Search Documents

By Robert C. Meaders, Arthur R. MacPherson

Many attempts have been made to eliminate most of the crushing plant and all the grinding plant in the process of ore beneficiation by substituting a combined crushing and grinding unit which could take coarsely crushed ore and reduce it to a fine size in one unit. This unit normally would have no other grinding media than the ore itself. This is true autogenous grinding, as we understand it today, and should be clearly distinguished from pebble mill grinding, where pebbles are substituted for steel balls to grind a ball mill size feed. To compete in efficiency with normal methods of crushing and grinding, the autogenous mill must use less labor and steel to produce an equivalent product at equal or lower power consumption. In general terms, a unit to perform these functions must have means to crush the ore to fine sizes and to then further reduce the crushed pieces by grinding. In other words, to do efficient autogenous grinding, there must be a proper balance established between crushing and grinding rates. There is not much point in crushing at too fast a rate if the grinding means are not present to reduce the small particles to the required product size. The crushing means used in an autogenous mill are impact forces of two kinds, namely, (1) the rock travelling at high speeds striking the shell, and (2) the lifters travelling at high speeds striking the rock. Grinding is probably effected in a manner equivalent to pebble milling.

Jan 9, 1964

By L. K. Smith, E. M. de Kock, J. van der Walt

A unique and systematic approach for analysing alternative methods of ventilating and cooling large hot mines is presented. The important factors that have a bearing on ventilation and cooling requirements and practices, such as air flow through the mine, geographical distribution of heat loads, micro ventilation considerations etc., are dealt with. Analysis of these leads to the definitive ventilation and cooling strategies, air and water process design, detail specifications and design of associated plant and equipment.

Jan 1, 1982

By David C. Yang

INTRODUCTION Over the world, and especially in the United States, there is increasing dependence upon progressively lower grade ore deposits. These lower grade ores are frequently difficult or impossible to process due to complex mineral assemblages being very finely disseminated. Thus, many of the conventional mineral concentration methods are not applicable to these ores. For the last few decades, research in the more exotic mineral processing techniques has been conducted, both in universities and in governmental and industrial laboratories. Since its inception, the Institute of Mineral Research of Michigan Technological University (MTU) has devoted much of its attention to the problems of processing refractory, low grade ores. Recently a new flotation system was developed which shows promise of being applicable to a broad range of ore types. This process has been the subject of two allowed patent applications. This paper describes the details of such a flotation system which is potentially useful for treating ultrafine minerals. Some highlights of the testing program on a variety of iron ores and a group of lithium-bearing ores will be presented. EXPERIMENTAL PROCEDURES Both iron and lithium ore flotation treatments followed the same general procedures, with minor differences in pH and in reagent dosages. The method is rather simple, efficient and economical from the standpoint of recovery and the cost of reagents consumed.

Jan 1, 1979

NEW MEMBERS The following list comprises the names of those persons who became members during the period May 10 to June 10, 1915: Members ANDREEN, HARRY MAYO, Millman: and Assayer Thane, Alaska. BANKS, HUBERT RAYMOND, Min. Engr., Mill Staff, Consolidated Arizona Smelting Co., Humboldt, Ariz. BASSETT, ARTHUR F., Min. Engr., Care Consolidated Arizona Smelting Co., Humboldt, Ariz. BLACKNER, LESTER A., Slope Engr.... Care Ray Consolidated Copper Co., Ray, Ariz. BUSHNELL, C. E., Draftsman Butte & Superior Copper Co., Butte, Mont. CAVAGNARO, DAVID AMILE, Min. Engr., Genl. Supt., Wisconsin North Fork GravelMines, Forest, Sierra Co.; Cal. COGHILL, WILLIAM HAKES, Met., Ore Testing Laboratory, 3705 Hueco St., - - El Paso, Tex.

Jan 7, 1915

By Arthur Wade

During the year 1938, there was some drilling in Queensland, New South Wales and Victoria, as follows: Queens1and.—At Hutton Creek, lat. (approx.) 25° 45' S.; long (approx.) 149°, drilling was done by Drillers limited (subsidiary Oil Search) to a depth of 4688 ft., to the Lower Permian(?). There were small gas showings. The hole mas abandoned. At Mt. Bassett, lat (approx.) 26" 20' S.; long. (approx.) 149", Roma Blocks Oil Co. No Liability drilled to a depth of 4033 ft. The hole bottomed in granite. There were small showings of' oil and gas above bedrock in what may be Permian but is not yet determined. The company intends to run a formation tester. New South Wales.—At Kulnura, lat. (approx.) 33" S., long (approx.) 151°, the Kamilaroi Oil Company Ltd. (subsidiary of Oil Search Ltd.) drilled to a depth of 6293 ft. The Permian, probably Upper Marine Series, was reached. Drilling is to continue. Victoria.—At Romawi, lat. (approx) 37" 50' S., long. (approx.) 147" 45', a dry hole 3246 ft. deep bottomed in the Jurassic and was abandoned. It was drilled by the Governments of the Commonwealth and the State of Victoria. At Lakes Entrance, 1st. (approx.) 37" 50' S.; long. (approx) 748", a small showing of' oil (a few pints a day) was obtained from a well drilled 1275 It., to the Upper Oligocene-Glaucnnitc series, by the Austral Oil Drilling Syndicate, No Liability. Future Drilling Preparations is are being made by companies fur further test drilling in 1939, and the Governments of the Common wealth and the State of Victoria are continuing test holes for information only in the Gippsland district of Victoria. In Papua and New Guinea, no test drilling was done in 1938, but several companies are carrying on geological investigation and it is expected that, some test holes will be drilled during 1939.

Jan 1, 1939

By O. W. Ellis

The writer has dealt with the effect of various methods of melting copper upon the gas content of the metal.' The copper referred to in his earlier paper was melted in the foundry both in the oil furnace and the electric furnace. As the metal did not measure up to conductivity standard, the term "casting copper" was applied to the material in the title of the paper. It was thought that some information in regard to the gases in a sample of overpoled copper might also be of interest, and through the courtesy of C. R. Stevens, superintendent of the copper mill of the West-inghouse Elec. & Mfg. Co., such a sample was obtained. The metal was chill-cast in the form of an ingot about 7 in. long, 2 1/2 in. deep (from the base to the raised surface of the ingot) and from 1 3/8 to 1 7/8 in. wide. A photograph of part of the ingot is shown in Fig. 1. The effect of over-poling on the surface of the metal is here quite clearly shown.

Jan 1, 1929

By L. S. Panyity

The question of natural-gas supply is receiving careful consideration in many parts of the country, as in the winter months it is quite a problem to have on hand sufficient gas to satisfy the demand. Increasing the output of wells by the application of vacuum has been tried with various results and large companies have attempted to keep up the supply with gas compressors. The possibility of storing natural gas in the sands of exhausted gas pools has been 'tried in a few instances with satisfactory results. This method may prove of practical value in solving the problem, especially in the case of towns that formerly obtained gas from their immediate vicinity but now must search for new pools. In all cases, only part of the available supply is utilized during the warm weather, so that many wells are shut-in, yet during the winter months, the supply is not sufficient even with all the wells on the line; in such cases it would be of great value if a large volume of stored gas were on hand, obtained through wells that would have been standing idle during the summer. Idle producing wells having considerable "rock pressure" will force gas into the exhausted, or storage wells, and this gas will be used only when the regular supply falls short (Fig. I). If two gas wells of different

Jan 1, 1920

By Marcie A. Greenberg, John C. Patton, R. Tim Thompson

The Fence Lake Project is located in the Salt Lake coal field, an extension of the San Juan Basin. Geologic formations exposed in the Project area range in age from late Cretaceous to Quaternary. Coal is encountered in the Moreno Hill Formation (upper Cretaceous). Salt River Project (SRP) followed the basic textbook approach for the exploration, regional appraisal, detailed reconnaissance, detailed surface detailed and three dimensional sampling (physical exploration). SRP is exploring this property as a potential fuel source for the Coronado Generating Station. Therefore, for the physical exploration stage, the quality sampling program was designed from a utility company viewpoint to determine possible impacts to the Station. Exploration drilling was completed in spring, 1982; September, 1982, and summer, 1984. Engineering, environmental, and land acquisition studies - in the Summer, 1984 Program to more closely evaluate the potential Fence Lake Project coal supply option for the Coronado Generating Station. Studies, including drilling, are ongoing at this time.

Jan 1, 1985

Many definitions have been advanced and many limitations advocated in the use of the terms, veins, lodes and ledges. The following definitions appear to follow the best usage. [ ] A fissure vein, according to Lindgren, is a mineral mass tabular in form as a whole, though often irregular in detail, filling or accompanying a fracture or series of closely set and intimately related parallel fractures in the enclosing rock, the mineral mass having been formed later than both the country rock and the

Jan 1, 1932

By M. J. Pearse

The processing of fine particles inevitably produces slimes. These present a dewatering problem, for which gravity thickening provides a partial or preliminary solution. The paper shows the effects of practical factors in carrying out laboratory sizing tests for thickeners. Several methods of determining thickener unit area have been compared for a lightly coagulated phosphate slurry and a highly flocculated kaolin slurry. Practical techniques of mixing and flocculant addition have significant effects on batch settling data. Pulp temperature and cylinder dimensions are very important. Errors in sizing thickeners for highly flocculated slurries by the standard methods are discussed. Such methods are suitable for less compressible slurries, however. Rules of thumb for flocculant selection are given.

Jan 1, 1980

F. W. Gordon, Philadelphia, Pa.: There can be no objection to the use of cross-compound blowing-engines; and when they are condensing they are susceptible of great range of duty with slight loss in efficiency. By those who have use for the full heat of the waste gases, this type of engine is advantageous; but many furnaces are not so located. The pig-iron is their finished product, and the gases are to be employed only for furnace-use. In this case simple engines are preferable, being less expensive and having less parts to take care of. These reasons determined the introduction of the engines, a sketch of which is distributed at this session. There are three of these engines to furnish blast for two furnaces, for a make of abont 250 tons per day, using 75 per cent. anthracite and 85 per cent. magnetic ores; and they are expected to blow up to twenty pounds pressure per square inch. For blast-furnaces I prefer the single to the coupled engine, except

Jan 1, 1894

By Henry Logan

THE purpose of mine-hoist safety con-trollers is to prevent hoists from being operated at speeds above those considered safe and expedient, to ensure proper accel-eration and retardation near the ends of travel, and to prevent overwinding. In other words, they are to safeguard the normal speeds and movements of the hoist-ing drums and cages. The object of this paper is to explain the fundamental principles of hoist controllers, and to aid in their selection, installation, and maintenance. There have been many designs of me-chanical hoist controllers, the basic ele-ments of which as ultimately developed consisted of a flyball governor and another movable member supported by a frame and arranged to move in a vertical, horizontal, or rotary direction, depending upon the particular design, the whole mechanism arranged to be driven in synchronism with the hoist drum. In case of overspeeding, inadequate retardation, or overwinding, a pawl or catch controlled by the governor would engage teeth or dogs on the moving member, which through mechanical con-nections would cut off the power and set the brakes.

Jan 1, 1940

By George B. Clark

THE geological data emphasized so successfully in prospecting for new deposits, that is, structural controls, strength of solutions, and type of mineralization, are basically those required for successful exploitation. In the mining of newly discovered deposits the most economical methods should be employed as early as possible to keep the overall cost per unit produced at a minimum and to permit maximum extraction of valuable minerals. A crucial question is: How can geological data be translated into useful quantitative results which will aid in achieving this end? H. E. McKinistry1 has suggested that a solution may be reached in one of two ways: 1-the usual approach, use of judgment based on experience; or 2-mathematical calculations and tests on models, both subject to certain limitations. He also suggests that in addition to better use of geology more case data and theoretical data are needed on which to base sound judgment. Further research, therefore, is necessary. Perhaps in this field the emphasis should be on more specialization in mining methods and ground movement by men with thorough training in physics, engineering, geology, and underground mining. These specialists would be equipped to point out the most economical and scientific methods of exploitation.

Jan 8, 1954

Arthur H. Elliott, New York, N. Y.: We have all been very much interested in the results of Dr. Bone's work, which Mr. Ellis has presented to us this evening. The high temperatures attained by this method perhaps afford us an explanation of the temperatures reached in the puddling-furnace with its crude and almost primitive methods of burning fuel, by means of which we have, nevertheless, been able to melt iron in a comparatively short time, and keep it in a molten condition down to a high degree of purity. No doubt many of us have wondered, as I have done, how such a result could be obtained in such a way; and it occurs to me that, perhaps, Dr. Bone has supplied the explanation in disclosing the effect on combustion of burning gas and air after passing through, and in contact with, a porous refractory body. May not the fettling of the puddling-furnace have, in some degree, an effect upon the combustion like the influence of the porous diaphragm employed by Dr. Bone ?

Jan 1, 1913

By Donald M. Hausen

Microscopic evaluation of trace quantities of metalliferous phases in flotation products requires counting large numbers of particles. Particle counts of many thousands may be required for precision, but cannot be obtained practically by conventional microscopic techniques. A less tedious microscopic method for evaluating trace sulfides in mill tailings was developed for the O'okiep Mining Co. in South Africa. Hundreds of thousands of particles were evaluated by this method called "gross-counting." Gross-counting consists of counting microscopic fields rather than point-counting individual particles. Total counts are calculated by multiplying the average number of particles per field by the total number of fields examined over the entire mount. Total gross-counts range from about 20,000 particles for +200 to 100,000 or more for -400 mesh size material in lucite mounts. Sulfides and metallic particles in each field are identified and tallied along with field counts. Totals for each type of metallic particle are divided by the total gross-count to give volume percent which is corrected to weight percent by specific gravity factors.

Jan 1, 1973

By Peter Joralemon

Peter Joralemon's contention that Nevada contains one of the world's major gold belts is the result of 30 years' active involvement with the state's regional geology. He first suggested the possibility of an arsenical gold belt-tenuously based on two replacement deposits 480 km (300 miles) apart-in his 1949 doctoral thesis of the Getchell mine. In the years that followed, some 18 or 20 arsenical gold ore bodies have been discovered along the lineament Joralemon postulated. In this article, he uses the evidence that he's collected over the last three decades to refine his 1949 thesis. Joralemon's conclusion: A mineral belt containing a billion dollars worth of gold extends the length of Nevada, and a number of ore bodies are yet to be discovered.

Jan 7, 1978

By Henry Souther

It is generally admitted that a god, practical and commercial set of specifications for the use of the many purchasers of cast-iron does not exist. A few good sets are in the hands of large buyers, but even these are very different, contradictory, and not intended to cover a wide range of product. Furthermore, most of them have been prepared to cover but one branch of the industry. It is strange that purchasers of cast-iron have not looked into this question long ago and demanded good, uniform cast-irou. Probably cast-iron has been discarded from many uses because of its failure in a few instances, even though the failure was due to ignorance of the quality of the iron, or perhaps to abnormally bad iron. Some foundrymen seem to consider all gray iron from a given foundry as uniform, especially if they know that it has been made from certain well-known brands of pig. It is likely that with standard specifications and the increase of knowledge necessary for their intelligent employ-

Jan 1, 1905

By R. E. Boehler, N. C. Ludwig

At Buffington Station, Gary, Ind., Universal Atlas Cement operates fourteen 8 x 10Y2 x 155-ft cement kilns in mill 6 and two 11 x 360-ft kilns in the Harbor plant. The No. 11 and 12 kilns in mill 6 are equipped with Manitowac recuperator sections. This report describes studies in measuring exterior shell temperatures on several of these kilns and the development of a traveling radiation pyrometer with certain novel features.

Jan 2, 1960

By Lawrence Addicks

Discussion of the paper of LAWRENCE ADDICKS, presented at the San Francisco meeting, September, 1915, and printed in Bulletin No. 104, August, 1915, pp. 1471 to 1484. L. D. RICKETTS, New York, N. Y.--In the Southwest we have stored up millions of tons of tailings in which the copper exists partly as sulphide and partly in an oxidized condition. Mr. Addicks' first paper suggests a, likely process for the treatment of such material. His second paper 1 deals with the recovery of copper from clear solutions of notable strength, and such solutions may come from the sulphating roast or direct from the leaching of completely oxidized copper ores of which vast deposits are known to exist. What strikes me particularly about the latter paper is the keen perception shown and the clear manner in which the writer has attacked the fundamental principles of the process. He calls your attention to the fact that ferrous sulphate is necessary in the electrolyte and is an ideal depolarizer; that sulphurous acid must be, used to reduce the ferric sulphate produced and thus prevent re-solution of copper at the cathode; that mechanical agitation in the cell, in order to bring the ferrous sulphate in contact with the anode and the copper in contact with the cathode, is essential to efficient work; that lead anodes are

Jan 12, 1915

By A. Bauer, P. Calder, N. H. Carr, G. R. Harris

Smallwood mine is part of the Iron Ore Company of Canada's Carol Lake operation and is situated in Labrador, 240 miles north of Sept-Iles, Quebec. Last year, 15 million tons of crude ore were crushed to yield 6.3 million tons of concentrate and pellets. This year the figures will be 17 million of crude and 7 ¼ million tons of concentrate and pellets, which is the full plant capacity. Carol Lake ores consist primarily of specularite and magnetite mixed with quartz. Since both rotary and jet piercing drills are used, it is often desirable in planning to know in which regions of the orebody, or new orebodies, a particular drill will be most economic. This makes it necessary to establish a correlation between drillability and pierceability and some physical rock property. For the rotary drills a good correlation was found with penetration rate and grinding factor index. The jet piercers were found to have a reciprocal relationship in the sense that the best rotary ground was the worst jet ground and vice versa. It is also indicated how an economic comparison could be made using these penetration rate versus grinding factor index curves, the hole size distribution curves for single pass and chambered holes, and the mine distribution curve for grinding factor index.

Jan 9, 1965