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By Keith G. Wallace, Oscar Codoceo

This paper describes the ventilation planning that was per- formed at the Barrick Gold Corporation, El lndio Mine. The El lndio Mine is located at an elevation of approximately 4,000 m in the Andes mountains east of the coastal city of La Serena, Chile. The ventilation planning program consisted of a detailed ventilation survey of the mine and the establishment of a correlated com- puter model. A series of network simulations were conducted to determine the optimum position, size, and configuration of new ventilation raises and main fan exhaust system. Modifications to existing mine infrastructure including; driving of drifts, slashing of airways, and positioning of ventilation controls were examined. Detailed costing information was developed to optimize the location of the new main exhaust raises and fan system. The final ventilation system is expected to increase the mine airflow from the existing 157 m=/s to over 315 mls. This increase was necessary to accommodate an expansion in mine production, diesel equipment utilization, and deeper mine development. Furthermore, the increased airflow was required because of the de-rating of diesel equipment and large air volumes necessary to dilute diesel exhaust at high elevation.

Jan 1, 1997

By C. Woofter

Quarry operators must continue to change and adapt environmental compliance methods to meet the increasingly demanding regulations. To fulfill industry needs, a computer-based decision support system is being developed to facilitate decision making that mine operators are required to make regarding environmental responsibilities. This system can help to determine permitting and compliance measures needed for air, surface water, groundwater, noise, aesthetics, vegetation, wetlands, hazardous wastes, storage tanks and wildlife habitats during the development, operation, and closure phases of mining. Operators will utilize the system's user-friendly interface consisting of mouse driven responses and limited keyboard entries on a desktop computer. The system is easy to upgrade according to the user's needs and changes in current laws and regulations. Data input models, user interfaces, and support of decision making are explained. The program permits inclusion of the decision maker's own insights through "what-if' analysis, in which the user can change ad hoc entries and check the related consequences. Using this approach, the user has complete control over all steps of the decision making process. A storm water example is selected to demonstrate the potential benefits of the support system to environmental decision makers.

Jan 1, 1995

By D. Kaja

The Symons Cone Crusher was invented by Edgar B. Symons in 1923. It was quickly accepted as a superior secondary and tertiary crusher. Nordberg manufactured crushers for the Symons Brothers Co. and in 1928 acquired the Symons Cone business. Since then, the Symons cone has become the standard of the Mining Industry. This is due to the basic rugged design and Nordberg's continued efforts to modernize and upgrade the crusher design over the years. In 1930, the Heavy Duty model was introduced with a 225 kW (300 HP) rating. Then in 1931 the Short Head version was developed to handle finer crushing applications. In 1950, the 7 Ft. XHD design was produced which provided higher crushing force capabilities for harder ores and for smaller product size requirements. Finally, in 1978, the 7 Ft Super Heavy Duty design was created to expand the power rating to 500 HP and to further increase the crushing force limits. The first 7 Ft. Super Heavy Duty crushers were delivered to Bougainville Copper Ltd. in 1978 for the production of primary ball mill feed in a three stage crushing plant with the third stage in closed circuit. The product size was 80% minus 6.35 mm (1/4 in).

Jan 1, 1998

By V. A. Scovazzo

The analytical pillar design procedure employing the Wilson equation is based on the site-specific material strength of the floor, pillar, and roof rock. Stable pillars so designed will sometimes be larger than those designed using empirical methods thus providing more stability or at other times smaller than empirically designed pillars thus conserving natural resources. Presented here is a detailed procedure for the analytical design of soft rock pillars using the Wilson Equation. An example of this procedure is presented that uses data from a mine in the Owl Seam in Southern Appalachia. These Owl Seam pillars are now in use and are performing as expected. Also addressed is an assessment of the Dr. Scovazzo?s analytically designed pillars based on pillar performance data gathered by Dr. Mark in the Southern Appalachian Coal Field.

Jan 1, 2010

By J. Gawler

In June 2005 the Minerals Council of Australia signed a Memorandum of Understanding (MoU) with the Australian Government which states an intention ?for mining companies and government to work together with Indigenous people to build sustainable, prosperous communities in which individuals can create and take up social, employment and business opportunities in mining regions?. Implementation of the MoU has begun with demonstration sites established across Australia. All sites are using a Regional Partnership Agreement (RPA) model as a framework for enabling local people to find local solutions to local issues in partnership with mining companies, governments and Indigenous communities. Mining and resources companies can provide important input into regional economic development and capacity building by working through local partnerships. Company benefits include gaining a social licence to operate, access to a reliable skilled workforce, better longterm relationships with Indigenous communities and sustainable regional communities. All levels of government, Australian, State and Local, are working collaboratively to address unemployment and other issues in remote Indigenous communities. The Australian Government has adopted RPAs as one mechanism for implementing its whole-of-government approach to Indigenous affairs. This leading edge work is unique to Australia and the model has applications and significant learning for other countries and industries.

Jan 1, 2007

By W. M. Schafer

The risk that water quality will be degraded by mining activity can be evaluated using risk analysis techniques. Water quality impacts can occur where water-rock interactions with tailings, waste rock, or leached ore lead to increased loading of constituents into surface or groundwater. Constituent loads contributed by mining facilities are determined by the migration route and chemical evolution of mine water. Mass load contributions from mines can be determined by estimating the prototype pore water in contact with mining waste, predicting the rate and timing of flow, assessing the degree of geochemical attenuation, and modeling chemical mixing with natural surface or groundwater. Mining facility siting and design measures can alter the chemical evolution of mine water by varying the quantity or quality of flow. Stochastic risk management techniques provide a powerful tool for quantitatively identifying the environmental consequences of various siting and design alternatives.

Jan 1, 1998

By John Lovering

The Afton property is located 180 air miles East-Northeast of Vancouver and nine miles West of Kamloops, a city of 60,000 people, in South Central British Columbia, Canada. The mine is adjacent to the Trans-Canada Highway at an elevation of 2,200 feet above sea level. The orebody is a porphyry, copper deposit that has undergone supergene alteration. The-major economic minerals in the supergene zone are native copper and chalcocite with chalcopyrite and bornite in the hypergene areas. The grade is one percent with an overall copper distribution: 70% native, 25% chalcocite and 5% chalcopyrite with bornite and covellite. The ore also contains important, but variable amounts of gold and silver.

Jan 1, 1985

By M. Murphy

The multibillion dollar cost of cleaning up thousands of environmentally contaminated sites across the country created by decades of inadequate disposal of hazardous waste has led to a search for "deep-pocket" sources of cleanup funds. The resul1:: is the emergence of a growing body of law that could have a profound impact on commercial financing transactions and other investment activities when present or past owners of contaminated property are involved.

Jan 1, 1988

By R. L. Kloberdanz

Compania Minera Disputada de las Condes S.A. (Disputada) is proactively implementing closure and reclamation planning activities at its mining and beneficiation facilities (mining facilities) in Chile where regulations governing mine reclamation are not yet fully in place. These activities are being implemented to improve currently employed measures to protect human health and the environment and to enhance reclamation and facilitate future closure with regard to these areas when mining is completed. As part of this process, Disputada, with the assistance of Shepherd Miller, Inc., developed recommendations and guidelines for future closure and reclamation of the Disputada sites. These recommendations and guidance incorporate planning and operational and post-operational design considerations and practices, and standards used by the mining industry and regulatory agencies around the world. The criteria presented in the guidance are based on achieving conditions that will be suitable for the anticipated post-mining land use. This paper discusses the process and approach taken, and the results.

Jan 1, 1999

By E. H. Christiansen

Gem-quality red beryl in the Wah Wah Mountains of southwestern Utah formed as a post-magmatic mineral in a topaz rhyolite flow. Unlike topaz, this beryl occurs along fractures in devitrified rhyolite, rather than in lithophysal vugs. The flow occupies a graben and perhaps a significant paleo-drainage. Beryl occurs at medial depths within the eroded flow, about 170 m below overlying mafic lava flows. Both beryl-bearing fractures and the host rhyolite show an unusual amount of argillic alteration compared with other topaz rhyolite flows. Alteration may be related to the incursion of surface water along shrinkage fractures within the flow. Whole-rock concentrations of CaO within the host rhyolite are very low (<0.01 % to 0.18%) compared with other topaz rhyolites and Be concentrations (about 20 ppm) are about average. Low Ca activities prevented fluorite precipitation and allowed Be transport as fluoride complexes. Beryl probably grew at subsolidus temperatures (-300-650°C), but above the temperature of kaolin development (200-300°C) as fluoride-rich vapors, released by devitrification, encountered fractures and mixed with vapors derived from surface water flowing through the fractures. Beryllium fluoride complexes reacted with water vapor, silica minerals, alkali feldspar, water, and Fe-Mn oxides along fractures to produce red beryl. Continued reaction of the cooling flow with surface water at lower temperatures probably produced a boiling, more acidic fluid that produced the argillic alteration. Consequently, eruption of low-Ca topaz rhyolite followed by entrance of surface water into medial portions of a devitrifying and still hot lava flow appear to be critical factors that led to red beryl formation.

Jan 1, 1996

By S. K. Palm

Volatility is a fact of life in the mining industry. Prices of and demand for mineral products are among the most volatile of those for any product. The volatility of these markets wreaks havoc on both corporate management and the personal lives of mining people. Yet, until recently, it has been difficult to assess the impact of volatility on business strategy. This paper discusses how mining firms can profit from market volatility through an operations strategy that stresses operating flexibility. The foundation for our strategy analysis is the observation that a mine is analogous to a stock option. Techniques based on those developed to value stock options have recently been extended to the field of mine valuation. The insights provided by option pricing are very valuable in the development of mine operating strategy.

Jan 1, 1986

By E. C. Ekedahl, R. J. Heath

Introduction Potassium, together with nitrogen and phosphorous, is an essential nutrient required for growth. Since all living things need potash, the major demand for potash - about 95% of the total - is as a fertilizer. Agricultural productivity has increased dramatically in recent times. This increase in crop yields requires substantial amounts of added nutrients to keep the soil fertile. It follows then that potash will always be in demand. There is no substitute. Other fertilizers that contain phosphorous (P) and nitrogen (N) are complementary and not competing products. Fireplace ashes (pot-ashes) have a relatively high potassium content. Their value as a fertilizer had been recognized for centuries. But today&apos;s potash industry did not begin until deposits of potassium-rich ore were discovered and exploited in Europe during the 19th century. Canadian potash development Potash in Saskatchewan was first recognized in 1943. It was discovered as a byproduct of an oil exploration program. But it was several years later before the existence of a major commercial deposit was acknowledged, and not until 1951 that the first attempt at development occurred. That attempt was unsuccessful. The shaft flooded and was abandoned. It did, however, demonstrate the need for new technology to penetrate the waterlogged Blairmore layer. This was eventually developed and the first mines were brought into production in the early 1960s. Once the technology was available, and the extent and quality of the potash beds became known, a number of companies proceeded to develop mines. By 1970, seven mines were in operation and three more were nearing completion. Combined, total capacity then was 7.6 Mt/a (8.4 mil¬lion stpy) K20. At that time, world potash consumption was about 15 Mt/a (16.5 million stpy). This increase in supply from Canada produced a large potential surplus that shattered the prevailing balance between supply and demand. Although world demand increased steadily throughout the 1960s and early 1970s, it was several years before world supply and demand were again in balance. Saskatchewan capacity has been expanded a number of times. It now stands at 10.7 Mt/a (11.7 million stpy) K20. Actual production has not approached this figure, however. Two new mines in New Brunswick have recently been built with a combined annual capacity of 1.2 Mt (1.3 million st) K20. Total Canadian capacity of about 12 Mt/a (13 million stpy) now amounts to 30% of world capacity. Central offshore marketing organization Canadian Potash Exports Ltd. (Canpotex) was created in 1970 as the offshore marketing organization for Canadian producers. Canpotex is owned by Saskatchewan producers and is their exclusive marketing organization for offshore business. Each company handles its own sales in Canada and the US, but all sales to other markets are handled through and by Canpotex. The Saskatchewan industry has an ore body of a size and consistency unmatched anywhere in the world. Large efficient mines have production costs that compare favorably with other producing countries. On the minus side, Saskatchewan is remote from most major markets. It therefore needs the ef¬ficiencies that stem from one organization that coordinates all offshore shipments and minimizes distribution costs. Agriculture guides potash market In the period following World War II, potash was a classic growth industry. World demand increased each year from 1945 to early 1970s. Since then, demand has been more erratic. Some years show substantial increases, but are followed by significant declines. For about the last decade, the pattern has been unclear and future demand has become correspondingly difficult to predict. North America and Europe together account for about 40% of the world potash consumption. In both areas, farming is characterized by surplus production, declining crop prices, and expensive government support programs. Under those circumstances, farmers respond by minimizing input costs. Fertilizer is one of the items they reduce. Potash is retained in the soil. It is possible to reduce potash application with no immediate deterioration in crop yield. The lower yields occur only when potash levels are depleted. So, farmers can econo-

Jan 12, 1987

By Ian M. Loomis, Keith G. Wallace

The Waste Isolation Pilot Plant (WIPP) is a U.S. Department of Energy research and development facility designed to demonstrate the permanent, safe disposal of U.S. defense-generated transuranic waste. The waste storage horizon is 655 m (2150 ft) below surface in bedded salt. To date the WIPP project has not emplaced any waste. There are three intake shafts used to supply air to the underground. All air is exhausted though a single return shaft. The total design airflow during normal operations is 200 m3/s (424,000 cfm). The ventilation system is designed to provide separate air splits to construction, experimental, and storage activities. Separation is achieved by isolating the storage circuit from the construction or experimental circuits with bulkheads. Any air leakage must be towards the storage area of the facility. Field studies have shown that the pressure differential necessary to maintain the correct leakage direction is susceptible to the effects of natural ventilation; therefore, extensive studies and analyses have been conducted to quantity the natural ventilation effects on the WIPP underground airflow system. A component of this work is a monitoring system designed to measure the air properties necessary for calculation of the natural ventilation pressure (NVP). This monitoring system consists of measuring dry bulb temperature, relative humidity, and barometric pressure at strategic locations on surface and underground. The psychrometric parameters of the air are measured every fifteen minutes. From these data, trends can be determined showing the impact of NVP on the ventilation system during diurnal variations in surface climate. Both summer and winter conditions have been studied. To the author&apos;s knowledge this is the first reported instance of automatic and continuous production of time and temperature variant NVPs. This paper describes the results of the initial monitoring study. INTRODUCTION The ventilation system at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico, is designed to perform two distinct functions. First, it supports normal mine ventilation requirements complying with all state and federal mine regulations. Second, the system is designed to prevent an uncontrolled release of radioactive contaminants from the storage and transportation areas of the facility. Although a nuclear radiation release in the facility is considered unlikely, many special features are implemented in the ventilation system to prevent the possible spread of contamination. The facility is constructed with the waste transportation and storage areas separated from the mining and non-radioactive experimental areas. The ventilation system is designed such that air leakage is from the mining and experimental areas to the storage areas. Furthermore, radiation detectors are located throughout the storage and waste transportation areas underground and an exhaust filtration building is installed on surface to prevent the possible release of radiation to the environment. For over two years the underground ventilation system has been rigorously tested and balanced. It was during this period that the adverse effects of NVP were noticed and subsequently quantified. From extensive field studies and computer models, several mitigating features were designed and constructed and special operational procedures were implemented to control the impacts of NVP. To quantify more accurately the NVP at the WIPP, a continuous monitoring system was installed. This monitoring system consists of measuring dry bulb temperature, relative humidity, and barometric pressure every fifteen minutes at strategic locations on surface and underground. From this psychrometric data, the NVP is calculated. Fan operating pressures and flows and strategic differential pressures are recorded from the site Continuous Monitoring System (CMS). The monitoring system provides a means of evaluating how the ventilation system behaves in regard to climatic conditions and to judge the efficacy of the mitigating features and operational procedures. To the author&apos;s knowledge, continuous calculation of NVP as a function of time and surface temperature has not been previously reported. Overview of the Waste Isolation Pilot Plant The U.S. Department of Energy determined that the plastic nature of bedded salt may provide the best solution to isolate transuranic (TRU) waste from the biosphere. Initial evaluations at the WIPP site began in 1974. In 1979, the United States Congress enacted Public Law 96-164 for the construction and development of the WIPP project. The mission of the WIPP is to demonstrate the safe, long-term disposal of TRU waste generated by the national defense programs of the United States. TRU waste is classified as a low to medium level waste. The waste is stored in drums and does not produce significant heat (not greater than 1 W per drum). The WIPP site is located approximately 47 km (29 miles) east of Carlsbad, New Mexico in the Chihuahuan Desert. The repository is located in the 630 m (2000 ft) thick Salado Formation. This Permian Basin salt deposit is about 225 million years old and appears to have been minimally disturbed by earthquake, faulting, and ground water activity since it was deposited. The underground facility is 660 m

Jan 1, 1993

By T. Karlkvist, H. R. Kota, F. Andreas, B. I. Pålsson

"Separation of different calcium minerals have long been an interesting and challenging problem. In this investigation calcium mineral separation is examined by: microflotation, zeta potential measurement and adsorption, using novel collectors having two functional groups instead of one. In theory, by varying the distance between the functional groups, it could be possible to preferentially target one calcium mineral by matching the spatial distance between the sites on the mineral surface. In this investigation two new surfactants have been tested to estimate their ability to float apatite and/or calcite. Preliminary findings show that an increase in distance between the functional groups favors one mineral over the other, and this might be due to differences in the mineral surface structure. INTRODUCTION Apatite is a strategically important mineral which has both great value for industrial use as a precursor to phosphoric acid; and in the agricultural industry as an important source of phosphorous in fertilizers. This has led both the European Union and the United States to recognize it as an important resource for the future. Currently there is no lack of apatite in the world, but it is important to develop the beneficiation to ensure future supply. A common problem in apatite flotation is the selectivity towards calcite, which it is commonly associated with. Although calcite is an important industrial mineral its abundance makes it not usually worth to extract from apatite ores unless it is easy to separate1,2. Both apatite and calcite are semi soluble minerals with calcium as one of their constituents. The most common way to separate apatite and calcite is to use flotation. A process that involves making the mineral particles to extract from the system hydrophobic by adsorbing a collector on the mineral surface. One way to study collector adsorption on a mineral surface is by zeta potential measurements. The zeta potential is the charge at a slip plane a short distance from the surface. By measuring the zeta potential with and without the presence of collector it is possible to investigate if the collector is present at the surface or not, a change is indicative of collector adsorption. The zeta potential of fluorite, apatite and calcite without collector can be seen in Figure 1. The small difference in zeta potential between apatite and calcite shows the similarity in their surface properties and gives an indication of their separation difficulty. One additional problem with semi soluble minerals is their tendency to slightly dissolve in the pulp and thereby change the ionic composition of the solution. This makes separation and research problematic as the freed ions may readsorb on the mineral surface and interfere with the collector adsorption on the mineral surfaces3–5."

Jan 1, 2016

By Terry L. Muldoon

On July 7, 1971, noise regulations for underground coal mines were implemented under provisions set forth in the Federal Coal Mine Health and Safety Act of 1969. These same regulations now also apply to coal mine surface facilities. In August 1971, in anticipation of these regulations, the Bureau of Mines, through the cooperation of the mine operators, conducted extensive noise surveys in three coal cleaning plants. The survey was conducted in an attempt to identify those occupations where exposures would exceed the proposed regulations.

Jan 1, 1972

By Lawrence W. Teufel

Knowledge of in situ stress and natural fracture distribution at depth improves our ability to stimulate and produce low permeability reservoirs. The focus of this study is three closely spaced, 2.5 km deep vertical wells in the Piceance Basin of Colorado. The wells were completed through the tight lenticular and blanket gas sands of the Mesaverde Group. In situ stress directions and magnitudes were determined from hydraulic fracture tests and anelastic strain recovery measurements of oriented core. The distribution, orientation, and characteristics of natural fractures in the subsurface were determined from detailed observations of over 1300 m of core, of which 400 m was oriented. Stress measurements clearly show that horizontal stresses are strongly influenced by lithology. In a sandstone/shale sequence at a depth of about 2.0 km in situ stresses in sandstone formations are anisotropic, with the average ratios of the minimum and maximum horizontal stresses to the overburden stress being 0.82 and 0.96, respectively. In sharp contrast bounding shale formations are lithostatic. This stress contrast between sandstones and bounding shale formations could act as a barrier to hydraulic fracture propagation during stimulation and impede vertical fracture growth. Natural calcite-filled fractures are present in over 7 percent of the core, with several horizons having a much higher frequency of fractures. Fractures are found primarily in sandstone. The fractures have a strong preferred orientation of N 1060E[+]110, which is aligned with the maximum horizontal stress and direction of hydraulic fracture propagation. The interaction between a well developed fracture fabric and anisotropic stresses in sandstone formations produces a permeability anisotropy, with the maximum permeability aligned with the fracture fabric and maximum horizontal stress.

Jan 1, 1986

By David D. Rabb

Leaching or solution mining, a relatively simple and economical process for beneficiating metallic ores, is likely to find increasing application in the treatment of low-grade ores that are impractical to mine by any other means. This process may be carried out in two different ways: 1. Dump leaching, where the ore is moved from its original location to be leached at another site. 2. In situ leaching, where the ore is leached in place by introducing the leach solution at the top, letting it flow down through the ore under gravity, and then recovering it plus the dissolved metals it contains.

Jan 1, 1969

By Milton Hood

The Copper Flat Property is located approximately 6 miles NE of the small town of Hillsboro in Sierra County, N. M. (Fig. 1). Hillsboro was the center of considerable mining activity in the late 1800&apos;s and early 1900&apos;s following the discover, of gold bearing vein deposits and later discovery of, placer gold along the east slopes of the Animas Hills. The Copper Flat orebody is a porphyry type deposit occurring in a small quartz monzonite porphyry stock that has intruded the center of a circular andesite plug (Fig. 2). The primary ore mineral is chalcopyrite. By-product values are contained in gold, silver and molybdenum.

Jan 1, 1983

By Christopher Laughton, Michael P. Bruen

At Fermilab, a 4000-ft long underground complex has recently been constructed for a high-energy physics experiment. The complex is sited up to 350 ft, below grade principally in bedrock. The rock excavations were mined by TBM and drill and blast methods and supported by a combination of rock bolts, dowels and shotcrete. Water control was achieved using a combination of pre- and post-excavation grouting, drainage systems, drip shielding and air desiccation measures.

Jan 1, 2003

By T. S. McGahey

The southeastern region of the United States has long been a major market area for coarse and medium particle size natural ground calcium carbonate fillers. The primary market for calcium carbonate in the southeast traditionally has been as fillers in building materials such as carpeting, joint cement and roof shingles. In these applications the economic value of the calcium carbonate in the final product is weighted more toward lessening the cost of the final product, as opposed to contributing any desirable physical characteristics. For example, in carpet backing applications the calcium carbonate filler does little more from a physical standpoint than add weight and body to the backing adhesive. The important factor in the use of calcium carbonate in carpet backing is that it can be used at high loading levels to replace the more expensive latex binder, thus lessening the cost of the final product. It is estimated that calcium carbonate producers in the southeast sell in excess of 200,000 tons (181,436,000 kg) annually for use in latex compounds for carpet backing applications.

Jan 1, 1986