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By Jack Fox

It is some time since these columns have contained a report to the members on just what is doing in the Society of Mining Engineers. Accordingly, even though it is now a month and a half after the Annual Meeting in Denver, it seems that a report on what transpired at the SME Board Meeting there is in order. First off, I'd like to say that the Members of the Society of Mining Engineers can be justly proud of their representatives on the SME Board of Directors. Of 21 members and officers on the "Old" Board of Directors, 19 were present. President Brower Dellinger chaired the "Old" Board Meeting. Of the 21 members on the "New" Board of Directors, every single one was present. James Boyd, the outgoing AIME President, attended and expressed his appreciation of the support that the Society of Mining Engineers had given him during his year as President of AIME. Members Multiply Robert S. Shoemaker, Chairman of the SME Membership Committee, pointed out that based on figures available, the Society of Mining Engineers had a net gain of 523 members during 1969 while SPE had a 490 net gain and The Metallurgical Society a net loss of 159. This is probably the first time in the last 20 years that anyone has exceeded the SPE net gain in membership. While SME still has a way to go to surpass the Society of Petroleum Engineers in number of members, we did have, on December 1, 1969, 16,369 members. However, 419 were dropped at the end of that month leaving us with a net for the year of 15,950.

Jan 1, 1970

By W. L. Zeigler

THE Galena mill of the Callahan Zinc-Lead Co. is of 150 tons daily [ ] capacity and is situated at Lake Gulch, 2 miles west of Wallace, Idaho. (Fig. 1. It was constructed during the summer of 1926, work having been started late in June and the plant placed in operation Oct. 15, following.

Jan 1, 1928

By W. L. Zeigler

The Galena mill of the Callahan Zinc-Lead Co. is of 150 tons daily capacity and is situated at Lake Gulch, 2 miles west of Wallace, Idaho. (Fig. 1. It was constructed during the summer of 1926, work having been started late in June and the plant placed in operation Oct. 15, following.

Jan 1, 1928

By Pierre R. Hines

The first progress in American ore dressing practice was made in the mills of the Mother Lode in Calif., the Comstock Lode in Nev., and Gilpin County in Colo., during the years 1861 to 1870, when the ancient wooden stamp battery, with square wooden stems, was converted into the 'California' stamp made of wrought and cast iron, with round stems which rotated. Eli Whitney Blake invented the jaw crusher in 1858 for stone crushing, and it was soon used for crushing ore. F. W. Gates' gyratory crusher followed twenty years later. S. R. Krom, Thomas A. Edison, and others improved the Cornish rolls by increasing their size and spring pressures; the Symons Brothers made horizontal and vertical disc crushers; W. Ball and E. T. Leavitt designed powerful steam stamps for Lake Superior native copper ores; and jigs were mechanized. William B. Frue, a mill superintendent in the Lake Superior copper district, invented the vanner in 1874. Arthur F. Wilfley built his riffled concentrating table in 1895, just after Dr. Robert H. Richards commenced his Ore Dressing. The Wilfley table so changed concentrator flow sheets that Dr. Richards was compelled to revise his text, and its publication was delayed until 1903. The value of sizing or classifying before concentration was recognized. Dr. Richards had persuaded the Anaconda Copper Mining Co. to install round tables with special surfaces to catch the 'extremely fine free mineral.'l Gravity concentration had achieved almost every refinement for recovering or separating minerals by the difference in their specific gravities. However, one serious problem remained unsolved, i.e., how to retrieve the enormous loss of the extremely fine mineral in the slime portion of the ore. Slime, then, as now, was not a precise term due to the variation in the mineral composition of the ores and the different requirements in crushing, grinding, sizing, and classifying. At that time, slime was considered to be fine sand and colloidal material passing 100 mesh.2 Most sulfide ore minerals are more friable than their associated gangue minerals, so that crushing and grinding increased the proportion of the extremely fine ore minerals in the slime. Sparkling specks of galena, chalcopyrite, argentite, or ruby silvers, according to the ore, floating away on the tailing stream from vanners and slime tables, were familiar sights in the old gravity concentrators. Gravity concentration practice was aimed at recovering the ore minerals at the coarsest possible size because the recovery was higher and unnecessary

Jan 1, 1962

By G. H. Walrod, J. M. Mutmansky, Y. J. Wang

The selection of a shaft size for ventilation purposes is a classic problem of concern to mining engineers. This presentation is concerned with the sizing of conventionally-sunk circular shafts with concrete or shotcrete linings. Costs of sinking shafts of three different depths, from 150 m to 300 m (500 ft to 1000 ft), and six different diameters, from 4.27 m to 7.32 m (14 ft to 24 ft), were obtained through questionnaires to shaft contractors. The primary objective of the economic model presented is the balancing of detailed annual capital and operating costs to achieve the minimum overall cost of the shaft installation over its life. The economic model is similar to previous analyses but treats several of the individual cost categories in an updated fashion. Included in the paper is a detailed analysis of the effects of varying power costs on optimal shaft size. Also included are a statistical analysis of current shaft costs and comments on the choice between shotcrete and concrete linings.

Jan 1, 1979

By Jan M. Mutmansky, Gordon H. Walrod, Y. J. Wang

The selection of a shaft size for ventilation purposes is a classic problem of concern to mining engineers. This presentation is concerned with the sizing of conventionally-sunk circular shafts with concrete or shotcrete linings. Costs of sinking shafts of three different depths, from 150 m to 300 m (500 ft to l000ft), and six different diameters, from 4.27 m to 7.32 m (14 ft to 24 ft), were obtained through questionnaires to shaft contractors. The primary objective of the economic model presented is the balancing of detailed annual capital and operating costs to achieve the minimum overall cost of the shaft installation over its life. The economic model is similar to previous analyses but treats several of the individual cost categories in an updated fashion. Included in the paper is a detailed analysis of the effects of varying power costs on optimal shaft size. Also included are a statistical analysis of current shaft costs and comments on the choice between shotcrete and concrete linings.

Jan 1, 1980

By John D. Sullivan

Leaching of copper ores is a comparatively old art, probably dating back to medieval times. The leaching of mixed oxidized-sulfide ores, however, is modern. The first modern plant leaching mixed ores was at Ajo, Ariz., where commercial operations commenced in 1917. While the ore at Ajo was primarily oxidized there was always some sulfide present. The Inspiration leaching plant, which was put in operation in 1926, may be considered the first plant constructed for the extraction of both sulfide and oxidized copper. The pioneers in leaching mixed ores had a difficult task before them since they had very little fundamental data on the chemical and physical factors of leaching. For the very large amount of painstaking experimental work that was done before building the Ajo and Inspiration leaching plants the reader is referred to the original articles.' For a period of several years the writer worked on problems connected with the chemistry and physics of leaching mixed oxidized-sulfide ores. This paper summarizes the experimental work and discusses various factors involved in leaching ores. It also presents many data heretofore unpublished. Among the new data are those on chrysocolla, pages 518 to 519, inclusive; dioptase, page 519; covellite, page 529; virtually all those on chalcopyrite, pages 531 to 533, inclusive; enargite, page 533; and tetrahedrite and tennantite, pages 534 and 533. The oxidized copper minerals of commercial importance in American ores are azurite, Cu3(OH)2(CO3)2; malachite, Cu2(OH)2CO3; chrysocolla, CuSi03.2H2O; tenorite (or melaconite), CuO; and cuprite, Cu2O. Dioptase, CuSiO3.H2O is less common. Brochantite, CuSO4.3Cu(OH)2, while the chief mineral in the ore at Chuquicamata, is not of major importance in the United States. Metallic copper, while chemically not so, is frequently classed as an oxidized mineral of copper. The most important sulfide minerals are chalcocite, Cu2s; covellite, CuS; bornite, Cu5FeS4; and chalcopyrite, CuFeS2. Less important complex sulfides are enargite,

Jan 1, 1934

By Franklin J. Kay

Introduction The methods used in surface, mining vary throughout the world, depending on many variables such as: the types of over- burden materials, the depth of the overburden, the thickness of the seam, and other operational choices, both financial and functional. However, the stripping machines are typically draglines, stripping shovels, excavators, scrapers, loaders, and bulldozers. In all cases the economic feasibility of mining thin seams depends on the market needs, the market location, the equipment used, the mine management, the quality of the coal, and the labor market. Slight negative combinations of these parameters have closed many mines while positive combinations allow others to exist. The limited mobility or slow movement of large stripping shovels, draglines, and bucket wheel excavators make them more economically fitted to areas where large quantities of overburden are to be moved. This is necessary to keep the transfer and setup time between pits a negligibly small percent of the total operational time. Equipment such as the scrapers, loaders, backhoes, trucks, and bulldozers that are either very mobile or can be trailered is more versatile and can be used in the smaller area mines.* Mobile equipment is also more practical in areas with shallow overburden because of the constant movement required while removing overburden. In thin coal seams the equipment is usually paired such that the operational equipment can be listed as: (1) dragline-loader, (2) shovel-truck- loader, (3) scraper-loader. (4) loader-truck-loader, or (5) loader-loader. In these operations the overburden is removed with the first machine(s) of the pairing and the loader or loaders are used for coal production. Recent articles in Coal Age (Chironis, 1978) and Mining Engineering (Wiebmer, 1978) have discussed varying philosophies in mining similar seams of coal. One operator uses draglines for competitive mining while the other uses scrapers for the same purpose. Both cite strong cases sup- porting their choice of equipment as good sound economic decisions and their success supports their choices. The drag-line operation is adding new larger draglines to decrease the cost of mining, rather than to increase coal production. The scraper operation has also gone to more and larger scrapers for basically the same reasons. These operations and all

Jan 1, 1981

By N. E. Norman, R. Stier

The mining industry is continually seeking out new and better underground mining techniques. One of the most recent-also, perhaps, the most significant-of the new concepts in underground mining is the use of mechanical rock-boring machines. And one of the problems that concerns us all in this matter is the cost of mechanical rock tunneling. To help answer the oft-quoted question "What will it cost me?" the following pages deal with the operating costs of so-called "medium to medium hard rock" boring machines-i.e., those designed to meet the drilling requirements in 8000 psi to 25,000 psi rock. A few machines are capable of drilling hard rock above 25,000 psi, but the economics of mechanical tunneling in rock that hard is limited at the present time. [ ] For mechanical rock tunneling, there are five main cost factors influencing the expense: Capital Investment, Cutters, Labor, Power Requirements, and Maintenance. These factors give us a good basic picture of the cost of excavation, although muck handling, erecting supports, and other costs directly related to conventional tunneling and mechanical boring enter into the final picture.

Jan 6, 1967

By Kenneth E. Mathews, Ross D. Hammett, S. Byron Stewart

Theoretical models have been important throughout the history of engineering as a means of understanding past experiences and predicting future performance. Most modelling involves assumptions and a degree of idealization, and it is shown that it is important that the effects of these be recognized when making use of models. One of the principal concerns in underground mining is the effect of the excavations on the states of stress in the rock adjacent to these excavations. As mining proceeds to depth, stress concentrations may be sufficiently high to cause inelastic behaviour of the rock and yielding along joint surfaces. At this stage, attention must be given to the sequencing of the mining process to ensure that the ground control techniques applied are optimized. Increasing use is being made of computer modelling techniques to assist with design. Three case studies are presented to illustrate the application of computer models in mine planning and ground control. In all cases, the data available for design was limited, but the mines were fully developed and openings could be inspected. The mining methods studied are cut and fill stoping, room and pillar stoping, and longhole stoping.

Jan 1, 1983

By S. J. Hubbard, S. D. Michaelson, A. W. Last, B. H. Ensign

Of the seventeen western states, five-Arizona, Utah, New Mexico, Montana, and Nevada-produce about 90 pct of this country's primary copper. All seventeen of these states occupy 60 pct of the nation's land area but receive only 25 pct of the country's total precipitation. Seventy percent of this precipitation returns directly to the atmosphere through evaporation and transpiration, leaving very little for ground reservoir recharge or immediate domestic, agricultural, or industrial use. With so limited a supply available for all, competition for water rights among users is severe. The result does not always permit using the limited supply to produce the most valuable end product. Most of industry and much of agriculture can shop around for suitable operating locations. Where water is critical to their purposes, they can and do locate in areas where the needed amounts are available. Such is not the ordinary lot of the mining industry, which must locate in the area of the deposit it is planning to mine and concentrate. In the case of copper this happens to be, for the most part, right in the heart of the semi-arid regions of the West.

Jan 7, 1960

By R. D. MacDonald

The search for metalliferrous deposits in the Labrador-Ungava Trough of Canada dates from 1929 when non-ferrous minerals were the main quest of prospectors in this area. Many gossans, resulting from the oxidation of sulfides, were located and examined but none of these led to any orebodies of commercial value. However, such investigations did much to arouse interest in this area and fostered further mapping and prospecting. Since this early period in the history of prospecting in the Trough, the presence of iron ore deposits and potential iron producing sites has commanded the center of attention of exploration personnel. The iron-bearing rocks of southwestern Labrador have in recent years come into prominence as possible sources of iron ore of the beneficiation type. Exploration and development work has been carried on in concession areas granted by the Newfoundland Government to the Labrador Mining and Exploration Co. Ltd. and to the Newfoundland and Labrador Corp. In the course of evaluating its holdings in the Wabush Lake area (Fig. l), Labrador Mining and Exploration Co. has conducted geological, geophysical and diamond drilling programs.

Jan 10, 1960

By F. Newton Parks

SOUND management organization is as essential to a mining operation as sound mining practices, exploration methods, concentration processes, or marketing methods. In fact, if a mining company is well organized, with the right people in the right management positions, it can be reasonably assured of the adequacy of its operating practices. Management problems in mining are unique, but certain principles of organization are universal. These principles should be used as ground rules in mining as they are in other industries.

Jan 5, 1958

By E. P. Mathewson

DURING the past 35 years it has been my privilege to deal with hundreds of recent graduates from engineering schools all over the world. In consequence, I, feel that I have learned something about the training of, engineering students. In the first place, I believe that too great specializa-tion is a mistake. A student should receive general training in engineering for at least three out of the four years of the course, and any specializing that may be required should come in the fourth year. Too great emphasis can not be laid upon the fact that the four years' training does not make an engineer; on the contrary, the graduate is only fitted to enter the pro-fession. He becomes an engineer in the true sense of the word only after years of practice; the college train-ing merely shows him where to look for information and develops his intellectual powers. Some of our engineering schools have lengthened the term of study to five years and talk of increasing it still further. This, in my opinion, is a mistake. A young man who spends more than four years in college is apt to become too academic and theoretical. It is better to stiffen the matriculation examinations than to prolong the years of study in college. No matter how good the faculty may be and how carefully selected the course of study, the graduate can never become an engineer unless he has some natural qualifications for the vocation. There are one or two subjects in which most recent graduates seem to be weak; these are accounting, the command of English, and training in the writing of reports. A short course in general accounting should always be included in the curriculum. To this should be added instruction in the preparation of estimates and cost statements. In making reports it should be borne in mind that these reports are to be submitted to busy men,-and not to technical men. The busy man wants the gist of the report summarized on the front page of the report. He wants to know that if he expends a certain sum of money in a certain way, he will get certain results and make so much profit. This should be put clearly before him in short statements, free from technical terms. The details of the report can follow .at greater length; it should be remembered that the employer is not going to read these details, but will confine his attention to the summary.

Jan 1, 1923

By J. Kitagawa

INTRGDUCTION The Paragsha concentrator is the largest of Cerro de Pasco Corporation's base metal beneficiation plants operating in Peru. At present, this plant is treating an average of [ ]

Jan 1, 1970

By Marvin P. Barnes

The Sacaton open pit copper mine has recently been placed into production. Some problems have been encountered in maintaining grade control due to differences between early block estimates and actual production grade. A study was made using three methods for computing grade for 50' x 50' x 40' size blocks from exploration and development drill holes; 1) The polygonal method, 2) The inverse distance squared method, and 3) The geostatistical kriging method. The results of each were compared against a control block file created by using the assay results of all blast holes drilled in the ore over three benches of the new pit. Results indicate that the kriging technique gave better estimates for grade of individual blocks than did the other two methods for this particular deposit.

Jan 1, 1977

CHARLES G. ROEBLING Charles Gustavus Roebling, president of the John A. Roebling's Sons' Co., of Trenton and Roebling, N. J., and of the New Jersey Wire Cloth Co., of Trenton, and vice-president of the John A. Roebling's Sons' Co., of New York, died at his home, No. 333 West State Street, Trenton, on Oct. 5, 1918. Mr. Roebling, who was born in Trenton, was a son of the John A. Roebling who finished the plans for the Brooklyn Bridge just before he died. The bridge was completed by his sons, Charles G. Roebling and Col. Washington A. Roebling. Upon graduation from the Rensselaer Polytechnic Institute in 1871, Charles Roebling became associated with the Roebling company as a mechanical engineer. He was engineer and builder of the suspension

Jan 12, 1918

By Christine Alexander

Twenty years ago, the northern Oquirrh Mountains overlooking Salt Lake City were bare. Heavy logging and overgrazing combined with erosion and uncontrolled forest fires had severely denuded the mountains by the turn of the century. As a final coup de grace, a copper smelter was built there in 1906, and for the next 50 years its sulfurous fumes killed off what little vegetation remained. In 1956, Paul Rokich, a biology student at the Univer¬sity of Utah, started to surreptitiously restore the mountains. For the next 17 years, Rokich devoted his spare time and money to replanting the Oquirrhs, with the result that several thousand acres of the mountains are green again, and animals have returned: deer, elk, and rabbits thrive among olive, maple, and fruit trees, wheat grass, and sunflowers.

Jan 10, 1975

By Ross W. Smith, M. E. Wadsworth, T. James Smolik, A. S. Peck

Ross W. Smith (Acting Instructor, Department of Mineral Engineering, Stanford University, Stanford, Calif.) and T. James Smolik (Kennecott Copper Corp., Salt Lake City, Utah) - Professors Peck and Wads-worth have made an interesting contribution to the study of fluoride activation of beryl. We have a few comments to make regarding the paper and a question to ask of the authors. We note that glass containers were used in the study. Hydrofluoric acid should react with glass to produce SiFg2 in quantity which could adsorb onto the beryl surface (onto either beryllium or aluminum sites). The authors propose that individual F- ions actually go into the mineral surface lattice rather than onto the surface by adsorption of siFi2 ions. Based on infrared reverse bands with an untreated

Jan 1, 1969

By J. A. Herbst, J. L. Sepulveda, J. D. Miller

Effective bismuth removal from flue dust residues has been accomplished for flue dusts from both zinc and copper smelters. Selective dissolution of bismuth, with respect to silver and lead, can be achieved by the proper manipulation of temperature, sulfuric acid addition and sodium chloride addition. Optimum levels of these variables were determined using a response surface technique to maximize the objective function: Y = %Bi/(1 + %Ag). In the case of the flue dust residue from a zinc smelter, which contains bismuth as an impurity (0.05%), 86% bismuth removal can be realized with less than 1% combined silver and lead dissolution. Similarly, in the case of flue dust from a copper smelter, which contains bismuth as a primary constituent (3.3%), 93% bismuth removal was obtained with little dissolution of silver and lead values.

Jan 1, 1977