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By S. C. Fall

The basic aims of the drilling and blasting program at the Mission mine are fourfold: 1. To provide 100,000+ tpd of broken alluvium and rock material for shovel excavation; 2. To obtain fragmentation that will permit the most efficient digging of the broken material and provide an acceptable crusher feed; 3. To conduct the drilling and blasting program in accordance with approved safety procedures; 4. To obtain these objectives at the lowest possible cost. The material that is mined from the pit is divided into four different rock types and the overlying alluvium. Each of these materials is broken by using procedures tailored to its individual characteristics.

Jan 9, 1965

By James Gayley

The paper presented to the Institute in 1910, by H. O. Hof-man, on Recent Progress in Blast Roasting,' has called the attention of the iron industry to the adaptability of these processes to the reclamation of by-products such as flue-dust and blue billy, and the better preparation of concentrates and fine ores for use in blast-furnaces. The waste of valuable iron-ore through the production of flue-dust has increased at an enormous rate, and much of it has in

Jan 1, 1912

By David Cole

The appearance of the Wilfley table in 1897 marked an epoch in the art of concentration of ores. The table has merited and received an almost unprecedented measure of public approval, lasting through its whole patent life. It has been very little improved in itself, or improved upon by competitors. The new machines bidding for popular favor have been of the Wilfley family, but without ability to do markedly better work than the parent machine, or to do more work except by the use of superimposed decks, the latter having obvious disadvantages. During the past three years there has been developed at Morenci a new type or arrangement of riffles applicable to the Wilfley type of concentrating table which corrects many of the objectionable features or limitations of the older system and obviates most of the difficulties encountered with it, particularly when handling ores having a low ratio of concentration. The new type is known as the Butchart1 riffle system, and its general arrangement is shown in Figs. 1 and 2. The old system accomplished stratification satisfactorily but has

Jan 1, 1915

By Ray W. Amstutz

The shaft was drilled on US government land m the Piceance Creek basin and was funded by the US Bureau of Mines (USBM). It was drilled to 723 m to provide access to rich deposits of oil shale, nahcolite, and dawsonite for geotechnical test work and environmental mining research. Rotary drilling and dual-string, reverse-air, jet-assist circulation methods were used. Drilling required eight months. Site preparation, running, and cementing the casing required another four months. A 2.44-m ID steel welded casing, 508 mm thick was installed and 2.7 kt of cement were slurried and pumped into the annulus.

Jan 1, 1982

By Walter E. Heinrichs

Since World War II exploration geophysics has derived its scope from the following factors: first, the usual post-war interest in exploration to rebuild war-depleted reserves; second, the impetus supplied by the uranium prospecting boom; third, increased demand for natural resources due to the Korean War; fourth, the discovery of substantial metallic ore by geophysical means in Canada, the U. S., and other countries; and, finally, continuing discoveries of commercial oil by geophysical methods throughout the world. The past year's national business slump has severely curtailed mining exploration in general and correspondingly has brought about even greater reductions in applied geophysics in mining. Petroleum exploration, conceived and executed on a broader statistical basis than mining, has kept up its geophysical programs relatively well, although domestic work has been substantially reduced.

Jan 7, 1959

By James Yancik

The Howe Coal Co. is mining the Oklahoma Lower Hartshorne bed which ranges in seam thickness from 38 to 42 in. and pitches approximately 7° to the northeast. The raw feed to the cleaning plant averages about 20% ash and 1.10% sulfur, being reduced in the cleaning process to 4.8% ash and 0.9% sulfur with a free swelling index of 8 or 8%. This coal rivals the Pocohantas seam in chemistry and coking characteristics but has better fluidity than the Pocohantas seam coal. The coal is presently being prepared for the Japanese steel market in an 85-tph pilot plant designed and constructed by Roberts & Schaefer. The cleaning-plant flowsheet is discussed in detail.

Jan 1, 1972

By Gail Moulton

THE oilfields in Illinois are located principally along the LaSalle anticline in the southeastern part of the state. The oil produced comes most largely from beds of Pennsylvanian and Mississippian age, but there is an increasing important production from deeper horizons, as will be noted under new development. The oil is largely of paraffin base, and has an average specific gravity of about 35° Baume. The rank of Illinois as an oil producer has dropped from third since 1913, when its production was exceeded only by that of California and Oklahoma, to eighth in 1923. This has been the result of failure to find new pools of considerable size to offset the declining production of the old wells and of the greatly increased production of some of the other states. The noteworthy features of petroleum production in Illinois during 1924 are: the low rate of decline for the state as a whole; the smaller percentage of dry holes; and the larger average initial yield of the new wells.

Jan 3, 1925

By Gail Moulton

THE oilfields in Illinois are located principally along the LaSalle anti-cline in the southeastern part of the state. The oil produced comes most largely from beds of Pennsylvanian and Mississippian age, but there is an increasing important production from deeper horizons, as will be noted under new development. The oil is largely of paraffine base, and has an average specific gravity of about 35° Baume. The rank of Illinois as an oil producer has dropped from third since 1913, when its production was exceeded only by that of California and Oklahoma, to eighth in 1923. This has been the result of failure to find new pools of considerable size to offset the declining production of the old wells and of the greatly increased production of some of the other states. The noteworthy features of petroleum production in Illinois during 1924 are: the low rate of decline for the state as a whole; the smaller percentage of dry holes; and the larger average initial yield of the new wells.

Jan 3, 1925

By Gill Montgomery

The strong upward curve of fluorspar consumption continued through 1968, with domestic producers unable to furnish more than 30% of U.S. requirements. Stocks of all grades were quite short at all points during most of 1968. This resulted in price increases as both domestic and foreign producers sought to cover spiralling labor costs. Further increases are probable for 1969. All Illinois mines were closed by strikes in January and February. The strong trend in metallurgical imports reflects the increased use of fluorspar in steelmaking, as new oxygen process steel plants come into production. The growth of use of all fluorocarbon chemicals continues to require additional acid grade fluorspar, with military uses a major factor. Several new aluminum smelting facilities coming into production are adding to the aluminum fluoride needs, bringing further pressure upon the world supply of acid grade fluorspar. The world-wide consumption pressure on all grades of fluorspar is pushing prices up, and no end to the tight supply is in sight, even assuming that all the new projects cited here are finished on schedule.

Jan 3, 1969

By Robert E. Ennis

This somewhat misnomered "continuous" face section is, in most mines today, still far from perfect continuity. Achieving uninterrupted flow of coal from the mining machine to the outside has been a long sought for goal. Clearly, the largest problem to be solved in continuous mining today is one of increasing the cutting time of the miner. Full machine utilization can never be achieved with the new high capacity miners as long as their performance is tied to that of the shuttle car. A recent development has proven, however, that truly continuous mining and haulage is possible. The Bell & Zoller Coal Co. working with the Research and Development Department of Hewitt-Robins Inc. developed and perfected a new mining system which offers advantages in terms of increased productivity at reduced mining costs and enhances the safety of personnel at the face. This new system involves the use of two pieces of equipment that form an unbroken link between the mining machine and the mine belt haulage system. These pieces are a Mobile Bridge Conveyor and an Extensible Panel Conveyor.

Jan 4, 1965

By W. J. Babyak, J. M. Sheehan, H. W. Paxton

THE- solubility of hydrogen and deuterium in solid niobium up to I-atm pressure has been established bv a number of workers.1-5 X-ray examination at room temperature of specimens reacted in hydrogen at high temperatures from 300° to 1000°C shows the presence of two phases—a bcc phase (a) based on the niobium lattice and with an u0, increasing from 3.30A for Nb to 3.32Afor NbHo.L, and an orthorhombic phase6n = 4.84A, h=4.90A, c =

Jan 1, 1960

Diesel powered machines are doing some specific operations in the cyclic order required by the technical process. The dynamics of this process in certain conditions has an essential influence on environmental health conditions in the working area. The main purpose of this paper is to show, using computer simulation, how the movement (dynamic) of diesel vehicles effects environmental health standards and also how to determine the required air quantity for ventilation.

Jan 1, 1985

By F. D. Dietiker

After determination of the requirements for a given application, proper selection of a belt conveyor is made from tables and formulas commonly used by conveyor designers. Belt conveyors, which are universally accepted as a means of transporting bulk materials, also perform the important functions of stockpiling and reclaiming.

Jan 1, 1978

By R. A. Turpin

Bethlehem Steel's Research Department is developing a set of computer programs as mine-planning tools for Bethlehem's coal mines. Several of these computer programs have been completed and have been in routine use by Bethlehem Mines personnel since early 1975. The production scheduling and ventilation planning programs have been installed on an interactive time-sharing computer. The use of time sharing allows mines in remote locations to access these planning tools through standard phone lines and low-cost computer terminals. The capabilities of the interactive production scheduling and ventilation planning programs are briefly described. The advantages of implementing them using time sharing are discussed. A case study illustrates some of the benefits that planning based on the use of these programs has already provided.

Jan 1, 1977

By Alvin L. Langstaff, Harold D. Raymond

The design of entry systems and mining panels in room-and-pillar oil shale mines seeks to optimize extraction while ensuring both short- and long-term stability of mine openings. Important criteria for optimization include the definition of allowable roof spans and minimum pillar dimensions. Factors considered pertinent to the design of roof spans and pillars are discussed in this paper. They include, but are not limited to, physical properties and grade of the oil shale, depth of burial, presence and frequency of partings and joints and adverse effects of blasting. Also discussed briefly are some of the ventilation and production considerations in mine design.

Jan 1, 1984

ON THIS page is a photograph of a machine that has played a key role in the recent history of Kennecott's Ray mine, situated in the Mineral Creek District, Pinal County, Arizona. It is a huge, rugged, Diesel-powered, rubber-tired truck, having a capacity for carrying fifty tons of ore. It has, to a substantial degree, revolutionized the business of moving broken rock by cutting down both maintenance and operating costs. From 1911 until the end of 1954 Ray had produced 79,000,- 000 tons of ore by underground block-caving. However, in 1947 [ ]

Jan 1, 1957

By J. M. Karpinski, F. P. White, R. L. Stone

By means of laboratory balling tests and a procedure for determining bentonite concentration in a green ball, the present study revealed that the bentonite savings by mulling concentrate and bentonite prior to balling was sufficient to warrant installation of a full-size unit in a pellet plant. On the basis of this work, a muller was put on stream at Bethlehem Steel Corp.'s Cornwall pellet plant in June 1969, and has operated continuously since then. Plant tests showed that the use of the muller resulted in bentonite savings of about 50% without any loss of green, dry, and fired ball quality. Virtually no maintenance problems have been encountered. This information is important to future pelletizing operations both from the standpoint of product quality and economics.

Jan 1, 1972

By M. T. Erickson, C. A. Rowland

Ball mills 5.5 m (18 ft) in diameter and larger tend to use energy delivered to the mill less efficiently than smaller diameter mills, particularly when the large mills carry 40% by volume ball charges. This paper will explore factors used in scaling up ball mills, showing where the advantages of one factor can possibly be negated by another factor. The paper will propose possible operating limits and areas for further study to establish selection and design limits.

Jan 1, 1985

By A. Sainato, E. Baker, J. Cervik

In Europe, water infusion is used widely to reduce generation of respirable dust during mining. Its use in the US is limited to a few plow operations in the deeper parts of the Pocahontas No. 3 Coalbed. The technology for infusing water into retreating longwalls is described and results of a recent Bureau test in the Lower Sunnyside Coalbed demonstrated dust reductions ranging from 47% to 64%. Because water infusion increases moisture content of the coalbed, face air velocities in excess of 2.5 m/s (500 fpm) are possible, further diluting dust levels before dust entrainment occurs. An economic analysis shows a 23% reduction in operating costs when coal production is increased by changing from unidirectional to bidirectional mining with water infusion.

Jan 1, 1986

The elite group of companies below represent the mining sector of Fortune magazine's June Directory listing the 500 U.S. industries that chalked up the largest dollar sales volume in 1966. The companies are listed according to their 1966 sales rank, which is given along with their 1965 rank for comparative purposes. All of the firms except two-Freeport Sulphur and Texas Gulf Sulphur-were in the Fortune Directory last year, and both these exceptions have been counted among the top 500 in former years. The one mining name that is missing from last year's list-Consolidation Coal-has actually jumped from number 217 to 4 by virtue of its merger with Continental Oil. As can be seen from the Industry Medians, the mining industry as a whole boosted its sales 17.8%, in 1966, making it the seventh largest gainer among the 22 industrial classifications covered in the Directory. By comparison, 1965 mining sales increased 10.2%, a gain which was surpassed by 13 other industries. In two other comparative tables, mining leads the field, topping the entire list in return on sales and in assets per employee.

Jan 8, 1967