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By Gary E. Slagel

The federal Office of Surface Mining (OSW) has undertaken an effort to revise many of their permanent program regulations. Numerous procedures for compliance are being rewritten to allow for greater flexibility while meeting the requirements of the Surface Mining Control and Reclamation Act. This study investigates, for certain select provisions, the cost differential between complying with the original OSM standards and the more flexible, state-specific standards being allowed in many of the revised regulations. Estimated cost savings that could be realized under a few of the revised regulations are substantial and should provide a basis for seeking revisions to the state regulatory programs.

Jan 1, 1982

By Mark E. Gershon

A mixed-integer formulation of the mine scheduling problem is discussed and applied for the purpose of optimizing both the mine production sequencing and the mill blending and processing problems simultaneously. Previous attempts at solving these problems separately, although successful, fail to take into account the interrelationships between these problems. Project structure serves as the outline of this paper, which is directed towards a mining engineering audience. Generalized in its organization, this concept is useful for long, intermediate and short range scheduling. Actual applications are mentioned which show that the concept is also applicable to mining a variety of ores.

Jan 1, 1982

By Thomas F. Torries

It does not take sophisticated economic analysis to determine the current status of nickel production and demand (Figure 1). One only needs a quick glance at the balance sheets of the major nickel producers to learn that prices are down and profits are supressed to the point where they are major losses. Operations have been closed, and those remaining in production have reduced output. What Is now of interest Is, when will the nickel market improve and to what degree? The purpose of this paper is to attempt to answer these questions. This will be done by the normal method of projecting nickel demand, chosing a production scenario, and analyzing the results.

Jan 1, 1982

By G. L. Hohmann

The Waste Isolation Pilot Plant (WIPP) project is authorized by legislation to provide a demonstration of the safe disposal of radio- active wastes generated by the national defense programs and activities of the United States. The U.S. Department of Energy (DOE) is proceeding with the implementation of the WIPP project in accordance with the "Department of Energy National Security and Military Application of Nuclear Energy Authorization Act of 1980" (PL 95-164).

Jan 1, 1982

By J. P. Nichols

Modern vibrating screening dates from about 1910 at which time the forerunner of the present day two bearing and four bearing circular motion inclined vibrating screens were first introduced. These simple machines consisted of a screen box holding some kind of a screening surface to which was attached an off-center shaft or a shaft with an off-center weight which was rotated. The rotation of these shafts caused a shivering motion to the screen box and produced the first vibrating screen. In the 1920's and early 30's, the box designs were improved and the mechanisms designs were also improved and by 1940, vibrating screens were an important part of most process plants. In the early days when the screen sizes were dictated by how much could be shoveled onto the screen box and by the force that a particular mechanism could produce, not much thought was given to the proper sizing of the particular units. As mechanism and body design improved the ability to predict vibrating screen capacity at various openings became more important. In the late 1930's, a set of empirical capacities came to be used. with few modifications, these capacities are still in use today, both by those companies that use a formula involving only the amount of fine material in a feed, and by those companies using a formula in which the total feed to a particular screen is used. In either method of calculation, the empirical values are based on these ideal conditions: (1) The material being fed to the screen contains 25% oversize. (2) The feed to the screen contains 40% half size material. (3) The material has a bulk density of 1.6 T/Cu.M. (100 lbs/cu.ft.). (4) The screening surface has an open area of 50%. (5) The material is dry, free flowing and relatively cubical. (6) The maximum screening efficiency required is between 90 and 95%. It is obvious that these conditions do not occur in natural or crushed size distributions. Therefore, modifications must be made to these empirical values to allow for the calculation of a vibrating screen for a particular set of conditions. Before we consider these various modifications, let us look at what happens to material as it is acted on by a vibrating screen so that we can better understand why the modifications are nec-

Jan 1, 1982

By Robert L. Marovelli

The major mining health and safety problems of concern to United States Government and private industry researchers in 1981 included the difficulty experienced by longwall operators in complying with the Federal 2 .0-mg/m3 respirable dust standard, the accident rate associated with falls of ground and materials handling hazards, and the upsurge in the incidence of disasters after the steady decline in recent years. Although the many mines and manufacturing companies involved in the research projects to be described are not specifically identified, it is important to note their significant involvement. This is not by way of acknowledgement, but rather to establish that these projects, using mostly Federal funds, represent close cooperation between the U.S. Government and the mining industry. The ongoing work to be described on the development of critical longwall dust control technology is a classic example of Government-industry participation through the phases of problem identification, planning, cost-sharing, and implement at ion.

Jan 1, 1982

By David W. Houseknecht

Probabilities of encountering coalbed discontinuities during vertical or horizontal drilling in a specific coalbed can be estimated based on analysis of mined-out areas of the coalbed where the size, shape, orientation, and distribution of discontinuities are known. The result- ant probability estimates can be applied to cost-risk evaluations of drilling programs proposed for exploratory, developmental, or methane drainage purposes in undeveloped areas of that coalbed. Data compiled from mine maps of the Beckley Coalbed in southern West Virginia were used to estimate the probabilities that discontinuities would be encountered in two illustrative hypothetical drilling programs--one for drilling vertical boreholes and the other for drilling horizontal boreholes. Analysis based on a mined-out area of the Beckley Coalbed indicated that vertical methane drainage boreholes spaced 1,000 feet apart in a square grid pattern would each have a 29 percent probability of encountering a discontinuity in a geologically unexplored area of the coalbed. It was also determined that exploratory vertical drilling could locate most of the discontinuities if a borehole spacing of 2,500 feet were used. For horizontal drainage boreholes in the Beck- ley Coalbed, the analysis indicated a linear relationship between hole length and the probability of encountering a discontinuity.

Jan 1, 1982

By William E. Bruce

This paper is intended to provide an improved understanding of natural draft (natural ventilating pressure) and the effect of natural draft on underground mine ventilation circuits. Attention is focused on measurement of natural draft pressures during ventilation surveys in mechanically ventilated mines and on different methods for modeling natural draft using the measured data. A number of examples are presented which utilize data collected during absolute air pressure surveys made by personnel of the Ventilation Division of the Mine Safety and Health Administration's Safety and Health Technology Center, Denver, Colorado. Examples are used to illustrate how the data from absolute air pressure surveys may be interpreted to determine whether natural draft pressure is present and what its magnitude is. In addition, two different methods are described for mathematically estimating the magnitude of the natural draft pressure. Comparisons are made of results obtained using the different methods. Different procedures are described for modeling natural draft using the MSHA-modified Penn State computer program. Use of the routines is described and illustrated relative to drafts that aid or oppose the mechanical ventilation system. Tabulations of results facilitate comparison of outcomes obtained using the different modeling procedures.

Jan 1, 1982

By M. H. Erten

Most of the fourteen workable coal seams in the State of Missouri have high ash and sulfur levels and need beneficiation in order to meet customer and Environmental Protection Agency requirements. If proper ash and sulfur removal methods can be designed, more Missouri coals will be mined and used within the state. One of the main objectives of this research is to investigate the possibility of removal of sulfur of Missouri coals by conventional beneficiation methods.

Jan 1, 1982

By Asheim, Harald A.

Parameter estimates affect both the optimum field development decisions and the economic result. A general methodology for assessment of the effects of parameter uncertainty in offshore development decision situations is proposed, and used to analyze aspects of the initial development situation for the Statfjord field.

Jan 1, 1982

By W. Edwin Dill

For the mining industry, the Internal Revenue Code and regulations offer a range of choices in arriving at the allowable depletion. Each case is essentially unique. Two prerequisites can optimize these opportunities: communications between the mining company's tax specialists and its technical staff; and an understanding of IRS definitions. For the latter, a logical starting point is consideration of exploration and development, since they precede production and depletion is unallowable prior to production. Criteria for selecting engineering and accounting options for exploration and development indicate the necessity of interaction between these company functions to achieve the most favorable tax position.

Jan 1, 1982

Australia is tightening its rules governing mineral processing and the purchase of rural land by foreign investors" Rural land purchasers in the future will have to demonstrate to the Foreign Investment Review Board, the applicable governing body, that they will introduce new techniques or developments that will benefit Australia. In mineral processing, the criterion will be the availability of maximum opportunities for Australian equity capital. The changes are designed to discourage absentee landlords and speculators from abroad. A diamond field discovered several years ago in the northern section of Western Australia, known as the Kimberley region, is now thought to be one of the largest in the world, according to Conzinc Riotinto of Australia Ltd. (CRA). Figures released late in 1981 by CRA indicate that the main orebody of at least 100 million metric tons contains possibly 500 million carats of diamonds with a conservative market value of $8 billion. The diamond stones in the 100-acre deposit are about 10% gem-quality, 30% near gem, and 60% industrial. Initial production is expected to be about 17 million carats annually, which could be expanded to 25 million carats annually. World production of natural diamonds has been about 40 million carats per year from a reserve base of about 700 million carats.

Jan 1, 1982

By N. J. Ferguson

An upsurge in demand for Australian coal has seen a much needed programme for a new generation of coal ports. This paper discusses design concepts in planning a large modern terminal, with the 25 Nt/a Port Kembla and the 50 Mt/a Newcastle facilities as practical examples. The need is emphasised for a studied Master Plan, in-built materials handling flexibility and staged development. Trends in bulk ship design and loading methods are noted. Features of these Australian designs include methods of dealing with poor ground conditions, functional civil engineering for environmental protection and optimal marine structure designs.

Jan 1, 1982

By Richard G. Burdick

The Bureau of Mines conducted this research to determine the feasibility of using soil redox measurements, a relatively new method in mining geophysics, to locate or define a variety of conditions that are hazardous or otherwise of interest to the mining industry. The method was used in three widely separated areas in an attempt to de- fine subsurface concentrations of methane, the edges of coal-burn areas, and a hydrothermal vein set. Both a description of the method used and test cases are given in this report.

Jan 1, 1982

By Ronald T. Cosburn

The Province of Ontario covers an area of some 400 thousand square miles, however the subject I will be talking about today, the licencing of pits and quarries in southern Ontario, refers to about one quarter of this total area but contains better than 93% of the total population of the province or about 8 million people. Southern Ontario had and still has many inviting features to industry. The Great Lakes almost surround us, hydro power has been relatively inexpensive and abundant, but more in line with our topic today are the ample deposits of sand, gravel and limestone, all of which are used directly or indirectly throughout and are the mainstay of our construction industry. I say we are fortunate to have these non-renewable resources in abundance in close proximity to our industrial and metropolitan areas, but like so many of our resources we have taken them for granted for too long. What has happened in our case, as I am sure is common in many of your own similar situations, because of the recent, current popular trend by naturalists and environ- mentalists to preserve our natural heritage at the expense of all else, through parklands and indiscriminate zoning policies, these once abundant reserves have been tremendously eroded.

Jan 1, 1982

This section of Minerals and Materials analyzes the following three factors affecting the recent performance of the U.S. and world mineral industries: 1) the health of the U.S. and world economies, 2) the level of interest rates and 3) the performance of productivity in both the U.S. mineral industry and the general economy. While these indicators do not exhaust the possible critical factors, they represent an initial attempt to probe some of the considerations underlying the performance of the U.S. minerals and materials industry. The U.S. and World Economies It is essential to analyze the state of the U.S. and world economy because the demand for minerals and materials is a derived demand; that is, since minerals and materials are used in the productive process, the demand for them is a direct function of the demand for the finished products of which they are a basic input. Thus, the demand for minerals and materials is directly affected by changes in present and planned consumption and investment expenditures. The past two issues of this publication have highlighted the generally discouraging performance of the national and inter-national economies. Briefly, the world economy is in the third year of the first long recession in recent history where inflation rates have remained above 5 percent. With many countries either unable or unwilling to support domestic spending while inflation continues, there has been a growing tendency to institute trade-restrictive policies to support domestic demand. The resulting weakened demand conditions in exporting nations have had a direct effect on the mineral industry.

Jan 1, 1982

By Francois E. Heuze

This paper summarizes the geomechanics programs conducted in two hard rock underground mining operations in the Western United States, between 1966 and 1981. The two projects were directed towards understanding the behavior of the rock masses, at the scale of the caverns. To this end, the emphasis was put on large scale field measurements, complemented by limited laboratory testing. The results of these observations were used to build realistic finite element models of the underground chambers. In the marble mine, at Crestmore, California, the models were applied to the structural optimization of the room-and-pillar pattern. In the granite mining, at Climax, Nevada Test Site, the models explained some unusual stress changes observed during excavation. Based on the large number of geomechanical techniques employed, specific conclusions and recommendations are offered regarding the quality, applicability, and usefulness of the various methods. The two case histories clearly indicate chat numerical models are extremely useful for a detailed understanding of the structural behavior of mine openings. To be realistic, these models must be based first and foremost on large scale field observations. The lessons Learned on these two projects also are directly applicable to the design and analysis of nuclear waste repositories in hard rocks such as basalt, granite, and welded tuff.

Jan 1, 1982

By Bruno A. Fichna

Longwall mining offers low cost potential for coal with high capital investment. As opposed to two shifts-per-day operation in most long- walls, Saarberg Mines in Germany increase utilization of capital by operating their longwalls around the clock. Differentiation between capital and operating costs, corrective maintenance versus preventive maintenance, improved roof conditions, and economical life of equipment was investigated. A surprisingly high degree of improvement was attained. Capital costs at Saarberg longwall coal mines have been reduced through a step-by-step research and trial program. This reduction was particularly influenced by the high performance pilot longwalls at the Ensdorf mine. The following presentation shows data and figures of those longwalls. End results were 40% reduction in capital costs, which could contribute favorably to investment decisions in the coal industry in a supply side economics environment.

Jan 1, 1982

Despite modest improvements in the performance of domestic interest rates and gross national product,1 fixed investment in domestic producers' durable equipment continued to weaken during the second quarter of 1982 and declined at a 12.8 percent annual rate compared with the first quarter.2 Large declines occurred during the second quarter in expenditures on many of the major mineral-consuming industries such as aircraft, computers, agricultural and construction machinery and mining and oil field equipment. These data appear to be consistent with the low level of business investment plans for 1982 reported in the DOC's Bureau of Economic Analysis survey of expenditures on new plant and equipment.3 Domestic and foreign industrial production and mineral industry production activities continued to decline in the most recent period because of weak demand conditions (Tables 1 and 2). The U.S. mining production index declined 7.7 percent between April and June as compared with 1.2 percent for total U.S. industrial production (Table 1).

Jan 1, 1982

By L. H. Gevantman

A program for the compilation of evaluated physical and chemical numerical properties data is being pursued at the National Bureau of Standards within the Office of Standard Reference Data. This program is being sponsored by the Department of Energy and managed by the Battelle Office of Nuclear Waste Isolation in Columbus, Ohio. The intent is to assemble a reliable body of numerical properties data concerning candidate mineralogical materials in which high-level radioactive wastes are to be buried. The ready accessibility of the data to site designers and the credibility achieved through the evaluative process are designed to help assess and compare the feasibility of each candidate material for use as a disposal site. Both generic and site-specific data are to be assembled. To date, generic rock salt properties have been assembled and published by the NBS as NBS Monograph 167. Details of the effort to produce this book are discussed.

Jan 1, 1982