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By R. V. Ramani

One area of study in the Coal Mine Injury Analysis project was to illustrate and enhance the ability of mine safety management personnel to apply analytical techniques to injury experience data and to justify requests for funds for safety enhancement actions on a cost/benefit and other quantitative basis. Four volumes of this final project report detail (1) the objective and scope of the mine safety management research, (2) the results of literature review, and case studies, and (3) models developed for mine safety management. The four volumes are titled as Volume III: Mine Safety Management, Volume IV: Analytical Techniques for Mine Safety Management; Volume V: Mine Safety Management Case Studies and Volume IX: Training Cost Model. In this volume, the following material is presented: (i) review of related literature, (ii) mathematical models to perform quantitative analyses of accident/ injury experience data using the tools and techniques of risk analysis, time series analysis, and the Markov process, and (iii) descriptions of the HDBSEL and ACIM programs which are used to perform accident/injury experience analyses and cost analyses, respectively.

Jan 1, 1993

By B. L. Chulu

In the carbothermic reduction of lead sulfate to produce lead, the inclusion of soda ash (Na,CO,) in the charge provides for the control of sulfur dioxide in the effluent gas. An important mechanism in the process appears to be the carbothermic reduction of the sodium carbonate whereby sodium gas and carbon monoxide are produced. These intermediates then participate in the reduction of the lead sulfate to produce lead metal and stable sulfur species in the molten slag phase. In addition, there is some evidence that the presence of lead metal in the charge may also serve to increase the lead recovery in the process. These aspects were investigated by conducting laboratory-scale smelting tests with small charges (;3g), at 1173°K(9000C). Recovery did not exceed 74w% and the role of incipient lead metal in the charge could not be clearly assessed.

Jan 1, 1993

By Eugene F. Mehr, Dennis C. Martin

"Development of the final slope for the 340 m (1200 ft) high hanging wall at Cassiar Mine precipitated an area of deep seated instability involving an estimated 17.6 million tonnes. The deformation mechanisms involved squeezing of soft deformable serpentinite rocks in the toe which caused planar sliding and graben toppling of the stronger sedimentary rocks in the middle and upper sections of the slope. Although movement rates up to 150mm/day were recorded, by understanding the controls on failure, the mine was able to install a suitable monitoring system and complete the open pit with only minor loss of the mineable ore. Accelerated mining was required in the last full year of operation. This paper describes the deformation behaviour, failure mechanisms and back analysis results for the failure. The monitoring systems and operational aspects related to the failure are also presented.IntroductionCassiar Mine is located in steep mountainous terrain in northern British Columbia approximately 1200 km north of Vancouver (Fig. I). During the final mining phase of the open pit, instability developed in the approximately 340 m high hanging wall (east wall) slope. A unique graben toppling mechanism was identified based on detailed assessment of slope monitoring data and visual observations. Comprehensive slope monitoring enabled mining to continue even though movement rates as high as 150 mm/day were being recorded. Three-dimensional limit equilibrium back analyses and numerical modelling have been used to assess the various controls on the slope movements and to understand the failure mechanism."

Jan 1, 1993

By Robert G. Harris

During the last five years there have been significant improvements in face support monitoring techniques particularly in respect of face pressure. The measurement of support loading pressures was originally conceived as a maintenance aid for the hydraulic systems but recent work has also included geological loading displays of the complete face as well as individual supports. This paper briefly examines the means of obtaining this information, together with some examples of actual face data. Also included is a summary of the benefits of such monitoring and an outline of future development work.

Jan 1, 1993

By Jeffrey S. Walker

Abandoned underground mine openings are susceptible to collapse because of the mining methods used, the character of the overburden, and the typically large, wide entries with minimal roof support. The final effect of the collapse of the underground workings is surface subsidence. To reduce the probability of subsidence, methods to backfill the mine void with various types of materials have been developed. This U.S. Bureau of Mines report describes the available technologies for subsidence abatement and discusses their operation and application. The basis of these abatement methods is the replacement of the mined material with mine waste. Backfilling of mine voids is the most common method of stabilization used to abate subsidence and protect surface structures. Hydraulic flushing and grouting, using remote methods from single or multiple boreholes, are the most often-used methods for the placement of backfill material. Other subsidence abatement techniques are available and may be more appropriate under different conditions. These other techniques include pneumatic stowing, either by in-mine or remote methods, and various point support methods that do not completely fill the mine void and are used for the protection of small areas of the land surface and surface structures.

Jan 1, 1993

By J. E. Lowe

The unique application of a large walking dragline in the mountains of southern West Virginia was developed and implemented by Hobet Mining, Inc. Hobet is an independent operating subsidiary of Ashland Coal and is headquartered at the No. 21 Mine in Boone County, West Virginia, near Danville. Hobet also operates the 07 Mine located in Logan County, West Virginia, near Holden. Both mines are similar in equipment and manpower used; both produce over 2,000,000 tons of clean coal annually. Each site encompasses large, contiguous properties with access to rail service. The larger of the two is the Boone County property; it totals nearly 40,000 acres and has ample reserves. In 1977, Hobet was in the process of constructing a preparation plant (Beth Station) at its 21 Mine site with a capacity for two million tons. One of the first orders of business was to design a mine plan that would provide production for the capacity of the plant. Coal production would come from a more than adequate reserve base using the most economical mining methods available. Hobet looked at different deep and surface mining methods to use in order to develop the property; ultimately, it was determined that the mountaintop removal method with the use of a large dragline was the most economical way to develop reserve. Prior to this time surface mining in mountainous Southern West Virginia was generally done by contour mining and/or augering techniques.

Jan 1, 1993

By V. P. Bystrov

Vanyukov process has been developed and investigated in Russia over the last 25 years. It has been established that various kind of material could be treated in Vanyukov process. The results of the pilot plant trials as well as industrial experience are presented in this paper.

Jan 1, 1993

By J. Brent Hiskey

Recently basic concepts of semiconductor electrochemistry and solid-state electronic structure theory have been applied to the dissolution of mineral electrodes. In this paper, fundamental aspects of semiconductor electro- chemistry and interfacial charge-transfer processes are reviewed. Information regarding the electronic and semiconductor properties of chalcopyrite is summarized. The electrochemical response of chalcopyrite in acidic solution is analyzed in terms of initial dissolution processes. The initial charge- transfer reaction involves the consumption of holes. It has been shorn that Fermi level pinning is consistent with observed electrochemical and dissolution behavior. Semiconductor electrochemistry has proved helpful in explaining the formation of intermediate surface films produced during the initial stages of chalcopyrite dissolution

Jan 1, 1993

By Chris M. Healey

"Abstract- The Jasper Gold mine in northern Saskatchewan produced a total mill feed of 140 127 tonnes at an average grade of 19.0 g/t Au. Both diamond drilling and chip samples from under­ ground workings returned extremely high values, up to 12 851 g/t (375 oz/I) Au over 0.10 meter from a chip sample. In the presence of such extremely high grades, the accurate estimation of reserves is a major problem.ln the first part of this study, production data from the mine were used to evaluate the results of a variety of reserve estimation techniques in this environment. In two out of three cases studied, indicator kriging with assays cut to 342.9 g/t (10 oz/I) gave extremely good results. In the third case, however , indicator kriging gave unacceptable results. Instead, lognormal kriging of uncut data gave the best results.Secondly, from the same database, a number of drill-hole spacings were simulated, and reserves estimated from the simulations. As may be expected, the results of this analysis show increasingly better results with tighter drill-hole spacing. However, even with a 5 m by 5 m spacing the variation from actual grade was quite large. This is not a systematic under- or over-estimation of grade, rather a random scatter of results .The results of this study show very clearly the problems of deriving good estimates of reserves when extremely high-grade samples are encountered. There is a high degree of randomness to this database, so reserve estimation in this situation will remain a high-risk operation."

Jan 1, 1993

By J. M. Floyd

Technology in use commercially and available for commercialisation for injection processing of base and precious metals in bath reactors is surveyed and compared. Differences between bath smelting and suspension smelting systems are highlighted in relation to important smelting criteria. The factors affecting the results achievable with various tuyere and lance injection bath smelting systems are discussed in relation to the various smelting, converting and refining operations involved in copper, nickel and precious metal processing steps. Process chemistry, process dynamics and heat and mass transfer rates are discussed for the different systems.

Jan 1, 1993

By C Hunter, K Fedak, J P. Todoeschuck

"Perimeter wall control has a direct effect on the overall grade of any underground miningoperation. Mine management at INCO's Birchtree Mine in Thompson, Manitoba requiresmaximum perimeter wall control to meet high safety standards and to maximize nickel orerecovery. If footwall or hanging wall contacts are damaged by over_blasting, the ore maybe greatly diluted, mine productivity may be reduced and safety problems can arise.Excessive or poorly distributed explosive energy is a major cause of damage to the hostwall rock."

Jan 1, 1993

By Michael E. Stout

M.A. Industries, Inc. has developed and is now offering on a commercially available basis, complete systems to recover and recycle lead from spent SLI batteries. The system begins with the breaking and separation of the component parts of the batteries and subsequent treatment of the effluent water produced by this operation. The recyclable materials recovered from this process are metallic lead, lead paste and polypropylene. The lead paste is introduced into a process to convert it from a lead sulfate to a lead carbonate. The process also regenerates the salt solutions into reusable carbonate. The lead carbonate is then leached into an acid bath where it is later recovered by a proprietary electrolytic process. The metallic lead is recovered in a short rotary furnace producing metal for further refining and alloying. The polypropylene is further washed and then introduced to a reclaim extruder along with the proper modifiers and additives. The resulting resin can then be sold on the open market to injection molding processors. This complete system greatly reduces the amount of waste to be disposed of and completely complies with all applicable EPA guidelines.

Jan 1, 1993

By Lawrence P. Goldfarb

This paper presents the results of the geotechnical investigation for the repair of the Fashion Island Boulevard Bridge, Bridge No. 350160, in San Mateo, California. The concrete, precast girder bridge suffered considerable damage during the Loma Prieta earthquake. The existing 36-inch, precast, prestressed concrete piles cracked and spalled at their tops. Based on analyses performed by Biggs Cardosa Associates, structural engineers, the piles did not have sufficient strength and ductility to resist the dead plus seismic loads specified in the Caltrans "Bridge Design Specifications". Additional support for the bridge was needed and the repair strategy consisted of installing large diameter pipe piles at the existing bent and abutment locations. This paper describes the geotechnical engineering analysis and design decisions for the large diameter pile design.

Jan 1, 1993

By G. C. Van Bever, J. J. Zaluski

Introduction The Surface Mining Control and Reclamation Act (Public Law 9587) (hereinafter the "Act" or "SMCRA") passed by Congress in August 1977 represents a comprehensive federal scheme for controlling surface coal mining and the surface effects of underground mining through permitting requirements, performance guidelines and reclamation planning. While the provisions of the Act have been the subject of numerous legal challenges and court battles over the years, it is difficult to identify a more controversial program within the Act than the provisions for designating lands as unsuitable for surface coal mining operations. The lands unsuitable designation process provides for the acceptance and review of petitions submitted by citizens or organizations seeking to have specified land areas designated unsuitable for all or certain types of surface coal mining activities. In filing these petitions, the interested parties or petitioners are required to make allegations about potential adverse impacts on people or the environment and submit evidence supporting their allegations. In 30 U.S.C. § 1272, Congress provided that "[a]ny person having an interest which is or may be adversely affected shall have the right to petition ... to have an area designated as unsuitable for surface coal mining operations." Under the Act, an area can be designated as unsuitable where the mining operation will (1) be incompatible with existing state or local land use plans, (2) affect fragile or historic lands, (3) affect renewable resource lands where mining operations could result in substantial loss or reduction of long-range productivity, or (4) affect natural hazard lands where such operations could substantially endanger life and property. In enacting SMCRA, Congress mandated that each state establish a process to determine which, if any, lands within the state are unsuitable for all or certain types of surface mining operations. In response to this federal legislation, the Kentucky General Assembly adopted a state regulatory program for surface mining that included provisions direct¬ing the Secretary of the Natural Resources and Environmental Protection Cabinet to establish a program for designating lands as unsuitable for surface mining as required by the Act. In recent litigation in Kentucky, several environmental groups filed a lands unsuitable petition, later joined by the University of Kentucky, challenging a proposal by Arch Mineral Corporation to surface mine over 3 million tons of recoverable coal. The petition sought to designate over 10,000 acres of land adjacent to Arch's proposed operations as unsuitable for surface mining operations, basically alleging that the mining would disturb an outdoor laboratory. The filing of the petition activated Kentucky's regulatory scheme for reviewing lands unsuitable petitions that can result in an absolute prohibition against surface mining on the petitioned land for historical, environmental and other related reasons. The designation process involves vague petition requirements creating a situation that Arch argued is devoid of constitutional due process and subject to abuse by the petitioner on many fronts. Arch maintained that the lands unsuitable regulations do not grant adequate protection to Arch's legitimate property rights under the due process clauses of the United States and Kentucky Constitutions and are thus void and unenforceable. The entire process resulting in a decision on the petition took just under 12 months in the Arch case, and although Arch was ultimately successful in preserving its right to mine, Arch's surface mining permit was held up for this period of time. This delay led to the cessation of mining operations by Arch and the idling of over 250 workers. This paper will review the lands unsuitable designation process and the significant implications the process has for existing surface mining operations, currently proposed operations and even those long-range operations not yet contemplated. Special emphasis will be given to Kentucky's lands unsuitable program. Finally, the recent litigation involving Arch Mineral Corporation and its effort to surface mine 81.5 acres of Arch controlled property will be utilized to illustrate this very unusual regulatory scheme. Regulatory background Chapter 30, Subchapter F of the Code of Federal Regulations (C.F.R.) promulgated to implement the provisions of SMCRA, requires that each state establish procedures under the state's surface mining program for designating non-federal and non-Indian state lands as unsuitable for all or certain types of surface coal mining operations. 30 C.F.R. § 764.1. The C.F.R. establishes minimum standards for state lands unsuitable programs and sets out requirements for filing a Lands Unsuitable Petition (hereinafter "LUP"), processing LUPs, decision-making guidelines and hearing requirements. Kentucky has adopted regulations providing for the implementation of the lands unsuitable process as part of the state's regulatory program under SMCRA. The following discussion summarizes the principle components of the Kentucky lands unsuitable program.

Jan 1, 1993

By D. K. Dysinger

The U.S. Bureau of Mines investigated leaching of chalcopyrite with sulfuric acid-oxygen under conditions anticipated during in situ leaching. A central composite experimental design was chosen to study oxygen pressures of 150, 300, and 450 psi, leach temperatures of 35?, 65°, and 95° C, oxygen-to-chalcopyrite mass ratios of 0.5, 1.0, and 1.5, leach times of 8, 16, and 24 hours, initial acid strengths of 0.6, 1.2, and 1.8 g H2SO4/g chalcopyrite and pyrite to chalcopyrite mass ratios of 0, 1, and 2. The leaching kinetics were consistent with the shrinking core model. A quadratic response surface model was used to determine linear and interaction effects of the design factors on rate constants from Arrhenius correlations.

Jan 1, 1993

Innovative mining technology came to Texas in the form of bucket wheel excavator/cross-pit spreader systems. Texas Utilities Mining Company put the first system to work at its Big Brown Mine in December 1985. The second such system was put into operation at the Monticello Mine in February 1991. The cross-pit spreader systems are mobile, electrically powered, excavation and conveyor systems, the principal components of which include bucket wheel excavators (BVE) and an across-the-pit conveyor (spreader). These crawler mounted machines operate as a unit; the BVE's excavate overburden, feed it via conveyors to the spreader which in turn conveys the material across the open pit and onto the developing spoil bank. The system at the Big Brown Mine is composed of 2 BVE's and an across-the-pit conveyor while the Monticello system is made up of 1 BVE and a spreader. The BVE's prestrip overburden preparing a dragline bench for the final removal of overburden. Numerous evaluations, including lignite production requirements, economics, overburden characteristics, rehandle reduction, spoil stability, and the compatibility with dragline operations, led to the selection of the cross-pit spreader system at the Big Brown Mine. The system has proven itself as a viable and economical means of prestripping. The system's success at the Big Brown Mine led to the development of a second such system at Monticello. The advent of the cross-pit spreader system is viewed by Texas Utilities Mining Company as a viable solution to recovering deeper lignite reserves in a safe and economical manner.

Jan 1, 1993

In the western Woodlark Basin, propagation of seafloor spreading is occurring directly into the continental crust of Papua new Guinea. The spreading is not strictly in a back-arc tectonic setting, rather it appears associated with microplate rotations related to the complex convergence of the Indo-Australian and Pacific plates in the southeastern Pacific region. Volcanic rocks along the western Woodlark spreading axis range from normal mid- ocean ridge basalts to basaltic andesites with back-arc geochemical affinities. Rare peralkaline rhyolites also occur. Hydrothermal deposits occur at a basaltic andesite volcano located on the neovolcanic zone near its westernmost propagating tip. Franklin Seamount is a 250m-high cone constructed largely of pillow lavas and talus which sits astride a 450m-high ridge of similar lavas oriented subnormal to the spreading direction. At its crest, 2150m below sea level, there is a 100m-deep caldera.

Jan 1, 1993

By Clifford R. Miercort

When it was announced that the economy grew at an annual rate of 4.7 percent in the Fourth Quarter of 1992, it appeared that our long awaited recovery from recession was here. Unfortunately that much growth proved to be unsustainable, and in the First Quarter of 1993, the number dropped to less than one percent. Today it is clear that the recovery is continuing, but at a very slow rate. One of the Most disturbing statistics during this recovery is that unemployment has not improved as one would expect but has been hovering around 7 percent for over a year, making this recovery a ?jobless? one. In a recent Harvard Business School presentation, a professor reported that the United States has slipped from its leadership position in almost every manufacturing category since World War II. From the production of cars to consumer electronics, we have lost significant world market share to others, most notably Japan and Germany. Obviously this is not new news, but the magnitude of the loss and the number of industries affected was surprising to me. The result has been that our negative balance of payments has soared, and the United States of America now has the dubious distinction of being one of the world's largest debtor nations. It has been common for politicians, and political want-a-be's, to blame all of our trade problems on industry. They say that the moguls of American industry spend too much time seeking short-term gain at the expense of long-term growth. They say that we are interested more in our own perks and economic security than in producing quality products that can compete in the world marketplace. One of the stared goals of the Clinton Administration is the targeting of strategic industries to receive help from the government so they can compete on the world stage more effectively. Personally. I think that is an oxymoron. My experience has been that whenev-

Jan 1, 1993

By Richard D. Hangi

Process mineralogy techniques are uniquely applicable to industrial problems related to the extractive metallurgy of nickel, cobalt, and associated metals. Reflected 1ight microscopy, together with selected determinations by scanning electron microscopy-energy dispersive spectrographic analysis and electron probe microanalysis, provides the means to identify the ore minerals cobalt and nickel ores, determine the abundance of each ore mineral, assess the extent of intergrowth between the cobalt and nickel minerals and other ore and gangue minerals in the ores and concentrates, and predict the potential success of cobalt and nickel extraction by grinding, flotation, pyrometallurgical, and hydrometallurgical treatments. In addition, the extent of locking of the cobalt and nickel minerals with each other and with the gangue minerals can be directly observed by reflected light microscopy. Where ores have been treated by hydrometallurgical procedures, reflected light microscopy can serve to determine the causes of excessive leach consumption. Finally, the partitioning of cobalt and nickel between high-temperature synthetic phases produced by pyrometallurgical treatment can be precisely determined by process mineralogy techniques. Case histories from cobalt and nickel deposits illustrate the value of applied mineralogical techniques in the study of cobalt and nickel ores, beneficiation, hydrometallurgial, and pyrometallurgical products.

Jan 1, 1993

By Yu. A. Polozov, V. A. Lagunov, O. Yu. Lushinkova, Yu. I. Svirskiy, Eh. Ya. Kipko, Roy A. Williams

The STG integrated method of grouting can be divided into the several phases as outlined in preceding chapters. For convenience in describing technical procedures, they can be grouped as: 1. Investigations in non-geotechnical, exploration bore¬holes. 2. Drilling the holes necessary for geotechnical investiga¬tions and for grouting. 3. Conducting appropriate hydrogeologic tests in those holes and consequent calculations. 4. The preparation of a clay mortar. 5. The preparation of a clay-cement grout with additives. 6. The injection of the grout. 7. Checking the quality of the grout curtain. Items 2, 4, 5 and 6 are discussed below. These activities contain the procedural aspects of grouting. 7.1 DRILLING GROUT HOLES Grout holes belong to a very select class of drillholes. The necessary drilling equipment must enable the operator to drill the holes in inclined, twisting directions. In addi¬tion, the equipment must permit drilling under structurally and hydrogeologically complex conditions. The equipment must permit the operator to conduct specific testing activi¬ties in the drillholes. These activities include hydrodynamic analyses, flowmetric analysis, and the installation and re¬moval of deflectors, packers, grouting plugs, casings, lin¬ers, pumping facilities and other work. As explained in Chapters 5 and 6, the grouting of sat¬urated rock is conducted both through holes drilled from the surface and through holes drilled from the face of a shaft, drift, or tunnel. The drilling of grout holes from the surface can be carried out by an aggregate of equipment that can be the same equipment used for drilling exploration boreholes. Depending on the projected depth of the holes, the STG ZIF- 1200MR and ZIF-650 drilling rigs (or modifications of them) are used. The SKB-4, SKB-5 and SKB-7 high-output drilling rigs (workover rigs) have been used in recent years. The STG BMP-24 drilling rigs are used for carrying out the descent-lifting operations for drilling holes from the sur¬face. In a number of cases, the UKB-500C, URB-3AM and URB-2A power-fed drilling equipment is used for drilling holes from the surface. It should be noted that the drilling of grout holes usually requires an electric drive assembly. Drilling with diesel drive assemblies would be used only to preclude the possi¬bility of losing electric power during drilling operations. Turbine drilling would be used only for appropriate techni¬cal-economic reasons. The selection of the grout hole design is determined by the hydrogeological and structural geological conditions at the site as interpreted in Chapters 2 and 3. The design of grout holes must be as simple as possible in order to min¬imize costs. Hole design guidelines can be adopted as a basis for this purpose, unless site-specific conditions require otherwise. The mouth of the drillhole must be outfitted with a guide-pipe having a length of at least 2 m and an outside diameter from 219 to 234 mm. The upper part of the hole must be attached by a jig consisting of borehole casing that has a diameter ranging from 108 to 146 mm. The length of the jig h is determined by the equation [ ] where k = 1.1 to 1.2 is the load factor; P,, is the injection pressure of the grout into the mouth of the drillhole; D is the external diameter of the jig pipe; m = 0.6 to 0.7 is the work condition factor; T[ ].1 MPa is the bonding value of the rock cemented to the jig. The grout hole is drilled from the jig shoe to the de¬signed depth using a rock-crushing bit with a diameter of 93 mm or more. However in complex hydrogeological condi¬tions when the shaft intersects unstable rock, other hole designs can be used. The diameter of grout holes must permit an aggregate of investigations to be conducted in them using down-hole borehole geophysical and flowmetric logging instruments. It is necessary to cement the casing strings reliably in the grout holes, thereby permitting the injection of the grout under high pressure through the pres¬sure tight mouth of the borehole. Technological details for drilling grout holes such as the rotational rate of the drill bit, the axial load on the rock¬crushing bit, and the drilling fluid flow rate are optimized for the specific rock-hydrogeological conditions largely by experience. The hole diameter and type of rock crushing bit are important variables in these details of drilling. It is advisable to drill holes using water as the drilling fluid. However in those cases where the hole walls are unstable or under very high ground water pressure, the use of a well¬ engineered drilling mud should not be precluded. Unfortu¬nately, drilling mud can influence test results. When steeply dipping fractures with inclination angles of more than 60 to 70° are encountered, it is necessary to drill guided, inclined grout holes. This procedure permits the maximum number of fractures in each hole to be stu-

Jan 1, 1993