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By John R. Riede

The use of radioactive gages in beneficiation plants is relatively new However, enough applications have been made so that it is now possible to positively state that these gages have definitely progressed from a laboratory device to a very rugged and reliable on stream process measuring instrument. Gamma Ray Gages of the type presently being used in the beneficiation industry consist of three basic components: (1) A source of radiation (2) A radiation detector (3) An electronic amplifier The source is usually a radioisotope such as cesium-137, or cobalt-60. This source, adequately protected and ruggedly mounted, is most commonly placed on one side of a pipe or vessel. The radiation detector is then mounted on the opposite side, Since the absorption of gamma radiation as it passes through various materials is a function of the density of the material, the change in radiation measured by the detector is proportional to the change in specific gravity of the product in the pipe or vessel. One popular type of detector in use today is a cell which converts radioactive energy directly into electrical energy1. This electrical energy, when amplified, presents a usable output for metering and control devices. There are, of course, many other components which are part of a working gamma gage installation, such as zero compensators, lead shielding, mounting brackets, equivalent absorbers, etc.

Jan 1, 1958

By B. Yarar

Samples of coal from an adit in the Fording River District of British Columbia showed hydrophilic properties between depths of 0-24.5 meters and was naturally hydrphobic at higher depths. Laboratory experiments indicated that weathered samples (i.e., those mined at 0-24.5m) could be upgraded by froth flotation at pH<2 following slimes removal. The i.e.p. of samples varied regularly between pH=1.6-4.1, the weathered fractions being at the lower end of the pH scale. These values followed a pattern comparable with the flotation behavior of samples. A patchwise structure for coal surfaces determining the resultant disjoining pressure, which in turn determines flotation-non flotation relationships is postulated.

Jan 1, 1982

By Vijenac Quarry, A. Iljazagic, t. Knezicek, T. Omeragic

Limestone quarry Vijenac, is one of the key limestone producers in B&H. Conventional massive drilling and blasting is the technique applied for limestone exploitation. Utilized blasting scheme causes appearance of large oversize stone pieces, uncontrolled flying stone and undesirable seismic effects. In order to reduce or eliminate exposed disadvantages and to improve environment in the area of Vijenac quarry, an innovative blasting scheme was tested. Conventional blasting scheme was changed from single row, deep inclined blast holes combined with two lines short horizontal holes to multi row, inclined blast holes combined with a single line short horizontal blastholes. Applied innovative blasting scheme reduces negative blasting impact on the environment through safer working conditions, reduced amount of dust after blasting, reduced explosive and energy consumption, reduced appearance of explosive gasses and reduced earth and air vibrations as the result of seismic effects.

Jan 1, 2005

By Stephen C. Moore

The Grossschloppen vein-uranium deposit, Bavaria, West Germany, was examined utilizing underground workings during 1980-82 by Esso Erz GMbH, an affiliate of Exxon Minerals Company (EMC). Geologic evaluation entailed dense drilling of a portion of the deposit from workings constructed specifically for the program. Discovered in 1977, the deposit was initially explored by surface diamond drillholes which allowed definition of a 30-60 m wide vein system discontinuously mineralized along a 1000 m strike length and to at least a 450 m depth. The underground program was conceived as a cost effective procedure to answer questions on vein correlation, grade continuity and variability. A 1200 m decline allowed access for detailed sampling of approximately 10% of the known area of mineralization. Fanned drillholes, logged by gaga probe, were spaced to provide intersections of veins at 10 to 20 m intervals. Six cross cuts also penetrate the pitchblende and uranophane mineralization which occurs in 0.1 to 2.5 as thick quartz veins. Detailed cross-sections and level plans were constructed for resource estimates of the intensively studied portion of the vein system. The program resulted in the discovery of local, high grade areas and an average grade in the evaluated area nearly double that expected from surface drilling.

Jan 1, 1983

By R. Jin

The hydrophobicity of six coals ranked from lignite to anthracite is studied through contact-angle measurements, bubble attachment-time measurements, FTIR spectroscopy, and Hallimond-tube flotation. The preliminary study shows that the hydrophobicity of coals can be told by the bubble attachment times of coals (a kinetic criterion) or by the contact angles (an - equilibrium criterion). A general agreement between flotation response of coals and measured bubble attachment times or contact angles is observed in the present study. However, the study also shows that the hydrophobicity of coals can be predicted by FTIR spectroscopy work with proper manipulation of the spectra. Both hydroxyl and carboxyl groups in the coals are proven by FTIR work to be responsible for the change of coal hydrophobicity. A new criterion for the hydrophilicity index of coals from FTIR spectra is introduced through the study.

Jan 1, 1987

By . A. Drouin, J. -M. Lalancette, D. Lemieux, C. Chouinard

"A gold bearing pyrite concentrate was treated at the demonstration scale (15 t/d) for the extraction of gold using a cyanide-free process. The pyrite was depressed in the flotation circuit in order to promote the flotation of copper and to achieve a sufficient copper grade to meet the copper smelter criteria. However, the recoveries of copper were 80% and only about 50% for the gold was found in the copper concentrate. The balance of the gold (50%) and copper (20%) contained in the pyrite concentrate as a reject from an overall flotation circuit. The gold grade in the pyrite concentrate is 5.40 g Au/t and copper about 0.77%. About 170 tons of pyrite concentrate were processed in the DST demonstration plant. The concentrate was first oxidized using a fluid bed to produce a calcine. Copper was then extracted as copper sulphate using diluted sulphuric acid. The residual solid was submitted to the DST chlorination process for gold extraction. Thereafter, the gold was recovered from the pregnant brine by precipitation over silica using DST proprietary process. The maximum gold recovery by chlorination was 90%. The average gold recovery by cyanidation of these calcines was 71%. INTRODUCTION Dundee Sustainable Technologies (“DST”) has developed a chlorination process as an alternative to the conventional cyanidation process for the extraction of precious metals from ores or concentrates. The technology offers viable and efficient gold recoveries and the ability to handle refractory ores and contaminated material (As, Hg, etc..). The process was successfully demonstrated on hundreds of samples provided by various mines, exploration and development projects and has evolved from laboratory experiment to demonstration at an industrial scale. DST’s chlorination process operates in a closed loop circuit, which implies that no liquid effluents are generated. The chemistry and process design allows precious metal deposits containing base metals to be treated viably. The tailings from the process are inert and non-toxic, sulphide depleted and thus non-acid generating. The efficiency of the process has demonstrated excellent gold recoveries within a fraction of the time needed for cyanidation to obtain similar results. The company completed in 2015 the construction of the first industrial demonstration plant operating with the DST technology. The plant has a capacity of 15 tons per day of mineral concentrate, and the ability to extract gold and silver utilizing DST chlorination technology. DST has tested its chlorination technology at demonstration scale on the refractory pyrite concentrate containing 5.40 g Au/t and 0.8 %copper. This auriferous pyrite concentrate, was by-product of copper concentrate respecting the copper smelter norms, is produced in a country where cyanide is prohibited and refractory to cyanidation. The pyrite concentrate was initially processed successfully (gold recoveries: > 90%) by the DST technology at laboratory (2011: 20 kg) and pilot (2014: 5 tons) scales to extract gold. About 170 tons of this pyrite concentrate were processed in the DST demonstration plant located in Thetford Mines."

Jan 1, 2017

By H. Singh

Principal source of rhenium is molybdenite. Depending on the mineral processing route, rhenium can be recovered by one of the several alternative solvent extraction processes. Extensive experimental work has been carried out on the development of tertiary amine extraction process for treating very dilute highly impure scrub solutions obtained during scrubbing flue-gases of molybdenite oxidative roasting. Equilibrium data has been obtained under various process conditions by tracer analysis using radioactive Re-186. Extraction with 1% solution of a high molecular weight tertiary amine in kerosene, followed by scrubbing of organic extract with a solution of sulphuric acid and stripping with ammoniacal ammonium sulphate yields high recovery, concentration, and purification.

Jan 1, 1982

By K. L. Bickel

Catalyzed diesel particulate filters (CDPFs) are used for reducing diesel particulate matter (DPM) concentrations in underground mines. The U.S. Bureau of Mines is conducting research on how catalyzed diesel particulate filters perform. Two CDPFs, with two different catalysts, are used on vehicles in two mines. The CDPFs are periodically removed from service and evaluated in the laboratory to determine their DPM collection efficiency, regeneration temperature, and effects on gaseous hydrocarbon (HC) and carbon monoxide (CO) emissions. This report summarizes the results of the laboratory evaluation, and the mines&apos; experience with the CDPFs. Both CDPFs have operated over 2,000 h. One was evaluated after 1,646 h; its collection efficiency at one operating condition was 87.3 pct. After 2,135 h of operation it was removed from service because it was damaged. The second CDPF continues to be used after 2,328 h of service. The laboratory evaluation indicated its collection efficiency decreased after 1,584 h of use and its regeneration temperature increased from 405&apos; C to 420&apos; C. The mines&apos; experiences with the two CDPFs varied. While being used on mine vehicles, both CDPFs became plugged with DPM on a number of occasions because of insufficient regeneration. CDPFs are capable of lowering DPM concentrations in diesel exhaust. They can also lower emissions of CO and HC, depending on the type of catalyst used. In this study, the performance of the CDPFs changed with use. Recommendations are given in this report for proper use of CDPFs in mines.

Jan 1, 1994

By R. L. Grayson

The health and safety of employees, efficiency of the operating system and production are paramount goals in underground coal mining. The section foreman assumes responsibility for making his part of the total system function to meet these goals. However, section foremen often have not been prepared to assume the full range of their responsibilities upon becoming a supervisor. This discussion addresses the full range of section foreman responsibilities and concomitant authority. Management principles that must be mastered by him are presented, and performance expectations as well as criteria for their evaluation are examined. The benefits realized from effective foreman training are discussed.

Jan 1, 1985

By Richard C. Neavel

Among the many compositional parameters used to judge the quality of a steam coal is the fouling factor of Attig and Duzy1 [% base in ash % acid in ash X % Na20] in ash. The higher the fouling factor, the more likely the heat transfer surfaces of the boiler will acquire a deleterious deposit of sintered ash. While examining the elemental composition of ash from various size and gravity fractions of coals from Illinois, we noticed that variations in the fouling factor were attributable mostly to variations in the sodium content. Further, sodium content was essentially the same in all sink-float fractions from a given coal. In other words, sodium was related neither to the ash nor to the organic material. We therefore concluded that the sodium was most likely in the pore water, which was approximately a constant proportion of all fractions. This led to the supposition that the sodium might be removable through water extraction. This supposition tended to confirm the observations of Daybell,2 Daybell and Gillham,3 and Gluskoter and Ruch4 that much of the sodium in coals existed as water soluble sodium ions. In passing, it should be noted that most sodium in Western U.S. coals (i.e., Wyoming, North Dakota, Montana) is not water soluble, but rather is fairly strongly held in association with the organic material (ion-exchanged).5 Because data reported in the literature were not very conclusive about the typical proportions of sodium that might be removed by water extraction, and because there were few data indicating extraction rates, and finally, because our calculations showed a favorable economic incentive to lower sodium contents, we initiated an experimental program to investigate water extraction of sodium from Illinois coals.

Jan 1, 1976

By Ted H. Eyde

Nearly 17 years ago a major producer of synthetic zeolites started an extensive exploration program for natural zeolite deposits which resulted in the discovery of over 170 occurrences in the western United States. A few years later several of the other producers and consumers of synthetic zeolites also started similar exploration programs. Since then, small quantities of natural zeolite minerals have been produced from at least 12 deposits in the United States. Of these the Bowie deposit, about 13 miles north of Bowie, Arizona, is the most important,having produced over 5,000 tons of vitric tuff zeolitically altered to the mineral chabazite and minor amounts of the minerals erionite and clinoptilolite. Mining Districts and Mineral Deposits of Arizona compiled by Charles A. Mardirosian, Consulting Geologist, estimates the value of the total production from the Bowie deposit at a very conservative $2,000,000. Unfortunately, none of the companies responsible for the discovery and the initial production of natural zeolites made any effort to develop the high volume, low cost applications of this unique mineral raw material. Instead, they developed only the high unit value uses to supplement their existing synthetic molecular sieve product lines. With the producers of synthetic zeolites thinking in pounds and not in tons, further development of natural zeolite deposits stagnated for over a decade.

Jan 1, 1974

By Brahm D. Prasad

As in other mineral deposits, variation in bitumen saturation, thickness of ore and discard occurs throughout Alberta&apos;s Athabasca Oil Sands deposit. The economic stripping ratio developed here to determine surface mineable limits takes into account capital and operating costs, crude oil prices, quality of ore, thickness of overburden, and thickness of inter-ore waste. The surface mining systems employed to remove bituminous sands (oil sands) from huge mines at depths of 60-70m use gigantic draglines, bucket wheel excavators and reclaimers, and large mobile equipment.

Jan 1, 1982

ShouSteel Mining Ltd., a subsidiary of ShouSteel (Group) Co., was founded in 1959 and is located in QianAn City in Hebei Province, China. ShouSteel?s pelletizing plant uses iron ore as a raw material combined with limestone, dolostone, or olivine, with bentonite as a binder. After mixing the raw materials and forming them into small, spherical balls, ShouSteel then fires pellets in kilns for hardening. The company sells the finished pellets as raw materials for blast furnaces used to produce industrial metals such as iron. ShouSteel?s handling capacity is approximately 24.5 Mt/a (27 million stpy) of ore. The company?s production capacity is 3.2 Mt/a (3.5 million stpy) of oxide pellets and 560 Mt (650 million st) of sinters. Until recently, ShouSteel Mining had not replaced its electronic scales in its series of ingredient chambers. Because of the wear and tear on these older scales, the weighing system began to encounter regular problems. The company experienced a high failure rate from the integrator, an unstable signal, weak anti-interference ability and low accuracy. ShouSteel also found that spare parts required during repairs were consistently high in cost and that system calibration was becoming increasingly frequent.

Jan 1, 2012

By Rodger C. Smith

The topic chat has been assigned to me ?Economic and Political Climate of the Potash Industry? is a function of two basic facts: 1. Potassium is absolutely essential to plant and animal growth. Along with nitrogen and phosphorus it is one of three major plant nutrients, the three nutrients required in largest quantities for plant growth. 2. United States is unequivocally an "have not" nation with regard to potassium. Quantity of potassium ores is limited and, more disturbing, the cost of production at all U.S. potash mines is marginal in comparison with the major producing countries, i.e. Canada and U.S.S.R.

Jan 1, 1983

By Egon Pohl, Peter Eckl, Friedrich Steinhäusler, Johanna Pohl-Rüling

RADON EXPOSURE AND CARCINOGENIC CELL TRANSFORMATION The highest radiation burden to miners is due to inhalation of radon and its short-lived decay products. The quantification of the risk associated with this radiation burden is complicated by modeldependent lung dosimetry, insufficient accuracy of past human exposure data as well as lacking knowledge about potential synergism of various carcinogens. Nevertheless, it is evident from epidemiological studies of miners that inhalation of elevated levels of radon daughters is correlated with increased lung cancer incidence (UNSCEAR, 1977). The situation is further complicated by the lack of reliable data on the biological variability of the latency period for the development of lung tumor under varying exposure conditions. At present information on variation with age is scarce, however, it is indicated that the excess lung cancer rate for workers exposed to high radon levels is considerably higher, if exposure occurs at ages over 40 years as compared to under 30 years of age (Sevc, Kunz, Placek, 1976). Furthermore, latency period is shorter by 6 - 7 years for smokers exposed to elevated radon levels than for non-smokers (Fry, 1976). Analysis of US- and CSR-uranium miner data revealed that the mean latency period is in the order of about 15 years (Jacobi, 1973). These uncertainties, together with medical diagnostic shortcomings, lead to the dissatisfying situation that at present the detection of radon induced injury of mining personal is primarily the assessment of the endpoint, i.e. radiation induced cancerous transformation of lung cells with typically less than 10% chance for recovery. Therefore it would be advantageous to develop practically applicable diagnostic aids to indicate already early precancerogenic changes of cell characteristics. This would permit the identification of specific population groups at increased risk for the development of lung cancer, thereby increasing the chances of more successful medical treatment. Despite continuous improvements in the reliability of test methods for the diagnosis of cancer cells there is still need for techniques, which enable the detection of transformed cells before the onset of invasion of the host organism. It is generally recognized that the transformation of a cell into a malignant state leads to a change of the cell surface, indicating a correlation between membrane-specific immunological properties and loss of growth control. Surface alterations on cells appear to be responsible in part for the malignant state and are not simply secondary effects of the transformation (Schnebli and Burger, 1973). Furthermore, membranes of cancer cells differ significantly from those of normal cells, particularly, in permeability properties (Rastogi, 1976). In dying cells, proteins, glycoproteins, peptides, aminoacids and their breakdown products are released, which block the permeation of the membrane itself. A mammalian cell can be considered as a 3-phase system (interior, boundary, environment) with the membrane forming a heterogeneous barrier between two subsystems. Under normal circumstances a difference of chemical potential is maintained on both sides of the membrane, causing an ion gradient across and fixed surface charges on the membrane. This results in a membrane resting potential (MRP) between cytoplasm and the bulk medium. It has been shown that MRP is a highly sensitive indicator for cellular reactions due to physical, chemical and biological agents, particularly whenever phenomena of transport and ion gradients as well as permeability are involved (Redmann, 1980). The primary interaction of the agent "ionizing radiation" with any form of living matter occurs at the cellular level. The component with the highest hit probability is the cell membrane. In the study presented MRP-changes of human cells were investigated with simultaneous measurements during irradiation and post-irradiation intervals up to six days. Furthermore, the suitability of MRP-measurements of human cells was tested as an indicator for early changes of cellular properties prior to the histological confirmation of carcinogenic transformation. EXPERIMENTAL METHODS Lung cells The biological specimen used were cultured human lung cells and human lung biopsy samples. Monolayers of lung fibroblasts (W138) were grown in petridishes using conventional culture techniques. In addition, transformed lung cells (W138SV13, subline 2RA) were used applying similar culture methods. All petridishes were incubated at 37°C and only cells in logarithmic growth phase were used. Freshly excised lung biopsy samples were obtained from randomly selected male and female patients (20 cases), where suspected or unclear malignancies were indicated by clinical or X-ray observations. At the time of sampling 80 % of the patients were or had been smokers in the past. The samples were taken by means of a stiff bronchoscope introduced into the trachea under local anasthesia with 1 % Novesinsolution (preparation with Atropin and Pantopen). This permitted the observation of both main bronchi down to the segmental bronchials. From each patient two tissue samples were excised from the mucusepithelial layer under visual control with fiber optics and transferred immediately into 1 % NaClsolution. One sample was taken from the suspected

Jan 1, 1981

By K. K. Bhattacharyya

In the Gulf Coast area lignite deposits occur in Texas, Louisiana, Arkansas, Mississippi and Alabama. Lignite has been mined in Texas since the early 1800&apos;s reaching a production of over 900,000 metric tons (1 million short tons) in 1910. With the availability of inexpensive oil and gas, production fall to as low as 16,000 metric tons (18,000 short tons) by 1950 (Henry, 1976). With the advent of the oil and gas shortage in early 1970, lignite production began to increase again. The purpose of this paper is to discuss the geotechnical considerations of mining lignite in the Gulf Coast area, particularly Texas and Louisiana. Lignite deposition occurs in unconsolidated sand, silt and clay environments. Extensive sand units saturated with water may be present within the potential mining depths. This paper describes the geotechnical considerations for designing a surface mine in this geographical area. These factors include geology, hydrology, mining method, and equipment utilization.

Jan 1, 1982

By B. Pesic

Northwest Alloys, a wholly owned subsidiary of Alcoa, produces magnesium from dolomite by reduction with ferro silicon and aluminum. This process produces alkaline by-products in quantities that allow their consideration for use as commercial by-products. Two such products are dicalcium silicate slag, Di-Cal, and magnesium oxide condensate, MgO. The alkaline properties of these materials offer acid neutralizing capability comparable to the traditionally used lime, therefore, warranting a study for their use in applications where the neutralization of acidic waters or process solutions is required, such as treatment of mine waters. In this ongoing study, three mine waters (Bunker Hill Mine, Berkeley Pit, and Blackbird Mine) were selected for treatment with Di-Cal and MgO. Lime was used as the background control. The solid precipitates were subsequently contacted with pure water at four different pH conditions for stability testing of prepared metal precipitates (expanded TCLP). It was found that neutralization with Di-Cal results in precipitates which are of equivalent to superior stability than those from lime treatment.

Jan 1, 1999

By Stewart W. Daniel

Competitive pressures involving product duality, uniformity and economics are increasing the interest in and accelerating&apos; the adoption of automation by the cement industry. The demands of this industry on instrumentation and control manufacturers for more effective and reliable control of process variables is also increasing. The trend to replacing small grinding mills with a fewer number of larger mills is lowering the investment requirement per unit of capacity both for the mills and for their automation. Cement process control systems of today are more sophisticated than the equipment installed two or three years ago, not because the process itself is more complex but because todays demands require a higher degree of control action and accuracy. Because of increasing labor costs, an important objective of an automation program is a reduction in the process labor content. This can be realized by allowing the operator free time for other duties, by increasing the number of grinding circuits one operator can supervise and by removing to. a large extent the need for the operator to make process&apos; adjustment decisions.

Jan 1, 1965

By Wilfred Walker

A working hypothesis is presented herein mineral belts are split as all world oceans opened. Rather than plate tectonics, expansion is favored as the most recent expression of the sequence of convecting systems in the Earth&apos;s mantle. Throughout the geological record this sequence has produced similar mobile belts. This similarity lends itself to both stratigraphic classification and the theme of mineralization in mobile belts demonstrated by Y. A. Bilibin. Crustal evolution should, therefore, serve as an important guide in understanding Pacific mineral belts.

Jan 1, 1982

By M. G. Mudrey

Considerable potential for metallic mineral resources in the lower Proterozoic rock of the Lake Superior region exists (Mudrey and Kalliokoski, in press). Most of the identified resources occur within a 2.0- to 1.9-b.y.-old lithotectonic assemblage characterized by extensive sedimentary strata in the north and thick volcanic se- quences in the south, all deposited on a two-terrane, composite basement of Archean age (DeMattis, 1989). Since the late 1960s, measured resources of nearly 90 Mt (100 million st) of typical volcanogenic massive sulfide at eight localities in Wisconsin have been discovered. The largest of these, near Crandon, contains about 61 Mt (67 million st) of ore averaging 5.6% zinc, 1.1 % copper, and 0.5% lead. Although none of these properties are in production, estimates by Mudrey (1978) suggest that Wisconsin could become a major contributor of newly mined zinc and copper in the United States. These discoveries and uranium and gold discoveries in the Canadian Precambrian are what have led to in- creased metallic mineral exploration throughout the northern half of Wisconsin (Fig. 1). In this chapter, we discuss the geology and legal framework in which the Proterozoic volcanogenic massive sulfide deposits were found. Exploration activities for other metals have generally been negative, and have been background noise for the legislative activities related to the massive sulfide discoveries. Uranium exploration has been consistently negative, although several different environments have been assessed. Other metal discoveries. such as titanium/vanadium, have been subeconomic.

Jan 1, 1991