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By William F. Brandom

INTRODUCTION Cross, et al. (1974), produced a retrospective study of standard setting for underground miners. This report had two distinct components; i) criteria of importance for the protection of the miners, and ii) economic considerations for standard setting. The methods for setting radiation safety standards reviewed were: dose calculations and consensus methods; epidemiology; pathology; bioassay; animal experiments; sputum cytology; chromosome aberrations; and, the Mantel-Bryan Model. By looking back, the authors intended to enable officials to look ahead in making future decisions based on reasonable conclusions. Now it may be time to consider underground miners' protection from another perspective: are there miners who may be especially susceptible to toxic environments?; and if so, are there any biomedical assays that might be indicative of exceptional sensitivities to toxic substances? The human population is genetically very heterogeneous. The data of Saccomanno, et al. (1973), reveal great variability in individual response to radon daughter exposure and only a small portion of the miner population subject to toxic inhalants develop squamous cell metaplasia (Saccomanno, et al., 1970). The majority of the miner population is either not susceptible or is resistant to the toxic agents. This information suggests the existence of a small subpopulation with increased sensitivity or reduced resistance and underscores the need for indicators from biomedical assays that might prove of value for the detection of such individuals. The heightened awareness of the contribution of pollutants in the environment for the potential induction of mutations and carcinogenesis lead to a profusion of short-term bioassays to circumvent the high cost and time-consuming large toxicity animal studies. Over 100 bioassays across taxa from microbes to man are at various stages of use or development (Hollstein, et al., 1979). Less than a dozen tests currently offer early promise for application to[ in vivo] effect studies of man. Many are still in early development, lack the sensitivity needed for a retrospective or prospective study at current permissible exposures, are impractical to conduct in the field, or are not cost effective. The purpose of this paper is to review some of the bioassays that may now, or in the near term, prove applicable for the detection of individual underground miners with increased susceptibility to toxic agents. Throughout this statement, it is assumed that any single test may give false negatives or false positives and, therefore, a tier of tests should be investigated. The possible tests are in various stages of development; some tests better proven than others with a firmer data base and, therefore, with greater probability of usefulness. Some of the less proven assays are not ruled out if they have practical or theoretical promise as indicators. Table I summarizes the assays critiqued for their potential to monitor the effects of [in vivo] exposure to genotoxic substances. POTENTIAL INDICATORS OF HIGHLY SENSITIVE MINERS Assays of Body Fluids It is desirable to have data on the agent(s) to which subjects are exposed when humans are monitored by biomedical effects. Obviously, to varying intensity, the underground mining environments are monitored for radon daughters and it is recognized that the miners are also exposed to other pollutants, most notably, uranium ore dust and diesel fumes. Further testing for the metabolites of the pollutants can be done on body fluid, urine. [High Performance Liquid Chromatography (HPLC)]: This is a very sensitive method for the detection of mutagenic metabolites in urine. The urine is treated with the enzyme sulfatase and beta-glucuronidase to permit identification of substances that are made nonmutagenic by conjugation as glucuronides. The sample is then passed through an XAD-2 resin column and the absorbed organic molecules eluted with acetone. The sample is then split and evaporated to 1 ml and used for direct chemical analysis using HPLC. One drawback to the test is the inability to measure cumulative exposure, but multiple samples can be obtained and comparison to baseline (control) and exposure samples can reveal qualitative differences as a consequence of exposure to mutagens. [The Ames/Salmonella Microbiological Assay]: The Ames/Salmonella microbiological mutagen test is the most extensively used short-term bioassay, with over 2,600 chemicals having undergone testing by this method (Hollstein, et al., 1979). The method, thoroughly worked out and tested for 10 years, consists of taking the second split urine sample from the HPLC preparation, evaporating to dryness and dissolving in dimethylsulfoxide (DMSO). The sample is then applied directly to

Jan 1, 1981

By Ian Kilgour

The development of the Escondida concentrator is described, from the design of the original 35,000 tpd concentrator through successive expansions and modifications to the 115,000 tpd plant currently under construction. Operating problems, and the steps taken to overcome them, are briefly discussed. Reasons for key equipment choices and flowsheets modifications in the expansions are explained, with some emphasis on the flotation circuit.

Jan 1, 1995

By C. Ostrowski, Z. Fajklewicz, K. Jakiel

Results of the application of the micro-gravity method in predicting rock bursts and rock mass deformations are discussed. Research was done in the Daisy black coal mine, Upper Silesia, Poland, during 1979-1980. At that time, microgravity investigations helped increase the safety of coalbed exploitation in progress. During the first stage of exploitation, a mining shock of 107 J energy was predicted in a region where 40 miners worked.

Jan 1, 1987

By Maurice Deul

Limestone can be used effectively in treating acid mine water. Aside from a lower cost than for other treatment agents, limestone has the advantages of easy storage and effectiveness even when impure and in slack sizes. Limestone incorporated into waste piles in layers or as riprap can inhibit acid formation; limestone rubble packed in a mine entry offers promise in formation of a low-cost autogenous resilient seal.

Jan 1, 1974

By John Jonkman

During the decade of the eighties, the mining industry was able to take advantage of numerous advancements in computing technology. The development of the desktop workstation and the tremendous increase in power of minicomputers have cause many of the technical computing applications to be taken out of the "glass house", or central computing facility, and distributed to where the work is actually performed. This trend, combined with the significant price/performance improvement being experienced, has resulted in computers becoming more readily available at a reasonable cost for research and development activities, thus increasing the amount of new development taking place. The papers in this session discuss research and development work which has resulted in advancements in mining technology applications in the following areas: - Technical Parameterization - Linear Programming - Dynamic Programming - Computer Aided Design

Jan 1, 1989

By H. J. Sohn, S. G. Doo

A systematic study was carried out to investigate the reduction reaction mechanism of oxygen on pyrite surface using electrochemical techniques. The polarization curves showed two distinct regions, the Tafel region for superoxide formation and limiting current region for diffusion of dissolved oxygen to form hydrogen peroxide. These results were confirmed with a-c impedance measurements.

Jan 1, 1990

By Ferdi Camisani

The ‘Bible’ 1977 & 1981 ‘South African Mine Valuation’ by C. D. Storrar. Proved reserve (=’measured ore’ USA; ore reserve = the payable portion of the proved reserve) -Fully developed (…immediately available…) -Partly developed (…not immediately available…) -Undeveloped (…unavailable…) Probable reserve (=’indicated ore’ USA) Possible reserve (=’inferred ore’ USA) Life-of-mine reserve (Proved + Probable + Possible)

Jan 1, 2003

By A. F. Raschenko, V. V. Elschin, Y. E. Golodnov

Kinetics and mechanism of gold and silver sorption from thiocarbamide solutions by activated carbon were studies using tne method of equilibrium-kinetic analysis. The intradiffusonal character of the process was determined and the kinetic and thermodynamic constants were calculated. The electrostatic component of the adsorption interaction was estimated by the electro - chemical investigations. The optimal parameters of the desorption of noble metals thiocarbamide complexes were determined. The intensification of gold and silver desorption process is reached through the use of activating additions to the eluent and electro - chemical polarization of activated carbon. Methods for complex and selective extractions of gold and silver from thiocarbamide solutions and pulps by activated carbons were developed.

Jan 1, 1995

By John C. Edwards, Robert C. Bates

Modeling uranium mine radiation control methods and natural environmental radon variations is an extremely complex endeavor. A number of authors have examined particular facets of the problem and have proposed models for their area of interest. Bureau of Mines personnel brought together many of these individual studies, and from them have attempted to develop a coordinated plan for modeling radon daughter concentrations in the uranium mine environment. This approach is described.

Jan 1, 1981

In analyzing cost performance, managers must initially consider the issue of scope. Is the analysis for a single responsibility center or multiple centers? For a single period or a number of periods? If multiple responsibility centers are being examined, how can managers compensate for differences in their sizes? Several techniques have been developed to analyze the relationships in a set of financial statements at a single point in time and the trends in these relationships over multiple periods. Cross-sectional techniques focus on the first of these, and time-series techniques look at the latter. Although this text focuses on cost performance, these methods also can be used for revenue-related analyses.

Jan 1, 1999

By E. Topuz

This paper compares the production rates of the conventional shuttle car/ belt conveyor haulage with battery or diesel shuttle car haulage by using computer simulators developed at Virginia Polytechnic Institute and State University. The haulage parameters evaluated in the analyses include discharge rate and capacity of a feeder located at the section dump point, and the number and capacity of haulage units. The results allow many decision points to be identified including the optimum number of haulage units to maintain production above that obtainable from a shuttle car/conveyor system.

Jan 1, 1982

By Peter J. Tarkoy

The use of personal computers (PCs) is increasing in underground construction applications, specifically, for estimating, record keeping, construction performance analysis, project cost reporting, and the effective application of construction experience for estimating and aggressive bidding. Applications particularly suited to the PC are analyses of construction performance and differing site condition claims. The advantages of using a PC in the analysis of differing site conditions claims is that the PC: requires quantitative and factual data, allows vast data manipulations, calculations, and sorting, and provides a simple graphic representation of complex data and issues. The restrictions imposed by a PC are conducive to the focus on essential facts, issues, quantitative analyses, and inherently, the truth. As computer thinking is established, a clearer, more precise and accurate focus on the elements of a differing site condition is essential for successful evaluation and presentation.

Jan 1, 1987

By David L. Gefvert

A general review of the role of cationic flotation reagents in the beneficiation of phosphate, iron, and potash ores. The three major types of cationic collectors-amines, ether amines, and condensates will be compared and contrasted. The effect of particle size, water chemistry, and water temperature on the choice of cationic flotation reagents for each industry will be discussed.

Jan 1, 1986

By A. Perelli Cippo, R. Granata, D. A. Bruce

During the last few years, significant advances continue to have been made in aspects of grouting technologies used for ground treatment in advance of tunnelling. In permeation grouting, fundamental researches have continued into improving the penetrability characteristics of cement-based grouts. The twin advantages of field regrinding normal grouts to reduce cement particle sizes, and incorporating special additives into stable grouts, are now being systematically exploited in major soft ground tunnelling projects in Europe. The methodologies of jet grouting continue to be developed with special attention being paid to qa/qc issues, reducing unit production costs, and improving predictive capabilities for subsequent settlements.

Jan 1, 1993

By Krystyna Raszka, Jerzy Iskra

The paper presents results of spectrophotometric investigations concerning the adsorption of sodium oleate on silicon carbide in the presence of the cations of multivalent metals, applying the ATR IR technique with computer-aidedprocessing of the spectrum. The analysis of these spectra indicates the occurance of distinct OH and COOH bands in the pH range in which the hydroxy complexes of metals of the type MeOH+ and MeOH++ reach in the respective cases the highest concentration in the solution. The correlation of these results with those of flotation, measurements of the zeta potential confirms the proposed mechanism of activation of the flotation of silicon carbide, applying sodium oleate as a collector, the collection taking place over the adsorption of hydroxy complexes of the type MeOH+ and MeOH++

Jan 1, 1995

By M. Liu

In-situ soil washing using surfactants shows great potential to remove hydrophobic organics from subsurface environment. Lab scale soil washing experiment were performed using Sodium Dodecylsulfate (SDS), an anionic surfactant, and anthracene, a highly hydrophobic compound. The results of this research show that solubility of anthracene increases linearly with an increase in SDS concentration above the critical micelle concentration. Furthermore, SDS can be effective in removing anthracene from contaminated sand.

Jan 1, 1992

By Ahmed Alghamdi, Salem AlGharbi, Aisha AlHarbi, Owain Morton, Norah AlMuhaisen

This paper addresses the challenges in optimizing the phosphate flotation process, specifically focusing on the variability in P2O5 recovery. An artificial intelligence (AI) driven Flotation Prediction Model was developed to accurately forecast P2O5 grades. Leveraging real-time data from various operational sources, the model provides insights into how operators can opstimize key flotation parameters to enhance product quality and recovery rates. The results demonstrate the effectiveness of AI predictive modeling in addressing operational variability, marking a crucial step toward intelligent operations in the phosphate flotation process.

Feb 1, 2025

By P. Zhang

The Crago “Double Float” process is widely used in upgrading phosphate ore. This process is inefficient, as it floats about 30-40% of the sands in the flotation feed twice and requires a deoiling step. This paper summarizes several research projects on improving phosphate flotation. The University of Utah investigated a new flotation chemistry for efficient flotation of phosphate in a single step. The Florida Institute of Phosphate Research developed several single-collector, all-anionic flotation flowsheets using various sizing schemes. In addition, Eriez invented the HydroFloat separator, which demonstrated great potential for processing coarse flotation feed in one step.

Jan 1, 2004

By Roshan B. Bhappu

The extraction of gemstones, except for diamonds, continues to be a more or less handpicking type operation all over the world. However, considering the physical properties of gemstones such as density (sp.gr.), color, size, shape, luster, brilliance, reflection of light and the like in contrast to the relatively ‘dull’ physical characterization of the associated gangue minerals, it should be feasible to recover several gemstones using modern mineral processing techniques. This paper illustrates the unique physical characterization of several gemstones and suggests appropriate mineral processing techniques that could be used to recover these precious stones. Special emphasis is placed on the versatility of the Heavy Media Separation (HMS) process for processing of the gemstones. Finally, a few examples of commercially viable operations involved in the recovery of emeralds and rubies are presented.

Jan 1, 2005

By M. Cambridge

The extractive industries are currently, and will continue to be, major contributors to the world economy, particularly in the developing world where economic growth is dependent upon a sound supply of primary materials. However, tailings dam and other mine failures have been very much a feature of recent anti-mining publicity, particularly in Europe, and thus instrumental in inhibiting new mine developments. Although, superficially, the record of dangerous incidents might support the anti-mining position, closer inspection suggests otherwise. This paper reviews the failures which have occurred over the last 50 years and demonstrates that, though poor practice is an ongoing problem for the industry, the record is one of improvement in both design and practice. Examples are provided of significant events which have led to dramatic advances in design and operation. The paper assesses the improvements made in technology and practice, and concludes that historic events must continue to form the underlying basis for design and operation of future mining projects.

Jan 1, 2005