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By G. T. Lineberry, L. Adler

Reduced clearance a one of the most important characteristics of encumbered space in underground coal mining. Another key variable is the maximum velocity at which a piece of mobile mining equipment can operate in this limited space. Typical velocity-clearance curves for different mine transportation systems are developed and characterized. Applications of the relationships are examined, emphasizing their significance in designing and controlling mine materials handling system.

Jan 1, 1985

New York Meets first Wednesday after first Tuesday of each month. DAVID H. BROWNE, Chairman. JOHN H. JANEWAY, Vice-Chairman. F. E. PIERCE, Secretary, 35 Nassau St., New York, N. Y. P. A. MOSMAN, Treasurer. LEWIS W. FRANCIS. BENJAMIN B. LAWRENCE. Boston Meets first Monday of each winter month. HENRY L. SMYTH, Chairman. ALFRED C. LANE, Vice-Chairman. HENRY A. WENT WORTH,. Secretary-Treasurer, 60 India St., Boston, Mass. A. H. EUSTIS. F. G. STANTIAL. Columbia Holds four sessions during year. Annual meeting in September or October. FRANK A. ROSS, Chairman. RUSH J. WHITE, Vice-Chairman. LYNDON K. ARMSTRONG, Secretary-Treasurer, P. O. Drawer 2154, Spokane, Wash. FREDERIC KEFFER. - FRANCIS A. THOMSON.

Jan 12, 1915

By Atsushi Watanabe

Japanese Operations Research Committee for Mining Industry is one of the committees in The Union of Japanese Scientists and Engineers. Members of the committee are Dowa Mining, Furukawa Mining, Mitsubishi Metal Mining, Mitsui Mining and Smelting, Nippon Mining and Sumitomo Metal Mining. This paper is an annotated summary of study reports of the committee.

Jan 1, 1969

By W. Scott Dunbar

INTRODUCTION Methods of linking boundary integral (BI) solutions with finite element (FE) solutions have been well described theoretically in other publications (e.g., Zienkiewicz, et al., 1977). The purpose of this paper is to point out some practical aspects of implementing these linkage algorithms for rock mechanics applications and to describe an alternative linkage algorithm. A not so obvious motivation for using FE-BI linkages is illustrated in Figure 1. The cost of modeling the excavation of the crusher station by the BI method can equal or exceed the cost of an equivalent FE model. This is due to the large surface area which must be modeled by the BI method. In such cases, a more economical approach might be to model the region immediately adjacent to the crusher station by finite elements and link the solution at the periphery of the FE model with a solution for the exterior region. Further economies can be realized if some flexibility in the type of exterior solution is possible. For example, it would be desirable to use a coarse discretization of the FE-BI interface for a BI solution, which would be less demanding of computer storage and time, or to use an analytical solution for the exterior region. The alternative linkage algorithm to be discussed allows such flexibility. BOUNDARY INTEGRAL METHODS There are basically two formulations of BI methods: the direct and the indirect. FE-BI linkage algorithms depend on which formulation is used. The purpose of this section is to briefly describe each method.

Jan 1, 1982

By G. F. Comstock

H. M. BOYLSTON, Cambridge, Mass.-It might be asked, since this test is so simple, why it was not discovered before. It seems to me the explanation is that when we have used the sodium picrate solution, it has .generally been on a very, high-carbon or hypereutectoid steel; to detect . the presence of free cementite, and when we have looked for sulphides, it

Jan 4, 1917

By John M. Lovejoy

I take pleasure in transmitting herewith "Petroleum Development and Technology in 1927," in which we have attempted to set out in a series of 40 papers with attendant discussions the advances made in Production Engineering and Refinery Engineering during the year. The volume also contains a digest of round table discussions on Petroleum Engineering Research problems and Petroleum Engineering Education. In addition to the above we set out in 16 papers a review of production of each producing area of the United States and of the more important foreign countries, together with a review of the world's production and forecasts for 1928. We also include 8 papers on the Economics of the oil industry. The papers and discussions included herein represent the contributions of more than 200 engineers, including the foremost in each line. These papers were presented at technical sessions held in Fort Worth in October, 1927, and at the annual meeting in New York in February, 1928. We desire to express our thanks and appreciation to all those who have contributed to this volume. As in previous years, we have attempted to emphasize the value of both written and impromptu discussions. -We have made a practice of returning all impromptu discussions to the authors for correction and amplification, and because of this practice we feel that the discussions contained herein are in very presentable and readable form. It was decided by the nominat,ing committee when meeting for thc purpose of nominating officers for 1928 to eliminate the vice-chairrnanship for Transportation Engineering, as that branch of the industry seemed to come more naturally under the activities of the American Petroleum Institute. It was also decided by this committee to institute a new vice-chairmanship for Petroleum Engineering Research. Wc have had heretofore round table discussions on engineering research, but through the newly created vice-chairmanship, to which Mr. L. C. Uren was elected, we expect to have more comprehensive sessions on engineering research than heretofort.

Jan 1, 1928

By R. W. Callen, W. A. Hockings

This paper describes a computer program which calculates material balances for complex steady-state material flow circuits encountered in mineral processing. The program determines mass flows in the various process streams of a flowsheet from multicomponent analytical data obtained from samples of the streams. The program, Metallurgical Balance System (MBS), has been used extensively in treating Pilot plant test data, in production evaluation and control, and in plant design. The program performs well even on ill-conditioned data. Input to the program is easily accomplished by unskilled personnel and the output appears in well-formatted tables.

Jan 1, 1981

By A. Whillier

Methods are given for estimating heat flows into mining excavations of various types, with an example to illustrate how the refrigeration requirements are then determined after allowing for the cooling effects of the ventilation air.

Jan 1, 1981

The work of the Committee during the year 1914 was especially directed to the securing of a larger representation in the Institute of those engaged in coal mining and coking. While these industries exceed in volume and in monetary importance all other mining industries in the United States, the membership of the Institute representing them has in recent years been relatively small. It was thought that an increase in the membership of the Institute obtained from among those engaged in these industries was desirable in order to increase interest in the work of the Institute, for this result can only be reached by securing the presentation and publication of a larger number of papers relating to these industries. It is evident that the reading of such papers will tend to increase the attendance at the local and general meetings of the Institute. Sessions of the Coal and Coke Committee were held and a number of papers relating to these subjects were presented at the meetings at Butte, Salt Lake, and Pittsburgh, the Pittsburgh meeting especially being planned with this in view. The activities of the Local Section of the Institute organized in the Pennsylvania Anthracite region have reawakened interest in that district and it is hoped that the same object can be obtained in the bituminous coal fields, either through the organization of one or more. local sections, affiliation with some of the local coal-mining societies, or through activities of the Coal and Coke Committee. Referring to the work of the Committee in its efforts to increase the membership of the Institute, the Committee desires to acknowledge the services rendered by many members scattered throughout the various coal-mining districts of the United States, in compiling lists of those qualified for membership in the Institute, but who have not yet become members. The lists so compiled comprised about 1,100 names, which were furnished to the Committee by the co-operation of 40 or 50 members of the Institute.

Jan 3, 1915

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 C. A. Sobotowski, J. Eagan

Computer programs applicable to coal mining have been available for some time, especially in the academic sector. However, the computer has not routinely been applied to actual mining operations. This paper discusses how a computer system was set up as an important tool in mining design and decision making. The project was completed within the allotted timeframe of two months by taking advantage of existing technology. Key points include the selection of programs to meet the specified needs of the project, conversion of the programs to be compatible with a computer of a different manufacture, simplification of the data entry process, development of procedures for using these programs, and an explanation of how the reports generated from the programs were used for mine planning and decision making.

Jan 1, 1983

By J. Menashi, D. A. Douglas, A. S. Rappas

A process has been developed for recovering the refractory metals chromium (Cr), vanadium (V), molybdenum (Mo), and tungsten (W) in mixed secondary source materials, such as contaminated grinding wastes. The wastes are calcined with sodium carbonate in air to yield water-insoluble oxides of the base metals iron (Fe), nickel (Ni), cobalt (Co), and copper (Cu) and water-soluble salts of the refractory metals. An aqueous leach separates these two classes of metal values. Cobalt, nickel, and copper can be recovered from the oxidic residue by conventional processing methods. The leach solution is purified and then treated to recover the refractory metals. The process can accommodate a wide range of feed compositions and generates a minimum of aqueous effluents.

Jan 1, 1985

Discussion of the paper of L. W. BAHNEY, presented at, the New York meeting, February, 1915, and printed in Bulletin No. 9S, February, 1915, pp. 339. to 344. E. J. HALL,* New York, N. Y. (communication to the Secretary+).- The Chiddy method for determining gold and silver in cyanide solutions has been subjected to so many proposed modifications, of which L. W. Bahney's is one, it is natural to suppose the method is defective. There is no denying that this method is capable of giving inaccurate results, but so is any other method of quantitative determination. However, proof has not come to my notice that the troubles are inherent and not in the detail application, and I am inclined to think from our experience that in many cases it is the latter. Errors in this method may be occasioned by: (1) The retention of zinc in the sponge, which tends to desilverize the molten lead in cupellation, similar to the action in the Parkes process, removing gold and silver in a crust of zinc oxide. Failure to remove zinc may result from lack of concentration of hydrochloric acid, clue to neutralization by salts present, volume of liquid too great for the specified amount of acid, or the use of weak acid. (HCl rapidly loses its strength unless kept in perfectly tight containers. The HCl gas escapes even from the ordinary glass-stoppered acid bottles after the plaster seal has been broken.) Undissolved zinc, is likely to be held in the upper part of the lead sponge, which floats above the liquid, and unless the solution is boiled it will escape action. Mr. Bahney's modification makes this

Jan 5, 1915

By Jennifer Drake, Edward T. Moriuchi, Jennifer A. Hill

SEAMSYS and CSD/SMP are sets of computer programs that assist geologists and mine engineers in modeling and evaluating coal properties. The systems are tailored for treatment of waste and coal quality data, including metallurgical coal product capabilities. The gridded SEAMSYS model honors all drillhole data and incorporates user- defined mining parameters, losses and dilutions, and operational constraints. A variety of reserve reports and graphic displays are available from the model. Preliminary mine planning is accomplished through automatic cut generation and production targeting. CSD/SMP refines the preliminary plans to help anticipate the consequences of various mine schedules and evaluate equipment capacity requirements.

Jan 1, 1983

By H. H. Pentz

THIS paper gives the derivation of a practical formula for the calcu-lation of slopes in seismic reflection prospecting. The derived formula is an approximation and can be used where the slope of the reflecting horizon is less than 250 ft. per 1000 and the depth to the reflecting horizon is greater than 2500 ft. The slope of sediments in oil regions is generally considerably less than 250 ft. per 1000. This is particularly true of the Gulf Coast, with the exception of the salt domes, which usually have the sediments at a greater slope than 250 ft. per 1000.

Jan 1, 1937

RAYMOND M. Howe (author's reply to discussion*).-Dr. Unger states that magnesite will hardly supersede dolomite in fettling after a heat; that it is hard to believe a slag composed of oxide of iron containing about 6 per cent. of phosphorus is the active corroding, agent in a boil in a furnace; and that boiling cannot be said to be the result of the chemical action of a high-phosphorus slag on a basic bottom. These are well-established facts that no one would venture to question. The authors were misinterpreted in the statement that "in the summary, it is claimed that magnesite low in lime, or of greatest purity, ranks first in resistance to slaking," etc. On the contrary, the position has been taken throughout that while a low lime content is advantageous, the presence of several per cent. of iron oxide (an impurity), is necessary in order to confer the proper bonding and sintering properties in dead-burned grain magnesite to be used for furnace hearths. We cannot subscribe to the view that pure magnesia is no better fitted for a refractory than pure lime,' nor that the pure natural varieties of magnesite; such as Grecian or Washington, must necessarily be burned with silica and oxide of iron to produce a satisfactory material. On a small scale, pure magnesia has been satisfactorily used as a refractory in the form of crucibles. In the production of dead-burned grain magnesite from the Grecian or Washington mineral, iron oxide is added but the addition of silica is neither customary nor desirable. It is possible to manufacture brick of good quality from both the Grecian and the Washington material without adding either silica or iron oxide, providing they are burned at a sufficiently high temperature. This is regularly done on a commercial scale both in America and abroad when brick of. exceptionally high refractoriness or special purity are desired. The following analysis is of an English brick of Grecian magnesite which is extremely low in all impurities.1

Jan 6, 1919

By Rudolph G. Wuerker

WITH the growing complexity of ore dressing processes and the diversity of equipment, efficiency control has become increasingly important in beneficiation. In the case of iron ore dressing, there have been sporadic attempts'-3 to establish the optimum separation for various ores so that grade and recovery would be readily predictable. But no rigorous statistical analysis and graphical presenta- tion of such tests could be found in the literature of this country. Tests Made with Iron Ores Expanding upon existing methods of plant supervision and efficiency control, an investigation was started in the ore dressing laboratory at the University of Illinois on the applicability of distribution analysis to iron ores. A sample of crude ore was obtained from the Ohio mine of Cleveland-Cliffs Iron Co. at Ishpeming, Mich., consisting mostly of alternating bands of hematite and siliceous gangue, both about 1/4 in. wide. The ore was heavily coated with limonite, which often filled the cracks.

Jan 1, 1959

By S. C. Termes, P. E. Richardson, R. L. Wilfong

This paper discusses recent Federal Bureau of Mines research on the selective flocculation of various minerals with insoluble cross-linked starch xanthate (ISX). ISX is insoluble, has a shelf life of more than a year when kept cold, and has a higher molecular weight due to cross-linking than the soluble, non-cross-linked starch xanthate used in previous flocculation studies on nonsulfide minerals. ISX readily flocculates a number of sulfide mineral fines, but no silicious gangue. Floc formation, floc size, and settling rate are dependent on pH. The pH dependence, however, differs for each mineral. Bornite has been selectively flocculated from bornite-quartz mixtures, and the bornite-containing flocs were separated from the unflocculated quartz using decantation and washing procedures.

Jan 1, 1984

By John J. Dran

The elaborate analytical techniques for risk analysis used by the large mining companies in conjunction with the valuation of mineral reserve sites are totally inappropriate for the small miner. The small miner does not possess the financial and technical resources which are available to the large companies for such risk analysis. Even if these resources were available to him, the relatively small size of his investment would not justify a huge expenditure for risk analysis. What is required by the small miner is an improvement over the single point estimates provided by the valuation techniques that he currently uses. Such improvement should provide an indication of the extent to which the true value (known only after the fact) might differ from his estimated value of the mineral reserve site. In addition, a rough indication of the chance of occurrence of various differences between the true and estimated values would be helpful to him. These improvements must be obtained at low cost to be useful to the small miner. Such improvements would have to be based on a simple system requiring very few additional estimates by the miner. The small miner is not accustomed to dealing with sophisticated risk analysis techniques. Hence, any complex, time-consuming approach would be doomed to disuse or possible misuse. A simple, uncomplicated approach requiring a minimum of additional estimates by the miner can be based on a system devised by Frederick S. Hillier Although Hillier's method can be applied to various mineral reserve valuation methods used by the small miner, this note is specifically oriented to the discounted cash flow model. The basic discounted cash flow (DCF) approach provides a single point estimate of value and introduces the concept of risk (i.e. the possibility that the annual cash flows may differ from their estimated values and thus lead to an incorrect investment value) through the use of a risk-adjusted discount rate. This approach simply lowers the present value estimate with increases in the discount rate (i.e. increases in the risk assessment). The single point estimate still remains. Although the lower value estimate makes it less likely that the risky investment will be deemed profitable and undertaken, it provides no indication of risk that is suitable for examination and analysis. In addition to the "best guess" estimate of annual net cash flows required in the DCF model, application of the Hillier risk analysis model requires that the miner

Jan 1, 1976

By Alan Stanley

THE Maclntyre Development of National Lead Co. is located at Tahawus, N. Y., in the heart of the Adirondack Mountains. Operations involve the mining and concentrating of a titaniferous iron ore to produce ilmenite and magnetite concentrates. A general description of the operation and metallurgy has been given by Frank R. Milliken.1 Pigment plant production demands that the MacIntyre mill produce a 44.7 pct. TiO2 ilmenite concentrate. To achieve the required ilmenite grade and tonnage it is important that the table concentrate grade be closely controlled. Unfortunately, however, the titaniferous orebody which feeds the Maclntyre mill is not uniform. Ore dressing characteristics vary from one end of the orebody to the other, and from one level to the next.. The changeable nature of the mill feed precludes a single adjustment of the equipment for long periods of time. Thus the operators must constantly watch the equipment to insure a uniform concentrate from the fine and coarse tables and Wetherills, or dry magnetic separators. Chemical assaying of mill products requires about 4 hr from the time the sample is taken until assay results are obtained, and this is available only on a two-shift basis. The ore may change rapidly, even several times during a shift, so that assay results lose most of their control value by the time they are reported to the mill operating crew. Members of the crew have therefore tried to evaluate the table and Wetherill concentrate by visual inspection, since through long experience the shift operators, under most circumstances, can gage closely the grade of the mill products. However, there are times when the, physical nature of the ore is radically different from normal. Under these conditions visual inspection is of no value, and at such times final ilmenite as low as 43 pct TiO2 has been produced and shipped before the assay results have been received. The specific gravity method of assaying for TiO2 has been attempted to eliminate the shipping of ilmenite below normal grade as well as to help control day to day and hour to hour mill production. Table I shows the minerals found in the Maclntyre ore along with their average weight proportions and specific gravities. The first two products considered for the specific gravity method were fine and coarse table concentrates. It was reasoned that these products were essentially ilmenite with the higher specific gravity gangue minerals. Since they were always produced the same way, and the desired grade of TiO2 was always constant, the specific gravity of these materials would increase or decrease as the amount of ilmenite increased or decreased. Thus for table concentrates which assayed 40 pct TiO2 a constant gravity would invariably be obtained, and as the TiO2 value changed the specific gravity would change in direct proportion. The third product considered was Wetherill ilmenite. It was assumed that a desired grade of 44.7 pct TiO2 would also always contain the same amount and type of gangue minerals along with the ilmenite, and thus would always have the same specific gravity. As the TiO2 value of the ilmenite concentrate changed so would its specific gravity. Dr. Kenneth Vincent, chief metallurgist of the Baroid Division of National Lead Co. at Magnet Grove, Ark., ran specific gravity tests on 17 samples of the desired products. The lowest specific gravity reading assayed the lowest in TiO2 and as the specific gravity increased the trend was for the TiO2 assay to increase, see Fig. 1. Since these results warranted further investigation, a 500-g capacity Torsion balance and 250 ml Le Chatelier specific gravity bottles were obtained. [ ] Shift samples of fine table concentrate, coarse table concentrate, and final ilmenite were tested. Each sample was split and 85 g weighed on the Torsion balance. The Le Chatelier bottle was filled with water to a zero mark. To avoid wetting the neck of the bottle it was found necessary to do this

Jan 1, 1952