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P.IISTRACTThe Pacific Rim is advantaged by the uniqueness and diversity of its geological features. Why then is geology given so little regard in the education systems of the countries of this region? Not that these countries differ greatly from those in other parts of the world. Papers presented during the Precollege Geoscience Education session at the 28th International Geological Congress (28th IGC) held in Washington, July, 1989, indicated strongly that the problem is universal. There is a marked decline in interest in the Earth sciences and many nations are looking towards methods that might change this trend. Problems affecting geological education include the lack of purpose and direction, its obsolete curricula and the difficulty in attracting gifted students.The world-wide plight of geology comes at the very time when it should be fundamental to a public understanding of the global effect of human population pressure. There is a universal awareness of "the environment" but very little awareness of the science that has supplied most of the data. Geology, as the science of the Earth, is of paramount importance to an understanding of our life on this planet, particularly in its role as the source of our every need.

Jan 1, 1990

By J. G. Henning, T. R. Yu, J. E. Croxall

"Test work was carried out to investigate the thermal response of loose and solid rock under varying environmental conditions. The primary interest was to develop a technique that could be used to increase the thermal variation between loose and solid rock for better detectability of loose rock underground with a thermal imaging infrared scanner.A variety of thermal enhancement methods were evaluated both in the laboratory and in the mine environment. Air temperature variation created by the exhaust from diesel driven, mobile mining machinery was studied in detail. When sufficient hot exhaust was supplied to the air, unsteady thermal conditions became more pronounced on the rock surf ace. This allowed a greater percentage of loose rock to be detected by a high-resolution infrared scanner within minutes.The degree of thermal enhancement of loose rock was found to be dependent directly on the thermal conductivity of rock, looseness, air temperature change, and inversely on the size of loose, airflow rate and distance downwind from the heat source. It was also found that an air temperature rise of at least r c, or rock temperature differential of1°C was necessary for minimal thermal enhancement required f or infrared detection."

Jan 1, 1990

By Jan H. Hommen

TRENDS IN MINE FINANCE Reviewing historical trends may help in dealing with future funding strategies. The first trend is the increase in the use of debt to fund corporate America. Surprisingly, when comparing that with other corporates in the global marketplace, the U.S. does not look too poorly. Japanese, in particular, but also German companies, are much more leveraged than their U.S. counterparts. Note that in Japan and Germany the government and the consumer have shown substantial restraints when it comes to credit. Not so in the U.S. where the savings rate (4%) is much lower than that in Japan (20%) and in Germany (14%). As a result, the cost of leverage is substantially lower in Japan and in Germany than in the U.S. Lower debt costs in these countries allows one to obtain more of it for the same price. The close relationships between financial institutions, corporations and governments in Japan and Germany also make the risk of leverage more bearable and understandable. Also note that interest rate volatility in these countries is more subdued. The investor base in common stock is also changing. Private pension funds have been net sellers of equities during the last few years while public pension funds have been net buyers. Individuals are basically out of the market. It is estimated that over $330 billion of equity was retired in the U.S. through 1986-1988. The reasons are well known: restructurings, buy-backs, takeovers, mergers, and buy-outs. This de-equitization is likely to continue as the cost of equity capital is higher than the cost of debt capital, even on a before-tax basis. Because there has been no market for equity since October 19, 1987, junk bonds have replaced equity capital in the corporate finance structure. The non-investor-grade borrower has access to the public markets through high-yielding debt securities that often look like senior equity. Deregulation has also provided 24-hour markets; securitization can now liquify assets that before were rusting on balance sheets; information processing and communication tools give facts that are instantaneously available, creating the need for products to cover risk and exposures unknown before the start of the information and technology explosion. Thus we now have swaps, options, futures, options on futures, caps, as well as program trading, portfolio insurance, index funds, etc. Globalization will be unstoppable. Today's environment demands it. Corporations are now global competitors, even though they may have never shipped a product off-shore. Boundaries are disappearing and impediments have been removed. Stocks can be issued in a global offering with distribution in all major financial centers of the world. The high leverage of Japanese companies has made common stocks very scarce, which with the high savings rate, makes equity capital inexpensive in Japan. If markets were perfect everyone would issue stock in Tokyo and buy it back in New York. This would certainly stop the bleeding on the balance of payments. With the deficit balance of payments in America, it is no surprise that the cost of money is expensive here. The risk-return relationship on U.S. equity is not favorable enough to appeal to Japanese equity investors. The Tokyo-market, helped by a stronger yen, surpassed New York as the most important equity market in the world. The question is, will the Tokyo market hold up when Japanese domestic consumption increases at the expense of savings? In the U.S. debt markets, the plain vanilla debenture is making a comeback after a period of absence. Commercial paper has replaced short term bank borrowings for working capital funding by larger corporations. The banks have made an interesting comeback with loan sale programs that will continue to attract borrowers. There will be a continuing

Jan 1, 1990

By Henderson N, Schaap H

In large companies with mining operations spread over multiple sites, it is essential that consistency between sites is maintained in preparing and classifying resource and reserve estimates. The endorsement by The AusLMM and AMIC of the "Australasian Code for Reporting of Identified Mineral Resources and Ore Reserves" and the subsequent incorporation of reference to the code into the ASX listing rules for mining companies has provided a basis for the consistent classification of resources and reserves. However, compliance with other criteria more or less stringent than the Australasian Code can present some reporting difficulties. Examples include listing requirements for foreign stock exchanges, particular Acts of Parliament that may apply to individual leases, constraints imposed by individual companies on their own leases, and ultimately, reserves for short, medium and long term planning. Confusion can arise when any two or more sets of reserves for the same lease are compared.. To alleviate this confusion, a standardised procedure was developed for the calculation and classification of coal resources and reserves. The procedure which is geostatistically based incorporates a technique called "Irregular Block Kriging" where specific mining blocks are directly kriged. The procedure has enabled those engineers and geologists with only a basic understanding of geostatistics to apply the technique and not feel hampered by some of the complex mathematics which in the past has tended to inhibit and overcomplicate the use of geostatistics. The procedure has resulted in "cleaner" data bases and hence more reliable reserve estimates.

Jan 1, 1990

By T. Cienski

The paper presents and discusses the results of a detailed study conducted on the subject of energy consumption in the comminution of industrial minerals. The study was based on pilot circuit testing, plant operating data collection, detailed equipment data and literature research. The areas covered by investigations include: high efficiency classification; air classifiers for cement grinding circuits; grinding aids in dry grinding: dry grinding circuit, control based on particle size measurement. Results obtained indicate a large potential for the reduction of energy consumption, in particular in the traditionally high cement clinker grinding circuits. Better classification techniques and correct application of grinding additives can significantly reduce power used per ton of product and also substantially increase grinding circuit output.

Jan 1, 1990

By G. P. Larson

We define a specialized mineral market as follows: Specialized Markets are markets where a low volume of a given mineral is used to convey a large benefit to a specific product. Sales of these value added minerals to small markets generally require a different marketing approach compared to bulk or commodity markets for traditional minerals. Specialized and commodity markets are differentiated by several characteristics as listed in Table 1.

Jan 1, 1990

Develop a user-friendly, personal computer-based numerical modeling program that performs structural analyses of underground tabular deposits, making these readily available to the mining industry. Background When ore is extracted from an underground mine, the overburden weight is redistributed to unmined areas, recompacted gob zones, and artificial structures such as packwalls and/or cribs. This redistribution of stresses continually changes throughout the mining cycle and can be especially complicated when multiple-seam mining is involved. Numerical mine structural analysis methods provide a way of calculating the redistribution of overburden stresses and the resulting loading for any given area of an underground mine, thus enabling engineers to design safer and more productive mines. In 1973 Crouch and Fairhurst developed a mine structural analysis computer program called MINSIM. This computer program was based on the three-dimensional displacement-discontinuity approach, a subvariation of the boundary-element method. In 1979 Sinha expanded MINSIM's capability to provide an analysis of parallel multiple seams. Sinha called his program MULSIM. During 1984 and 1985, the Bureau of Mines upgraded and completely restructured MULSIM into what is now called MULSIM/BM.

Jan 1, 1990

By R. C. Bunge

A magnetogravimetric separation is the consequence of two competing forces with opposing directions, i.e., magnetic buoyancy and gravitation (or centrifugal force). While magnetic buoyancy is a function of particle volume, gravitational force depends on particle mass, thus permitting a separation according to specific gravity. Since magnetic buoyancy is not a phenomenon of common knowledge, this chapter is meant to briefly introduce the theory of magnetogravimetric separations. A particle that is suspended in a magnetic fluid which is exposed to an inhomogeneous magnetic field experiences a repulsive force -the so called magnetic buoyancy. In order to illustrate this effect, an analogy with the more familiar hydrostatic buoyancy is drawn. Hydrostatic buoyancy occurs due to unsymmetrical pressure distribution 'above' and 'below' a suspended particle (fig. 1).

Jan 1, 1990

By R. Watts, R. A. Laybourne

This paper describes how a 'mined out' coalfield is being mined successfully by opencast methods. The coalfield is that at New Vaal Colliery, which is situated in the Vereeniging-Vanderbijlpark-Sasolburg industrial complex. Al three coal seams at New Vaal had been mined previously, when the better-quality coal had been removed. The coal-preparation plant at New Vaal, which is also described, supplies coal to the 3600 MW Lethabo Power Station. The Colliery has been designed to supply 600 million sales tons of coal over its forty-year life.

Jan 1, 1990

By Rudolf E. Greuer, Linneas W. Laage, Xinton Chang

Data or input files are used to describe the mine's ventilation system and physical characteristics necessary for ventilation calculations as well as the physical or mechanical disturbance to be modeled and simulated Data files are organized into lines of categories or groups of information Each line contains multiple sets of information or data items Data lines are read by the program, and the data items provide information to the program variables The data file is in American Standard Code for Informa¬tion Interchange (ASCII) format, sometimes called a DOS text format Creation or modification of a data file is accomplished with text editor software Most word pro¬cessors are also capable of making the required ASCII type files A sample data file and its associated output are included in appendix B. When selecting software for editing the data files, the user should be aware that the software will also be used for viewing the output of the simulation The output file can be quite large (several megabytes), if a lengthy simulation is performed The output can be sent to a printer for a hardcopy fisting, however, the user should also be aware that most printers currently used with PC's print at rates of 100 to 300 characters per second and large output files may take several hours to print Viewing the output with a text editor can save much time and paper DATA FILE MANAGEMENT The data files describing the event and mine to be simulated can reside either on a floppy disk or in a directory on the hard disk drive When the program starts, the user is prompted for the data file location and name The user response is in the form of a standard DOS path and file name For example, if the data file is on a floppy disk located in drive B and the disk has a directory MYMINE with the data file MYDATA DAT in that directory, then, at the prompt

Jan 1, 1990

By J. Iannicelli

Kaolin, normally an inert filler when compounded with polymers, is converted into a strongly reinforcing pigment by prereaction with certain functional silanes. Modification of kaolin with amino and mercapto silanes allows it to form crosslinks and confers significant improvements in modulus, abrasion resistance, compression set and other physical properties of a broad range of polymers.

Jan 1, 1990

By Margaret R. Egan

A study of the combustion emission products of rigid ventilation ducting was completed by the U.S. Bureau of Mines. The ducting was composed of fiberglass-reinforced polyester resin. Four properties of the ducting were evaluated: (1) propensity to ignite, (2) smoke characteristics, (3) gas emissions, and (4) heat release. Particle sizes, obscuration, optical densities, and production constants for gas and smoke were also calculated. These results provide comprehensive data about the emission products, detectability, and relative hazards of fiberglass-reinforced plastic ducting and other mine combustibles under realistic fire conditions.

Jan 1, 1990

By N. S. Dalal, Xiaoya Sun, Xianglin Shi

"The in vivo toxicity of vanadium(V) has been found to correlate with the depletion of cellular glutathione and related non-protein thiols. With a view to understanding the mechanism for this observation, we have investigated the oxidation of glutathione, cysteine N·acetylcystcinc and pcnicil· lamine by vanadium(V), using electron spin resonance (ESR) and ESR spin trapping methodology. The spin trap used was 5,5-dimethyl-l-pyrroline I-oxide (DMPO). It is found that the oxidation of these thiols by vanadium(V) generates the corresponding thiyl radicals and vanadilim- (IV) complexes. The results suggest that free radical reactions play a significant role in the depletion of cellular thiols by vanadium(V) and hence in vanadium(V) toxicity. 1. INTRODUCTIONThis communication reports on the identification of thiyl radicals formed as intermediates in the reaction of vanadium(V) with glutathione (GSH) and related nonprotein thiols. This study was undertaken because the biochemical mechanism of vanadium toxicity is still not fully understood,. despite being a topic of current research activity [1-20). As to possible clues, it is known that vanadium is most toxic when administered in its pentavaient state [21), and that vanadium(V) administration into laboratory mice reduces cellular levels of NAD(P)H and GSH [22). While the oxidation of NAD(P)H by vanadium has been studied extensively [16-20), that of glutathione and related non-protein thiols has been paid less attention. On the other hand, GSH and related thiols are important cellular antioxidants [23). Their functions include decomposing lipid peroxides and protecting cell membranes [23-25). Thus any reduction in the cellular contents of such nonprotein thiols after vanadium exposure may result in the accumulation of lipid peroxides which might ultimately lead to tissue injury. With a view of finding the mechanism for this thiol depletion process, we have investigated reactions of non-protein thiols with vanadium(V). Particular attention has been paid to the detection of thiyl radicals, since it has been postulated [l] (but not experimentally proven) that the glutathionyl radical (GS·) might be an intermediate in the reaction between vanadium(V), NADH and GSH. We have used electron spin resonance (ESR) and ESR spin trapping methodology for investigating the reactions of GSH, cysteine, N-acetylcysteine and penicillamine with vanadium(V). The results show that the corresponding thiyl radicals are indeed formed in the one-electron reduction of vanadium(V) by all of the above mentioned thiols."

Jan 1, 1990

By J. P. Allen

Cobalt, nickel, and manganese can be recovered quickly, cleanly, and selectively from cobalt-rich manganese crust by leaching in dilute acid solutions in the presence of hydrogen peroxide. Common selective precipitation methods can then be used to recover these metals from the leach liquor. The leaching reaction produces only oxygen as a byproduct, and the waste residue from leaching was tested and found to be non-hazardous under existing EPA specifications. The leaching process is effective in either fresh water or seawater. This research is a part of the Bureau of Mines program to identify the mineral resources of the Exclusive Economic Zone and devise methods for recovering their valuable components.

Jan 1, 1990

By Luiz A. Teixeira

A process is described whereby worn, deffective or crystallized photoconductive Se-As layers can be stripped off from aluminium photocopier drums, using hydrogen peroxide solutions in conditions such that the aluminium substrate is preserved from chemical attack. The process allows the stripped drum to be recoated with a new photoconductive layer, and to be put again in use.

Jan 1, 1990

By III Kimball

Mining wastes have received individual attention under the Resource Conservation and Recovery Act (RCRA) since its inception, in recognition of the special characteristics that distinguish mining wastes from other solid wastes. The Environmental Protection Agency (EPA) has recognized that: - Mining wastes are generated in much larger volumes than other industrial wastes. Most material handled in mining is waste (over 99% in many cases) and not marketable product, whereas waste is a small portion of raw materials used in most industries. Consequently, controls used for hazardous wastes may be technically infeasible or economically impractical. - Nearly all mining waste is managed at the site of generation and is land-disposed. . - Mining wastes typically pose lower hazards than other industrial wastes. Mining operations are located predominantly in sparsely populated areas and in arid or semi-arid areas with little surface water runoff and deeper water tables.

Jan 1, 1990

A comparison of gold, platinum and sulfide ion selective electrodes was made in this investigation for determination of Eh in solutions containing sulfide ions as a model system. The comparison was made in terms of the accuracy of the measured response, response time, pH dependence, and reproducibility of measurement. In addition, the sensitivity of each electrode towards changes in sulfide ion concentration was measured in terms of the change in measured Eh per decade change in concentration of sulfide ions. On the basis of a detailed investigation of the electrode processes occurring at the surface of gold and platinum electrodes, it was postulated that within the pH range investigated these electrodes respond to changes in the hydrosulfide ion, HS-, concentration in solution. In comparison, the sulfide ion selective electrode is known to respond to changes in the sulfide ion, S-, activity in solution. Although the potentials measured with gold and platinum electrodes were mixed potentials, pretreatment procedures can be used to obtain a signal suitable for process control. For control of sulfide ions in flotation pulps, the use of a gold electrode pretreated at 1.0 V with respect to a standard hydrogen electrode is recommended.

Jan 1, 1990

By Rynn J. M W, Paynter A

Recent studies by the authors have concerned themselves with assessing the earthquake risk to north-eastern Australia, based on available historical earthquake data for the area. There have been several significant earthquakes (Richter local magnitudes of the order of 6) concentrated in the Wide Bay - Burnett region in central eastern Queensland, although none of these has occurred close to a significant centre of population or development. Using derived average acceleration attenuation relations and world-wide data on earthquake-induced damage as a basis, conditions under which earthquake-induced liquefaction may occur have been investigated and presented in graphical form. Historical earthquake data for north-eastern Australia have been overlain on this graphical presentation and it has been demonstrated that the Wide Bay - Burnett region, in particular, may in the past have been on the verge of earthquake-induced liquefaction, where ground conditions are susceptible. When this is viewed in the context of the rapid growth in population and development in this area over recent years, the risk can no longer be ignored with impunity.

Jan 1, 1990

By Jeffrey L. Zelms

Environmental issues and how they are addressed -- or not addressed -- by the lead industry in the 1990s will determine the eventual fate of lead mining in both the U.S. and worldwide. Clearly, governmental regulation throughout the West will become harsher. Equally clearly, the industry has? failed to educate the public regarding lead. Instead of public support for a critical mineral, we face widespread public ignorance and paranoia. If we can demonstrate the public interest benefits of the industry, the 1990s will be a decade of continuing growth -- not dynamic growth, certainly, but growth at least comparable to the world economy. If, however, we fail to demonstrate the industry's public interest benefits, the 1990s could mark the beginning of the end of our business.

Jan 1, 1990

By Michael F. Gleason

In 1986, Gold Fields began negotiations with a large Nevada electrical power utility to supply power for its Chimney Creek Mine In northern Nevada. After the long negotiations reached an impass over various costs associated with the power line, a decision was made by Gold Fields to generate its own power. Self-generation is not uncommon overseas, but it is rare for any but very large or very small operations in the United States. Surprisingly, under certain conditions a mine can generate its own power profitably and Gold Fields has found that the associated operating and maintenance problems are minimal. The following report details what factors went into this decision and how it works. Hopefully, it can serve as a guideline for those who may find themselves in a similar position.

Jan 1, 1990