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There are two types of shovels currently used primarily as mining tools-the stripping shovel and the quarry-mine (Q-M) shovel. The two types have basically the same features, the main difference being in size. The stripping units are giant four-crawler shovels that operate by placing overburden alongside in a mined-out area. The Q-M units, on the other hand, are two-crawler shovels that usually load into trucks or trains. Powering Systems A typical stripping or Q-M shovel is fully electric, receiving power through a trailing cable that is connected to a large motor-generator set with multiple generators. In the full Ward-Leonard system, each generator furnishes d-c power to separate motors which drive the mechanisms for the principal motions of the shovel-hoist, crowd and swing.

Jan 10, 1967

By Ivan B. Cutler, Milton E. Wadsworth

Coprecipitation of anionic and cationic polyelectrolytes has been applied to flocculation of several mineral systems. Results obtained in a study of the flocculation of kaolinite and hematite suspensions of polycationic and polyanionic electrolytes are presented. Greatly increased settling rates were observed following precipitation of positive and negative polyelectrolytes on the surface of finely divided minerals in aqueous suspension. The ratios of polycationic to polyanionic electrolytes required to produce maximum sedimentation have been shown to correspond closely with the equivalence points obtained by light scattering studies of systems containing the positive and negative polyelectrolytes by themselves.

Aug 1, 1956

By R. G. Aspden, D. A. Colling

THE {120}(001) texture has been reported in near 50 pct Ni-Fe alloys <0.004 in. thick1,2 and in copper 0.014 in. thick.3 This texture is one of two types of secondary recrystallization textures observed to replace a cube texture matrix and is desirable in Fe-Ni alloys because of its unique magnetic characteristics.1,2 However, the conditions for and mechanism of the {120}(001) formation are not well understood.3 During an investigation of the influence of alloying elements on the magnetic characteristics of 49 pct Ni-Fe alloys with a sheet thickness of 0.014 in., we have observed the growth of {120}(001) secondaries when strong deoxidizers such as aluminum and calcium were present. It is believed that this observation in unique and provides additional insight with regard to the mechanism for {120}(001) texture formation. Three alloys were prepared with electrolytic iron and nickel and contained a nominal 49 wt pct Ni. Alloy A was a straight binary Fe-Ni alloy, whereas intentional additions of 0.013 wt pct Ca to alloy B and of 0.59 wt pct A1 to alloy C were made. Ingots were forged at 1100 C, hot-rolled to 0.150 in. gage, pickled, and cold-rolled to 0.014 in. Standard U-shaped magnetic test specimens were punched, deburred, sprayed with MgO, and annealed in ~50°C dew point hydrogen. Textures were identified with the aid of etch pits, the

Jan 1, 1970

Jan 1, 1970

By Charles R. Keyes

the leaching of near-by rocks, had had no other result than to bring out from obscurity three certain features of practical lmport, all the labor of that controversy would have been well expended. These three points are : (1) a clear distinction between the vadose and the profound zones; (2) a determination of the manner in which the latter may be invaded by conditions of the former; and (3) an establishment of the general truth of the lateral-secretion theory when vadose conditions prevail, and of the. ascension-theory under profound conditions. In the practical consideration. of ore-deposits these generalizations are fundamental. Their wider application must be productive of great industrial advantages. Of first importance in the broader scientific survey of ore-genesis is the recognition of a sharp distinction between vadose and profound conditions. To many who listened to Professor Posepny&apos;s remarkable paper, read at the Chicago session of the Institute during the Columbian Exposition in 1893, this seemed, as Dr. S. F. Emmons has already observed, its most valuable and suggestive feature. Notwithstanding Posepny&apos;s implications to the contrary, and his vigorous berating of Sandberger&apos;s views, the immediate and lasting .effect of the . argument was really to strengthen greatly Sandberger&apos;s position. For it completely and sharply separated the lateral-secretionists from the ascensionists, raising the sphere of the former bodily above the line of permanent water-level and at the same time confining .the sphere of the latter to regions below that horizon. A little later, Professor Van Rise showed in some detail how meteoric waters may deeply invade the profound zone and carry vadose conditions into it. The zonal limitations of two great and apparently opposed agencies being thus definitely fixed, it is found that neither of the theories based thereon is susceptible of general application. If the generalizations of the lateral-secretionist be propounded solely for vadose conditions, we are able to agree with all of his more-important contentions; while there is general acquiescence in the views of the ascensionist if their application be restricted to the profound zone. Of the ore-bodies of the world that are mined to-day, the majority are essentially vadose in origin, and probably originated

Jul 1, 1910

By AIME AIME

T HE 121st meeting of the Institute held in New York City, February 16 to 19, 1920, was a great success despite vicissitudes of weather of unusual severity. On account of tremendous snowstorms, only two members of the Canadian contingent arrived, and several of our members from the west arrived thirty hours late. Two weeks prior to the meeting, the heaviest snowstorm in 34 years wrecked the surface transportation in New York; and it was only by special dispensation that arrangements were effected, with the New York Street Cleaning Department to clear away 39th street in front of this building so that vehicles could reach the curb. The total registration of members and guests was 1138.

Jan 1, 1920

Jan 1, 1970

By AIME AIME

FIVE days, extending from Monday, Feb. 18 to Friday, Feb. 22, inclusive, will be required for the annual meeting this year. The first fours days will be devoted to reading and discussion of papers, general and committee business meetings, two lectures, luncheons, dinners and all the pleasures of a big, general reunion. The fifth day will be given over to an all-day excursion for both men and women by special train to West Point, in celebration of the birthday of the first President of the United States. Washington having been an engineer and now after one hundred and thirty-one years the country having selected as President another engineer in the person of Herbert Hoover, our own past president and honorary member, it is proposed to celebrate with a good old-fashioned picnic and inspect the school. The authorities at the Military Academy have undertaken to welcome the engineers and do whatever they may to make our pilgrimage notable. Other social features planned for the week are numerous. Luncheon will be served as usual at the building each day of the meeting to all members and guests. This year a very nominal charge will be made, primarily to overcome deficits due to irregular attendance. Monday noon, the Non-metallic Minerals Committee will lunch at the Engineers&apos; Club and in the evening the Milling Methods Committee will dine there. The Annual Smoker will be held at Hotel Astor after dinner. Professional entertainment of high order is promised, but not too much to interfere with the numerous group reunions that characterize this func- tion.

Jan 1, 1929

By John S. Brown

The northeastern United States embraces that area of the Appalachian Mountains, and adjacent territory, beginning on the south at the Potomac River. It thus extends from the flat-lying Paleozoic terrane of the Appalachian plateau on the west, across the folded Paleozoics of the Great Valley and adjacent ridges (Paleozoic and Precambrian), over the Piedmont and New England metamorphic complex (mixed Paleozoic and igenous rocks), broken by the great Triassic rift remnants, onto the subdued coastal plain of Cretaceous and Tertiary sediments. Although not noted as a metal mining region, the area does contain numerous substantial and several outstanding mines, chiefly of the more prosaic metals, particularly iron, zinc, and copper, as well as many minor occurrences of these and a few additional items. These deposits occur to some extent in every subdivision of the area. The region to date (1966) has produced almost 500,000,000 tons of medium to lowgrade iron ore, especially magnetite, including ilmenitic magnetite; 50,000,000 tons of highgrade zinc ore; and 5,000,000 tons of lowgrade copper. In the past, it has yielded small amounts of chromite and nickel, and at present is a large producer of titanium. Precious metals are conspicuously absent, and so also are the Tertiary or Mesozoic igneous phenomena so commonly associated with mines of the West. Hence, a survey of the extensive mineralization · of this region should be instructive

Jan 1, 1968

By H. Jehn

Like some other Pt-group metals palladium shows a low but considerable solid solubility of oxygen, which was found already from oxidation studies. The oxygen solid solubility of palladium in equilibrium with gaseous oxygen has been investigated at 900 - 1300 °C in oxygen (665 mbar) and air by gassing and analyzing polycrystalline samples. The 0-concentrations range from 40 to 90 ppm and decrease with rising temperature. The isobaric solubility can be represented by the least-squares fit log c0 = 0.5 log p02- 0.32 + 920/T (c0 in wt. ppm, p02 in mbar, T in K). The thermodynamic data of the exothermic solution reaction are calculated to ?H°= -17.6 kJ?mol-1 and ?S° -76.5 J?mol ? K-1. The behaviour of palladium in an oxygen atmosphere is characterized by the simultaneous reactions of the solution of oxygen in the metal and the formation and evaporation of volatile oxides besides the pure metal evaporation.

Jan 1, 1984

By AIME AIME

THE 122d meeting of the Institute was held in the Lake. Superior Copper and Iron Country Aug. 20 to Sept. 3, 1920 with an approximate registration of 1100 members and guests. This is the &apos;first visit of, the Institute to this vicinity since 1904 although previously it held meetings there every six or, seven years. &apos;The eastern party assembled at Buffalo and sailed on the S. S. "Tionesta ". on Friday morning, Aug. 20, arriving at Houghton, Mich., Monday, Aug. 23. En route stops were made at Detroit, where sightseeing auto trips were taken, and at Mackinac Island, where a short stop permitted a visit to the picturesque and historic Fort Mackinac.

Jan 1, 1920

Jan 1, 1967

By Khosrow Bakhtar

A series of nineteen shear tests were performed on fractures 1 m2 in area, generated in blocks of sandstone, granite, tuff, hydro- stone and concrete. The tests were conducted under quasi-static and dynamic loading conditions. A vertical stress assisted fracturing technique was developed to create the fractures through the large test blocks. Prior to testing, the fractured surface of each block was characterized using the Barton JRC-JCS concept. The results of characterization were used to generate the peak strength envelope for each fractured surface. Attempts were made to model the stress path based on the classical transformation equations which assumes a theoretical plane, elastic isotropic properties, and therefore no slip. However, this approach gave rise to a stress path passing above the strength envelope which is clearly unacceptable. The results of the experimental investigations indicated that actual stress path is affected by the dilatancy due to fracture roughness, as well as by the side friction imposed by the boundary conditions. By introducing the corrections due to the dilation and boundary conditions into the stress transformation equation, the fully corrected stress paths for predicting the strength of fractured blocks were obtained.

Jan 1, 1984

By John Dilworth

THE word "development," as used in connection with .mining, is a rather general term and in most instances must be qualified or explained before the exact thought in the mind of the user is made clear. For instance, by the development of a mining district is often meant its entire facilities of mineral production, such as railroads, towns, mine plants, etc. In speaking of the development of a property its prospecting by test pits or diamond drill borings may be referred to; or it may be the mines, strip pits or quarries from which the coal, ore or rock is won. But, as a rule, when the development of an individual mine is spoken of the idea in mind is the system of underground workings by means of which the mineral is recovered and transported to the surface. It is this character f development that is considered in this paper. The discussion will be confined to the ordinary room-and-pillar, system of mining. practically horizontal coal seams that is used in most bituminous coal mines in this country, and to only two phases of this subject; viz., what is properly included under the head of "Development"&apos; as it appears on the books of a coal company or the inventories of an examining engineer, and how its "value" should be determined -by the accountant or engineer. No absolute rule or definite agreement covers these points, yet these questions are far more than academic. Development is often an important part of a mining company&apos;s assets, affecting the amount of its invested capital (and hence its rate of taxation under present Federal income tax laws) as well as the value of its total assets and the amounts chargeable to cost of coal and to depreciation.

Jan 7, 1921

By L. W. Bahney

MANY methods for the determination of gold or silver, or both, in cyanide solutions have been published, which with care in manipulation, and modification in some cases, will give results that are satisfactory. It is possible to classify or group these methods as follows: 1. Evaporating the solution in a porcelain or agate-ware dish containing litharge,1 or in a "boat" made of lead foil. 2. Forming a lead sponge containing the precious metals by means of zinc shavings,2 zinc dust,3 or a piece of aluminum.4 3. Decomposing the cyanide solution with an acid and precipitating the precious metals by the use of one or a combination of some of the following: Copper sulphate,5 sodium sulphite,6 hydrogen sulphide,7 cement copper.8 4. Precipitating the silver by zinc dust held in a Hooch crucible and determination with a standard solution of sulphocyanate.9 5. Electrolysis.10 6. Colorimetry.11

Jan 2, 1915

By R. W. Raymond

(Pittsburg Meeting, March, 1910.) IN the long list of our illustrious and lamented dead, there are names which recall personality as well as career and achievement; social as well as scientific merit; devotion to the Institute itself as well as to some one of the professions which it represents. These men we remember because they did not forget us; besides our pride in their wider work and fame, we are proud of what they did with and through us; especially do we rejoice if our early recognition of them opened the way to a recognition by the world; and in their departure we claim to sorrow, not merely as members of an appreciative public, but also as. bereaved personal friends. In common with thousands, we regret our loss, but we do not regret only-we mourn and miss. To this group of those whose death has brought to us the double sense. of public and private grief belonged our strong, bright, dear brother, in whose memory this inadequate tribute is offered. Charles Benjamin Dudley was born July 14, 1842, at Oxford, Chenango county, N. Y. He came on both sides of New England blood, his father being from New Hampshire and his mother from Connecticut. Emigrating from the rocky hills of their native States, they. settled upon the more fertile soil of what was then regarded as the West, and, with thousands of other pilgrim sons, imitating the pilgrim fathers, contributed to the foundation of new commonwealths. The Empire State owes much to this element of its population. Dudley&apos;s early education was obtained, like that of the sons of the pioneers generally, by attending the village school and academy in the autumn and winter, while he worked upon the farm during the rest of the year. But his ambition looked forward to a college-course; and this was almost within his reach when a passion still stronger took possession of him. The out-

Jun 1, 1910

Born, March 28, 1853 Died July 23, 1916 On July 25, 1916, the Board of Directors adopted the following minute and directed that it be entered upon the records of the Board & published in the Bulletin of the Institute, and thereof be sent to the family of Mr. Kirchhoff: Charles Kirchhoff was one of the oldest, most widely known and most highly esteerned members of the American Institute of Mining Engineers. On his return in 1875 from a European course of study, to begin a highly successful professional career, he joined the Institute, then just commencing to acquire both national and international recognition. He became at once, and-for more than 40 years continued to be, its earnest , and active supporter, serving it as Manager, Councilor or Director for terms aggregating 9 years,-as Vice-President for 2 years, and twice as President for a year. During the critical period of the erection of the United Engineering Society&apos;s building, and the transfer of the Institute to permanent head-quarters therein, Mr. Kirchhoff was its efficient representative in the United Engineering Society, and on the Building Committee. In 1910, amid the congratulations of colleagues, employees, and innumerable friends, Mr. Kirchhoff retired from active business as Vice- President and General Manager of a great technical publishing company. Yet he sacrificed of his well-earned leisure yet one more year, to serve the Institute as President through 1911.

Jan 9, 1916

ENGINEERS AVAILABLE (Under this heading will be published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member, technical graduate, aged 36. Experienced copper metallurgist and mining geologist. Familiar also, through 15 years&apos; broad practical experience, with mining, cyanidation, concentration (including oil flotation), metallurgical accounting, and mine and plant management. Best references. No. 237. Member, graduate engineer with 10 years&apos; experience in malleable, gray -Iron, and steel, as chemist., metallographist, and metallurgist. Researches and investigations by laboratory methods and under works conditions. No objection to some routine. No. 243. Member, technical graduate, broad experience in coal, oil, and clay. Will go anywhere as mining geologist after Sept. 1, 1915. No. 244. Member, technical graduate, aged 30, married, with over 10 years&apos; experience as chemist, engineer on construction, superintendent and general superintendent of bituminous coal and coke plants. SpeaksSpanish. References. No. 245. Member, open for engagement as mine safety inspector or as superintendent of bituminous coal mine. No. 246. Member, graduate mining engineer, with five years&apos; experience in coal mining as mining engineer, construction engineer, pit boss, and superintendent, open for engagement. Best references. No. 247.

Jan 9, 1915

By AIME AIME

PURSUANT to a recommendation made by the Section delegates at their conference at the Annual Meeting of the A.I.M.E. last February, the Directors, at their meeting on March 15, 1944, appointed a committee charged with the duty of investigating the present status of licensing and registration of engineers, and to make a report on the whole subject for the information of the mining fraternity. The committee consisted of E. W. Ellis, chairman, H. D. Keiser, Henry T. Mudd, J. J. Croston, and Simon Strauss. Messrs. Keiser and Strauss were unable to assist in the work of the committee, and Mr. Mudd was forced to resign in July, his place being taken by A. F. Greaves-Walker. Able assistance was given the committee by T. Keith Legare, executive secretary of the National Council of State Boards of Engineering Examiners, and by Ed. ward Larson, executive secretary of the National Society of Professional Engineers. The accompanying somewhat condensed version of the report of Mr. Ellis&apos;s committee, dated Oct. 15, 1944, is confined to facts rather than to recommendations. The "Model Law" to which reference is made was first drafted by repre¬sentatives of six national engineering societies in 1911. It has since been amended many times, the latest version dated June 1943 is recommended to the State Licensing Boards as a pattern for formulating or amending state laws. A copy of the "Model Law" in pamphlet form will be sent to any member on request from A.I.M.E. headquarters while the supply lasts. The report:

Jan 1, 1945

By Oswald J. Heinrich

THE origin of spontaneous combustion in collieries is, of course, chiefly due to bad system in laying out the pits, unclean workings, insufficient ventilation, and neglect in damming off works after they are exhausted of the main coal. This is particularly indispensable in the Richmond field, because it is difficult and dangerous here, on account of the inferior roof, to remove the last vestiges of coal ; and we are compelled also to retain all the slates and bands, as far as possible, in the pit, to help fill up, although such material is liable to fire. This, however, can be prevented to a great extent, as mentioned below. I am satisfied that the only system of working this thick coal is by cross-cutting (Querbau, ouvrage & travers) or working in benches, as practiced in France (Creusot, Rive de Gier, St. Etienne), in Silesia (Kiinigsgrube), which I have used as far as it is practicable in an old pit, almost torn to pieces by former workings. Modifications may, of course, be needed, even in the same pit, on account of irregularities in the seam. I am also satisfied for economical reasons (on account of the heavy cost for timbering) that pits here ought to be worked upwards, even if it requires a longer period of time to win the coal, and a greater outlay of capital to commence with. The various saddle-shaped " troubles " making natural minor basins in the main basin aid in the execution of this plan. A pit worked once ought to be worked out clean, given up, and dammed off forever. If sections of proper height are assumed, according to the required amount of production for a certain period of time, they ought to be worked out and filled in as much as possible, dammed off, and ultimately allowed to fill up with water, in order to protect the upper works in future from fire in the gob below. This I consider indispensable, because we may not be able profitably to fill in all the ground. To do so we have to use the waste of the mine, although it is liable to fire in time. In using this stuff, it ought to be surrounded by walls of rock not liable to take fire, laid firmly in clay, the gob being in the middle, and firmly covered and packed with clay on top. In