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By Frank E. Dalton, Forrest C. Neil

INTRODUCTION The Tunnel and Reservoir Plan (TARP) (Figure 1) was adopted in 1972 as the most cost-effective way to bring Chicago area waterways up to Federal and State water quality standards. TARP will significantly reduce pollution of these waterways and provide flood relief for Chicago and 53 adjacent suburban communities. These communities, covering an area of 971 sq km (375 sq miles), are at present served by combined sewers, which carry both raw sewage and stormwater. Because porous ground surfaces have been covered over in recent years by buildings, streets, and parking lots, stormwater runoff into sewers frequently exceeds the capacity of the sewers. When this happens, sewers back-up into hundreds of thousands of basements, and the overflows on the combined sewers discharge rainwater mixed with raw sewage directly into the area's waterways at 645 overflow points. The result is severe pollution of the waterways and flooding in 53 communities. During particularly heavy rains, overloaded rivers have to be relieved by opening the locks and allowing the polluted waterways to flow into Lake Michigan, the region's water source. Goals of TARP 1. PREVENT BACKFLOWS INTO LAKE MICHIGAN. 2. ELIMINATE WATERWAY POLLUTION CAUSED BY COMBINED SEWER OVERFLOWS. 3. PROVIDE AN OUTLET FOR FLOOD WATERS.

Jan 1, 1981

By Lyle A. Hale

The subject area known as upper Dry Valley is located 15 miles due east of Soda Springs in Sections 14 and 23, Township 9 South, Range 44 East, Caribou County, Idaho. The railroad extending from Soda Springs to its terminus at El Paso's Maybe Canyon mine is 8z miles to the north in lower Dry Valley. Initial data derived from trench work in 1962 revealed a variety of econom¬ically significant alterations of the phosphatic beds related to the rather unique geomorphic development in the northern part of phosphate lease 1-012989. It was apparent that such conditions, while valid for near-surface beds in a strike direction, would be misleading if projected to the proposed depth limits of strip mining. Consequently, a subsurface mapping program was initiated in 1963 to determine: (1) the depth and horizontal extent of weathering and related phe¬nomena, (2) the depth, thickness, and quality of ore beds and intervening strata, and (3) structural geology as a guide for mining procedures. Successful use of a scintillometer in 1956 to detect the subcrop position of phosphate beds in the Smokey Canyon area of southeastern Idaho led to the conclusion that gamma radiation surveys of drill holes could be a useful aid in subsurface mapping. The objectives of this paper are: (1) briefly to describe geologic features characteristic of the phosphate lease area and (2) to demonstrate the practical application and theory behind gamma radiation logging as an effective tool in the economic evaluation of a phosphate lease.

Jan 1, 1969

By Richard A. Bideaux

In mid-1975, the United States Borax & Chemical Corp., a member of the RTZ group, engaged Computing Associates, Inc. (CAI) in a continuing project to model their operating property at Boron, CA, with the goal of computerized assistance in medium- and long-range open-pit mine planning. Their property, 161 km (100 miles) northeast of Los Angeles, is the largest producer of borate minerals in the world. Because of unusual geological complexity, this unique deposit presents interesting problems in computer modeling, compared with the coal, uranium, and other metallic deposits with which CAI ordinary deals. Mine planning for Boron has historically been based on manually plotted contour plan maps and cross sections, with geological reserves derived from manual triangularization of the drilling pattern. Standardization and reproducibility of log interpretation, contouring, and reserve calculation were principal goals of using the computer. Additionally, it was desired to shorten both the time and cost of a planning cycle, while at least equalling the accuracy of the manual planning. The present recovery plant processes only water-soluble borates; at some time in the future it will be necessary to recover acid-soluble borate minerals as well. With computer assistance the economics of this changeover point can be more thoroughly evaluated.

Jan 1, 1979

By Robert P. Larkin

The necessity for mineral extraction and its impact on man and the natural environment is a subject of increasing concern to Americans. Rising living standards and new demands for energy require increased mineral extraction, whereas the "new environmentalism" and concern over social well-being warn of the dangers to both the environment and the social system. This dilemma can only be solved by a complete understanding and analysis of all the factors relevant to human welfare which include environmental considerations, economic implications, and the social and psychological dimensions. A decision-making framework is therefore necessary which will encompass all relevant views of the problem.

Jan 1, 1975

By J. D. Kennedy

The alchemists of old are remembered well for their tireless efforts in attempting to convert various common metals, such as lead, into gold. Not so well known generally, but no less intense, have been the efforts of certain individuals who attempted to manufacture diamonds over the last 100 years. Diamond, the most glamorous and permanent of gems and the hardest industrial abrasive, is carbon in a high-density unique crystalline form with a cubic structure and a density of 3.5. This contrasts with graphite at a theoretical density of 2.2 and possessing a hexagonal structure. Diamond is the hardest natural, material known and until very recently had no close competitor, natural or otherwise, with respect to hardness. The hardness of diamond exceeds that of any other industrial abrasive by a factor of approximately five. The early theories of diamond synthesis were rather vague. Since diamonds occurred in nature, man then looked to nature for clues as to how this might be accomplished. The original known diamond deposits of India are alluvial in character and provided little insight as to how diamond had been formed by nature, for in, these locales the diamonds have been washed by streams or carried by the glaciers long distances from the areas in which they occurred originally in the earth's crust. As a matter of fact, we are told that even today the locations of the mother ground for the Indian alluvial deposits are not known.

Jan 1, 1959

By E. C. Watkins

The fiber glass industry is an industry that. hopefully is still in its infancy and far from a mature business. Fiber glass, as will be discussed in this paper, deals with continuous strand glass as used in the textile laminate and reinforced plastics industries. More specifically, we are speaking of glass used for printed circuit boards, tapes, paper, cloth, pipes, tanks, boats, recreational equipment, roofing shingles, and automotive applications. Compared to the flat, container and decorative glass industries, we are very young. The early patents on fiber glass applications were issued in the 1930's. The type of glass most commonly used in the world and that discussed in this paper is designated as "E" glass. This is a boro-silicate type glass having specific chemical and electrical resistance and low thermal expansion properties.

Jan 1, 1986

By D. J. Shields

The goal of public policies is to connect desired ends with practical means toward their achievement. How the desired ends are determined, and whose goals and objectives they incorporate, depends upon the culture and political system of the country in question. With few exceptions, policies change over time to reflect changed perspectives and understanding of the world around us. This is true regardless of the policy area in question. Thus, how societies view and manage their mineral resources has evolved in response to public attitudes, societal needs, economic circumstance, cultural perspectives, political orientations, technological advancements, and geological knowledge. In this paper we examine how the scope of concern has changed for mineral policy. We then review the overarching issues that have in recent years been considered essential components of mineral policies. We point out how neoclassical microeconomics has influenced recent policy design. We then use a market flow diagram to illustrate how policies can be focused at specific market issues. We next discuss mineral resources in the context of sustainable development. We identify issues that become relevant when the frame of reference is enlarged beyond ensuring supply and capturing economic rent. We show that policy based solely on neoclassical economics may not be able to effectively incorporate these issues.

Jan 1, 2007

By W. Kuckshinrichs

Metallic raw material flows are characterized by a complex global network of producers and consumers, as well as by a multitude of ecological, economic and social impacts across national boundaries and on different scales. This leads to the need to develop methodologies, which allow identifying obstacles that prevent metallic raw material flows to contribute to sustainable development. From a scientific point of view CRC 525 (Martens 2003) has developed an holistic indicator set consisting of approximately 80 different indicators. This set is taking into account the multi-dimensional character of sustainable development. Moreover the indicators reflect different system boundaries according to different actor levels and decision contexts. The full indicator set is important in scientific considerations and suitable for scientific awareness creation. However, to fulfil the function of a decision support approach for political and economic decision-makers some modifications are of central concern. At first a reduction of the full indicator set by selection of core indicators enables decision-makers to deal with complex issues of contrary economic and societal protection targets. Secondly, as thresholds of indicators justify societal call for action, they are discussed against its political or scientific origin. The proposed methodology is exemplified by indicator-based studies of the material flow of aluminium.

Jan 1, 2003

By D. M. Wyslouzil

Conditioning, in the conventional sense, means providing sufficient agitation and contact time for the reagents to react with the minerals in the ground ore. High intensity conditioning (HIC) on the other hand, as described in this paper, recognizes the need to exceed this minimum power input over a suitable length of time to induce aggregation of the finest size fraction. Time alone is not sufficient to achieve aggregation. The threshold minimum power input, kW/m3, depends on many surface properties of the fine particles and can vary considerably. In addition, the mechanical aspects and the chemical conditions must be matched to achieve good aggregation. Treatment of complex sulphide ores, requiring fine grinding for liberation, offers a large field for the application of HIC. Improved flotation rates and enhanced selectivity are some of the benefits that can be expected. This unit operation has now reached the level of commercial application. Lakefield Research considered HIC not from a fundamental point of view but as a means of solving difficult mineral processing situations arising in actual operating plants. This paper summarizes the effects of the various chemical reagent combinations that had been applied to promote faster, more selective flotation, higher mineral recoveries and cleaner separations, using HIC.

Jan 1, 1995

By K. Irmscher

During the last years, using modular computer models on the software and distributed computer capacities on the hardware side has become quite common in the mining industry. When tackling real mining problems under the condition of heterogeneous systems, however, some problems become obvious: the incompatibility of the heterogeneous platforms in connection with the heterogeneously structured information and the necessity of interpreting the data. Knowledge based approaches are employed for solving different planning problems in the field of mining industry. The main problems here consist in the knowledge representation and data acquisition. Starting point of the investigation form classifications of mining planning problems and the corresponding models which can be transformed into information models for evaluation. With help of an expert system a practical solution is represented. Distributed systems with mobile computing and communication facilities for immediate access can be used as an additional support for planning and processing. On the base of public or private computer networks (including mobile networks) the foundation is given for a computer supported treatment of planning tasks. Additionally the use of teleworking scenarios in regions of mine planning and data collection in geological applications is prepared. Foundation forms a workflow system on an object-oriented distributed platform.

Jan 1, 1996

By Jed H. (Original by) Mosgrove

Good mine ventilation starts at the drawing board. A coal mine will either be adequately ventilated or not, depending upon how good a job was done in the planning. Poor planning will not only result in inadequate ventilation, but may also lead to low productivity. A mine foreman cannot achieve high productivity while trying to maintain 4.2 ma/s (9000 cfm) of air at his last open crosscut.

Jan 1, 1981

By Ben H. Daud

A computer model has been developed at Consolidation Coal Co.'s Central Engineering Dept. for preliminary economic evaluation of deep coal mine reserves. Since it was first formulated more than two years ago, the model has been used for the following purposes: (1) ranking studies of coal exploration projects, (2) marketing surveys, (3) preliminary sale and acquisition analysis of coal reserves, and (4) parametric analysis in conjunction with detailed feasibility studies.

Jan 1, 1979

By R. A. Womack, Alex Ruzycki

Over the past six years, 4.5 million tonnes (5.0 million short tons) of gold ore have been heap leached at the Alligator Ridge Mine. Ore is leached in successive lifts, resulting in heap heights of 20 m (66 ft). Recoveries from each lift are determined through an extensive post-leach drilling program. The relationships between heap height, recovery rate, ore preparation, heap construction, and leach solution application are discussed.

Jan 1, 1987

By M. E. Kuchta

Surface coal mine design can be facilitated with the use of an interactive graphics personal computer program. This mineral inventory and planning program (POLY CALC) is described and its use is illustrated with a case study. The case study deals with investigating a stripping sequence and associated dragline stripping requirements.

Jan 1, 1986

By P. Tsakiris

The increasing social interest for the environmental issues, forces the authorities to enact more rigorous regulations. The mining industry is one of the sectors that concentrate vigorous remonstrance. It is an absolutely justified reaction, as a result of the numerous contaminated and polluted sites that have been inherited by previous operations and they remain unremedied. The lack of a consolidated global legislation, transfers the burden of decisions to the national level. This paper consists of two parts. At the first part, it discusses the critical role of the state to form an effective environmental policy, feasible for the context of the national economy. Afterwards it analyses two of the main points, which must be considered by the regulator for the excavation activity, the abandoned sites and the duration of the mining investment. The aims are to defuse, in the short-term, the public pressure, protecting the economic growth and, at the same time, to form a basic structure for the development of the corporate social responsibility. The second part presents an alternative financial instrument for the Greek regulatory framework, conformed to the characteristics of the Greek Economy, and analyses the expected benefits both for the business and the social welfare.

Jan 1, 2002

By Owen E. Owens

INTRODUCTION This paper deals with the main components in exploring for and developing a gold ore deposit. It addresses geology, exploration drilling, ore reserves, and evaluation criteria in an integrated manner to present an overall picture. Gold forms such a small component of a gold ore body, that particular care should be taken in dealing with the data from a developing deposit. The paper lists the main gold ore deposit types and their character. Their differences, as well as differences to other types of ore deposits, are important to understanding exploration approaches, and problems of ore reserve definition. Gold exploration has enjoyed a great boom in recent years. Many new ore deposits have been developed but experience shows that definition of gold is not a simple straight forward process and this outline attempts to point out some of the important aspects of ore reserve definition including some pitfalls. GOLD DEPOSIT TYPES The Witwatersrand deposits in South Africa produce about 50% of the world's gold. The gold occurs as fine grains in thin beds within gently dipping quartz pebble fan conglomerates usually with associated pyrite grains. It is characterized by rather uniform distribution of gold along thin layers within the conglomerate.

Jan 1, 1988

By Keith G. Wallace, Gary K. Rogers

As a supplement to an analysis involving methodologies for the estimation of airflow resistance in shafts used for both ventilation and hoisting, a detailed shaft characterization survey was distributed worldwide. The survey provided detailed information which enabled verification of recommended velocities and established limitations on fill factors and relative velocities. This paper evaluates the information obtained for 37 shafts and presents a statistical evaluation of the results. Apart from airflow rates, conveyance rates, and physical characteristics, qualitative information regarding means of conveyance stability and velocity control techniques at unloading and loading points are also presented. Calculations of fill coefficient, free area velocity, and most importantly, relative velocity between the airflow and hoist, are conducted. These results are presented by frequency diagrams which illustrate the trends, as well as provide limitations for these parameters. The data illustrates that, commonly, the fill coefficient for two or more conveyances, does not exceed 30 %. A limit of 50% is suggested for a single conveyance shaft. A recommended free area velocity of 10 m/s (1,970 ft/min) for combined ventilation and hoisting shafts, is sup- ported by these results. Relative velocities of 30 m/s (5,905 ft/min) are most frequent and 50 m/s (9,840 ft/min) being a practical maximum.

Jan 1, 1987

By J. Cheung, H. Rabia

The traditional methods for predicting mine air temperatures are based on steady state heat transfer models as developed by Voss (1969) and Starfield (1983). These models are useful in providing approximate predictions of air temperatures in trunk and gate roadways. More complex models are required to provide predictions along faces. In practice, the heat flow in underground mines is of transient nature and recent observations in some British Coal mines show temperature variations of up to 5°C during a working week at any one point. In addition, the recent introduction of district recirculation of mine air in British mines requires a more precise prediction of air temperatures during start up of the system or during breakdown. A transient heat transfer theory based on the work of Jordon is presented. The method lends itself easily to computers due to the large number of calculations involved. The proposed transient model is validated using actual temperature data collected in roadways in Wearmouth Colliery in the North East of England. The transient results are compared with the steady state predictions of Voss (1969). Finally, predictions of air temperature in roadways for a recirculation system will be made using both the transient and steady state models. Temperature predictions along faces will be made using a separate model.

Jan 1, 1989

By G. C. Knutsen

The Post deposit is located in Eureka County, Nevada, about 37 km (23 miles) northwest of the town of Carlin. Post occurs on the Carlin Trend, a northwest alignment of 14 major gold deposits, each containing more than three tonnes (t) (100 000 ounces) of gold. Deposits of the Carlin Trend are epithermal, sediment-hosted, disseminated gold occurrences, collectively containing more than 622 t (20 million ounces) of gold. Three major gold producers active on the Carlin Trend are Newmont Gold Company (NGC) (12.4 t/400 000 ounces of gold per year), Western States Minerals Corporation (WSMC) and Pancana Minerals joint venture (1.56 t/50 000 ounces of gold per year), and Dee Gold Mining Company (1.4 t/45 000 ounces of gold per year). The Carlin Trend has also been referred to as the Lynn-Railroad Mineral Belt. This district is characterized by open-pit mineable, micron-sized gold, hosted in Paleozoic sedimentary rocks. Six geological subdistricts comprise the Carlin Trend, each characterized by differences in host lithology, structural controls, alteration assemblage, or style of mineralization. The six geologic subdistricts include, from south to north, Bullion (Railroad), Rain, Maggie Creek, Lynn, Bluestar-Goldstrike, and Bootstrap. With the exception of the Bullion subdistrict, which was primarily a producer of base metals, each sub-district contained mineable reserves in excess of 31 t (one million ounces) of gold.

Jan 1, 1987

By William C. Cooley

Modern tunnel boring machines are subject to excessive cutter wear and bearing failures when used in hard and abrasive rock. In very hard rock, the high cost of cutter and bearing replacement, combined with slower excavation progress, make it more economical to drive tunnels by conventional drill and blast methods. The use of high pressure water jets to break rock provides a promising alternative. Experimental data indicate that the specific energy (the energy expended per unit volume of rock broken) decreases as the water jet pressure increases. Continuous jets are generally limited to pressures below 100,000 psi, whereas pulsed jets from a water cannon can attain much higher pressures. Therefore, the Federal Railroad Administration of the U. S. Department of Transportation has sponsored the design (Ref. 1 & 2) and the fabrication and testing (Ref. 3 & 4) of a water cannon to determine its effectiveness in rock disintegration at very high pressures. This paper reports the results of laboratory tests with pulsed jets against large rock samples at pressures of 125,000 to 650,000 psi and field tests against dolomitic limestone and granitic gneiss at pressures near 450,000 psi. Although initial tests were made with a small nozzle, operating at off-design conditions (Ref. 4), this paper only covers results with the full-size nozzle, including 55 laboratory test shots and 67 field test shots.

Jan 1, 1974