B. Altringer, R. O. Dannenberg

The US Department of the Interior, Bureau of Mines conducted laboratory tests to devise a process for recovering a marketable grade of tungsten from the brine of Searles Lake, Calif. The brine contains only 56 ppm W (70 ppm W03). Using ion exchange resins synthesized by USBM chemists, 98% oft he tungsten was extracted from the brine and 92% of the tungsten was recovered as a marketable iron-tungsten concentrate containing 44% tungsten as tungsten trioxide. Although major technical problems have largely been resolved, research is progressing to escalate testing in a process research unit to provide more reliable data for an economic appraisal.

Jan 8, 1979

By M. J. Miller

In modern mill design, a stockpile storage system for raw and/or semiprocessed ore has become almost indispensable. This paper discusses the benefits of such stockpile storage as well as the available types of belt conveyor stockpiling units. Alternative reclaiming arrangements for stockpiles are reviewed, and the advantages and disadvantages of each arrangement are discussed.

Jan 1, 1982

By W. R. Ingalls

SOME months ago, I had occasion to make an investigation that introduced the subject of blue powder that is produced as a byproduct in zinc dis-tillation. Although every zinc smelter is aware that more or less blue powder production is inevitable and there is a common practice as regards the treatment of it, the specific and quantitative data respecting the subject were more imperfect than would have been expected. I had reports from eight important works. Some of the data were especially determined for my investigation. Speaking generally, there is a good deal of uniformity in the figures, all of which show that the blue powder product, bears a large proportion to the ore originally charged into the retorts; that a large proportion of the retort capacity is devoted to the redistillation of blue powder; and that of the spelter product of a furnace about 30 per cent. is derived from blue powder, i.e., it is zinc that has been distilled twice. The figures from the works are given in the following table:

Jan 4, 1922

By K. Osseo-Asare

LIX63 In combination with DNNS selectively extracts nickel and/or cobalt from acidic leach liquors with pH values as low as 10 Nickel/cobalt and cobalt/nickel selectivities are achieved by varying the relative concentrations of LIX 63 and DNNS Increasing LIX63 concentration retards both extraction and stripping rates while DNNS has the opposite effect. Slope analyses of equilibrium data Indicate that both LIX63 and DNNS are present in the extracted complexes. Examples of possible flowsheets are presented.

Jan 1, 1981

By H. Sato, I. Matsuoka, T. Kawai, S. Hasebe

In a limestone mine, a large amount of slime is washed off in order to remove impurities such as clay minerals. A fine sized calcite is, consequently, wasted and freight for carring the slime to reclaim land is expensive. The separation of calcite from the slime has been investigated by the flotation process, using sodium oleate as a collector. A satisfactory flotation of calcite from the slime requires great amounts of sodium oleate, because sodium oleate is consumed by clay minerals. But, the amounts of sodium oleate required are reduced to half by adding suitable amounts of sodium silicate. After rougher and cleaner flotation, the concentrate containing more than 97% calcite is obtained with 70% recovery; thereby the amount of slime to be reclaimed is reduced to 40%.

Jan 1, 1976

H. N. EAVENSON, Gary, W. Va.-Judging from our own experience, the statement that only 40 per cent. of the accidents are caused by the human element is very low. We have adopted all the measures that Mr. Wilson recommended, such as systematic timbering, use of permissible expolsives and practically everything that anybody has suggested or can think of, and even after all that has been done, done for several years, and a systematic campaign maintained all the time to reduce accidents, we still

Jan 4, 1918

By Christopher Haycocks, Lawrence P. Johnson, George M. Neall, James M. Townsend

No method of roof control yet devised has proven to be universally acceptable for the wide range of strata conditions experienced in U. S. coal mines. However, a relatively new innovation, the roof truss, has proven itself capable of preventing roof failures which both conventional and resin bolting could not. Presently, the economics of roof trusses are not favorable when compared to bolting due primarily to drilling and installation procedures, but this is expected to change with improved truss and equipment designs. To realize the full potential of this new method of roof control, design criteria are needed which can optimize the effect of the truss for varying strata conditions.

Jan 6, 1978

[ ]

Jan 1, 1938

By P. Sen

Frequently during the processing of minerals very fine particles are generated which are difficult to recover by conventional separation techniques and are rejected with waste water from mills. A method has been evolved for the continuous recovery of such fines by allowing the suspensions to flow through a rotating cylinder. Theoretical analysis of the trajectory of particles have shown that the efficiency of separation increases with R.P.M., tube diameter, particle diameter and density. Experiments carried out with the overflow from a hydrocyclone containing particles in the size range of 2-10 microns gave a separation efficiency of 60-70% with an R.P.M. of 3500 of the rotating tube.

Jan 1, 1980

LOCAL SECTIONS (There are 60 Local Sections in the United States, 4 Foreign ) ADIRONDACK Established June 18, 1952 Paul W Allen, Chairman William Webb, Vice-Chairman Edwin Briggs, Secretary-Treasurer National Lead Company Mac Intyre Development Tahawus, New York Paul W Allen, Section Delegate R G Fleck, Alternate Section Delegate

Jan 1, 1954