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Commodities statistics and otter information are available through the following t et systems: Internet Access: To acccess the USBM Gopher server on Internet, connect to: gopher.usbm.gov port 70, using gopher client software. Or contact the Systems Administrator for technical questions: Matt Klevemann, 412-892-6499 (klevemmc@miner.usbm.gov) These USBM materials are available on Internet, with more to come in the future: Publications and other research findings, including this bimonthly publications list, newsletters, tech transfer updates, enviromental technology research, health and safety information. USBM software products Media materials and speeches. Mines Data: Computer bulletin board. Log on via modem through 202/501-0373, or call 202/501-0406 for technical assistance. Mines FaxBack: Return fax service. 1. Use the touch-tone handset attached to your fax machine's telephone jack. (ISDN [digital] telephones cannot be used with fax machines.) 2. Dial 202/219-3644. 3. Listen to the menu options and punch in the number of your selection, using the touch-tone telephone. 4. After completing your selection, press the start button on your fax machine.

Jan 1, 1995

By James P. Bennett

The U.S. Bureau of Mines, Tuscaloosa Research Center, is conducting a review of the usage of different types of refractories, the current industrial practices to recycle/dispose of spent refractories, and the concerns associated with these practices. This information will serve as the technical basis for initiating a research program to recycle or find alternate uses for spent refractory materials. Approximately 1.6 million metric tons of clay based and 1.2 million metric tons of non-clay based refractory materials were manufactured in the United States in 1992 alone, representing a value of almost 2 billion dollars. Landfill has been and remains the disposal means of choice. Issues such as environmental regulations, concerns over landfill disposal, future liability, and product stewardship programs have brought about increased emphasis for recycling or alternate material use. Information on refractory consumption and the issues associated with recycling or disposing of used materials will be discussed, including current recycling practices.

Jan 1, 1995

By J. Gathje

Normal process development for pressure preoxidation treatment of refractory gold ores starts with laboratory batch autoclave tests, followed by operation of a continuous autoclave pilot plant for confirmation of the various process options. This scheme will generally provide good information showing the effects of such variables as grind size, time, and temperature, and will indicate whether autoclave preoxidation will produce solids that are amenable to cyanidation for gold recovery. However, several recent test programs conducted over the last three to four years have shown that the cyanide leaching responses of treated solids from the batch tests can differ considerably from those achieved by the continuous pilot plant autoclave. Examples are provided to demonstrate these differences and to show the importance of extending the laboratory investigations to include the use of a semicontinuous autoclave test procedure. A test case is cited in which this procedure provided data that could not be obtained from batch tests.

Jan 1, 1995

By Abdullah Arik

Verification of computer generated reserve models is essential since the computer does not automatically check the validity of methods and assumptions selected by the user and their results. For the computer to do model verification would require an expert system which would perform tests on the model and determine if the model is valid. Since such an expert system is not available, it is up to users to verify the models they develop.

Jan 1, 1995

By Larry Hopkins

The molten metal circulation pump has become a staple for melting aluminum in reverberatory furnaces. The forced convection that is created in the melt efficiently provides circulation while dramatically improving melt rates, lowering fuel consumption, extending refractory life, and providing metallurgical homogeneity. Two metallurgical guidelines that are important to many casthouses are molten metal inclusion levels and hydrogen gas content. In order to improve molten metal quality, furnace and casting practices must 'manage these molten metal defects, Today specialized in-line degassing and filtration equipment is used downstream of the furnace to accomplish these tasks. In contrast, the molten metal gas injection pump has metallurgical contact time in the process for hours during the charging/homogenization cycle. The qualitative benefits of employing a gas injection pump to "pre-clean" are outlined and discussed against historical empirical information obtained with alternate methods. Further, a recent study quantifies the merits of this gas injection technique as an effective molten metal quality improvement tool. Specifically, the effects on inclusion level as determined by PoDFA?, gas content as determined by A1SCAN? sampling and alkali metal content as determined by spectrographic analysis are examined in relationship to various gas feed compositions and flow rates.

Jan 1, 1995

By R. Poulin, R. Pakalnis, D. Peterson

Introduction A comprehensive project has been completed at the University of British Columbia that focused on the development of a commercially competitive composite cable bolt. Laboratory evaluation consisted of pull tests, preliminary shear tests, grout column testing and scanning electron microscope evaluation of the composite cable bolt. Field implementation at five underground mines throughout Canada were completed for technical and overall performance evaluation of the new product. The project began in 1989 under the sponsorship of HDRK Ltd., a consortium of mining companies including Inco, Noranda and Falconbridge Ltd. The objective was to develop a cuttable cable bolt that would serve as support for a continuous miner within a hardrock environment (Mah, 1994). The bolt was required to be cuttable by a continuous roadheader without adverse effects to equipment, personnel and the milling process. From the beginning, the focus was to employ existing cable bolt installation technology (Goris et al., 1994) whereby the cable bolts are grouted within a 4.8-cm-diam (1.08-in.diam) or larger employing a portland cement grout having a water: cement ratio between 0.35:1 to 0.4:1. The prototype, developed from Phase I, was technically comparable to that of conventional steel cable bolts. However, high cost and limited accessibility hindered its commercial acceptance. The second phase of the project was sponsored by the British Columbia Science Council and Pacific Pultrusions Ltd. of British Columbia to locally develop a glass fiber cable bolt. This phase of the project has resulted in the DAPPAM cable bolt (Pakalnis et al., 1994). DAPPAM Cable bolts are the second most used support method in Canadian underground mines after mechanical rock bolts. It is projected that 870,000 m (2.9 million ft) of cable bolts are installed annually in Canada (Poulin et al, 1994). The objective of the research program was to develop a glass fiber cable bolt with similar pullout strengths to the conventional steel cable bolts (267 kN - 60,000 lbf). More than 200 laboratory pull tests were conducted employing standard cable bolt test procedures, as outlined by the US Bureau of Mines (Goris, 1994), to assess optimum rod and surface composition, geometry, number required, pullout and shear characteristics, among others. This resulted in the DAPPAM cable bolt (Fig. 1). It consists of 10 individual 0.6cm-diam (0.25-in.-diam) rods enveloping a 2.2-cm (0.8-in.) outside diameter, high-density polyvinyl grout tube. The composite used in the construction of the rods is comprised of about 65% glass fiber within a 35% polyester resin matrix (by volume). Through pultrusion (a continuous fabrication technique), the fibers and resin are combined into a composite material. The strength of the overall composite is largely governed by the material properties, the alignment [ ] of the fibers relative to the applied load and the density and interaction of the overall components within the composite. A further modification to the composite was the addition of a sand grit to the surface of the individual rod. This increased the overall bond strength between the rod and the cement-based grout, used to solidify the cable bolt to the rock mass. The grout tube has an inside diameter of 1.9 cm (0.75 in.) and is rated at a pressure of 1.72 MPa (250 psi). During installation, the grout is pumped through the annulus of the grout tube thereby filling the hole from toe to collar. Laboratory and field trials concluded that a minimum drill hole diameter of 4.8 cm (1.08 in.) be used to ensure optimum grout coverage. Table 1 compares the design strengths (as tested) for DAPPAM vs. the ultimate strengths for a conventional 1.6cm (0.6-in.) steel cable bolt. The characteristics for the steel cable have been derived directly or indirectly by Goris et al. (1994). A design tensile strength of 289 kN (65,000 lbf) was proposed for the composite developed. However, recent tests have indicated maximum breaking strengths of more than 400 kN (90,000 lbf) (Fig. 2). Figure 2 shows the load vs. displacement pull out curves for steel and DAPPAM cable bolts. The methods of testing were standardized so as to be able to compare the results directly. The shear strength of the fiberglass cable is largely a function of the surface area sheared. Shear strengths of 89 kN (20,045 lbf) were obtained for the configuration shown in Fig. 1 when sheared normal to the axis of the cable. The testing procedure was similar to the shear tests performed on steel by Goris (1993). It is important to reinforce the implication that critical bond strength has on the success of an overall support system.

Jan 1, 1995

By J. B. Hanlon

In order to protect coal mine owners, operators, and lending institutions from potential environmental liabilities, responsible parties must maintain a thorough understanding of the environmental disposition of the property they control, and the ramifications of impending laws and regulations. The best way to accomplish this is to periodically conduct a Phase I Environmental Audit. The systematic approach of an audit will reveal areas of DOD compliance with SMCRA and EPA regulations which the coal owner and/or operator will be able to use to correct deficiencies and prevent the occurrence of conditions which could lead to permit block, fines, and ultimately reduced productivity.

Jan 1, 1995

By A. D. Wunderlich

Providing a safe & secure environment for your employees and other company assets is absolutely necessary in our litigeous society. Security hardware is no different than computers or other technical equipment, in that new equipment is developed each year that makes older equipment obsolete. This presentation will help to explain how your existing security system and security procedures can be updated to meet industry standards without the expenditure of a great deal of money. If you are concerned about potential security problems and how to address these problems, this presentation is a must.

Jan 1, 1995

By L. M. English

In the past 30 years, the research arena has changed significantly in all fields, mining included. The relative representation of the topics of research, how the research is performed, and who has performed the research have all changed significantly over these decades. Although there are a lot of subjective ideas concerning these changes, and there is a fair amount of anecdotal "analysis," there has been no actual study of these trends to verify the facts. The period studied is divided into six five-year periods for the purposes of comparison. Some of the trends analyzed are as follows: ? Co-authorship ? Research areas ? Research sponsors ? Cooperative efforts

Jan 1, 1995

Many USBM research and information products are available through the systems or formats listed below: Mines FaxBack: Return fax service. 1. Use the touch-tone handset attached to your fax machine's telephone jack. (ISDN [digital] telephones cannot be used with fax machines.) 2. Dial 202/219 3644. 3. Listen to the menu options and punch in the number of your selection, using the touch-tone telephone. 4. After completing your selection, press the start button o your fax machine. Mines Data: Computer bulletin board. Log on via modem through 202/501-0373, or call 202/501-0406 for technical assistance. CD-ROM: This USBM disk is updated quarterly and sold by GPO's Superintendent of Documents. For information on the latest product, please contact Rodger Wedgeworth, 202/501-9557. Internet/World Wide Web: Text and graphics. Access via PC-based browsing software such as Netscape or Mosaic. Universal Resource Locator (URL) is: http:/www.usbm.gov Internet/Gopher Server Text and tables only. Using Gopher client software, access via port 70 as follows: gopher.usbm.gov Internet System Administrator: webmaster@usbm.gov (or contact your local System Administrator).

Jan 1, 1995

By T. J. White

Each year, thousands of tons of toxic concentrates are produced as the unwanted byproducts of industrial operations and smelting activities. The fate of these materials remains open, as in general their consumption is limited and potential markets contracting. Xtaltite (pronounced crystal-tight) is a Synthetic Mineral Immobilization Technology (SMITE) optimized for the concentration, detoxification and consolidation of toxic metal wastes. In this approach, we seek to mimic nature to produce durable synthetic minerals that survive for aeons in well characterized geological settings. This approach has high public acceptability because the concept is easily understood by the layperson and the long term stability of the waste form may be predicted with confidence. In addition, where Xtaltite is used for mine backfill, a system of ecologically sustainable mining development is established. This paper details the design and fabrication of Xtaltite under oxidizing and reducing conditions. To illustrate and contrast these stabilization regimes, specific reference will be made to the treatment of thallium, chrom~um and arsenic wastes. Waste form performance under TCLP, dynamic boiling water tests and in other leaching media will be compared and discussed with respect to their relevance to different disposal options.

Jan 1, 1995

By F. Robert Hubbard

IMCO Recycling Inc. has developed a new, patented technology for the production of fertilizer, K-SOIL?, as a by-product of its aluminum recycling operations. This new technology can substitute for conventional technology which now results in a saltcake residue that is placed in 'landfills. Four years of research and development work by IMCO culminated in a U. S. patent issued April 5, 1994. As part of the technology development effort, IMCO engaged the services of a nationally renowned research organization and a prominent university. These two organizations have conducted in-depth agronomy studies In the laboratory, greenhouse, and the field. Results have shown K-SOIL? to be performance equivalent, on a nutrient content basis, to conventional potash fertilizer. The first field applications on commercial farms were made in the spring of 1994. K-SOIL? is a potassium-bearIng, granular solid which may find use in fertilizer blends, direct application, and other forms of fertilizer products. The overall benefit of this new technology is to create a useful by-product rather than generate a useless residue and, thereby, reduce or eliminate the amount of salt cake now placed in landfills. As such, It is a significant, step toward IMCO's ultimate goal of complete recycle.

Jan 1, 1995

By R. Hurman Eric

The electrode in a slag-resistance electric furnace is the central factor in the design and operation of the furnace by its role of conveying the smelting power, i.e. heat needed for the operation. The control parameters are the size and positioning in the slag bath which are defined by slag resistivity, furnace resistance, cell constant and power input sequence all of which are closely interrelated. The flow of heat generated by the electrode current determines the energy distributions and thus the furnace dimensions. Heat flow models concerning vertical, horizontal and combined two-dimensional flows are discussed. All these considerations are based on the experimentally determined slag properties such as its resistivity.

Jan 1, 1995

By Frank E. Kottlowski

Widespread high-calcium (HC) limestones in New Mexico and adjoining areas, are low in magnesium, but some units include shale interbeds that would be deleterious for usage in sulfur removal. In southwest New Mexico, southeast Arizona, and adjoining parts of Mexico, limestones in the thick Mississippian Escabrosa, Pennsylvanian-Permian Horquilla, and Cretaceous U-Bar units are HC as are strata in the Mississippian Lake Valley, Pennsylvanian formations, Permian Hueco, and parts of the Permian Capitan Limestone of south-central and southeast New Mexico and west Texas. In north-central and central New Mexico, many limestones in the Pennsylvanian Madera Formation are HC as are some of the Cenozoic travertines. In northwest New Mexico, where the present-day mine-mouth coal- fired power plants occur, there are no HC limestones, but to the north in southwest Colorado some beds of the Mississippian Leadville Limestone and Pennsylvanian Hermosa Formations are HC. HC limestones considered contain at least 95 percent calcium carbonate and less than 3 to 5 percent magnesium carbonate. Limits for other impurities are alumina, 1 percent; silica, 2 percent; sulfur 0.05 percent; phosphorous, 0.02 percent; and iron oxide, about 1 percent. Chemical and physical requirements differ slightly depending upon the ultimate use.

Jan 1, 1995

By P. K. Kaiser, D. D. Tannant

"A support system for large ground convergence conditions or burst-prone ground must contain holding elements (rockbolts, cable bolts, etc.) that are strong yet capable of sustaining large deformations, i.e., they must absorb as much energy as possible. Steel wire rope anchored in a borehole by a friction bolt provides these desired yield characteristics if the frictional anchorage is placed deep enough into the rockmass, i.e., in non-yielding rock or beyond the expected depth of rock ejected during a rockburst. Pull-out tests were conducted on wire ropes anchored by inflated Swellex bolts to assess the feasibility of this support concept. The test results demonstrate that a Swellex bolt generates a frictional anchorage that allows the wire rope to slide at high loads and to absorb significantly more energy than either a Swellex bolt alone, or a cement-grouted cable.The rope/friction bolt combination can be engineered to provide the desired energy absorption and allowable deformation by varying the installed lengths of the friction bolt and the rope. For yielding rope support, the contact length between the rope and Swellex bolt must be short enough to ensure that the rope can slip well before its tensile capacity is reached. A safe maximum overlap length is about one metre for the wire rope used in this testing. When used as support in the backs of drifts, a swaged button on the ropes end must be used to ultimately mobilize the full rope capacity thereby protecting against gravity-driven falls of ground."

Jan 1, 1995

By C. A. Young

The remediation of cyanide (CN-) and nitrate (NO)-) anions in mine and agricultural waters by various photolytic methods has been reviewed and investigated. Photolytic methods such as direct photolysis, homogenous photolysis, and heterogeneous photocatalysis are briefly described and compared. Results and discussions show that each method has certain advantages and disadvantages. For each method, Eh-pH diagrams prove useful for determining reaction mechanisms. Preliminary results obtained for cyanide oxidation and nitrate reduction show that homogeneous photolysis can be superior due to faster kinetics than the other methods. The photolytic methods were individually, not simultaneously, tested and compared. Differences in concentrations of products were obtained and attributed to differences in photoconversion efficiencies and other inherent characteristics of .the photolytic methods. Various reaction mechanisms are proposed in accordance with the literature as well as measurements obtained from solution analysis using ion selective electrodes and ion chromatography .

Jan 1, 1995

Our ultimate resources come from the Sun and the Earth System. At this time we face a world crisis in energy, water and soil resources. Global pollution problems are increasing in almost all nations. There is an urgent need to use our vast knowledge with a new wisdom and this requires new integrated teams of experts to provide the best alternatives for the needed new development problems. These teams must include economists, engineers and a broad spectrum of scientists. Today it is possible to produce clean energy, stop soil erosion, clean water and reduce and use wastes of many types.   There is a great need to improve science, natural science, education at all levels. All people must know how our planet works and that fluctuations, some inevitable, some controllable, are inevitable and that we must prepare for them. And it is clear that protecting the environment, eliminating pollution, preserving bio diversity is good economics. Ecology Economy cannot be separated.  

Jan 1, 1995

By Andrea B. Baldwin

In recent years, federal and state regulatory agencies have tightened air emission standards. Two of the acid gases, hydrochloric acid (HCI) and sulfur dioxide (SO2), are under heavy scrutiny for reduction. . Most traditional scrubbing systems, i.e. wet scrubbers and spray dryers, meet the standards but they typically are high in capital cost, have significant space requirements for equipment, and are difficult to maintain. Dry sodium injection (DSI) is a alternative technology that has been shown to be effective in HCl and SO2 removal while being the inverse to the problems listed with traditional systems. This paper covers the mechanics of dry injection scrubbing using the most effective sorbents, sodium bicarbonate and mechanically-refined trona (natural sodium sesquicarbonate). It presents DSI performance data for Chambers Medical located in Hampton, SC. This facility incinerates local medical and municipal solid waste. Chambers Medical has used mechanically-fined trona for HCl and SO2 removal since late 1991.

Jan 1, 1995

By D. C. Martin

Construction of the Cerro Colorado on-off leach pad in northern Chile required placement of approximately 3,000,000m3 of fill over a P1an area of approximately 600,000m in irregular terrain with relief of up to 40m. Earthwork construction was completed in approximately six months using mine waste which was placed in 4 to 6m lifts using mine haul trucks. The lift thickness was reduced and the compactive effort increased in the upper 10m to enable development of a mat and additional resistance to possible differential settlements under dynamic (earthquake) conditions. A single 80 mil (2mm) HOPE liner was used below the leach pads and this was protected from the loading and unloading equipment using an engineered liner system consisting of screened sand, gravel and silt from local sources as the bedding and cover layers, and a heel of screened gravel and primary crushed low grade ore. Settlement monitoring, field testing and subsequent assessments of liner performance have indicated an adequate design was achieved and the project proceeded with considerable savings in time and construction costs.

Jan 1, 1995

By J. M. Newell, G. R. Peatfield

"The Red-Chris porphyry Cu-Au deposit is located between Ealue and Kluea lakes, southeast of the village of Iskut on the Stewart Cassiar highway in northwestern British Columbia. It was explored by Texasgulf Inc., in a joint venture with Great Plains Development Company of Canada, Ltd. and Silver Standard Mines Ltd., during the period 1973 to 1980. Exploration resumed in 1994, following acquisition of the interests originally held by Texasgulf and Great Plains Development by American Bullion Minerals Ltd.Prospectors were first drawn to the area by prominent limonitic stain zones exposed in creek gullies in the western part of the property. These zones are developed on the alteration halo at the western periphery of the deposit. The potential ore zones do not crop out and were first exposed in a bulldozer trench excavated in 1971. Subsequent exploration was by percussion and diamond drilling, guided to some extent by induced polarization surveys. In 1976, estimated resources contained within two crudely designed open pits were 41 million tonnes with an average grade of 0.56% Cu and 0.34 g/t Au, with a cutoff grade of0.25% Cu. New resource estimates based on a major drilling program completed by American Bullion in 1994 were released as this paper goes to press. These estimates were calculated using various copper cutoff grades; at the 0.4% Cu cutoff, the ""in-situ geological reserve"" is given as 100 million tonnes grading 0.58% Cu and 0.46 g! t Au (American Bullion Minerals Ltd., 1995).The deposit consists mainly of pyrite, chalcopyrite and increasing bornite at depth, in zones of quartz-vein stockwork hosted by an elongate body of altered monzonite porphyry of latest Triassic or earliest Jurassic age. The stock intruded volcanic and sedimentary rocks of probable Stuhini Group affinity and is in faulted contact with sedimentary rocks of the Jurassic Bowser Lake Group. Gypsum stockworks are developed in the higher levels of the subvolcanic porphyry system. Late-stage quartz-carbonate veins carry small amounts of galena and sphalerite. Complex faulting within the deposit makes drill-hole correlations difficult. Alteration assemblages include an early potassic phase, almost completely destroyed by later phyllic alteration, and surrounded by a propylitic assemblage dominated by ankeritic carbonates in altered sedimentary rocks.The deposit has characteristics of bath the alkalic and calc-alkalic classes of porphyry copper deposits. The development of quartzvein stockwork suggests a calc-alkalic affinity, but the hostrocks contain little or no free quartz, molybdenum is present in trace amounts only and gold values are significant. Copper grades vary between wide extremes with unusually high grades in some sections of the deposit. The weight of evidence available in the 1970s led us to place the Red-Chris deposit firmly in the alkalic family. The quartz-sericite alteration assemblage was attributed to breakdown of potassium feldspar in a near-surface alteration environment in which seawater may have had a significant role. These interpretalions are retained here, but preliminary conclusions from the most recent work suggest that they may require some modification."

Jan 1, 1995