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By D. M. Walters, C. M. van der Vyver, L. J. deVulliers

The occurrence of underground fires in narrow tabular ore- bodies where high density timber support is used is a dangerous and disruptive occurrence. The containment and extinguishing of the fire remains a very important consideration in reducing not only the loss in production time but also in limiting the extent of the area damaged by the fire. Mindful of this, Gold Fields have adopted and developed the inert gas generator system from its origins in Poland for use in Group precious metal mines. The system generates an oxygen- deficient atmosphere which is introduced in the fire area after this has been sealed. A number of problems had to be overcome to operate this system successfully within the infrastructure of these mines. Of particular significance is the operation of a jet engine, the prime component of the system, at air pressures encountered below sea level. The modifications have been found to be satisfactory to the point where, since 1992, ten underground fires have been extinguished using this system. Invariably, the areas affected by these fires were extensive (over 1 000 000 m3) and required continuous operation of these units over extended periods of time (in some cases in excess of 400 hours).

Jan 1, 1997

By B. Campbell

This paper will detail the successful construction methods of a 20- foot diameter wet well shaft, approximately 180 feet deep in overall depth and 150-feet below the water table, adjacent to Lake Nacimiento, in San Luis Obispo County, California. In addition to this, highlights will include the selection process in determining the most economical support of excavation, while minimizing risk of large water inflows as indicated in the Owner?s Geotechnical Baseline Report (GBR).

Jan 1, 2010

By Schebek, J. Warsen

"Data and information from sustainable development (SD) reports can be seen as a promising and easily accessible source for an Life Cycle Assessment (LCA), i.e. for generic Life Cycle Inventory (LCI) data in particular. The reliability and comparability of LCA results crucially depends on the quality of LCI data, that is defined by specific normative requirements. In parallel the GRI (Global Reporting Initiative) provides a set of guidance documents for enhancing the quality, rigor, and utility of SD reporting with specific reporting principles that address similar issues on a company level comparable to LCI data quality requirements on the process level. In order to assess the general suitability of the fundamental reporting principles for LCI data quality purposes selected reports from mining and minerals (M&M) sector are assessed within a detailed analysis."

Jan 1, 2005

By John E. Tilton

Mining is one of the oldest human activities. It goes back at least to the Bronze Age and possibly even the Stone Age. The Romans mined copper in Spain and tin in England some 2,000 years ago. The writings of Agricola in the 16th century show that mining was important in the Middle Ages. Today, more mineral commodities are mined in greater tonnages than ever before. This long and fascinating history closely tied with the economic development of the human race is one of the charms of the mining industry. It also, unfortunately, gives rise to some widespread misconceptions. Old industries are generally considered stodgy with mature and stagnant technologies. Costs tend not to decline as in newer industries, and may even increase with real wages. Costs are particularly expected to rise in the case of mining as the best mineral deposits are depleted. Thus, mining is often thought of as a sunset industry, destined to decline over time as the resource base is depleted. These perceptions have several important implications. They argue against economic policies that rely too heavily on mining and mineral processing to foster growth and development. The best and the brightest young people, along with society's other valuable resources, should be encouraged to enter newer industries. There the technological opportunities and the prospects for growth are more promising. These perceptions also suggest that the ability to compete in the mining industry depends largely on the quality of a company's or country's mineral deposits. Mining will take place first in countries with the lowest-cost deposits. Once these are exhausted, mining will shift to countries with the next best deposits. From time to time, new discoveries may also produce a shift in the location of mining, [ ] and may even for a time keep the costs and prices of mineral products from rising. Over the longer term, however, rising costs and prices are inevitable, as the world is forced to exploit poorer mineral deposits.

Jan 1, 1997

By D. Malhotra

Climax byproduct-plant tailing assayed 0.019 percent WO3. Pilot-plant and laboratory tests were performed to investigate the possibility of recovering additional tungsten values from the byproduct-plant tailing. The paper discusses the methodology used in the study and the results of this investigation.

Jan 1, 1985

By J. Chappell

The Nuggety Gully prospect is located 170 km (106 miles) south- east of Port Hedland and 40 km (25 miles) northeast of Marble Bar in the Pilbara Region, Western Australia. The area is held under title by Esso Exploration and Production Australia, Inc. The prospect covers a significant, but currently uneconomic body of molybdenum and copper mineralization of porphyry style, associated with Archean high level acid intrusives intruding sediments and volcanics of a narrow east-west Archean greenstone belt. The Nuggety Gully intrusive rocks have been dated at 3.2 b.y. ± 117 (de Later, oral communication). The current resource estimate for the deposit is 102 Mt (1 12 million st) of 0.1 1 % Mo and 0.15% Cu.

Jan 1, 1991

By Daniel J. Brunner

The U. S. Department of Energy (D.O.E.) requires that the prospective nuclear waste repository in Basalt at Hanford, Washington, comply with State of California mine and tunnel safety orders. These regulations require that all main fans be installed in such a manner as to permit prompt reversal of airflow. This paper evaluates the requirement of air reversal and the appropriateness of imposing such regulations on the proposed nuclear waste repository in Basalt.

Jan 1, 1988

By Joseph Renk, David Akers, Glenn Shirey

Each year, US coal cleaning plants landfill or impound millions of tons of high-quality, fine-sized coal. This coal is not only difficult and expensive to capture during cleaning, but, if captured, can pose serious materials handling problems. The GranuFlow. Technology was developed and patented by the U.S. Department of Energy (DOE) to address these problems. GranuFlow involves the addition of a coal binding agent such as an asphalt or heavy oil emulsion to coal to reduce moisture, dusting, and freezing and to improve the flow properties of the coal in bins and chutes (1, 2, and 3). When the emulsion is added before mechanical dewatering, the binding agent causes the formation of fine-sized coal agglomerates that dewater better than untreated coal. In addition, the binding agent increases the capture of ultra-fine coal in screen-bowl centrifuges. Previous work by DOE has also demonstrated that such treatment results in a significant reduction in dustiness and a reduced potential to freeze. To address concerns about the handling and combustion characteristics of GranuFlow treated coal, DOE performed a pilot-scale pulverization and combustion test (4). No problems were encountered during pulverization or combustion, and use of this fuel in a p.c. boiler was found to be feasible from a technical perspective. CQ Inc. has an exclusive license from DOE to market this technology and is currently performing a series of commercial demonstrations to determine if GranuFlow is both technically and economically viable.

Jan 1, 2005

By F. C. Appleyard

A couple of miles southwest of the town of Saltville in the western tip of Virginia is a little village called Plasterco. Gypsum has been produced in this area since about the year 1815, being originally found as small outcrops at the surface. Production in the early days was very small, and the use of the mineral was limited to that of "land plaster" or ground gypsum which was spread on the land to sweeten the soil. In the late 1800's, a small calcining plant was constructed and the production of gypsum plaster began. About this same time, the surface rock was depleted and it became necessary to begin underground mining operations in order to maintain a continuous supply of raw material. The United States Gypsum Company became interested in this property in 1909, and has operated there ever since, having enlarged the calcining mill and built a plant for the manufacture of gypsum wall-board in the middle 1920's. Production of gypsum continues from underground' mining operations, and the present mine at Plasterco is now about 1,000 feet below the surface, making it the deepest gypsum mine' in the world.

Jan 1, 1965

By William G. Holroyd

In January 1992, the Office of the US Trade Representative announced that the People's Republic of China had agreed to protect US intellectual property, including computer software, sound recordings, agrichemicals and pharmaceuticals. Under the agreement, China will make significant improvements in its patent, copyright and trade-secret laws. Ambassador Carla A. Hills, the US trade representative, said "this agreement should create significant opportunities for US firms interested in marketing high valued-added products to China." Principal beneficiaries will include the agrichemical and computer industries, as well as pharmaceutical, entertainment. The agreement will safeguard these industries' intellectual property, stimulating new exports to China and helping to generate additional growth in the US. Refractory grade bauxite was included in the mineral category of the $1.5 billion of Chinese products on which the US government threatened to impose an immediate 100% trade tariff. Refractory bauxite is available from Guyana and Brazil at higher cost and in different grades. However, refractory brick manufacturers would have had little choice but to pass on the costs to their consumers. Although the United States and China are separated by political ideology and internal governing structures, this agreement recognizes the importance of a $19 billion trading relationship. Consequently, the renewal of China's most favored-nation trading status in the US congress in -June 1992 was all but assured. Many US companies doing business in China and Hong Kong have been quietly increasing their investments since 1989. These companies can now concentrate on developing sales to the domestic Chinese market. This market is expected to surpass 1.2 billion people in 1995 and approach 1.3 billion by the end of the century.

Jan 1, 1993

This paper reviews the historical literature and the author's experience with regard to the effect that the selection of grinding ball size or sizes has on ball mill grinding efficiency. The conclusions presented provide guidelines for single and multi-size charging prac- tices in commercial milling operations.

Jan 1, 1998

By K. A. McDonald

This paper will describe the experiences of Hibernia Holdings, Inc. in constructing a mineral processing facility in Mexico. It will attempt to set forth a guideline on what companies attempting to operate in Mexico can expect and what actions they can take. Ownership laws, import/export laws, labor laws, security, transportation and operating experiences will be discussed.

Jan 1, 1994

By Peter Zhang, Daniel Su, Bo Kim, Berk Tulu

This paper summarizes significant findings from the ongoing NIOSH Gas Well Stability research over the past decade; in particular, the important ground control engineering considerations. Longwall-induced surface and subsurface deformations may induce gas well casing deformations and stresses, depending on a few parameters such as overburden depth, overburden geology, topographic relief, strata dip, gas well setback distance, and a gas well casing cementing alternative. Overburden depth to the mining seam is one of the most influential factors; shallow overburden depth induces large horizontal displacement and resulting casing deformation and stress, while deep overburden depth induces large longwall-induced vertical pressure. Overburden geology is another important factor affecting the longwall- induced casing deformations and stresses; the large contrast of bending stiffness at the soft-to-hard rock interfaces tends to induce large casing deformations and stresses. Large surface topographic relief and the presence of soft-to-hard rock interfaces below the stream valley bottoms may shift longwall-induced subsurface gas well casing deformations closer to the surface, thus having less impact on underground. mining operations. Strata dip magnifies longwall-induced deformations by 20% per degree of strata dip for down dip longwall excavations. The gas well setback distance is also a critical geometric parameter; the effect of longwall-induced deformation decreases exponentially as the setback distance increases. Longwall-induced casing deformation and stress will be mitigated or totally uncoupled for uncemented production casing.

Jun 25, 2024

By Paul Eimon

The 1981 Fall field trip of the Denver Region Exploration Geologists' Society focuses on Creede. That is appropriate - because significant mining history has been made and is being made in this off-the-beaten track, high-country mining district. Creede is one of the few Colorado bonanza towns which was big in the 19th Century, had its ups and downs, and produced almost continuously since its discovery. Creede is important to geologists for its: precious and base metal production, current exploration activity, and research into near-surface hydrothermal systems. United States Geological Survey research and field geologists zeroed in on Creede some 25 years ago and their steady, consistent work is now being spotlighted and appreciated.

Jan 1, 1981

By C. E. Ekburg

Gold Quarry is a sediment-hosted, epithermal disseminated gold deposit located along the Carlin Trend. Gold, hosted by allochthonous Ordovician siltstones and cherts, is localized at the intersection of structures sympathetic to the major Good Hope and Gold Quarry faults. The magnitude of Gold Quarry was discovered in 1979 by surface exploration and by percussion holes drilled near the Maggie Creek orebody. Four years of development drilling delineated an open pit mineable gold deposit that contains 130 Mt (144 million st) of ore at an average 1.68 g/t (0.049 oz per st) of gold and includes a high-grade core of 46 Mt (51 million st) that average 2.64 g/t (0.077 oz per st) gold. Milling of the higher-grade portion began in 1985.

Jan 1, 1987

By William E. Little, William R. Sharp, Edward R. Kennedy

Cost o f mechanical tunneling requires the knowledge of many machine/rock parameters such as rock types, machine power, penetration rate, cutter life, maintenance schedule, etc. Capital investment, labor requirements, and project scheduling will all play an important role in defining the economics of the overall project. Knowledge of the cost sensitivity of different project parameters will improve the overall success of any particular tunneling project if this information is incorporated into an effective management plan. Through the use of an interactive graphic computer program written for a microcomputer, one has the ability to quickly evaluate relative costs for a variety of parameters for either an existing project or for a proposed site.

Jan 1, 1983

By R. E. Brewer

Pilot scale flotation tests were conducted with a 1-ft-diam column at the Barrick Resources (USA) Mercur mine, Tooele County, UT, to scavenge unleached (0.01 to 0.018 oz/st) gold values from the tailings of a carbon-in-leach (CIL) circuit. The optimal recovery was 35 pct of the unamenable-to-leaching gold, at a grade of 0.353 ounces of gold per short ton, using a mixture of dithiophosphate, xanthate, and diesel fuel as a collector. This was achieved by floating approximately 1.6 wt pct of the CIL tailings. The gold values are believed to be contained in arsenic-bearing minerals, attrited carbon, and carbonaceous material in the ore. Redox potentials were measured with a gold electrode during the conditioning stage prior to flotation. The correlation between flotation recovery and redox potential values could be used to control reagent additions. Treatment of a previously leached and weathered tailings material, averaging about 0.055 ounces of gold per short ton, was also investigated using the column. The tailings were first water leached at approximately 600 C, and the water-leached tailings, which contained approximately 0.03 ounces of gold per short ton, were then fed to the column flotation unit. The effects of pH and sodium sulfide addition on gold flotation recovery and redox potentials were examined. maximum gold recovery, 36 pct, was achieved at pH 8.5 with a sodium sulfide addition of 0.18 lb/st.

Jan 1, 1989

By Sotiris N. Kamenopoulos, Zach Agioutantis

Rare earth elements (REEs) are considered critical minerals for the industrial and defense sectors. In 2018, the U.S. Department of the Interior presented the final list of critical minerals that are vital to the U.S. economy and defense [1], which included REEs among other mineral commodities. REEs are not rare, despite their name, but economically viable deposits of REEs can be found only in certain geographical areas, and the political and social conditions characterizing these areas may not always be in favor of mining operations. Mining operations may be placed in great operational and financial risk if operations are planned in such areas. Erroneous decisions by decision makers may lead to a chain of events that can completely shut down a mining project. 

By J. H. Jennekens

INTRODUCTION "Most people would probably agree that some degree of government control and regulation is essential in modern society, and it will likely continue as an important part of our social organization for the foreseeable future. But most of us tend to be ambivalent about it. In one situation or another we are likely to see government commitment to social benefit programs or regulatory devices either as an expanding encroachment on the freedom of the individual or as an undue interference with private enterprise or with the rules of the market place. But even where there is agreement as to the desirability of government initiatives, either in general or in a particular context, it by no means follows that there will be approval of the mechanisms or procedures used or the means of carrying them out." The above statement is taken from a 1980 Working Paper of the Law Reform Commission of Canada prepared in connection with its study of the exercise of administrative law in Canada and the practices and procedures of administrative tribunals. The Atomic Energy Control Board (AECB) is one such administrative tribunal, and as the federal nuclear regulatory authority, it is responsible for licensing the production, possession and use of nuclear materials, equipment and facilities and enforcing compliance with licence conditions governing the health, safety, security and environmental aspects of the activities involved. Although the AECB was established 35 years ago with the passage in August 1946 of the Atomic Energy Control Act, like many administrative tribunals its role and functions and the regulatory process which it applies have evolved significantly during this period. The changes which have taken place over the years reflect not only the vast scientific and technological developments which have occurred but also the marked differences between contemporary society and the social milieu of the mid-1940s. However, the basic philosophy of nuclear regulation in Canada and the underlying principles of the regulatory process have changed very little. Certainly, the process is far more open in terms of the general public, it has become appreciably more comprehensive and systematic in terms of the depth and extent of both the pre- and post-licensing technical evaluations which are conducted and the ensuing compliance program. Furthermore, it now applies to the whole of the nuclear fuel cycle as well as the industrial, agricultural and medical applications of radionuclides. Nevertheless the following fundamental principles remain unchanged: a. primary responsibility for achieving high standards of nuclear safety and environmental protection in the design, construction, commissioning and operation of nuclear facilities resides with the licensee; b. the credibility of the nuclear regulatory process depends not only upon its technical correctness and practicability, but also upon acceptance by the public-at-large of its perceived effectiveness and efficiency; c. regulatory criteria and principles should be concise, clearly stated and understandable; d. regulatory decision-making should be based upon stated criteria and principles taking into account pertinent scientific and technical facts only; e. fairness and impartiality must characterize all regulatory decision-making; f. the regulatory process should be subject to a comprehensive periodic review and evaluation to ensure that it continues to produce the desired results at justified costs. EXPLANATORY NOTES The mere statement of a set of principles is a relatively simple task. Far more difficult is the explanation of what these principles mean in practical terms. To stipulate that a licensee bears the primary responsibility for achieving and maintaining high standards of nuclear safety and environmental protection may be regarded by some as an attempt by the regulatory agency to evade the responsibilities assigned to it. However, this is not the case. It is unrealistic for anyone to claim that a licensee only complies with accepted norms of public and occupational health and safety and of environmental protection because of the fear of prosecution. The vast majority of citizens conduct their affairs in a proper manner not because there

Jan 1, 1981

By David M. Parkes

Geology is frequently complicated, hence only more regular deposits are mined. Coal is generally thick, often steeply pitching and usually soft or well-cleated. Due to competition from open-pit mines, only two underground mines are operating, McIntyre and B.C. Coal. Several other mines are being planned, the method being evenly divided between hydraulic, longwall, and room and pillar. McIntyre mines in the flat part of their formation (up to 20 degrees) uses continuous miners and shuttle cars in the 3m and 6m seams. This company is considering a retreating longwall face. B.C. Coal operates a hydraulic mine in a 16m thick seam dipping at 10 to 55 degrees with a productivity of about 20 tonnes per manshift.

Jan 1, 1982