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Jan 1, 1966

By H. A. Baumann, A. J. Rostosky

EVER since the first installation of wet-washing methods of coal preparation, the removal of the water added by the washing process has created serious technical and operating problems. The rapid development and widespread adoption of wet washing has necessitated a corresponding development of dewatering methods and equipment. The amount of water retained by coal varies with the size of the coal. The moisture that is largely on the surface of the particles is easily shaken off coarse coal; thus coarse coal can be dried comparatively easily and quickly. Fine coal presents a larger surface area than does coarse coal, so its capacity for retaining moisture is greater. In fine coal, moisture below about 5 per cent is held between the coal particles and its removal is difficult. Draining and drying of the finer sizes is a major problem at many washeries. Two common problems of coal-washing practice that are intimately connected with dewatering and drying are the clarification of washery water and the prevention of stream pollution. The first field has been studied from many angles, including the use of coagulating and settling agents followed by vacuum filters to remove the solids, and the use of sludge tanks with dewatering screens incorporated therein. In many districts, the disposal of sludges into streams has been stopped by law. The lack of space for impounding sludges has created problems of disposal in other districts. Reduction in moisture means a saving in freight costs as well as the elimination of difficulties in unloading and storing. Excess moisture in coal causes it to freeze in localities where severe climatic conditions pre¬vail. Excess water in coals to be used in the production of coke and manufactured gas has a chilling effect on the walls of the oven or retort. Dryness of coal is important in producing good briquettes.

Jan 1, 1943

Jan 1, 1931

NAME AND OBJECT. SEC. 1. This Institute is incorporated under the Membership Corporation Law of the State of New York ; its corporate name is AMERICAN INSTITUTE OF MINING ENGINEERS; and its objects are such as are stated in its Certificate of Incorporation. ARTICLE II. MEMBERS. SEC. 1. The membership of the Institute shall comprise four classes, namely (1) Members ; (2) Honorary Members , (3) Associates , and (4) Honorary Associates Only Members and Associates residing within the United States of America, Republic of Mexico and Dominion of Canada shall be entitled to vote at the meetings of the Institute. SEC. 2 All Members, Honorary Members, Associates and Honorary Associates of the American Institute of Mining Engineers as the same existed on the day of the incorporation of this Institute, are Members, Honorary Members, Associates and Honorary Associates, respectively, of this Corporation SEC. 3. The following classes of persons shall be eligible for membership in the Institute, namely, as Members and Honorary Members, all professional mining engineers, geologists, metallurgists or chemists, and all persons practically engaged in mining, metallurgy or metallurgical engineering ; as Associates and Honorary Associates, all persons desirous of being connected with the Institute who, in the opinion of the Council, are suitable. SEC 4. Every candidate for election as a Member or Associate of the Institute must be proposed for election by at least three Members or Associates; must be approved by the Committee on Membership, as prescribed in the By-Laws ; and .must be elected by the Council. Not less than three-fourths of the votes cast shall be necessary to an election Every person so elected shall become a Member or Associate, as the case may be, upon payment of his first dues as herein-after prescribed Each candidate for Honorary Member or Honorary Associate, must be recommended by at least ten Members or Associates ; must be approved by the Council ; and must be elected by ballot at a meeting of the Board of Directors by the unanimous vote of all the Directors present ; provided, however, that the number of Honorary Members and Honorary Associates shall not at any time exceed twenty SEC. 5. If any person elected a Member or Associate does not, within sixty days after notice of his election, accept the same and pay his initiation fee and dues for the current year, his election may be cancelled at the discretion of the Council.

Jan 1, 1917

The Institute maintains a dual relationship with students: (1) an individual relationship with a Student Associate; and (2) a relationship with local organizations of students, known as Affiliated Student Societies or Student Chapters. 1. The conditions of Student Associateship are set forth in Section 8, .Article 1 of the By-laws of the Institute (see p. 45 and following pages) During 1934, sundry amendments were made for the purpose of improving the student relationship. Post-graduate students are now eligible; and the associateship can be maintained, with the payment of the regular dues of $2 per gear, for 18 months following graduation in June. A Student Associate is given a subscription to MINING A ND METALLURGY: he is accorded the privilege of getting special publications such as "The Porphyry Coppers" and "Ore Deposits of the Western States" at the reduced prices applicable to Members; he has the privileges of the Engineering Societies Employment Service and the Engineering Societies Library; and he is not only invited but urged to attend all meetings of the Institute, its Divisions and its Local Sections. The Institute wants to extend the hand of professional fellowship to students following mineral industries curricula.

Jan 1, 1936

By J. Norman Bulkley

Discussion of the paper of J. NORMAN BULKLEY, presented at the New York meeting, February, 1916, and printed in Bulletin No. 110, February, 1916, pp. 355 to 373. GRAHAM BRIGHT, E.. Pittsburgh, Pa.-On p. 265 mention is made of a change from steam hoist to electric hoist. The arrangement mentioned, of using a geared motor, and having the gearing and counter-shaft in a separate, self-contained unit, and then connecting that to the hoist by means of a flexible coupling, is very good. Sometimes, however, it is necessary to change a geared hoist over to an electric hoist. 'In that case the motor could be either direct-connected to the countershaft or geared to the countershaft, making a double-reduction gearing. Trouble has been experienced with this method on account of the hoist not being designed for electric drive. It may be of a rather light construction which will not stand the forces obtained by steam operation, the maximum being determined by the steam pressure which can be obtained in the cylinder. With motors of hoisting types, torques, can be obtained, which are so far in excess of anything that the steam engine could give, that this sometimes results in disaster when a motor is applied to a hoist of that type. If the operator gets a little careless, he may overstrain the hoist, And cause damage, so that this question should be looked into when changing from a steam hoist to an electric hoist. The hoist should be rugged enough to stand the torques which may be attained by careless operation, in which case, instead of using a three-bearing motor, with a pinion between two of the bearings, it is much better to arrange for a two-bearing motor, arranging for a coupling through a flexible coupler. In another place trouble is mentioned as due to the vibration of a geared hoisting motor. That can be overcome by supplying a flexible coupling between the motor and the hoist proper. You will find, if a flexible coupling is furnished, that the motor troubles will largely disappear. K. A. PAULY (communication to the Secretary*), Schenectady, N. Y. -This paper is deserving of careful consideration by all interested in general electrical mining problems and the recommendations made should be given weight because of the author's long experience in dealing with various problems encountered from the beginning of mine electrification.

Jan 5, 1916

Jan 10, 1950

R. W. Balluffi (Atomic Energy Div., Sylvania Electric Products Inc., Bayside, N. Y.)—Since porosity is known to form in the copper side of Cu-Ni couples during diffusion24,25 it is of importance to consider this factor in interpreting the large variations of chemical diffusivity with copper concentration reported for this system. The presence of porosity may affect the measurement of D in two ways: 1—density changes in the couple invalidate the usual solutions of the diffusion equation, and 2—the pores may act as short-circuiting paths when transport through the vapor or along internal surfaces is appreciable or else as open circuits when these effects are small. The error produced by the first effect may be estimated by a graphical analysis. Fig. 8 shows the porosity generated in the copper side of the Kirkendall interface of a pure nickel vs pure copper couple after diffusion for 350 hr at 1040°C in hydrogen. In Fig. 9 the actual diffusion curve which would be obtained by the usual slicing technique is shown as a solid line drawn to the same scale (from the data of da Silva and Mehl"). The amounts of porosity (obtained by lineal analysis) and of nickel are graphically represented by the hatched areas. The standard solutions of the diffusion equation are valid only when all volume elements of unit length and unit cross section contain equal numbers of atoms." It is possible to correct the experimental curve to satisfy this condition by shrinking the couple in the direction of diffusion in such a way as to eliminate the porosity.* The corrected diffusion curve obtained after

Jan 1, 1954

By G. W. Elger, H. E. Bell, J. E. Tress, J. B. Wright

This paper describes laboratory techniques and subsequent results of US Bureau of Mines (USBM) research to produce chlorination-grade feed- stock from an abundant, low-grade, domestic, rock ilmenite ore. The research is part of the Bureau effort to devise technology that may help decrease US dependence on imported raw materials. A rock ilmenite containing about 46 wt % TiO2 was smelted in an electric arc furnace with coke, wood-chips, and Na2CO3 to separate most of the iron as pig iron and to form a low-iron, titanium-enriched slug. The slug was ground, pelletized, oxidized, and then sulfated with mixtures of SO2 and air in a continuous 4.5- to 9.1-kg/h (10- to 20-lb per hour) apparatus at 1023° to 122J0 K (1380° to 1740° F). The sulfated slug, containing 60% to 65% TiOb, was reground and leached in water at ambient temperature to decrease the combined levels of the troublesome calcium, magnesium, and manganese impurities from 7.0 to 1.7 wt 70. The final product was upgraded to about 8.4 wt % TiO2. This material is potentially suitable for chlorination in a fluidized bed reactor. The most favorable results were achieved with leached slug sulfated at a feed rate of 4.5 kg/h (10 lb per hour) and at temperatures of 1073° to 1123° K (1470° to 1560' F).

Jan 1, 1986

Executive A R LEDOUX, Chairman ARTHUR S DWIGHT CHARLES F RAND E P MATHEWSON J V W REYNDERS Membership E DEGOLYER, Chairman W Y WESTERVELT, Vice-chairman WILLIAM H BASSETT H G MOULTON C MINOT WELD Finance WALTER H ALDRIDGE, Chairman GEORGE D BARRON GALEN H CLEVENGER Library GEORGE C STONE,' Chairman JOHN H JANEWAY ALEXANDER C HUMPHREYS, ROBERT LINTON FREDERICK F SHARPLESS

Jan 1, 1923

1. Any society of undergraduates at a technical school, comprising students in any branch of engineering, metallurgy, chemistry, geology, etc., may be recognized by the Board of Directors in its discretion as an Affiliated Student Society, and its name, together with the names of its President and its Secretary, may be published in the Bulletin or the Year Book of the Institute. The individual members of such a society will not be catalogued as individual members or associates of the Institute, but may at any time be proposed for election as members or associates of the Institute, in the usual way. 2. Membership in an Affiliated Student Society, certified by the official representative thereof, and accompanied with suitable testimony as to character and qualifications, will have special, weight with the Membership Committee of the Institute, in its consideration of the proposal of a candidate for membership or for Junior membership.

Jan 1, 1923

Jan 1, 1952

By A. A. Schweizer

A method to improve the quality of Magmont zinc concentrates to become acceptable feed to an electrolytic zinc refinery is described. The magnesia content of zinc concentrates produced was too high due to particle locking with sphalerite in coarse fractions. Regrinding the concentrates to a very fine particle size and then refloating the sphalerite was chosen to eliminate a sufficient amount of the magnesia to make the concentrates acceptable.

Jan 1, 1984

Jan 1, 1935

Jan 1, 1916

By Arthur B. Cummins

Diatomite is a siliceous rock of sedimentary origin, which may vary in degree of consolidation, but which consists mainly of the fossilized remains of diatoms. These are microscopic algae of the order Bacillaria. Diatomite is a unique form of silica, there being nothing else found in nature or produced by the manufacturing arts, that has its characteristic physical structure. There are numerous sediments which contain some diatom residues, admixed with a substantial amount of other materials-clay, carbonates or silica. While these are classified as diatomaceous silts, shales, or mudstones, they are not properly diatomite, a designation which is restricted to material of such qualities that it is suitable for commercial uses. The terms diatomaceous earth and kieselgur are synonymous with diatomite. The expressions infusorial earth and tripolite are obsolete. Diatomaceous silica is a definition best used to distinguish the basic component of diatomite, that is, the substance of the silica shell itself and is the major constituent of beneficiated diatomite or processed diatomaceous products. Some highly indurated materials, such as cherty shale, porcelanite, and opaline cherts which have resulted from diagenetic changes cannot be considered as diatomite although they may have been derived therefrom. On the other hand, diatomaceous oozes or loose sediments consisting mainly of diatom residues with or without much organic matter are source materials in process of becoming diatomite. Composition and Properties Pure diatomite is composed of opaline or hydrous silica, with small amounts of associated inorganic components-alumina, iron, alkaline earths, alkali metals, and minor constituents, all of which may occur in solid solution or as an essential part of the opal complex. Crude diatomite on the other hand may contain variable amounts of organic matter and soluble salts, and the usual contaminants of sedimentary formations-particles of rockforming minerals, sand, clay, or carbonates. As occurring in nature, diatomite contains an unusual amount of free water, which may vary from 10 to 60 pct or more. Diatomite, in the dry deposits which are characteristic of most of the important world deposits, occurs as a lightweight, comparatively light colored, "chalklike" material. The apparent density (dry basis) in situ varies from 20 to 40 lb per cu ft. The structure may be either massive or finely stratified. The earth is highly porous, usually soft and easily friable. It is nonreactive with acids and may be tentatively identified by the above characterizations. Confirmation is by microscopic examination which readily reveals the nature of the material. In deposits which contain organic matter the appearance of the material is totally different. The color may vary from light tan or gray to brown, greenish or nearly black. There is frequently difficulty in distinguishing it in the field from peatlike materials, but the difference is readily apparent after calcination. Powdered diatomite or diatomite products have an apparent density (loose weight) of 5 to 16 lb per cu ft, wet densities of 10 to 30 lb per cu ft, specific gravities 1.9 to 2.35, index of refraction 1.42 to 1.48. Diatomite is essentially micro-amorphous, but does show some tendency toward orientation in structure after a cristobalite pattern. Amorphous silica has been considered as a random association of cristobalite crystallites, the size of which are only slightly larger than a unit cell.20 The prop-

Jan 1, 1960

By H Haas

H. HAAS, San Francisco, Cal. (communication to the Secretary?). -Fig. 1 plainly shows that the comparison of the steam-turbine and Diesel-engine plants was made on a basis of 6,000 kw. continuous operating load. The tabulation of costs for an 8,000-kw. load is merely done to show the relation of increased output on' the unit power costs. Both plants would sacrifice their reserve capacity, which is to insure continuous operation, if operated to generate 8,000 kw. continuously; unless Mr. Hawkins advocates the operation of one of the turbines at 33.33 per cent. overload, retaining the other as a standby, which, besides overtaxing the turbine, results in a great loss of efficiency. It would he well for Mr. Hawkins to qualify certain of his statements. Thus, under the caption "Diesel Engines, Selection of Units," he says that "two of the largest Diesel-engine builders take the position that, in the present state of the art, they would not attempt to put out units over 1,000 kw.;" he should qualify it by saving that "two of the largest American Diesel-engine builders take the position that, in the present state of the art in the United States, they would not attempt to put out units over 1,000 kw." The reason that American manufacturers restrict themselves at present to units of that size is to be found not so much in a lack of experience in building large units as in a lack of a sufficient, demand for them in the United States to justify the heavy capital outlay connected with the development of such engines. There are relatively few localities in the United States where fuel prices are as high as they are in the Southwest, and regions of high fuel prices are sparsely settled and have a very limited demand for power. Where low fuel prices obtain, steam turbines are active competitors of Diesel engines for large power plants, particularly when the station load factor is low. As most of the American manufacturers of Diesel engines work under license agreements with European manufacturers, which limit their market to the United States and its possessions and Canada, a further limitation is imposed upon them, leaving to European firms practically the entire world as a market.

Jan 5, 1917

UNIVERSITY OF ALABAMA University, Ala Mining and Metalliaigical Society* G L Roberts, President T G Patterson, Vice-President B B Copeland, Treasurer K F Stark, Secretary G T Bator, Faculty Sponsor F H Crockard, Counselor

Jan 1, 1949

By J. Charles Miller

NATURAL carbon dioxide has recently been exploited in the United States in consequence of oil and gas developments in the Western States and the growing demand by transcontinental and transoceanic shippers for solid carbon dioxide. The discovery by drilling of commercial deposits resulted in consideration of its geographic and geologic distribution and occurrence. Its wide distribution in nature is evidenced by its occurrence in the atmosphere, hydrosphere and lithosphere. The question of origin of carbon dioxide involves consideration of theories similar to those concerning natural hydrocarbons, although available evidence favors an inorganic rather than an organic source. Areas favorable to development of commercial production appear to be those in proximity to igneous rocks or in the vicinity of decadent volcanic activity, where, it has long been known, the gas is evolved either free or dissolved in the waters of fumaroles, geysers or mud pots. Structure contour maps are presented showing the Wagon Mound anticline in New Mexico and the Farnham anticline, Utah. A well drilled on the latter supplies gas to a 20-ton plant manufacturing solid carbon dioxide at Wellington, Utah, on the Denver and Rio Grande R.R., whence it is shipped to surrounding territory and to the West Coast. Before funds are invested in a plant for the manufacture of liquid or solid carbon dioxide, whether supplied by wells or springs, an effort to ascertain the volume of gas available is advisable. The use of present methods of estimation of gas reserves with modifications to account for the quantity absorbed by any water present in the producing formation is recommended, The Farnham anticline is used as an example and cornputationa are made of the probable volume of gas originally present in the structure. No attempt was made to compute reserves in the Niland area, California, for the reason that in such areas it is believed the volume is indeterminate. INTRODUCTION Carbon dioxide, in liquid and solid form, has found a wide variety of uses other than its primary application in carbonating beverages. It is now used in more than 40 different ways, ranging from cooling or freezing to use in gas or liquid form for mechanical purposes, chemical industry, explosive, fire extinction, and tire manufacturing. Undoubtedly the chief supply of carbon dioxide is obtained from industrial plants or artificial sources and until recently natural deposits of the gas have received little consideration. Few will question the utility and perhaps dependability of artificial sources, which possess the advantage over

Jan 1, 1937

By G. A. Savanick

Borehole (slurry) mining, where a tool incorporating a water-jet cutter and a downhole slurry pump mines phosphate through a borehole, was field tested in northeastern Florida as part of a US Bureau of Mines program to increase the domestic availability of critical minerals. About 1.5 kt (1700 st) of phosphate ore were mined at 23.6 t/h (26 stph) from a depth of 76 m (250 ft). The borehole was filled with water during mining for roof support and to assist slurry pumping. Underwater cutting was enhanced with an air-shrouded water jet. Mined cavities were backfilled to prevent subsidence after abandonment. Roof subsidence during mining was avoided only when the cavity was filled with water. Environmental monitoring before, during, and after mining included hydrological studies and measurements of water quality. Significant water quality changes occurred only in the zone being mined and were confined to the immediate area of the borehole.

Jan 1, 1986