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By J. L. Goodier

The paper points up the hesitance of private capital to pursue development of offshore mineral mining endeavors due to the deterrent effect of the clouded legal status of such endeavors. Some states have no laws or regulations to protect the potential exploiter. Others have regulations which give no proprietary rights of exploration to mineral discoveries. The above factors and others are discussed and analyzed in some detail, covering, in turn, summations of the federal regulations and of each of the coastal states. Some comparative analyses are provided, and some recommendations for encouragement to capital investors are made.

Jan 1, 1968

By Paul Mitchell, Clive Potter, Miles Watkins

Meldon Quarry is a seemingly rare occurrence of acid rock drainage (ARD) in a quarrying operation.4 With surface waters discharging to a tributary of a salmon-bearing river, it is subject to stringent discharge conditions. The quarry predates effective environmental management, and preventative, control and treatment measures were not implemented until relatively recently. However, retrospectively implementing standard preventative approaches at the site is costly, technically difficult and of uncertain benefit. This paper overviews the recent site history and introduces data from a demonstration by KEECO (UK) Limited of its Silica Micro Encapsulation (SME) water treatment technology.

Jan 1, 2000

By F. L. Pirkle, D. A. Podmeyer

The mineral zircon is mined for use as specialty foundry sands, abrasives, ores of Zr02 and zirco¬nium metal, refractories and zirconium chemicals. It is produced as one of several products from heavy-mineral sand deposits associated with ancient shorelines. Because of its low coefficient of thermal expansion, its high melting point, its high refractive index and its chemical inertness, it is an attractive refractory material. Zircon varies from deposit to deposit in terms of grain size, grain shape and chemical purity. Thus, there is a wide range of commercial zircon products that differ in impurity levels, particle shapes and grain sizes.

Jan 1, 1993

By R. L. Grayson, S. S. Peng

Sampling of respirable dust and analyses of samples have been partially completed for a longwall panel. Physical and compositional properties which have been characterized include: 1. Respirable mass concentration, 2. Mineral composition, 3. Particle size distribution by mineral, 4. Particle shape distribution by mineral, 5. Particle angularity distribution by mineral, and 6. Respirable size distribution. Analytical techniques used in the characterization of samples are described, and results are reported with emphasis placed on relationships between the various characteristics and worker locations. Details of existing mining conditions, equipment arrangements, dust control methods and operating system parameters are presented.

Jan 1, 1986

By S. Nunoo

The shape of particles has a significant effect on the shear strength and deformational characteristics of granular materials. Weathering can change the grain shapes. For example, more weathered sands tend to be rounder regardless of particle size. Particle shape analysis was performed on samples collected from the Questa mine rock piles, a debris flow and the pit alteration scar. In order to increase the validity of the particle shape analysis, 4 persons including 2 geologists and 2 mining engineers were involved in describing the particle shapes. The results of this analysis indicate that rock fragments in the collected samples are mainly subangular, subdiscoidal and subprismoidal. The sphericity and angularity of the rock fragments of the older analogs are similar to those of the rock piles. This suggests that short-term weathering (<100 years) has not noticeably changed the particle shapes at the test locations. Rock piles made of more angular particles are more stable compared to rock piles with rounded particles.

Jan 1, 2009

By D. R. Schmitt, B. L. Jensen, T. J. Ahrens, C. L. Smither

The in situ elastic moduli of rock are measured holographically by a borehole instrument in marble and oil shale. A point force induced displacement field is recorded with double expo- sure holography. Data consists of a fringe pat- tern on the viewed hologram. The elastic moduli are determined by modelling of the fringe pattern. Only Young&apos;s inodulus is fairly constrained by the present data reduction. For an applied force of 520 [ ] 50 Newtons, a marble was found to have a Young&apos;s modulus of 56 [ ] 8 GPa, near an ultrasonically determined value of 48 [ ] 6 GPa. In an oil shale, an applied force of [ ]

Jan 1, 1986

By Jack M. Jodrey, Neil D. O’Donnell, R. A. Metz

Bituminous sands of the Lower Cretaceous McMurray Formation in northern Alberta constitute the ore for the surface mining operation at Syncrude Canada Ltd. These sediments represent a complex succession of fluvial, estuarine and marine depositional environments. Grade prediction is realized through a combination of geological interpretation, computer modeling, and reference to past mining experience. Accurate forecasts of feed grade permit reliable predictions of volumes for removal to meet budgeted synthetic crude oil production. This planning facilitates efficient allocation of mining equipment and resources. The feed grade to the Extraction Plant is monitored at various points along the delivery system.

Jan 1, 1992

By Edmond O’Donovan

Selection of conveyor drives is an area of great confusion that frequently leads to poor system performance or overcapitalization. Many papers have dealt with the performance characteristics of different drive types, but users have often found that this only leads to further confusion. This paper presents the drive requirements from the "conveyor&apos;s" point of view. The drive requirements of different classes of conveyors are examined to illustrate why some drive types work well in certain situations but poorly in others. The appropriateness and shortcomings of different drives are examined in this context, along with the recurrent issue of load sharing.

Jan 1, 2000

By Tom C. Palanglo, Norbert Maerz

Control of crushing and grinding circuits ideally requires continuous particle size measurements on both in- and outgoing streams. Until recently, size distributions could only be obtained by screening methods, which were neither cost effective, frequent enough, nor timely. Input streams are often composed of large fragments, making screening prohibitive. Optical image processing systems, such as the WipFrag System, have been developed to the point that they are an extremely valuable tool to characterize, control, and fine-tune the comminution process. Although accuracy is less than that of screening, measurements are precise enough to detect relatively small changes in size distributions.

Jan 1, 2000

By Bruce H. Van Brunt, Danny L. Taylor

Estimation of local recovered tonnage and its grade above a cutoff is of paramount importance during the exploration and development stages of any mineral deposit. The spatial dis- tribution of grades as well as the cumulative distribution must be defined. In this paper, Probability Kriging, an estimator based upon rank order statistics and the estimation of the distribution of point grades within a panel, is applied to the Manhattan gold deposit. Mapping the conditional probabilities that estimated panel grades exceed a cutoff is useful to the understanding of the distribution of mineralization in a structurally controlled gold deposit.

Jan 1, 1989

By Charles N. Alpers, D. Kirk Nordstorm

A variety of approaches have been used in the recent literature for the estimation of pre-mining (or natural background) metal concentrations in areas affected by mining. The following is a list of some of these approaches: (1) historical and anecdotal data, (2) remote analogues (other similarly mineralized areas), (3) proximal analogues (nearby mineralized areas), (4) sediment sampling (streambeds, lakes, estuaries, floodplain deposits, and soil profiles), (5) stable isotopes (hydrogen, oxygen, sulfur, and carbon), (6) geochemical modeling (forward, equilibrium-based), (7) geochemical modeling (forward, kinetic- and transport-based, and inverse), (8) statistical analyses, (9) mass balance on oxygen flux, (10) mass balance with age determination of weathered material. Examples of each approach are described, and the strengths and limitations of each approach are discussed.

Jan 1, 2000

By Clifford J. Lewis

The role of calcareous minerals in that area of the environmental improvement program involving the control or elimination of sulfur oxide emissions is discussed, and a new concept in gas scrubbing, rendering possible the use of calcareous rocks more extensively for this purpose, is presented. Calcareous rocks are defined as the more common limestones, consisting essentially of calcium carbonate and magnesium carbonate. The effect of magnesium carbonate on the reaction rate of limestones and lime toward sulfur oxides in aqueous scrubbing systems is pointed out. The relative economics of lime- stone versus lime as aqueous scrubbing reagents for sulfur dioxide are indicated.

Jan 1, 1974

By Larry B. Bramlett

Regional radiometric, magnetic and geologic data point to Copper Mountain as an area of general uranium favorability. Sub-regional radiometric and magnetic data direct interest to a specific section of an overthrust Precambrian granite. Detailed magnetic and resistivity surveys in this area show local targets of interest, one of which corresponds to Rocky Mountain Energy&apos;s North Canning deposit. On the basis of these data a second and previously untested target was drilled resulting in the intersection of uranium horizons similar to those at North Canning. This integrated geophysical approach can be used for uranium exploration in geologically similar areas.

Jan 1, 1979

By M. E. Gershon

Software for coal blending has gained a lot of recent attention as micro-computer programs have come on the market. Some of this software is appropriate and some is not. This paper looks at the types of models being used and points out the strengths and weaknesses of each. Recommendations are then made concerning the level of detail required for these programs, relating this concern to the various ways in which coal companies are using these programs. A checklist of company requirements for these programs and available pro-gram-features provides an aid in matching the program to the company.

Jan 1, 1988

By N. P. Reddy, Y. J. Wang

This paper describes an experimental setup for multiple fan ventilation systems at the ventilation laboratory of the West Virginia University Department of Mining Engineering. Housed in a 30-ft x 70 -ft room, the experimental setup consists of three 18-in., variable-speed, axial flow fans; an 18-in. -diam, fiberglass tubing; associated fittings for arranging networks; and a picot-tube measuring and data-acquisition system. The fiberglass tubing and fans can be organized into non-planar networks of two or three fans. The setup is mainly designed for studying the characteristic curves, operating points and fan stall for multiple fan ventilation systems.

Jan 1, 1993

By Gary L. Simmons

Over the past several years, Newmont Gold Company (previously Santa Fe Pacific Gold Corporation) developed a new technology for the flotation of refractory auriferous sulfide minerals which is referred to as the N2TEC flotation process. Starting in April 1997, the first commercial flotation plant utilizing N2TEC technology was successfully commissioned at the Lone Tree Mine near Valmy, Nevada. The Lone Tree flotation plant was designed to process 4,085 mt/d of ore producing 494 mt/d of sulfide concentrate. A flotation tails leach CIP circuit was added to recover cyanide-soluble gold from the flotation tails. A portion of the flotation concentrate is blended with whole ore feed to the Lone Tree autoclave, up to the limit imposed by the current oxygen plant capacity. The remainder of the concentrate is shipped to either the Twin Creeks autoclaves or the Carlin roaster for subsequent oxidation and gold extraction. This paper discusses the results achieved in the commercial flotation plant compared to pilot plant testing and engineering design flotation modeling. Capital and operating cost information are also presented.

Jan 1, 1999

By E. Woodburn, R. Putman, A. L. Mular

Optimization strategies of possible interest to mineral processing are reviewed and typical strategies initiated in processing plants to date are discussed. Both On-Line and Off- Line optimization procedures have been employed by industry, assisted either by operators or by digital computers. In every case, dollar benefits have accrued.

Jan 1, 1976

By R. L. Loofbourow, Robert R. Miller

Deep, stable, unlined space promises secure, efficient, acceptable solutions to several current problems. With truly favorable conditions, it can be economic as well. The basic requirement is sufficient sound, tight rock at required depth. This and unusual surface requirements point to special testing. An objective is to describe conditions for planners, estimators and contracts. A first stage concept study needn&apos;t be prolonged but should overlook nothing significant. Although observations and tests on core are considered essential, time and expense can be cut by supplementing then with tests on walls of rotary or percussion holes. In some places initial drilling could be shallow.

Jan 1, 1981

By M. Sagisaka

Coal is expected as one of the main energy sources for a long period because of vast deposits. However, two large barriers to utilize it are suggested, i.e. the carbon dioxide emissions and ash disposal. The authors chose principal methods and areas to utilize coal ash and analyzed the environmental impacts caused by the ash treatment considering the source of the ash. According to the analysis based on lifecycle thinking, an optimized ash treatment system can reduce the integrated environmental impact. It suggests that coal can carry out its role for several decades without disturbances from the point of ash treatment.

Jan 1, 2006

By R. H. Busch, S. M. Loscutoff, F. T. Cross, R. E. Filipy, P. J. Mihalko, R. F. Palmer

INTRODUCTION During the last decade, several studies in France (e.g., Perraud et al. , 1970; Chameaud et al., 1974, 1979 and 1980) and the United States (e.g., Stuart et al., 1978; Cross et al., 1978, 1980 and 1981) have demonstrated the systematic production of emphysema, fibrosis and tumors in the lungs of animals exposed to radon daughters alone or to mixtures of uranium-mine air contaminants. The studies in beagle dogs have been particularly interesting because of the uncertain etiology of the disease and the (apparently) diverse results of the studies at the University of Rochester and the Pacific Northwest Laboratory (PNL). In the Rochester studies, reported by Morken (1973), beagle dogs were exposed to "normal" room air dust loads and radon daughters from 200 to 10,000 WLM*, delivered in 1 to 50 days (rate of delivery, about 200 WLM per day of exposure). Histological examination of tissues was conducted at 1, 2 and 3 years after exposure for all exposure levels. No cancers were noted in these dogs that received estimated alveolar doses of 34 to 1700 rad (0.34 to 17 Gy). Pathologic changes were found only in the alveolar and bronchiolar regions of the lung. These changes were small, subtle, variable, and widely separated, involving only a very small fraction of lung tissue. Lesions appeared as focal thickening of alveolar septa, with some metaplasia of alveolar cells and some hyperplasia of bronchial epithelium. In the PNL experiments reported by Cross et al. (1978), beagle dogs were exposed in lifespan studies to mixtures of radon daughters (rate of delivery, about 14 WLM per day of exposure), uranium ore dust and cigarette smoke. One group of dogs was exposed to cigarette smoke alone. Except in control and smoke-only groups, the dogs died within 4&apos; years of the first radon daughter exposure, or were killed when death appeared imminent because of pulmonary insufficiency (characterized by rapid, shallow breathing). Control and smoke-only animals were killed at periods corresponding to highmortality periods in the groups exposed to radon daughters and mixtures of uranium ore dust and cigarette smoke. Emphysema and fibrosis were much more prevalent and severe in the lungs of dogs exposed to the mixtures. These dogs also had adenomatous lesions, which progressed to squamous metaplasia of alveolar epithelium, epidermoid carcinoma and bronchioloalveolar carcinoma. Pathologic changes in the upper airways of these dogs were most prominent in the nasal mucosa, and included a few squamous carcinomas in the nasal cavity. Respiratory tract neoplasia was noted after ~4 years exposure and at cumulative exposures exceeding approximately 12,000 WLM. Apart from differences in associated carrier aerosol (room air dust vs. uranium ore dust) and radon-daughter exposure rate (200 WLM/day, shortduration exposure vs. 14 WLM/day, long-duration exposure), the most obvious difference in the Rochester and PNL studies was the observation time following exposure (3 years maximum vs. >4 years). Although neoplasia may not have been observed in the Rochester animals because of the earlier termination of the experiments, it is surprising that other lesions, such as prominent fibrosis and emphysema, were not reported. A follow-up study (reported here) is currently in progress at PNL to determine the pathogenic role of uranium ore dust alone and, in particular, to clarify the role of the ore dust in the production of the massive pulmonary fibrosis observed in the earlier study. Pulmonary function testing (a recently acquired capability) was included in the follow-up study as an indicator of progressive change in lung tissue. MATERIALS AND METHODS Chronic (4 hr/day, 5 days/week) exposures began when the dogs were about 2 1/2 years old. Two identical exposure chambers provided space for simultaneous, head-only exposure of 24 dogs to ~l5 mg/m3 carnotite uranium ore dust. An aerosol diffusion system was incorporated in each chamber in order to channel fresh aerosol past each dog&apos;s head; uranium ore dust was added to the inlet room air with Wright Dust Feed Mechanisms* (WDFM). Uranium ore dust and condensation nuclei concentrations were measured daily; chamber aerosols were monitored occasionally for particle-size distributions as described for previous hamster experiments (Cross et al., 1981). The carnotite ore used in these experiments, from the Mitten mine in Utah, was furnished in 1970 through the Grand Junction, CO Office of the (then) U.S. Atomic Energy Commission (now the Department

Jan 1, 1981