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By Walter J. Johnson, Robert L. Chufo

A unique non-contracting coal thickness measurement technique has been developed to measure both the dielectric constant and thickness of a coal seam as part of a sensor array supporting an autonomous coal mining machine. The sensor measures the reflection of an electromagnetic signal from the coal/shale interface. Underground measurements of coal 6- in thick with a dielectric constant of 4 have been confirmed. Measurements were also made of a 31-in thick coal pillar for application of the sensor to highwall mining. The electromagnetic measurement technique, the data reduction process and field test experience will be presented.

Jan 1, 1992

By M. J. Humenick, K. Garwacka

A laboratory experimental research project was conducted to evaluate the use of chlorine for the oxidative destruction of residual ammonia that may remain in ground water after in-situ uranium solution mining operations. The work tested the idea of injecting high strength calcium hypochlorite solution into the mining zone to convert ammonia to nitrogen gas as a final cleanup process for ammonia removal from the ground water system. This paper details ammonia removal efficiency as a function of chlorine dose, reactant, and product material balances, and how the concept may be used as a final ground water restoration process.

Jan 1, 1985

By D. D. Lei, H. Sevim, S. M. Gwamaka

Three transportation and handling alternatives for delivering dry coal combustion residues from power plants to underground coal mines were evaluated both technically and economically. The objective was to transport, handle and inject the residues into the old workings of the mine at minimum cost. This was accomplished in the following two steps: simulation models were developed and utilized in identifying technically feasible designs for each alternative and the technically feasible designs were economically evaluated to obtain the cost per ton of material transported. An analysis was conducted for varyous distances and tonnages to reveal favorable operating ranges for each alternative.

Jan 1, 1998

The techniques originally developed to process digital images of Mars, later gained widespread acceptance when applied to Landsat data: they are now making a significant impact in fields of geology outside remote sensing. The three ingredients of success are seen to be firstly, the perceptual attributes of image displays and the use of colour; secondly, the absolute ability to register data from a variety of sources; and thirdly, the speed of specialist "interactive" digital image display systems. The future lies in further exploiting these attributes through a Geographic Information Systems (GIS) approach to data handling, integration and display.

Jan 1, 1986

High pressure grinding rolls have found widespread acceptance for cement processing, and are now making their debut in the metalliferous minerals industry. Significant energy and wear material savings appear achievable in many applications. This paper re- views the technical literature on this important, emerging technology.

Jan 1, 1997

By R. V. Horrigan

High purity ZrC14 (25 to 200 ppm of metallic impurities) can be readily prepared in simple apparatus by thermal decomposition of alkali chlorozirconate fused salts at 500° to 600°C and at atmospheric pressure. Suggested phase diagrams for the systems NaCI-ZrC14 and KCI-ZrCI, are presented. ALKALI chlorozirconate compositions — anhydrous fused mixtures of ZrCl4, NaC1, and KC1— are manufactured commercially and are used by the magnesium industry to introduce zirconium into magnesium alloys. Zirconium refines the grain size and improves the physical properties of many important magnesium alloys. In the course of working with chlorozirconate compositions of high ZrCl4 content, it was noticed that these salts decomposed progressively itwaswith increasing temperature to yield considerable amounts of a ZrCl4 sublimate of high purity together with a solid chlorozirconate residue. Further research led to: 1—improvements in the

Jan 1, 1956

By M Ruhrberg, J Grassmann, C Bauer

Within the context of acid mine drainage (AMD) associated with mining activities worldwide there has been a tremendous research effort to determine the extent of AMD and assess the influencing factors controlling this process. However, the majority of the current approaches focus on local and regional scale case studies and do not provide a global scale picture of AMD potentials. This study attempts to develop a method aiming at a global environmental impact assessment related to AMD. To confine the complex topic this study concentrates on acidic emissions from heaps in consequence of copper mining processes. In order to pursue this approach two factors are of significant advantage: a comprehensive environmental data base of more then 600 copper sites worldwide and a method which has been developed and proven to be successful in assessing environmental impacts related to land use. Current and future research efforts focus on using this background knowledge to enable both a comparison between sites and a categorisation of sites according to emission estimates.

Jan 1, 2003

By O. B. Bennett

WHEN diamond drilling was introduced in the Rhokana mines in 1939 it was used principally for pillar removal and for completion of the upper portions of shrinkage stopes which were being affected by increasing pressure. This method of drilling long blastholes proved so successful that it was extended gradually to cover stoping, pillar recovery, and hanging cave work. By 1949 virtually all the production of Mindola and Nkana was being obtained by this method. At the present time 87,500 ft are drilled each month by the 80 diamond drills in daily operation. Responsibility for control and issue of diamond drilling equipment and crowns, as well as tabulation of all performance figures, was taken over by a specially formed Roto drill department, which also investigated the problems encountered with this new method. To assist this department a fully equipped test chamber, Fig. 1, was established underground where performances of various types of machines and equipment could be studied under conditions as nearly uniform as possible.

Jan 12, 1954

By M. M. Tilman

The Bureau of Mines investigated the precipitation strengthening of lead¬-base alloys containing 0.5 through 4 weight-percent combined Cd plus Sb. The Cd and Sb were alloyed in a 1-to-1 atomic ratio which maintained compositions along the quasi-binary section Pb-CdSb. Tensile properties, creep rates, and stress-rupture values were obtained on alloys in the aged condition. The highest tensile strength was observed in an alloy of Pb-3 CdSb, After aging for 6 months at 90°±3° F, this alloy had a mean tensile strength of 8,950 psi with 15-percent elongation. An aged alloy of Pb-1 CdSb exhibited a steady state creep rate of 1.2 X 10-3 percent per day at a stress of 500 psi and a temperature of 90°±3° F. Times to rupture at stresses up to 4,000 psi and at a temperature of 90°±3° F were obtained for some compositions.

Jan 1, 1970

By Donald R. East

In the planning and design of mill tailing disposal facilities, the chemical and physical nature of the fine­grained material to be disposed of has to be fully understood in order to create an efficient and safe long­term storage facility. Disposal of tailing has become the single most important source of environmental impact for mining projects and the development of many promising ore bodies has been delayed or even stopped due to problems of facility siting and design under pressure of increasingly stringent regulatory require­ments.

Jan 1, 1992

By Tom McDonald, Rodney Burke

As mining progresses in the West, the depth of material has increased, making highwall stability a major factor in safety and production. The Jim Bridger Coal Mine has made highwall stability a priority, concentrating on safety as well as increasing and improving production. Overburden depths are increasing dramatically; the geological environment consists of medium to soft material, faulting, water, and current pit alignment not favorable to joint planes. Angle drilling the presplit at 20 degrees became necessary as vertical presplit drilling produced wall failures.

Jan 1, 1997

By Burt C. Mariacher

Two AIME sponsored symposia to be held during the year 1970 will examine copper, lead and zinc metallurgy in considerable depth. MBD and the Extractive Metallurgy Division of The Metallurgical Society will participate in both. Thus, the full field of minerals and metals processing including milling, smelting, and refining will be covered. Since these symposia hold special interest to MBD members, it was felt that a useful purpose could be served by devoting this column to a description of what has been arranged for the registrants.

Jan 1, 1970

By J. Franko, M. S. Klima

Wet-drum magnetic separators are used extensively for upgrading iron ore and for magnetite recovery in dense-medium separation circuits. In this study, the performance of a continuous, laboratory wet-drum magnetic separator was evaluated both with and without the application of ultrasonic energy when processing dense medium slurries. Test variables included magnetic-to-nonmagnetic ratio, solids concentration and nonmagnetic material. The results indicate that, under certain conditions, the purity of the magnetic material increased after ultrasonic treatment. Key words: Ultrasonics, Wet-drum magnetic separation, Iron ore

Jan 1, 2003

By Hanaoka K, Ikeda K

Kakogawa Works, Kobe Steel, Ltd. has two pelletizing plants and one sintering plant, and the blast furnaces have been operated with 30 - 50% pellets. At Kakogawa Works, various improvements in pellet quality have been carried out since the beginning of operation of the pelletizing plant. Especially, dolomite-fluxed pellets developed in 1975, have superior high temperature properties. The fuel rate of the large blast furnaces at Kakogawa Works has been reduced to 450 kg/t- hn by using a high percentage of dolomite-flux ed pellets.

Jan 1, 1980

Covering resources, production, uses, defense impact, and future outlook of nickle, Mining Engineering presents the third in a series of articles on strategic minerals. Preceding it are "Cobalt" in January and "Sulphur" in May.

Jan 8, 1951

By J. I. Paige, T. T. Campbell, A. W. Henderson, H. M. Harris

The chlorination of ilmenite concentrates and slags to produce Tic14 suitable for pigment or metal production was investigated by the Bureau of Mines along with the dechlorination of byproduct iron chloride to produce chlorine for recycle and iron oxide., Ilmenite concentrates or slag powders were fed into the bottom of a fluidized coke bed at 1,050º C using chlorine flow rates up to 20 l/min in a 10.2-cm-dim reactor. Tests showed that >95 percent of the various ilmenite concentrates reacted at optimum conditions, and recovery of TiC14 ranged from 95 to 100 percent of stoichiometric. Impurity dusts were removed from the vapors by cyclones and a fiberglass cloth filter. Iron chloride was condensed as a powder with less than 0.4 percent insoluble material. The TiC14 was collected in refrigerated condensers. Iron chloride was dechlorinated at 500º to 550º C by reaction with oxygen in a 16.5-cm-dim reactor using a fluidized bed of Fe2O3. Optimum processing was attained with a FeC13 feed containing 25 wt-pct Fe203 granules treated with 2 wt-pct NaCl catalyst; Under the above conditions, off gas chlorine concentrations of 62 to 90 wt-pct were obtained. During 2- and 3-day tests with technical-grade FeC13, conversion of FeC13 was 94 to 97 percent, chlorine concentrations were 76 to 90 wt-pct, and up to 92 pct of the stoichio- metric Fe203 was removed in the primary reactor discharge. Chlorine

Jan 1, 1976

FOLLOWING- the major explosion disaster in the Orient No. 2 mine of the Chicago, Wilmington and Franklin Coal Co., West Frankfort, Ill., on December 21, 1951, resulting in the death of 119 miners, an investigation was made by the U. S. Bureau of Mines under the direction of J. J. Forbes, Bureau director. The subsequent report concluded that the disaster. was caused by the emergence of a-large body of explosive gas from an abandoned area and simultaneous short circuiting of the ventilating current; the gas was ignited by an electric arc from nonpermissible electrical equipment and the flame was propagated throughout a large part of the affected area by coal dust and possibly by gas from other worked-out and abandoned areas. An immediate repercussion of the disaster was the opening of hearings by the. Senate Labor and Public Welfare Subcommittee on the Neely Mine Inspection Bill (S. 1310, introduced April 11, 1951) which would give federal coal-mine inspectors power to enforce safety recommendations by ordering the withdrawal of all employees where conditions constitute an imminent danger to their safety. Two days of testimony, January 24 and 25, disclosed that coal operators were not in agreement on the bill, although John L. Lewis, speaking for the UMWA, and J. J. Forbes, for the Bureau of Mines, were advocates.

Jan 1, 1952

By N. K. Davé

Water quality impacts of shallow water submersion of partially weathered and oxidized waste rock containing reactive sulphide minerals were investigated in laboratory column lysimeter studies. The waste rock investigated was highly reactive, contained oxidation reaction products from previous exposure and weathering, and had a low sulphur content of approximately 2 % S, mostly as pyrite. The submerged waste rock, though previously weathered, had high oxygen consumption, resulting in rapid depletion of dissolved oxygen in its pore water, within a shallow depth of ~2?5 cm from the surface. The surface and pore water qualities of the submerged waste rock were significantly impacted by the dissolution and release of previous-oxidation-reaction products, which contributed to their rapid acidification and having increased concentrations of dissolved SO4, Fe total and other metals: Al, Mn, Ca, Cu, Ni, Zn and Pb. Despite the high porosity and permeability of the waste rock, the diffusion controlled mass transfer from the submerged waste rock to the overlying water cover was relatively low for most ionic species. Additional surface oxidation of the sub-merged, partially weathered waste rock was on-going, but its impact on the overall surface water quality was low and masked by the dissolution and release of previous oxidation reaction products to both surface and pore water regimes.

Jan 1, 2006

Meeting, Apr. 25, 1913.-President Rand recommended the appointment of the Nominating Committee (see p. i), and a Committee on the Use of Electricity in Mines (see p. xliv), which committees were duly approved and appointed. President Rand recommended the establishment of. a Committee on Mining Methods, and requested authority for the President to appoint the members of this Committee, both of which recommendations were approved. The name of the Committee on Economic Geology was, at its own request, changed to the Committee on Mining Geology. The request of the Iron and Steel Committee, that a meeting of the Institute, under the auspices of this Committee, be held in the latter part of October, the place of meeting to be decided later, was granted.

Jan 5, 1913

Meeting of Dec. 18, 1914. Charles F. Rand, Karl Eilers, and William L. Saunders were appointed a Committee to audit the accounts of the Institute. The matter of the Committee to investigate the relative merits in metallurgical work of turbo-blowers and the reciprocating blowing engine was laid on the table. Benjamin B. Thayer was elected representative on the Board of Trustees of the United Engineering Society to succeed James F. Kemp. Upon the recommendation of the Committee on Membership, 32 Members, 8 Associates, 3 Juniors were elected, and the status of one Associate was changed to that of Member. Twenty-six members owing dues for from three to six years were dropped from the rolls in accordance with the provisions of the Constitution.

Jan 2, 1915