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By A. D. S. Gillies

The effectiveness of coal mine face ventilation and the ability of airflow to maintain satisfactory methane and respirable dust levels in the working face area has been studied through the use of scale modeling techniques and underground testing procedures. In particular, consideration has been given to examination of the effects of operation of a high airflow, machine mounted dust scrubber unit on face air patterns. Results obtained through a cooperative study with the Peabody Coal Co. demonstrate that new mining cycles can be considered that increase production efficiency while maintaining satisfactory ventilation conditions.

Jan 1, 1986

With over one year experience, Western Deep Levels Ltd., reports satisfactory operation with new features of its 200,000 ton per month gold reduction plant. Western Deep is Anglo American group's newest gold mine. It is situated 43 miles west of Johannesburg on the West Wits Line and will ultimately be extracting ore from a depth of 13,000 ft. Although the plant was put in production in March 1962, after a three month break-in period, construction of the fifth milling section was not completed until last month.

Jan 7, 1963

By C. Harries

The mechanism of blasting and the effect that blasting has on rock properties including the generation of new cracks and the opening of existing joints is discussed and compared with changes in seismic velocities. .Knowing the extent of blast induced damage and the overall stable slope angle it is shown that it is possible to design blasting so as not to induce any damage behind the toe of the blast area. Practical methods of blasting to meet this criterion and the results of these blasts are then discussed.

Jan 1, 1983

By Forbes Wilson

IN February 1952 Freeport Sulphur Company started exploration work on a group of lateritic deposits at Moa Bay, Cuba. As a result of successful exploration work and a vast amount of metallurgical research over the past five years, these deposits will soon become a new Free World source of nickel and cobalt. Moa Bay lies on the north coast of Oriente Province, the easternmost part of the island, about 600 miles east of Havana and about 40 miles east of the U. S. Government nickel plant at Nicaro.

Jan 5, 1958

By C. T. Cox

The title of this short paper necessarily implies that friction articles comprise a distinct and unique field and are different from the other metal-powder articles, such as bearings, electrical contacts, and magnets. However, this distinction is rather hard to define in that it is really one of degree and not Of kind. It would appear that the main distinction is that friction are are articles of rather large pressing area. In other words, they are articles in which the area Of the mold in which the metal powder is pressed is relatively large. Other articles made from meta1 powders are generally of rather small area, usually a few square inches, while in friction articles the area ranges up to several hundred square inches. The satisfactory production of meta1-powder friction articles involves many production problems and a large number Of these are accentuated by the large area' Since it is impossible in the short space of this Paper to describe adequately all the problems involved, I have thought it best to merely mention some Of them and to place particular emphasis upon a problem that is common to all metal-powder articles, although it is of greater importance in the making of friction articles. This problem has to do with the effect On the properties of a friction article of small variations in the composition. However, before discussing the problems, it is probably appropriate that some mention be made of the limitations on the use of friction articles. Most engineers are familiar with the general field that can be characterized as constituted by clutch facings and brake linings, and undoubtedly have heard many stories of how metal-powder friction articles have had a service life 10 times as long as nonmetallic friction materials, and of instances where metal-powder friction articles have operated satisfactorily where no other material could be used. These instances should not be regarded as criteria for the assumption that metal-powder friction articles are capable of universal use in the friction field and will always outperform other materials. On the contrary, metal-powder friction articles are unsuitable for numerous applications, either on a performance or on a cost basis. Metal-powder friction articles will not replace wooden block brakes for wagon wheels nor cast-iron brake shoes for railway car wheels, to mention just two obvious examples. Metallic friction articles cannot be used where they must act as heat insulatorsl for they have a relatively high thermal conductivity as compared with asbestos. This is a detriment in some uses, as in certain airplane brakes having hydraulic actuators provided with rubber seals. The metallic friction material readily transfers the heat developed at the braking surface back through the material to the rubber seal and destroys it. Within its limited field, metal-powder friction material has proved satisfactory, but many problems are involved in the Selection of the proper material to use in an application and in the commercial pro-

Jan 1, 1945

By Paul Torrey

IN his recent article, Stanley C. Herold described some of the principles involved in oil-field rejuvenation. The purpose of this paper is to present certain facts, based upon observations of systematic water flooding of oil sands in the Bradford and Allegany fields of northwestern Pennsylvania and southwestern New York, which, it is believed, will partially substantiate Mr. Herold's opinions. The writer gratefully acknowledges his obligation to the Forest Oil Corpn., the Kendall Refining Co., the Petroleum Reclamation Co., W. J. Healey, of Bradford, Pa., and the Producers Oil Corpn., of Olean, N. Y., for information included in this article; and he is especially indebted to Jerry B. Newby, of the Petroleum Reclamation Co., for helpful suggestions and criticism in the preparation of the paper. It is obvious that, in the calculation of mathematical formulas for the prediction of oil recovery, uniform conditions must be assumed; otherwise, the applicability of the results of such work will be, by necessity, restricted to the area or individual property for which they were designed. Geologic and physical conditions are so variable throughout the fields where water flooding is practiced that it is difficult to devise methods that can be universally applicable. However, it is believed that there are certain fundamental principles which, when applied with specific modifications designed to meet the conditions existing in local areas or individual properties, may yield considerably greater recoveries of oil.

Jan 1, 1927

By D. R. Walker, M. C. Shaw

THE laws of comminution of Kick and Rittinger have been debated for many years. Certain data obtained from ball mill and drop tests are found to be in approximate agreement with Rittinger's law while other data would seem to support Kick's law. In all these tests the energy required to produce a wide variety of particle sizes has been studied. Surface area has also been measured with considerable difficulty, at first because it was thought that the energy associated with crushing was that required to create new surface, later because of precedent and because a more fundamental variable was unknown. Tests made with the machine shop type of grinding process show that normally brittle materials that are usually crushed can behave like the more ductile metals. Brittleness is then a relative property largely dependent on specimen size and stress state. The machine grinding operation offers a convenient means for studying the comminution of materials in which the important size variable retains its identity. The energy required to grind a certain volume of material is shown to be strongly de- pendent on size. Kick's law is found to hold very well for particles below 1 micron in size, while Rittinger's law holds approximately in the comminution of larger particles. While a physical origin of Kick's law is established in terms of the theoretical strength of materials having a perfect lattice structure, there is found to be no physical basis for Rittinger's law.

Jan 3, 1954

By J. J. Beeson

The second part of the paper includes a detailed account of the processes of secondary-enrichment which have been effective in producing the disseminated ores. While both parts present new features, it is hoped that the discussion on secondary chalcopyrite and bornite may be of interest to those who are engaged in the study of secondary processes in other districts. The excellent work' Economic Geology of the Bingham Mining District, by J. M. Boutwell, was published in 1905. Since that time the extensive development work-surface cuts and underground drifting-of the Utah Copper Co. has made possible the collecting of samples for more detailed microscopic study. The writer has taken advantage of this fact and presents the following work, not as a criticism, but as a' continuation of the work which was begun by Mr. Boutwell. b. Acknowledgments.-The present study was undertaken at the suggestion of Dr. A. F. Rogers; to him, and to Prof. C. F. Tolman and Prof. S. W. Young, the writer wishes to express his thanks for criticism in the preparation of this paper. The writer also expresses his thanks to D. C. Jackling, Vice-President and Managing Director of the Utah Copper Co., for permission to publish this paper, and to William Spencer, D. W. Wadleigh, T. S. Carnahan, J. A. Caulfield, Percy Dayer, and Edward Norsefall, for the courtesies extended to him while a co-worker in the mines.

Jan 11, 1915

By L. Michael Kaas

On its tenth anniversary, the computer is a "fact-of- life" in the mineral industries. Its evolution as a practical mining tool was accurately summarized by Alfred Weiss, editor of the Proceedings of the 1969 International Computer Application Symposium, A Decade of Digital Computing in the Mineral Industry: "During the past decade, data processing and operations research developments within the mineral industry have evolved through states typical of any new technique. These have ranged from mere recognition, to cautious acceptance, to confident utilization, and in some instances, to substantial investment in computer hardware and software."

Jan 1, 1970

By Harold B. Foxhall

THIRTY per cent of the mineral wealth of the United States is obtained from seven states: Arkansas, Kansas, Louisiana, Missouri, New Mexico, Oklahoma, and Texas. This area, which produced 84,727,156,000 worth of minerals in 1948, constitutes an almost complete economic unit in relation to mineral resources essential to industry. All of these states are producers of fuels and some of metallics, but in the field of important nonmetallic industrial minerals the picture is near perfection-a mineral any one of the seven states lacks, one of the others has in quantity.

Jan 5, 1951

By Sergio G. Jarpa

A mining project is, at one and the same time, capital intensive and highly risky. Besides, because of its usual long projected life, the operating cost is more difficult to predict and offtentimes exceed, during the life of the project, the first investment manifold. The objective of this study was to evaluate the applicability of cost-capacity relationships as used in the chemical industry to mining operations and, when necessary, to develop new ones. With the aid of a computer library program available at the Computation Center of the Pennsylvania State University, the total investment in mining equipment was determined to vary exponentially with production capacity, and the scaling exponents for each class of equipment, i.e., drills, shovels, trucks and earth moving equipment, as well as for the total operation were calculated. Since the scaling exponent for the whole mining operation happened to be equal to 0.94, it was concluded that more significant economies of scale are achievable in processing plants than in mining operations. From the operating cost point of view, unit material cost was found to decrease more rapidly than unit labor for the same increases in production capacity. The analysis of cost centers revealed that drilling and blasting, which are materials-intensive operational stages, were the most favorable in achieving significant economies of scale. Hauling unit cost, on the other hand, decreased only slightly when production capacity increased.

Jan 1, 1977

By John W. Chandler

INTRODUCTION Where and how to spend the exploration dollar to net the greatest economic return, has always been a major problem for mining companies. Minerals are being consumed in ever increasing quantitie: throughout the world and the mining industry is being called on to meet this demand. In view of the present world-wide nationalistic trend, it is becoming more difficult to determine where exploration money can be spent most profitably. An exploration project should be evaluated continually--in the beginning, to define economic targets and later to determine, as early as possible, whether a project has a chance of developing into a venture that will make a profit acceptable to top management. At this point, a decision can be made whether or not to proceed with plans to bring in a new mine. Exploration, evaluation, and development, therefore, must be fully integrated in transforming an exploration project into a profitable mining venture. DEMAND FOR LEAD AND ZINC Lead and zinc are metals basic to our economy and the demand for them will continue to rise as the population in the world increases. If the population continues to grow at the present rate, it will about double by the year 2000. The accelerating demand for these metals is shown by statistics. Nearly half as much lead (48%) and more than half as much zinc (55%) have been mined between the two world wars as in all pre- ceding history. (1)

Jan 1, 1970

Man is born on Mother Earth without knowledge or skills. Soon he finds physical needs for food, clothing, shelter, exercise, and relaxation. His personal needs are self-expression, new experiences, and amusements, while his social needs have been classified as work, status, security, friendship, companionship, and love. He finds himself infinitesimal in comparison to the whole. Often- times when he feels smug, he is actually riding for a fall. And nothing is much worse than frustrated man. The postwar world does not provide the Utopia of peace and prosperity of which man had dreamed. In fact, it seems that the sacrifices and waste of that great struggle are being lost in the morass of stupidity, selfishness, and cupidity which unfortunately are still the most conspicuous traits of the human race. Perhaps it is too soon to expect the blessiilgs which are supposed to appear in a peaceful world, and man's thought is clouded with a pessimism engendered by the conflict itself, in which all activities tend to enhance his pessimistic nature. Must man submit that it is a law of nature for nations to go to war? The war has demonstrated that when faced with a common danger, peoples differing in antecedents, language, forms of government, and resources can unite for a time, pool their skills and abilities, and emerge victorious from a contest unparalleled in magnitude, ruthlessness, carnage, waste, and cost. This has been accomplished by great individual and national sacrifices, the

Jan 1, 1950

Mine Transitman.-Engineer, about 30 years of age, experienced in coal mine underground surveys. Must be good draftsman and possess sufficient personality to get results from the men. Location, Illinois. No. R 419. Coal Mining Engineer: Coal mining engineer of proved ability for position of manager f high-grade bituminous coal property. Location, Canada. No. R 427. Chemist or Metallurgical Engineer.-Chemist or metallurgical engineer for special library work. Man with scientific training with the ability and education -of a young instructor in a university. Duties would consist of working out a new method of indexing scientific information, more particularly in obtaining information for use of a Committee on the Heat Treatment f Steel. Location, Washington, D. C. No. R 470. Topographical Draftsman.-Civil engineering training and topographical and surveying experience. Unmarried man, under 40 years of age. Knowledge of Spanish not necessary. Discharged army or navy man preferred. Location, oil fields, Mexico. Salary, $5 per day, living and traveling expenses. No. R 483. Mechanical Draftsman.-Engineering training, familiarity with drawings of pumps, piping, etc., need not necessarily be a designer. Unmarried man, under 40 years of age. Discharged army or navy man preferred. Location, Mexico. Salary $5 per day with living and traveling expenses. No. R 484. Engineer Translator.-Engineer of Portuguese nationality who has received his technical training abroad, and has been filling engineering positions in this country, to translate material for catalogs of an engineering character. No. R 486.

Jan 5, 1919

By John L. Baum

GEOLOGISTS and engineers working around a diamond drill rig have often had the opportunity to observe the magnetic attraction of drill rods pulled out of the hole for core removal. This is sometimes an amusing pastime, but this same magnetic force inadvertently applied to a compass needle can cause it to lose its polarity entirely or to become reverse polarized when placed in the immediate vicinity of stacked rods. The first recommendation, of course, would be to avoid the rods, but in surveying an operating drillhole this is not always possible; therefore steps must be taken to neutralize the magnetic effect of the drill rods. Early in the summer of 1949 the geological department of the New Jersey Zinc Co. undertook at Franklin, N. J., an extensive program of surveying the course of deep diamond drillholes. The majority of the holes were surveyed while in the process of being drilled, and considerable difficulty was encountered. A pattern for the deviation of drillholes had been established for the district from surveys in holes from which the drill rig had been removed. It was observed that a certain operating deep drill- hole being surveyed did not fit this pattern. In the resulting confusion of repeated surveys and cementing a plug for wedging operations, the lower 1800 ft of the hole was lost. Because of this incident studies were initiated to determine the source of the difficulties and to develop safeguards against recurrence of faulty surveys.

Jan 12, 1954

SECTION I PAGE PAGE President's Western Trip v Presentation of the' John Fritz Hoover Makes Plea to. Stop Food Medal to Henry M. Howe.... xv Waste v International Mining Convention. xxxv. American Committee of Engineers Personal xl in London vii Employment xlii Proceedings, Meeting of Board of Local Section News xliii Directors : vii Forthcoming Meetings of Societies xlvii St. Louis Meeting V... Library xlviii The Woman's Auxiliary. xi Membership liv Members of the Institute in Mili- Biographical Notice of H. T. Chen. lxxiv tary Service xiv Institute Committees lxxv Officers and Directors lxxxii

Jan 7, 1917

I-institute of Metals Division S. SKOWRONSKI, Chairman ZAY JEFFRIES, Vice-chairman WILLIAM M CORSE, Secretary Executive Committee J. R. FREEMAN, JR, Local Section G E JOHNSON R S ARCHER, Non-ferrous Data Sheets P. D. MERICA EDGAR C BAIN, Journal Committee L W SPRING SAM TOUR, Papers Committee F. L. WOLI H. C. JENNISON, Membership Committee Local Section Committee J. R. FREEMAN, JR., Chairman R. J. ANDERSON, Cincinnati R L. DOWDELL. Minneapolis R. S WILLIAMS, BostoI G. H. CLAMER, Philadelphia W. A SCHEUCH, Chicago R. F. WOOD, New York

Jan 1, 1923

By Peter Sonnenfeld

Bedded potash deposits are known only from Phanerozoic evaporite sequences. They are composed of either sylvite or carnallite, of which only the former produces commercial potash ores. Both Permian and Neogene potash deposits have experienced sulfatization by percolating oxygenated surface brines, causing enrichment in the potash content. Permian potash deposits are mined in various parts of Europe and North America, Miocene ones only along the outer rim of the Carpathian Mountains and in Sicily. New discoveries of large Miocene rock salt bodies make it possible to predict the occurrence of potash deposits along their flanks.

Jan 1, 1985

By Albert D. Pernichele, Wayne C. Smith

Both water pollution and proposed solid waste disposal regulations have a definite effect on the copper leaching industry and some of the major factors affecting the industry are discussed in this paper. New developments of the NPDES are discussed with emphasis on the ‘toxic’ or priority pollutants, and EPA’s philosophy on the control of these pollutants. The protection of groundwater is the prime aim of RCRA through solid/hazardous waste management. Some of the major elements of the RCRA regulations that will effect the copper leaching industry are discussed.

Jan 1, 1980

By SME

"Comparison of Secondary Fe-Mn Oxides in Fracture Coating and Heavy-Mineral Concentrates as Sampling Media, Silver City Mining Region, New Mexico," a technical paper, appeared in the Aug. 1983 issue of the magazine. In Table 1, page 1182, the correct sequence of the first five metals in column 1 (Elements) should read: Zn, Pb, Cu, Fe, and Mn under "Central District" and Zn, Fe, Pb, Cu, and Mn under "Pinos Altos District." The published table shows the sequences transposed under the opposite districts. All other columns and sequences read correctly.

Jan 1, 1984