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By A. S. Paschoa, A. W. Nóbrega

INTRODUCTION There are now over twenty years since the radiological characteristics of the brazilian regions of Araxá, Tapira and Barreiros, three locations adjacent to each other, in the state of Minas Gerais, Brazil, started being surveyed by investigators from the Instituto de Biofísica da Universidade Federal do Rio de Janeiro (IB/UFRJ), Pontifícia Universidade Católica do Rio de Janeiro (PUC/RJ), and New York University (NYU) (Roser and Cullen, 1958; Cullen et al, 1980). The importance of the Araxá apatite – Ca5,(P04)3(OH, F, Cl) - and pyrochlore - NaCaNB206F - for the production of large quantities of fertilizers and niobium was early recognized (Roser and Cullen, 1958). Interesting data have been gathered and published throughout the years on the contents of naturally occurring radionuclides in geologic materials, soils, grass, foods and waters of the Araxá region (Eisenbud, et al., 1964; Penna Franca, et al., 1965a, b; Roser et al., 1966; Penna Franca et al., 1970; Cullen, 1977; Penna Franca, 1977; Cullen and Paschoa, 1978; and Cullen et al., 1980). The radioactivity of the Araxá region is associated with mineral deposits of niobium rich pyrochlore and phosphate rich apatite. There are in this region mineral ores with 3 to 5% pyrochlore with 2 to 2.5% Th as Th02 and 50 to 150 ppm U308 in the matrix, while the apatite deposits contain up to 150 ppm U308 and a thorium concentration similar to that of the pyrochlore deposits (Paschoa and Palacios, 1981). As an indication of the high thorium content of the Araxá soils the 228Ra and 224Ra activity concentrations were reported to range from 10.6±0.2 to 62.4±0.7 pCi228Ra/g soil in 7 samples and 2.1±0.1 to 104±1 pCi224Ra/g soil in 19 samples (Cullen, et al., 1966). The uptake of radium isotopes by edible roots vegatables and fruits growing in the soils of the Araxá region can be illustrated by the data listed in Table I. The biological availability of natural radium isotopes in some segments of the Araxá soil allows a large variation in the 228Ra, 224Ra and 226Ra concentrations in vegetables and edible roots, as can be seen in Table I. This fact makes quite difficult a quantitative local assessment of the radiological implications of mining the Araxá mineral deposits of pyrochlore and apatite for production of niobium and phosphate fertilizers, respectively; since one cannot easily separate the naturally occurring from the technogically enhanced radionuclide contents of foods. The position of the city of Araxá inside the contour of the state of Minas Gerais appears in the upper part of Figure 1, which shows the outlined map of Brazil with the positions of the cities Brasilia and Rio de Janeiro also indicated. The lower part of Figure 1 is a representation of the Araxá region in an expanded scale, which indicates the locations of the pyrochlore and apatite deposits in relation to the city of Araxá, as well as the nearby hydrographic basins. The distance between the city of Araxá and the pyrochlore deposit is about 8 km, and between the pyrochlore and apatite deposits is 4 km. This paper deals tentatively with the radiological implications of the industrial operations taking place in the Araxá region for the exploration of the pyrochlore and apatite deposits. However, one must bear in mind, firstly, that the radiological implications of these industrial activities are by far too complex to be covered adequately by the limited amount of data to be presented in this paper, and secondly, that such implications cannot be considered of local character only. INDUSTRIAL OPERATIONS The commercial exploration of the Araxá deposits of pyrochlore and apatite started only few years ago, motivated by the increasing demand of niobium and phosphate fertilizers in Brazil and the world. As a consequence of the industrial operations in Araxá, a redistribution of the uranium, thorium, and radium originally present in the local deposits of pyrochlore and apatite started occurring in the seventies, with possible radiological implications for the Araxá region and its immediate surroundings, not to mention the destinations of the end products of such industrial operations. A literature review on the radioactivity associated with the extration industries of selected minerals was made by the USEPA (Bliss, 1978). The low level radioactive wastes of the industries for copper ore mining and rare metals processing have been object of particular attention (Fitzgerald, Jr., 1976; Eng, et al., 1979), but the short and long term implications of the radioactivity associated with the niobium industry were also subjects of concern (Knight and Makepeace, 1978). Recently, high 232Th and 226Ra concentrations in samples from the tin mining industry in West Malaysia were reported (Hu et al., 1981). A great deal of attention has been dedicated to the implications of the redistribution of radionuclides originally present in the mineral ores used by the phosphate fertilizer industry (Moore, 1967; Menzel, 1968; Spalding and Sackett, 1972; Eisenbud, 1973; Guimond and Windham, 1975; Guimond, 1976; Roessler,

Jan 1, 1981

By Nelson R. Shaffer

Biotechnology has become a household word of the nineties, and it is expected to become as important in the next century as the computer is in the present. Numerous books and articles portray biotechnology developments as nothing less than a scientific revolution. Almost everywhere one looks new biotechnical breakthroughs are being reported that offer almost limitless opportunities to harness the force of living things to produce materials and manipulate their properties. Biotechnology has been broadly defined as any applications of biological organisms, systems, or processes to manufacturing and service industries. This seemingly new technology is, in fact, one of mankind's oldest scientific activities (Table l), which has been recently revolutionized by techniques of genetic engineering that arose out of basic research in biology, biochemistry, genetics, and information sciences. From fields as old as agriculture and medicine to those as new as monoclonal anti-bodies, transgenic plants, or biocomputers are encompassed by biotechnology. Like most human endeavors, industrial minerals play critical roles in biotechnology. In addition biotechnology holds real potential to improve extraction and beneficiation of certain industrial minerals themselves. BIOTECHNOLOGY OVERVIEW Companies using established biotechnical techniques make up large and diverse groups such as agriculture, chemicals, and pharmaceuticals. The massive US Pharmacopia (Anon., 1990a) provides detailed specifications for minerals used in medicines. Alumina, zirconia, apatite, and bioactive glass have seen service as implant materials (Williams, 1990) and new uses for minerals in health sciences are being actively researched. Agriculture produced $361 billion worth of food and drink during 1991 in the United States; organic chemicals, pharmaceuticals, and enzymes accounted for $68, $59, and $42 billion, respectively (Anon., 1992a). It is not possible to separate the contributions of industrial minerals to biotechnical products, but they represent a very large and rapidly growing new field of uses. The new biotechnology has nearly 300 small companies, plus 15 established companies with 742 biotechnology-related firms (Dibner, 1991b). Revenues exceeded $2 billion in 1990 and are expected to grow to $50 billion by 2000 (Anon., 1992c), with worldwide sales exceeding $100 billion (Burrill and Roberts, 1992). Federal research amounted to $3.4 billion in 1990 (Anon., 1992b). The United States is the world leader in biotechnology, but other countries have large, well-funded programs. Despite debate about safety, obstacles to new biotechnology products are declining (Embers, 1992, Gibbons, 1991). Fifteen biotechnology drugs valued at $1.2 billion (Thayer, 1991a) are on the market, and more than 100 are in various stages of testing (Edington, 1992). Many diagnostic tests are also in use or development (Demain, 1983, Anon., 1992). Large scale efforts to produce or transform important chemicals are also underway (Ng et al., 1983, Hinman, 1991), and research into geologic uses of biotechnology has begun. Much has been published about microbial mining, oil recovery, desulfurization, bioremediation, and other geologic aspects of biotechnology, but this chapter is the first attempt to explore interactions of biotechnology and industrial minerals. This chapter examines uses of minerals in biotechnology; how biotechnology can be used to discover, recover, and beneficiate industrial minerals; and speculates on some potential, but as yet untried uses. Definitions What exactly does the word biotechnology mean? Bud (1989) states that the first use of the term was by Karl Ereky in 1919 to cover the interaction of biology and technology, and in 1933 the term was used in Nature. After citing seven different definitions, Smith (1988) concludes that biotechnology is a series of enabling technologies involving practical applications of organisms or their subcellular components to manufacturing and service industries or to environmental management. Walker and Cox (1988) suggest a definition of "the practical applications of biological systems to the manufacturing and service industries and to the management of the environment." Primrose (1991) says that it is "the commercial exploitation of living organisms or their components." There is essentially an older broad use of the term and a new use. The US Office of Technology Assessment (Anon., 1984) uses a broad definition that includes any technique that uses living organisms (or parts of organisms) to make or modify products, to improve plants or animals, or to develop micro-organisms for specific uses. Definitions are different, but they all have several fundamental elements that include the control, management, or manipulation of living things for commercial, industrial, or useful ends. While such a definition encompasses all of agriculture in practice the "new" biotechnology is restricted to processes involving microorganisms-plant and animal cells, or enzymes. Many consider biotechnology to be recent, but it is one of our oldest technologies as evidenced by the prehistoric origin of brewing, cheese-making, and other techniques. [Table 1] gives some of the important developments in the history of biotechnology. Smith (1988) breaks down historical developments of biotechnology into four phases: 1) prehistoric with no understanding of underlying processes; 2) nonsterile processes; 3) sterile processes after 1940; and 4) genetic and recombinant DNA technology deliberate design of special organisms or processes.

Jan 1, 1994

By V. A. Shea-Albin

Sandstone escarpments surrounding western coal-bearing plateaus serve as critical habitat for animal species. Effects of mining subsidence on escarpment stability are not well documented; therefore, regulatory agencies may limit extraction of coal reserves underlying escarpments. Because millions of tons of this coal exist on Federal Lands, associated public revenues from Federal royalties, and valuable coal reserves, risk being lost. The U. S. Bureau of Mines is using numerical modeling techniques to analyze effects of subsidence on escarpment stability. Finite element models that incorporate bedding plane slip, gob formation, and movement along joints simulate escarpment subsidence observed in the field.

Jan 1, 1994

By A. J. Plumpton

Centrifugal air classification and li-quid-phase sedimentation are the principal methods of industrially sizing materials of dimensions smaller than those handled by screens. Increasing application of materials such as composites and high performance ceramics has furthered the need for closely-sized, fine, industrial mineral and synthetic products of controlled properties. Sedimentation can be used to separate very small sized particles but introduces problems of liquid-solid separation, de-agglomeration and drying. Some of the advantages and limitations of centrifugal air classification will be discussed and laboratory and plant measurements using centrifugal machines will be presented to support the discussion.

Jan 1, 1990

By RICHARD A. THOMAS, Liming Yuan, Lihong Zhou, DAVOOD BAHRAMI

Mine ventilation simulation software has become an essential tool for the mining industry to design and manage mine ventilation operations. Building a well-calibrated mine ventilation network is time consuming, however, and requires great effort. In the last several decades, the mining industry has seen a steady increase in the use of air velocity sensors to monitor airflow and detect unexpected abnormal airflow in some key locations in underground mines. The present research work was carried out to explore the possibility and methodology of calibrating a ventilation network model using atmospheric monitoring system (AMS) data on a routine and ongoing basis.

Aug 1, 2022

By Daniel Amponsah-Berko, Palas Kamlakar Borkar, Kwabena Boafo, Neha Sharma, Timothy Eisele

A series of iron-leaching experiments were conducted to test the ability of metal-reducing anaerobic organisms to reduce iron from Fe3+ to Fe2+ to dissolve it from iron ore tailings. This bioleaching process involves the fermentation of biomass from Typha latifolia (a common wetland plant) to generate organic compounds, which, along with metal-reducing organisms, reduce and dissolve iron. The concentration of dissolved iron over time was studied for one year. Iron concentration above 1150 mg/L was achieved at a pH range of 3.95–5.36. Tailings from multiple locations were examined.

Feb 1, 2025

By Chris A. Minnucci

In 1978, the U.S. Department of Energy funded a 2-year study to identify and quantify causes of the post-1969 coal mine productivity decline. A large number of factors hypothesized to have affected productivity during this period were analyzed using regression techniques. The results were particularly interesting for two of the factors--mining method and shift scheduling. The study results indicate that the use of longwall mining has an insignificant impact on overall mine productivity, compared to other methods, and mines operating on a two-production shift per day schedule are more productive than mines employing other shift schedules.

Jan 1, 1984

By D. A. Robbins

The application of remote sensing for environmental measurements is already being utilized. Aircraft mounted imaging spectroscopy has been utilized to evaluate areas of historical mining operations as well as active mine sites. To the extent that remote sensing can provide more sensitive, cost effective, and timely monitoring potential, the technology is of interest to the industry. Questions remain about the application and validation of the data and the availability of the technology in the private sector. This presentation will discuss some of the potential uses, benefits, and concerns related to remote sensing and efforts to monitor the technology's development.

Jan 1, 1999

By D. G. Kotlyar

Silver is an economically important component of many complex, massive sulfide ores. Current beneficiation for these ores is almost entirely by flotation. Silver recovery often is low, but little is known about the flotation behavior of the silver-bearing minerals. Floatability studies were conducted using silver-bearing tetrahedrite and lead-zinc ore. The effects of xanthate collector concentration, conditioning time, potentiostatic control of the mineral potential, and pH on mineral floatability were evaluated. The floatability of the silver-bearing minerals was shown to depend on collector concentration and mineral potential. The effect of controlling mineral potential during the flotation process is discussed.

Jan 1, 1994

By J. D. McKendrick

Alaska's Arctic Slope lies between the Brooks Range and Beaufort Sea and is a region about the size of Nebraska. It has some of Alaska's richest hydrocarbon deposits. In addition to containing petroleum and natural gas. Much of the area west from the Colville River has low-sulfur coal deposits which are shallow enough for surface mining. Developing those resources will require a firm and realistic' commitment to protecting and rehabilitating the natural habitats. Balancing such a commitment with economic constraints in a practical sense requires knowledge of the environment and its associated biological components, i.e. the soil/water-plant-animal relationships.

Jan 1, 1988

By RIINA SALMIMIES, ANTTI HAKKINEN, PAULA VEHMAANPERA

Better understanding of the mechanisms and kinetics of dissolution can benefit several industrial processes. For example, iron can be leached from clays, which can be further used as a raw material in the ceramic industry. Another important application is the regeneration of ceramic filter media, which are used in the dewatering of iron ores. Dissolution of iron oxides in mixtures of acids is fairly uncommon and a less well-understood phenomenon, but it can result in a more efficient process. This work also shows that the determination of dissolution mechanisms and kinetics is not straightforward in different acid systems.

By P. Grotjohann

In processing heavy mineral sands, the low feed concentration and respective high value of the desired minerals require high capacity production and sharp classification/separation techniques to reduce the specific production costs. The allflux® separator, a new process system introduced to the heavy mineral industry, meets these criteria in an economical way. Its two-stage process, a combination of rising current and fluidized bed technology, allows the treatment of extremely high massflows in a single unit. Using concepts that have proven successful in processing concrete sands for many years, testwork in coal, iron ore, and heavy minerals looks very promising.

Jan 1, 1998

By J. C. Draper

This subject was introduced last April in a paper presented in Birmingham, Alabama, by James E. Elkin, General Superintendent of Duquesne's Coal Department. This paper will cover some of the same data and in addition it will update and further describe our experience. Our Portal No. 3 was started in June 1965 with battery tractor-trailer face haulage. This mine is operating in the Sewickley seam in Dunkard Township, Greene County, in Southwestern Pennsylvania as shown on Fig. 1. The Warwick group of mines fronts on the Monongahela River and extends westward for some ten miles as shown on Fig. 2.

Jan 1, 1968

By CHENCHEN SUN, GUOPING LUO, GUOCHENG ZHANG

In this study, the conditions of raw materials and fuels were simulated for Bayan Obo iron ore concentrate by adding pure calcium fluoride (CaF2) in various concentrations to Australian iron ore. The mechanism by which the fluorine (F) content of the lattice influenced the reduction swelling properties of the iron ore briquettes during various stages of the reduction process was investigated. The results provide insight into the mechanism governing the reduction swelling process in Bayan Obo ore briquettes, which could be used to direct real?world production practices, particularly those related to the rational utilization of Bayan Obo ore resources.

By S. Tandanand

The Bureau of Mines, U.S. Department of the Interior, assessed the geological effects on the ratio of maximum subsidence and extraction thickness, hown as the subsidence factor, to develop a simple method for predicting the maximum subsidence. The study is restricted to the Northern Appalachian Coal basin where data were collected from 13 coal mines. A model previously developed to relate the subsidence factor with the lithology and with the width and depth of working panels was used in the assessment. The result shows the possibility of determining maximum subsidence without resorting to a rigorous method.

Jan 1, 1982

By V. K. Karra

An improvement in the present day screen sizing methods calls for knowledge on i) how material in the size range: 0.5 x 1.5 times the through-fall opening of the mesh on a deck, splits between the oversize and undersize streams of the deck, and ii) how near-mesh content of the feed affects the screening performance. In the throughput based sizing method given here, this is accomplished through the introduction of a generalized partition curve and a near-mesh factor. A newly developed efficiency factor is employed in addition to the traditional screen sizing factors.

Jan 1, 1979

By M. E. Lewellyn

A lower moisture content for a clean coal product means increased Btu content, or increased yields at the same Btu content, and lower operating costs. The conventional surfactant-based dewatering aids effeciently lower the moisture content but often the presence of residual surfactant in the filtrate and recycle water causes problems downstream. ACCOAL-DRI 1000, a surfactant-based dewatering aid, was developed to solve this problem by minimizing the downstream effects while efficiently lowering the moisture content. The theory of the use of surfactants in filtration will be discussed as well as the development and field evaluation of this new product.

Jan 1, 1988

By Helmut Goehring

Surface mining has been used primarily where deposits of minerals were exposed or close to the surface. Surface mining can, therefore, be considered the oldest branch of mining. As the most accessible deposits became uneconomical because of the lack of suitable high capacity conveying systems, deep mining took its place. Only in the twentieth century was this trend reversed as high capacity production and conveying systems were developed. This rapid development was triggered by the steadily increasing demand for raw materials and fossil fuels, as well as by the ever increasing ratio between overburden and deposits.

Jan 1, 1982

By James D. Bennett

Relationships among mine and injured miner characteristics and HSAC's degrees of injury are examined for 91,404 injuries in under- ground bituminous coal mines in the United States from 1975 through 1982. Injury severity varies by the mining system, geographical region, circumstances surrounding the injury, the injured miner's age, whether the miner was using powered equipment, the year which the injury occurred, and the location in the mine where the injury happened. Injury severity is not related to the injured miner's total mining experience, job experience, and experience in the mine in which the injury occurred.

Jan 1, 1984

By K. J. Sollman

With an ongoing concern for safety and health in the workplace, NYCO® requested three medical evaluations be undertaken to study possible health hazards of wollastonite. Two of the evaluations were conducted by the National Institute of Occupational Safety and Health (NIOSH). One was in 1976 (Ref. 1), and the second in 1982 (Ref. 2). The aim of the two studies was to answer the following two questions: 1. Do wollastonite workers exhibit more respiratory abnormalities than workers not exposed to wollastonite? 2. Is there a relationship between prevalence of respiratory abnormalities and accumulated expo-sure time to wollastonite?

Jan 1, 1988