Search Documents

By Howard W. Jacky

At Weed Heights, Nev., precipitation plays a major role in the plant operation. Almost two-thirds of the present copper production is leach-precipitation plant copper. The entire plant complex processes about 135,000 tons of low grade copper ore per week. Of this tonnage, 49,000 tons of about 0.78% sulfide ore are treated in the concentrator. This is handled in the conventional manner of crushing, grinding, and concentration of the copper sulfide by flotation.

Jan 6, 1967

By A. D. S. Gillies

One of the most difficult places to ventilate in any mine is the working face area. With an everchanging configuration, continual modification and extension to the ventilation system is necessary to maintain an adequate supply of fresh air and to avoid mixing and recirculation in the face area. In coal mines, methane emissions and high dust levels as coal is broken and removed from the face area can produce unhealthy and dangerous conditions if ventilation is not adequately monitored.

Jan 1, 1982

By J. C. Prof. Smock

(Read at the Philadelphia Meeting, February, 1878.) THE fire-clays of New Jersey belong in two geological ages, the cretaceous and quaternary, or post-tertiary. Three very small deposits of plastic clays have been discovered within the limits of the Archoean rocks. These are not refractory and of little importance, excepting in a geological consideration. They have resulted from a decomposition of the feldspars of the rock in situ, and they have been classified as inferior kaolins.

Jan 1, 1878

GENTLEMEN: Submitted herewith are the report of the Treasurer for the year 1940 and reports for the same year of the following standing committees: Admissions, Membership, Pa¬pers and Publications, Mining and Metal¬lurgy (Magazine), Library, and Student Relations. These reports present additional details. MEMBERSHIP For the third year in succession member¬ship reached a new high level for all time, as indicated in the accompanying tabula¬tion in which "Members" includes all categories except Student Associates.

Jan 1, 1941

By P. Somasundaran

Processing of fine particles in suspension is markedly affected by their state of dispersion/aggregation. In addition, tendency for a given component of the system to undergo selective aggregation or selective dispersion is an important property which may be put to use for processing. In this paper, principles governing flocculation, dispersion, and selective flocculation of mineral fines are discussed and then the role of major solution properties such as pH, ionic strength, etc. is examined.

Jan 1, 1980

By James Douglas

The Copper Queen mine was opened in 1880 by Messrs. Martin, Ballard & Reilly, and the first copper-furnace was blown-in on August 20th of that year. Prior to that summer nothing but prospect-work had been done on the copper Queen and on a number of adjacent claims. In fact, it was a small deposit, not of copper-ore, but of cerussite, which still remains undeveloped, on the western slope of the Queen hill, which

Jan 1, 1900

By Desmond De Villiers Oxford, Peter H. Williams

Nchanga Consolidated Copper Mines, Ltd., is one of the four mines operated by the Anglo American Corp. in Northern Rhodesia, now the independent nation of Zambia. Today Nchanga is the second largest single producer of copper in the world, accounting for more than 200,000 long tons of copper annually at a monthly milling rate of 430,000 tons of ore. The average mill-head grade is about 5.20% total copper, of which approximately 60% is copper sulfide. The remainder, referred to as "acid soluble," is copper oxide. Nchanga mines three separate orebodies varying in grade and sulfide-to-oxide ratio. Ore is processed in two separate grinding circuits feeding into three separate flotation circuits. A fourth flotation circuit treats leach plant residue for additional recovery of sulfides.

Jan 1, 1965

By E. L. Swarts

In the course of a program on high-temperature processing and electrowinning of uranium at the Knolls Atomic Power Laboratory,'' it became necessary to give attention to the interaction of molten uranium with graphite. Although it is known3 that a protective interface layer may form, details of this reaction have not been reported. Unfortunately it was impossible to complete the planned experimental program. However, the general problem is considered of sufficient interest to warrant reporting those preliminary results actually obtained. EXPERIMENTAL PROCEDURE Interface carbide layers were formed by melting samples of cleaned uranium metal in small closed graphite crucibles. Equilibrations were conducted in vacuo or in an atmosphere of dry helium at temperatures ranging from 1150" to 1400°C and for periods of from 24 to 240 hr.

Jan 1, 1960

FEB. 17-The past month found the average citizen backed off just a little more into his blind corner staring glassily at hydrogen bombs, unbalanced budgets, John L. Lewis, more inflation, a rising wave of strikes, the country's only active battleship on a mudbank, a famous scientist in gaol as a traitor, a favorite actress on a Roman holiday, and rising mountains of potatoes, butter and eggs begging for destruction. About the only bright spot has been industrial activity and employment, but even these are menaced by the coal shortage. Most industries have orders on hand or in prospect to warrant high operations for some time to come. The trend of the Reserve Board's production index is upward except as strikes may interfere. There has been heavy buying at the seasonal merchandise shows, particularly in furniture and house-hold goods. The demand for goods of this kind illustrates greater confidence in the Spring outlook than was generally felt a year ago. Further, the demand also reflects improved market positions due to curtailment of output and reduction of inventories in 1949 and sustained consumer buying power. It demonstrates the strong support that is given directly to many businesses, and indirectly to all, by the phenomenal construction activity that is now under way. The Commerce Department places the number of new dwelling units started in 1949 at the new all-time high of 1,019,000.

Jan 3, 1950

By P. CHARTERIS A.

THE following scanty notes on the Roumanian oil-region may serve as an introduction to more detailed future study and description. The Roumauian oil-belt, follows the outer edge of the sweep of the Carpathian Mountains, and may, in a broad sense, be regarded as a prolongation of the Galician belt. It is distributed over a tract of country from 300 to 400 miles in length, with a width of from 15 to 20 miles, and is believed to cover an area of at least 20,000 hectares (59,420 acres). The Government claims that 16,000 to 17,000 hectares of its land is petroliferous. The primary deposits of petroleum are considered to be in the Padeogene (Oligocene) and the Neogene (the salines of the Miocene) formations. Most of the other repositories, especially those of Muntenie, are only secondary, the petroleum there having been introduced by the orogeneric movements which raised the Carpathian Mountains. The oil-field has been divided by the Roumanian survey into two regions, the Flysch and the Sub-Carpathian, as is shown in the accompanying sketch-map, Fig. 1.(p. 518). So far as is yet, known, practically all the seepages and .productive pits and wells are situated oil anticlinals. Those which outcrop in the Flysch region. (called Paleogene anticlinals), as indicated in the sketch-map, Fig. 1, are : Solontz, Middle Oligocene; Moineshti, Moineshti and Tagu-Ocna-beds of the Eocene.

Jul 1, 1906

Virginia Polytechnic Institute, Department of Mining Engineering, Blacksburg, Va Otto C Burkhart, Professor of Mining. The titles of pertinent publications have been abstracted from the Bulletins on Research and Publication This material has also appeared, in most cases, under other auspices Presumably, the Bulletins whose titles are quoted may be had for the cost of postage The coals of Virginia (1927), Ceramic resources of Virginia and their development (1929), Effect of ilhum crucibles on volatile determinations of coal (1930), Possibility of briquetting southwest Virginia coals (1930), Coking of semi-anthracite coal of Virginia (in preparation), Distribution of ash in the Merrimac coal seam (1929); Unit coal studies on some Virginia coals (1931), Sulphur forms in Virginia coals (1931); Comparison of results of fusion point of coal ash obtained by two different methods

Jan 1, 1933

(Under. this heading will he published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member; age 31, technical graduate, 8 years' experience in copper and nickel mining, desires to make a change. No. 480. Member, age 34, married, 16 years' experience as railroad construction engineer and as superintendent of iron, chrome and manganese mines. Especially successful in rush construction work and development of new mining properties. No straight salary proposition will be considered. No. 481. Member desires change of position. Four years experience in flotation, cyaniding, and mill design and construction. Married, technical graduate. No. 482. Member, age 33, married, graduate Columbia School of Mines. Nine years' experience as engineer and mining and oil geologist; experience in Mexico, Peru and Siberia. Speaks Spanish and Russian. No. 483.

Jan 9, 1918

By O. Mellgren, A. M. Gaudin, P. L. De Bruyn

In the January 1956 issue: TP 4137B. Adsorption of Ethyl Xanthate on Pyrite. By A. M. Gaudin, P. L. de Bruyn, and Olav Mellgren. P. 65. Since P. L. de Bruyn is now a member of the AIME, the word "associate" should be removed in describing his status. The address of the third author, Olav Mellgren, should read: 74-2 Chingola, N. Rhodesia. P. 68, second paragraph, last line: the word "300-fold" should be replaced by "3000-fold." Also in the January 1956 issue: TP 4158B. Energy Transfer by Impact. By R. J. Charles and P. L. de Bruyn. The authors wish to express their disapproval of the omission of the abstract from the article, since they believe that an abstract fulfills a very important function in every paper.

Jan 1, 1957

By D. H. Yardley

ENGINEERS and geologists find the magnetic compass unreliable in many mineral bearing areas because of local magnetic attraction. This is the case in the vicinity of many contact deposits, and particularly true in the Lake Superior district where iron formation is wide spread and causes wide fluctuations of the magnetic needle. One of the most useful instruments for geologic traversing or running grid and claim lines under these conditions is the dial compass which does not depend upon magnetism. Difficulties encountered in the field because of local attraction can be overcome through transit observation of Polaris or the sun, or use of the solar attachment. However, a field party often lacks the equipment or time for work of such accuracy and it is here that the dial compass finds its use.

Jan 3, 1954

By Alan Lawley

AS part of a programme of experimental work on single crystals of rhenium and ruthenium, it was found necessary to have the crystallographic angles for these elements. The angles given in Table I were determined to the nearest minute of arc, by Univac Computer. The angle $ between (HKIL) and (hkil) is given by the formula: The angles given for rhenium should be particularly useful in view of the increasing interest in this element. For completeness, angular values are also given for cadmium zinc and magnesium; these form a more complete set of values than those given by Salkovitz.' The assistance of Professor J. Hobstetter and Mr. J. Crozier in the programming of this data is acknowledged. The work is sponsored by the Office of Naval Research under contract No. NONR 551 (19).

Jan 1, 1961

By Brian W. Mackenzie

Since mineral economics is often coupled with mining engineering in the solution of mineral industry problems, it is important that the principles of this science be a part of the mining engineer's education. Essentially, mineral economics is the application of economic principles to analysis of the multistage process by which minerals are converted from geologic resources to marketable products. In some instances, it may require only the analysis of case studies from a well- developed economics core. In others, however, it requires special skills, because some aspects of the mineral conversion process--such as mineral occurrence, exploration investment and depletion-have no complete parallel in general economics. The mining engineer has been an important contributor to the analysis of mineral economics problems because of his special knowledge of the mineral industry.

Jan 1, 1971

By Hans Rausch, Kurt J. E. Meyer

A PELLETIZING plant in Germany must be able to process ores of different origins, having quite different characteristics. This requirement was of great importance for the development of the Lurgi process. For the production of green pellets a ma- chine would, therefore, have to be capable of dealing with all kinds of raw materials, and hardening must be done in a furnace, the temperature of which is adjustable to the different temperatures of the ores. Making Green Pellets To produce green pellets, experiments were made on a number of machines, such as drums, vacuum extrusion presses, and compacting machines. In 1949, Lurgi was the first to use pelletizing discs to produce iron ore pellets; until then this type of machine had been used exclusively in the cement industry.

Jan 3, 1958

By Stephen E. Erickson

MORE and more hydrocyclones are being installed in beneficiation plants. This recent rapid increase is of special interest in the history of beneficiation, since development of the hydro- cyclone appears to have swung in a circle. To avoid any chance of confusion, it would be well first to review the accepted definitions. The size of a cyclone is expressed as the diameter of the cylindrical section. Size of the inlet orifice- which may be circular, square, or rectangular- is expressed as a diameter, or as width and length, or as an area (in square inches). The angle of a cyclone is expressed as the total included angle. The overflow or finest classification fraction leaves the cyclone through the vortex finder. The underflow or coarsest classification fraction leaves through the apex opening.

Jan 8, 1957

By Donald L. Anderson

Presence of hot water brought on by volcanic action nearby has severely complicated mining in the Limon gold mine in Nicaragua. Routine pumping problems have been multiplied and ventilation is a major problem. Enclosing rock is so hot that 20 pct of all power generated at the mine is consumed by forced ventilation. But hot water underground, however disagreeable and troublesome, may be handled and surmounted like any other difficulty if the estimated profit margin permits. Empresa Minera de Nicaragua's Limon mine is a 400-ton gold-silver producer located in western Nicaragua about 60 miles northwest of the capital city, Managua, and some 45 miles from the Nicaragua-Honduras border. Limon is situated in a low- lying district with a nearby chain of active and semi-active Tertiary volcanoes.

Jan 6, 1959

By T. O. Meyer, J. R. McVey

A 10-channel automatic data acquisition system has been assembled for underground use with the Bureau's "Tunnel Stress Relaxation Gage". The automated system was needed to improve data collection by providing a rapid, long-term printout of measurement data in tunnel stress relaxation experiments. Special unit assembling and packaging of all measurement equipment, to be used in typically hostile mine environments, is the subject of this report. Even though automatic data acquisition systems have been in use for years, none have been developed with the accuracy herein described for use in such an environment. The object of this report is to inform researchers of a workable, proven, dependable underground data acquisition system. We have found that giving attention to these packaging details many times spells the differences between success and failure of underground tests.

Jan 8, 1973