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By E. H. Boswell

The Mississippi embayment east of the Mississippi River is part of a vast geologic and hydrologic province. The abundance of water available is largely responsible for the agricultural history of the area and is perhaps the key factor in the rapidly accelerating trend toward industrialization. The multiple artesian aquifer systems that underlie the region, and the alluvial aquifer along the Mississippi River are virtually undeveloped sources of fresh water in that they are yielding only a fraction of the water available. The potential yield of the 12 aquifer systems is estimated to be about 25,000 mgd (million gallons per day), of which only about 600 mgd is presently being withdrawn. The amount of water in storage in these systems is about 1,600 trillion gallons. Ground water having a dissolved-solids content of less than 500 parts per million is generally available at depths of less than 1,000 feet, and water having a dissolved-solids content of less than 1,000 parts per million is available in some places to depths of more than 3,000 feet. Iron is the most common troublesome chemical constituent in the ground water. Water in varying amounts is also available from streams within the region. The amount of water which originates within the region and which leaves it as streamflow during a year averages about 50 million acre-feet (about 45,000 mgd). An additional 375 million acre-feet (about 340,000 mgd) leaves the region as streamflow during an average year, this amount having originated outside of the region. Some streams have considerable flow during periods of no precipitation, and the water during these periods generally has a low dissolved-solids content.

Jan 1, 1966

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 T. J. Lutz, S. Gallagher, J. R. Srednicki, J. J. Sammarco

The Illuminating Engineering Society of North America reports that an underground mine is the most difficult environment to illuminate (Rea, 2000). Researchers at the U.S. National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) are conducting ongoing studies designed to explore different lighting technologies for improving mine safety. Underground miners use different visual cues to escape from a smoke-filled environment. Primary and secondary escapeways are marked with reflective ceiling tags of various colors. Miners also look for mine rail tracks. The main objective of this paper is to compare different lighting types and ceiling tag colors to differentiate what works best in a smoke-filled environment. Various cap lamps (LED and incandescent) and lasers (red, blue, green) were compared to see which options resulted in the longest detection distances for red, green and blue reflective markers and a section of mine rail track. All targets advanced toward the human subject inside of a smoke-filled room to simulate the subject walking in a mine environment. Detection distances were recorded and analyzed to find the best cap lamp, laser color and target color in a smoke environment. Results show that cap lamp, laser color and target color do make a difference in detection distances and are perceived differently based on subject age. Cap lamps were superior to lasers in all circumstances of ceiling tag detection, with the exception of the green laser. The incandescent cap lamp worked best in the simulated smoke compared to the LED cap lamps. The green laser was the best color for detecting the tags and track compared to the red and blue lasers. The green tags were the easiest color to detect on the ceiling. On average, the track was easier for the subjects to detect than the ceiling tags.

Jan 1, 2013

By M. G. Ayat

Coal degradation is the breakage of coal particles to finer sizes due to the continuous forces of attrition and gravity to which coal is subjected during mining, handling and preparation. The objective of this paper is to determine the extent of degradation that a coal slurry experiences when transported through pumps and pipelines. The examination of degradation results for a number of different coal slurries have indicated that the extent of breakage is dependent upon the physical properties of coal and the time span of circulation. These results have also indicated that certain size fractions of coal are more susceptible to breakage than others.

Jan 1, 1986

By D. Spitty

Mining companies often have many disparate systems and repositories of data in their organization for planning and scheduling outbound mining supply chains. To optimize ore quality, throughput, transport logistics scheduling and delivery to contract, planning teams need to model and manage the value chain accurately and achieve a consolidated, enterprise view of operational performance. Planning teams coordinate a complex series of activities to ensure production forecast accuracy. They also negotiate and execute complex contracts often with disconnected and limited visibility of production forecasts, quality, and variability with little ability to accurately market potential product specifications over longer time horizons. This market is becoming increasingly dynamic, with increasing variability and the time for planning teams to react is decreasing. This is driving the need towards using science to generate the necessary scenarios required to support the decisions made by planners on a frequent basis. Resource-to-Market is a highly flexible, user-configurable supply chain management system for the mining and metal processing industries. This provides an integrated view of the supply chain that supports the dynamic nature of planning in a mining company, embraces variability of elements across the supply chain with the ability to optimize across all the functional areas of the operation to enable optimal decision making for often competing objectives such as throughput, quality, cost, revenue and profit.

Feb 23, 2014

By J. C. Haptonstall

Stoping methods at the Homestake Gold Mine through 1978 had been traditional overhand cut-and-fill, shrinkage or square set. High costs, low-productivity and safety concerns prompted the mine to search for and adopt a "bulk mining" technique as a primary stoping method. Blasthole stoping had been successful but it is very development intensive, and was not suitable for the mine's accelerated mining program. Vertical Crater Retreat stoping was selected, and today accounts for over 50% of ore production. Case histories representing both the successes and failures of VCR stoping in the mine are discussed.

Jan 1, 1986

By R. J. Jula

The process of treating granular activated carbon for return to service in the recovery of gold in Carbon in Pulp and Carbon in Leach circuits has been investigated. Carbons from four U.S.A. mines, one Canadian mine and one South African mine were characterized before and after regeneration. The use of thermal gravimetric analyses demonstrated the presence of inorganic compounds on the surface of the carbon. Thermal regeneration was investigated using factorial' analysis to determine the effect or interaction of furnace temperature, retention time and the use of supplemental steam. The operation of acid leaching prior to or after gold elution was investigated. The effect of water quenching, regenerated carbon was also studied. From the data obtained in this investigation, guidelines are given for effective regeneration operation.

Jan 1, 1985

By Nikhil Dhawan, Shrey Agrawal

India’s most extensive renewable energy expansion program targets 280 GW of solar energy by 2030. Due to the massive generation of photovoltaic waste (expected 34,600 T by 2030), stringent recycling effort to recover metal resources from endof- life PVs is required for resource recovery, circular economy, and subsequent reduction in the environmental impact. The present study investigates the recycling potential of end-of-life silicon solar modules. The feed characterization reveals that most of the values in PV modules are concentrated in the frame (pure Al), Si wafer (72–84% Si, 9–12% Al, and 0.13–0.71% Ag), and electrical connections (Cu wire coated with Sn). The Si and Ag values in the feed were beneficiated using water fluidization, and concentrate with 90% Si and 2% Ag was attained in the underflow concentrate. Ag values were recovered in the form of AgCl by leaching in nitric acid and precipitation. After the purification step, the residue containing 99% Si can be further utilized to fabricate Si wafer and Al-Si alloy. The preliminary cost estimations suggest that the proposed process is economically viable for the recycling of solar panels with the maximum value generated from the AgCl precipitate followed by Al panels and Si wafers.

Nov 14, 2022

By S. C. Suboleski

In a high risk venture such as mining where capital is committed and contracts are signed on the minimum of information, decisions are based primarily on production forecasts derived through consideration of such factors as management-labor relations, mining practice, variations in physical conditions and the equipment applied. Among these factors, the physical conditions offer the least opportunity for control and, due to the wide range of mining conditions that may be experienced, little effort has been made to develop objective methods for measuring their effects on mine out- put. The aim of this paper is to demonstrate a method for assessing these relationships that can be applied under a wide range of conditions both in new mines and in working sections where there is a need to determine the impact of proposed operational modifications. psing empirical data from active underground mines, a mathematical model was developed to derive a set of regression equations for predicting production as a function of mining conditions

Jan 1, 1980

By J. D. Vincent

The Mission By-Products Plant at the Mission Concentrator of the American Smelting and Refining Company, some 20 miles south of Tucson, Arizona in the Twin Buttes mining area, has been in operation slightly over a year. The plant produces a molybdenite concentrate a copper concentrate and, at times, a zinc concentrate. An intensive test program of over three years was conducted at Mission to make the recovery of molybdenum economic. Briefly it was found necessary to make a scavenger concentrate in the copper mill before it was possible to recover economic quantities of molybdenite. By so doing there were resulting additional recoveries of copper, silver and zinc. This program resulted in the design and construction of the existing plant. A paper by the authors discussing the test work and the design was presented at the, October 1965 meeting of the American Mining Congress in Las Vegas, Nevada, by Mr. Wayne Bossard.

Jan 1, 1966

By L. Martin, M. Raffaldi, M. Stepan, D. Benton

The Office of Mine Safety and Health Research, Spokane Mining Research Division, is continuing its high-energy, high-displacement testing of field-scale shotcrete panels. A test program was developed to determine the relationship between applied force, displacement and energy for both unreinforced and reinforced shotcrete panels. Reinforcement options consisted of synthetic macro-fibers, sprayed polyurea liners, chain-link mesh, welded-wire mesh and combinations of them. During testing, photogrammetry was used to measure the geometric changes of the panels, including volume changes and panel cracking. These measurements were correlated with the load and displacement data, allowing visual observation to be related to the applied force and displacement. The test results provide a comparison of the mechanical performance of the various panel types and can assist in interpreting the condition of installed surface support. Visual assessment of the loading cycle and strength capacity of shotcrete in underground excavations will improve mine safety by providing a means to better quantify the stability of installed shotcrete support.

Jan 1, 2016

By Dan S. Nilsson

Small-scale mines are today expected to provide much of the increased production of metals, industnial minerals and coal this country demands in the future. But what is the size trend in the mining industry?

Jan 1, 1980

By R. R. Klimpel

This paper describes four new families of flotation products which are currently being introduced at the industrial level. A brief summary of the chemical basis behind each product family will be given. This is then followed by a selection of flotation examples which illustrate the more important use characteristics that have been observed to date. It is becoming more apparent with further testing that these four new product families can offer both technical and economic advantages to the industrial flotation process operator.

Jan 1, 1992

By W. T. Walter

High-G centrifuges from five preparation plants were sampled to determine and quantify the various operating factors affecting performance. The operating factors that were considered include feed rate and percent solids, size of feed material, screen-basket type, hardness of coal and age of the flights. The performance parameters that were measured include product surface moisture, recovery and degradation of the coal. Regression equations with good significance levels were developed.

Jan 1, 1982

By Robert D. Schmidt

The US Bureau of Mines is cooperating with Cyprus Mineral Park Mining Co., Columbia University, and the US Geological Survey in investigating the feasibility of applying in situ leach mining methods to fracture-hosted, supergene copper sulfide (chalcocite) ores. This paper presents the initial findings of mineralogical, hydrogeological, and geochemical characterization studies conducted at the Mineral Park mine, located in the Wallapai mining district of northern Arizona. A design for in situ leaching is proposed that would minimize the need for blasting prior to leaching, and would enable economical development of deep reserves at the Mineral Park mine. The in situ leaching design would also reduce the potential for long term acid rock drainage.

Jan 1, 1995

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 Roy A. Grancher

Construction materials indeed face a dilemma...as does the building industry as a whole. A stop & go economy; a severe drop; in housing starts; lingering indecision over just what corrective steps are to be taken or to their degree of commitment; no less basic disagreement in regard to which of the, Nation's problems is really the most pressing -- inflation or recession? Optimism has become a rare quality these days. At moat the cautious view is that this new year will see a long, hard struggle back, with hopes that 1976 at least can truly mark a dual anniversary celebration for the United States and its economic health. Yet the paradox is that once recovery does return, those very construction minerals and materials --which in recent years have experienced the ups and downs of overcapacity, shortage, and now declining demand again-- will once more face the spectre of mass inability to service revived and growing needs for its product. Mounting costs, present marginal expansion investment, and substantial lead times required for new facilities to come into production, could well form a bottleneck to economic upswing. The result again can be another cycle of shortage-induced inflation, and with it continued gyrations within the demand supply relationships of the country's building industries.

Jan 1, 1975

By Hemendra N. Kalia

Several attempts have been made in the past sixty or so years to commerciliaze the vast oil shale deposits of the United States of America. However, the industry has yet to become viable and economic. To date, it has not been possible to produce oil from the oil shales at a competitive price when compared to the oil produced from oilfields by conventional methods. However, the development work has been quite fruitful in furthering the art of thick bed mining and technology of in situ retorting. The in situ method has the potential of recovering oil from thick beds and the resource recovery potential is much greater than that from underground mining and surface retorting. In situ methods require that the shales/ marlstones be fragmented ' in place to induce adequate porosity and permeability to allow in situ' heating of the fragmented shales. This can be accomplished by using explosives. However, it has been found that the existing blasting systems, though very efficient, are somewhat lacking. The explosive become insensitive when shot in multiple vertical decks. They can also become insensitive when spaced horizontally at close proximity to other charges. Also, since the blasting is done in a very limited free face, this limits the delay time that can be allowed between charges. Consequently it is not always possible to predict the performance of the blasting system on a routine basis. Furthermore, since it is not possible to undertake secodary blasting, it is imperative that the blast design function properly. Recent, successful retorting by Occidental Petroleum Company of retorts seven and eight suggests that some of these problems may have been overcome. This paper addresses some aspects of in situ retorting and problems those have impeded the development of a viable oil shale industry in the U.S.A.

Jan 1, 1983

By M. Ishaq, J. Rosami, J. Brune, E. Sidrow, C. Tsai, S. Slouka

Respirable rock dust poses serious long-term health effects to workers in mining and tunneling underground hard rock environments. When inhaled, respirable silica particles commonly found in quartz and other minerals will scar sensitive lung tissue and cause irreversible lung diseases. Characteristics such as concentration, type of mineral, particle size, and particle shape inhaled can harm workers to various extents. Therefore, this study characterizes rock dust particles less than 100µm in aerodynamic diameter that are released from cutting hard rock in the underground mining environment. In this study, laboratory full scale cutting tests on samples of potash rock were performed with radial picks to generate dust. Three stages of pick wear were tested: new, moderately worn, and severely worn. Comparisons between different stages of pick wear to dust concentration, size distribution, and particle shape characteristics are drawn from this study to start determining the scenarios when the released airborne dusts become potentially most hazardous for workers. Although further testing needs to be conducted to make viable conclusions, the moderately worn pick, or the pick with the most blunt tip, in these experiments are potentially the most dangerous. The blunt pick tip released the highest concentration of dust and generated particle shapes with the highest aspect ratio compared to the other two picks. The preliminary results of this study allow for the further development of optimum bit management and maintenance systems to control the exposure of respirable dust to mine workers.

Mar 2, 2022

By Douglas W. Barr

If some of you have been through the long hot summer in the southwest, you may find it refreshing to turn your thoughts to the wintertime problems of mineral processing in the northern climates. The purpose of this paper is to point out some of the ways in which heat is gained or lost in the tailing basin operation and the problems that can result if too much heat is lost.

Jan 1, 1980