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By Raymond E. Zimmerman

Abstract-The Swirl Cyclone developed in Japan, although based upon the same principles as the standard cyclones for heavy-media or water-only cyclones for cleaning coal, is novel in that it is invested with the apex on top, discharging rejects at the top, and clean coal at the bottom. It also uses a variable air vent tube for controlling the vortex. Tests conducted indicate that its efficiency is not only as sharp as standard cyclones but it also performs using a much coarser grain magnetite, promising higher magnetite recovery. The author describes the results of tests conducted in Japan on a very difficult coal.

Jan 2, 1978

By T. H. Miller

THE CHAIRMAN.-This session has to do largely with the question of specifications and conservation as regards secondary metals produced from scrap. We are all familiar with the many varieties of scrap metals and the astonishing number of secondary metals of various specifications produced from the treatment of those scraps. The impact. of the war on this industry has required a great many changes in the types of secondary metals produced from scrap, and in their utilization. In the short period available we cannot cover very much of this field, but we do hope to give you through the various papers a brief introduction to some of the principal problems. Mr. James S. Earle will present the first paper. Mr. Earle:

Jan 1, 1943

By Bryan Denby

The curvilinear nature of shear strength envelopes for rock discontinuities may be simply and precisely represented by a power curve. The development of shear strength criteria applicable to rock discontinuities is reviewed and related to a theoretical basis for curvilinearity. An approach is reported to enable the quantification of the two power curve indices using a nomogram based on empirical studies. Using a knowledge of discontinuity basic friction angle and peak dilation angle the relevant indices ranges may be predicted for mine slope studies.

Jan 1, 1984

By W. Mostowitsch, H. O. Hofman

In our investigation of the Behavior of Calcium Sulphate at Elevated Temperatures with Some Fluxes,' we incidentally studied the decomposition of ferric oxide when heated in a current of dry air. We found that at 1,500° C., with 15-min. periods of heating, Fe²,O³, hardly changed in weight, the greatest loss being 0.23 per cent., and we therefore concluded that the compound remained unchanged at 1,500° C. in a current of dry air. In a more recent experiment we heated Fe²,O³, in a current of dry air and found that there was a decided loss in weight. A new investigation upon the behavior of Fe², O³, using a larger amount of substance and heating for a longer period of time, revealed the fact that a measurable dissocia-

Jan 1, 1910

Prior to World War I, zinc was universally made by the distillation process. Small plants were operated at Cockle Creek, N.S.W., and Port Pirie, S.A. Then the electrolytic process was developed at Great Falls, Mont., in 1915 and at Trail. B.C. encouraging the Broken Hill companies to investigate the process. England's war-time need for zinc gave impetus to the development, and the site at Risdon, Tasmania, coincided with the developing hydro-electric power there. Experimental work was begun in 1917 by a proprietary company formed and owned by Broken Hill interests. Then in 1920, the principal features of the process having been established, a public company. Electrolytic Zinc Company of Australasia Ltd. was formed, now known as E.Z. Industries Ltd.

Jan 10, 1964

The saying that a "prophet" is without honor in his own country does not always hold true, as is shown by the following from one of the local papers, which appeared under the above heading: "Edwin Ludlow, for more than seven-years vice-president of the Le-high Coal.& Navigation Co., with headquarters in Lansford, has resigned, to take effect July 1, when he will take up his residence in New York and engage as a consulting engineer. Mr. Ludlow, during the incumbency of his present position, has demonstrated his efficiency as an engineer and general manager in many directions, notable among which are the almost perfect methods in practice in the inside workings of the several operations under his charge and the erection of the most complete, most practical and most commodious breakers for the preparation of the mine product for market. In addition, his relations with organized labor have been cordial and his dealings with its representatives have been invariably based upon the principle of fair play."

Jan 7, 1919

By Herbert Lang

Cord-wood, sawn into blocks of about a foot in length, is a regular constituent of our fuel-charge at Mineral, Idaho, our work being the matting of silver-ores by fusion in a blast-furnace. The furnace is a round water-jacket furnace, of 36 inches diameter at the tuyeres, and the charge of smelting-mixture weighs 950 Ibs., requiring 110 Ibs. of Connellsville coke to drive it. I replace half this coke with 135 lbs. of fir-wood, cut from dead and apparently perfectly dry trees. This mixtrire produces as high a sn~elting-temperature as all coke, whence I infer that the smel ting-effeot of a given weight of wood is to that of the same weight of coke as 11 to 27, or 1 to 25/11. A cord of wood sawed ready for use weighs 2840 lbs., costs $5.00, and is

Jan 1, 1892

A rotary chambered blasthole technique has initially indicated a 30% overall improvement in drill and blast department productivity. The method, developed at several open pit copper mines in Arizona, centers around a chambering tool that can be used with existing high-speed rotary drills. The "Chamber Maker," manufactured by the Servco Div. of Smith International, Inc., produces an enlarged section or chamber near the bottom of a large diameter blasthole (Fig. 1). This enlarged cavity permits a greater concentration of explosives at the bottom of the blasthole, resulting in better fragmentation and reduced hard toe problems, and also lowers the number of blastholes required to break a bench area, says Servco's Gerald W. Laswell. Cost savings can therefore be achieved in reduced secondary blasting requirements, increased shovel efficiency, and subsequently, less shovel maintenance. All these factors would serve to lower the overall mine cost per ton figure

Jan 3, 1975

By E. O. Fromm, R. I. Jaffee, R. M. Evans

IN connection with a research on gallium alloys, a method for the thermal analysis of very low melting alloys was developed, which appeared to be worthy of more than passing interest. As used, the method was suitable for work in the temperature range, — 72° to 250°C. However, with suitable adjustment, the method could be adapted for use over broader temperature ranges. The Rosenhain temperature gradient furnace,' adapted for low-temperature use, was the basis for the method. The gradient was set up in a stainless steel tube. The specimens were lowered through it at a constant rate while time-temperature or inverse rate data were taken. It was essential to maintain careful control of the top and bottom temperatures of the gradient. Also essential was good heat transfer from the walls to the specimen. This was accomplished by a liquid heat-transfer medium.

Jan 1, 1953

By H. D. Kiddle

IN mining in Malaya has been a courageous ad- venture in private enterprise, attended by all the hazards of prospecting in unexplored areas of tropical jungles-jungles that still cover four-fifths of the country. To assess the contribution of an industry to a country's revenue, it is necessary to consider not only duties levied on the products, but also the revenue from all businesses and individuals directly and indirectly deriving income from the industry. Exact figures are not obtainable, but from 1850 until shortly before the first World War, tin mining in Malaya was a dominant factor in the Federation's development. Even at the turn of the century, tin export duty alone represented 45 pct of total Government revenue, while in the 40-year period up to the end of 1937, tin ore duties collected by the Federated Malay States Government amounted to 383,- 81 0,284 Malayan dollars,* approximately one-fifth of the total revenue for the same period.

Jan 11, 1957

By James Douglas

Once—and fortunately only once—before this occasion, was it my sad duty to express the loss we had sustained in the death of an eminent member. Dr. T. Sterry Hunt* was a student of chemistry who, by his investigations into the properties of the elementary bodies, had assisted emineiltly in the progress of the technical arts, and, more than any American of his generation, had helped to lay the foundations of chemical geology. William Earl Dodge, whose death we deplore to-day, occupied a rank not les~ importaiit in the army of industrial workers

Jan 1, 1904

PERSONAL (Members are urged to send in for this column any notes of interest concerning themselves or their fellow-members.) Members and guests who registered at Institute headquarters during. the period May 10 to June 10, 1915: Robert M. Keeney, Somersville, Conn. C. A. Moffett, Birmingham, Ala. Emilio Mosonyi, San Salvador, C. A: A. W. G. Wilson, Ottawa, Canada. Junjiro Nagazumi, Fukuoka, Japan. G. H. Glover, Jr., Short Hills, N. J. Francis R. Pyne, Elizabeth, N. J. R. W. Brock, Vancouver, B. C. F. C. Alsdorf, Los Angeles, Cal. J. L. W. Birkinbine, Philadelphia, Pa. W. J. Loring, London, England. Roy H. Allen, Jamesburg, N. J. R. A. Bull, Granite City; 111. Francis Andrew Thomson received the degree of Master of Science from the Colorado School of Mines at the recent commencement exercises. The subject of his thesis was Stamp Milling and Cyaniding.

Jan 7, 1915

By E. E. Malouf

Rapid depletion of the world's mineral deposits combined with the expanding demand for metals places great pressure on our ability to provide technologically and economically feasible processes to recover greater amounts of metals from progressively lower grade sources. Chemical mining is one area in which expanding research and development can provide new processes or refinements to existing ones. These new techniques could result in increased production of metals from materials now considered uneconomic to process by current technology. To mine by chemicals requires the interaction of such disciplines as hydrometallurgy, microbiology, chemistry (both organic and inorganic), fluid flow, mineralogy, geology, and of course, economics. One of the least understood areas but one which may end up being an essential part of any chemical mining process is microbiology, i.e., the role of microorganisms in altering minerals and metals in solution.

Jan 1, 1971

By L. W. Pommier, L. R. Plitt, F. B. Brien

L. R. Plitt (Assistant Professor of Mining and Metallurgy, University of Alberta, Canada.) — It is indeed encouraging to see rheological studies being carried out in a mineral engineering school. The bulk of the work being done today in applied rheology seems to be concerned with the behavior of polymeric solutions and thus has limited application to the solid-liquid systems encountered in mineral beneficiation. The authors have approached the problem by carrying out a dimensional analysis which showed that for power law fluids the drag coefficient, Ds, must be some function of a generalized Reynolds number which has the form: If the power law adequately describes the behavior of a fluid, the dimensional analyses predicts that the Ds - RN function should hold for all values of n' or any other dependent variable. The experimental evi-

Jan 1, 1968

By John W. Stevenson

At Jim Walter Resources Alabama coal property, the first of twelve projected longwall mining systems started to operate In March, 1979, at the No. 3 Mine. The second longwall started to mine adjacent to the original workings in June, 1980. At the end of 1980, 2 ½ panels had been extracted using the same basic ventilation plan. A single split of air ventilates each longwall panel with intake air traveling the headgate across the face to the tailgate where it is directed and controlled to a 1500 foot deep fan shaft specifically located to exhaust from the longwall area and the gobs associated with longwall extraction. The simplicity of the system makes it easy to understand, apply and control In a relatively gassy coal bed.

Jan 1, 1981

By G. R. St. Pierre, A. Ghosh

In the Si-C-0 system at temperatures of interest in process metallurgy there are four stable condensed phases—silicon, carbon, silica, and silicon carbide (Sic). Silicon melts at 1683oK1 and shows negligible solubility for carbon and oxygen at 1700°K. However, silicon dissolves approximately 1.5 at. pct C at 2500oK.2 Carbon in the form of graphite remains pure and dissolves negligible amount of silicon.' Silica (crysto-balite) melts at 2001°K' and is essentially a stoichio-metric compound. Silicon carbide is a solid and shows negligible deviation from stoichiometry up to approximately 2800oK.2 Besides the condensed phases there is a gas phase

Jan 1, 1970

Geological Survey of Alabama, University, Ala. A complete list of publications will be sent upon request Requests for publications should be addressed to Walter B. Jones, State Geologist, University, Alabama Publications of the Survey, of most interest to the general public, comprise (1) Special Reports, (2) Monographs, (3) Bulletins, (4) Circulars, (5) Maps The Special Reports mostly deal with a special coal field, mountain, valley, or series of formations, while the Monographs treat of some industry, resource, or group of organisms throughout the state or as far as it extends The Bulletins deal with a variety of subjects, but are usually smaller and less technical than the Monographs and Special Reports Maps now available comprise a map of the Cahaba coal field, one of the Coosa coal field and a small geological map of the state, in addition to a large geological map, 28 by 42 inches, 8 miles to the inch (1926) (also bound with Special Report 14) Price of the large geological map of Alabama, folded in manila envelope, is $1.03 postpaid

Jan 1, 1933

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 5 of Article I. of said law, the existing unincorporated association known as American Institute of Mining Engineers, do hereby make, acknowledge and file 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.

Jan 1, 1923

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 5 of Article I. of said law, the existing unincorporated association known as American Institute of Mining Engineers, do hereby make, acknowledge and file 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.

Jan 1, 1923

SEC. 1. This Institute is incorporated under the Membership Corporations law of the State of New York; its corporate name in American Institute of Mining and Metallurgical Engineers, Incorporated; and its abbreviated title A. I. M. E. SEC. 2. The objects of this Institute, as set forth in its certificate of incorporation, are: "To promote 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 all lawful means; to hold meetings for social intercourse and the reading and discussion of professional papers, and to circulate by means of publications among its members the information thus obtained, and to establish and maintain a place for meeting of its members, and a hall for the reading of papers and delivery of addresses and a Library of books relating to subjects cognate to the sciences and arts of mining and metallurgy."

Jan 1, 1937