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By J. I. Schoenherr, T. A. Baloun

Mixed cable waste, which amounts to more than 200,000 tpy in Germany, is subjected to recycling. In most cases cable recycling means only recovering copper and/or aluminum metals. The remaining cable waste contains nearly 3-8% of the reusable materials, and is disposed of in landfills. Aluminum is recovered within copper products and leads to lower product prices. Preliminary laboratory tests show that the use of shaking hydro-tables as well as electrostatic separators result in less than 1 % of metals in the residual material. The products are high in grade at metal recoveries of more than 85%. Furthermore, applying a modified electrostatic separator may also lead to an efficient Cu-Al separation. The separation efficiency amounts to up to 95%.

Jan 1, 2002

By Mary Fu, Helen Leung, Colin R. Phillips

In uranium mines, the median size of the aerosol has been found to be about 0.1 micron or less. Such small aerosols are readily deposited or "plated-out" on dosimeter interior surfaces resulting in the recording of a low dose. The "plate-out" properties of the CEA alpha dosimeter head are described with respect to aerosol properties in controlled experiments in the laboratory. A simple model is derived to estimate the amount of "plate-out" in the CEA head.

Jan 1, 1981

By Jon Y. Kaneshiro, Blake D. Rothfuss, Gregory E. Korbin

A critical aspect of the planning, investigation, design, and construction of an underground excavation project is the portal. The portal is the primary access through which most if not all tunnel construction is carried out and it is the lifeline of the tunnel. Planning considerations include depth of cover, slope stability, economics of open cut versus shaft access, environmental impact, and contractor staging area. Critical aspects of planning, investigation, design, and construction of portals are considered by discussing portal design and portal failure case histories.

Jan 1, 1995

By M. C. Fuerstenau

Collophane, cryptocrystalline fluorapatite, is examined as a substrate for plant water and wastewater remediation. The attenuation of Fe3+, Cr3+, Fe2+, Cd2+, Hg2+ and Pb2+ is presented as a function of metal ion concentration, amount of collophane, initial pH and conditioning time. TCLP results for Pb2+ contaminated collophane are presented. Mechanisms of adsorption for divalent and trivalent species are suggested. Key words: Collophane, Wastewater remediation, Heavy metal removal

Jan 1, 2003

By Mark J. Schultz, William J. Francart, Michael P. Snyder

The Pittsburgh Safety and Health Technology Center surveyed MSHA Coal Mine Safety and Health Districts to monitor the implementation of computer based atmospheric monitoring systems (AMS) in underground coal mines. This survey was first completed in 1984, and has been periodically updated with the latest update completed in 1995. The utilization of computer based monitoring systems has steadily increased over the past 12 years, with over 16 percent of all producing underground coal mines using this technology in 1995. This paper discusses the results of the MSHA 1995 AMS Survey.

Jan 1, 1997

By S. O. Moshier, L. S. Barron, J. C. Hower

The Hardgrove grindability test, commonly used in coal characterization, was conducted on 13 Mississippian carbonates from Kentucky, Tennessee and Illinois. The results demonstrated that the grindability increases with a decrease in the Si02/(MgCO3+CaCO3) ratio, with fine-grained and petrographically-complex stones having lower grindabilities. Also, the relationship between the Bond work index and Hardgrove grindability is significant.

Jan 1, 1993

By D. A. Stanley, B. J. Scheiner

The Bureau of Mines, US Department of the Interior, has investigated the use of rheology to provide insight into the mechanism of flocculation. A technique developed by Tattersall has been modified and used to explain the flocculation of calcium montmorillonite with polyethylene oxide. The results indicated that there are two types of bond systems operating during the flocculation sequence. Also, flocculation results are highly dependent on the shear rate and the amount of polymer added.

Jan 1, 1990

By Cherie M. Tilley

Dynatec Mining Contractors (Dynatec) entered into a contract with Barrick Goldstrike Mines (Barrick) to develop the deep gold ore reserves at the Meikle Mine north of Carlin, Nevada. The Ventilation and Production Shafts were started in early 1994 and were completed in December, 1995. The mine development and mine construction programs were completed in November, 1996. This paper describes the Meikle Mine development program.

Jan 1, 1997

By M. Gaft, G. Panczer

Sedimentary francolite and magmatic apatite are characterized by specific laser-induced time- resolved luminescence, which allows phosphate to be distinguished from accompanying dolomite. The "selective window" parameters are: he, = 337 nm, delay time after laser pulse is 0.5-5 ps, and detection spectral range is 400-525 nm. In the case of nonuniform distribution of phosphate minerals, it makes it possible to accomplish lasero- luminescent sorting and to receive intermediate product with a lowered dolomite contents.

Jan 1, 1999

By D. Malhotra

This paper discusses the need for periodic auditing of mineral processing flowsheets and the potential benefits a company can gain from a study of this nature. A carefully designed flowsheet audit can have a significant impact on the metallurgical performance in the plant. Several case studies illustrating the potential benefits that can be attained from flowsheet auditing of mineral processing plants are discussed.

Jan 1, 1988

By M. S. Vernon, J. J. Kellar, W. M. Cross, R. M. Winter, F. J. Johnson, A. G. Pommer

Three substrates (MgO crystal, CaF2 crystal and Mg plate) were used to construct thin layers of Mg(OH)2. Various routes were used to modify these substrates, including surface hydration and sol-gel coating. In each case, it was found (by using Fourier transform infrared spectroscopy) that thin layers of Mg(OH)2 could be produced. In the case of hydrated layers, the surface morphology of the Mg(OH)2 resembles the bulk platelet shape of precipitated Mg(OH)2.

Jan 1, 2000

By Paul G. Greenhill

The Australian Mineral Industries Research Association (AMIRA) was established by the Australian mineral industry in 1959 to develop and manage collaboratively funded research projects. Owned and managed by industry, it coordinates research that answers questions defined by the sponsoring companies of the projects. Now over 35 years old, the Association is an excellent example of what can be achieved through collaborative research and an industry - backed research organisation.

Jan 1, 2000

By David A. Rice, Scott A. Shuey, William K. Tolley

The U.S. Bureau of Mines (USBM) is developing new dewatering technology to permit the recycling of iron values contained in wet steel plant sludges. In laboratory tests, Q-BOP fume sludge was dewatered to 12% moisture by displacing water with acetone in a plate-and-frame pressure filter. Acetone is reclaimed through distillation at lower cost than conventional thermal drying of the sludge. The projected additional energy requirement for acetone treatment of the sludge, including acetone recovery, is $5 to $7 per dry ton.

Jan 1, 1995

By O. K. Kuznetzov, L. A. Otrozhdenova, N. D. Malinovskaya, I. I. Maksimov, N. D. Khodov

While processing zinc cakes with application of Weltz-technology silver remains unrecovered and goes into clinker. In order to prevent it the elaboration of effective silver recovery methods from zinc cakes before their weltzing becomes necessary. A combined method of zinc cakes treatment with leaching and flotation in a closed water circuit has been worked out. The technological scheme envisages the use of sulphgydril collectors in combination and comprises a series of consecutive operations: leaching, filtration, precipitation(cementing) and flotation. Total silver recovery is approximately 94%. The technology elaborated has been realized in a project by which the construction of a new shop is under way now.

Jan 1, 1995

By R. Zaragoza M., M. C. Fuerstenau, C. O. Nebo, J. R. Kelso

The rate of adsorption of gold cyanide on activated charcoal was examined as a function of charcoal concentration and size, temperature, initial gold concentration, pH, and initial concentration of gold on the charcoal. Rate was found to be proportional to temperature, concentration of charcoal and initial gold concentration on charcoal, and to the inverse of charcoal particle size squared. An activation energy of 2.0 kcal/mol was determined

Jan 1, 1988

By Boris V. Vlasenko, Vadim P. Potapov, Gennady I. Gritsko

In this paper we consider the elements of an information geomechanic monitoring system which is used in computerized mine planning and mining operations control. The automated sys tem is a technical means of geomechanic monitoring, as a complex system of regulated observations, estimation and prediction of changes in geomechanic state of rock mass and workings during underground mining of coal deposits. Geomechanic monitoring at coal mines and the automated system execute data collection, analysis and calculations of geomechanic situation in the panel during planning, development and carrying-out of mining operations for ensuring geotechnical stability of underground mining.

Jan 1, 1996

By Dr. -Ing. Karlheinz Timtner

This paper deals with the complicated and often misunderstood relationship between torsional windup, load sharing and peak torques in conveyor backstops. The principals apply in low speed, intermediate speed or high speed applications. Once the controlling factors are understood, a reasonable approach to selection procedures can be achieved.

Jan 1, 1996

By J. Stachurski, N. A. Abdel-Khalek

Flotation tests were carried out on six coal samples of different rank as well as their oxidized samples. A mixture of diesel oil and alcohols was used in these tests. Surface oxidation caused a distinct decrease during flotation recovery with some improvement in the grade. The reduction in the recovery increased with increasing concentration of the oxidizing agent. The floatability of low rank coals was affected by oxidation to a higher degree than the floatability of medium and high rank coals. The recovery-size curves of oxidized samples were similar in shape to the recovery-size curves of non-oxidized coals.

Jan 1, 1991

By John N. Murphy, Edward F. Fries

The availability of fast, low-cost computer hardware and advanced software is opening new opportunities for minerals extraction and processing. Programmable Logic Controllers (PLC's) are currently used extensively in the minerals industries; this paper looks beyond PLC's and that vintage of “computer control”--it looks toward what the authors see as new in the next five years. Topics covered include expert systems, neural networks, intelligent signal processing, and hierarchical controllers as applied to mining and mineral processing operations.

Jan 1, 1993

By S. Michael Feroz, Paul Gribbon, Jan Rosholt

Approximately six billion gallons of combined sewage are discharged annually into Willamette River and Columbia Slough through Portland’s combined sewer system. The Columbia Slough Consolidation Conduit (CSCC) is an important element of mandated Combined Sewer Overflow (CSO) abatement. It includes2,548m (8,361 ft.) of 3.7 m. (12 ft.) internal diameter tunnel. The CSCC alignment traverses the UP railroad, Columbia Boulevard and parallels an old sewer. Geologic conditions include river alluvium and fine to coarse-grained flood deposits containing cobbles and boulders. This paper describes design and construction of a tunnel in soft-ground, with shallow cover and close to an old concrete sewer.

Jan 1, 1999