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By Timothy J. L. Haley

The population of the Rhondda underwent a spectacular rise as energy requirements increased in the mid-nineteenth century. The rapid expansion in the demand for coal transformed the population from a few hundred sheep farmers in the eighteenth century, into a thriving coal-based economy of some 168,000 inhabitants in 1924. Cochrane (1958) put forward the idea that the differential migration of more healthy men from the Rhondda Fach during the period since the peak of population in 1924, had resulted in a respiratorily-impaired residual population. This idea was used to explain the reduced survival of miners & ex-miners aged 55-64 years from this valley as compared with a similar group from Leigh in England. Using the proportional hazards regression model of Cox (1972), a comparison is presented of the exact twenty-year mortality of migrant and non-migrant miners & ex-miners and non-miners from the Rhondda Fach. The analysis makes allowance for the pattern of migration throughout the twenty-year period and adjusts for the confounding influence of variables such as age, occupation, and category of Simple Pneumoconiosis. The results indicate that contrary to expectation, any effect of migration upon mortality is manifest only at higher ages. Furthermore, for these men, the migrants have worse survival than the non-migrants. Also, contrary to expectation in the light of work by the British Coal Board (Soutar et al, 1982) there is no evidence of increased mortality amongst men with category I simple pneumoconiosis. INTRODUCTION [The Background] In September 1950, the Medical Research Council's Pneumoconiosis Research Unit at Penarth in South Wales initiated a study of lung disease in the smaller of the two Rhondda Valleys - the Rhondda Fach. At that time, the primary interest was in assessing the possible role of pulmonary tuberculosis in the aetiology of the serious (complicated) form of coal-workers' pneumoconiosis, i.e. Progressive Massive Fibrosis. The Rhondda Fach is situated in South Wales, some 25 km north-west of Cardiff. It is a narrow winding river valley about 12 km long, and approximately 1 km wide. The name means Little Rhondda; there is a corresponding Big Rhondda - the Rhondda Fawr. Together, these valleys make-up most of the Rhondda Municipal Borough. Following the initial survey in 1950-51, there have been several follow-up studies of this population. In addition, amongst numerous other investigations to unravel the aetiology of coal-workers' pneumoconiosis, Medical Research Council teams studied various other (sample) population groups, particularly in the industrial areas of the adjacent Aberdare Valley, and in Staveley and Leigh in England. The agricultural areas of the Vale of Glamorgan in South Wales, and Annandale in Scotland were also studied.

Jan 1, 1993

By Taneomi Harada

Mine drainage has high acidity and sometimes contains more than the allowable concentration of ionized iron. In such a case, mine drainage is neutralized with calcium carbonate and calcium hydroxide to separate precipitates, such as the iron hydroxide and gypsum generated. Currently, most of these precipitates are not utilized and are accumulated in tailing dams. As a result, the service life of the tailing dams is reduced. This becomes a matter of concern, since securing sites for such dams is difficult. A most effective means of solving this problem would be to promote utilization of these neutralized precipitates. This paper reports on the results of studies on neutralized precipitates produced at the old Matsuo Mine (Iwate Prefecture), which has the largest neutralization treatment facility in Japan. As a result of the studies, the following was proposed regarding application of neutralized precipitates. Utilization as ferrite: Mix ferrous hydroxide and ferric hydroxide in water to synthesize magnetite-like ferrite, to be used in the manufacture of magnetic markers for a mobility support system for blind pedestrians, or in producing magnetic fluids for sink-and-float separation of nonmagnetic metals and nonmetals. Utilization as hematite: Bake ferric hydroxide to produce hematite, thereby extracting metallic iron for paint pigment as well as for the manufacture of ironware by local industry. Production of aluminum sulfate: Precipitate aluminum ions from water and add sulfuric acid to produce aluminum sulfate.

Jan 1, 1995

By J. Keng, S. T. Chen, T. M. Shih

Kwanyin Tunnel is presently the longest (7.7 km) railway tunnel in Taiwan. Due to heavy railway traffic, a pass-by station will be built inside the tunnel to increase the traffic flow. Since the concentration of toxic gases released by the locomotives may reach dangerous levels, a research program was conducted for the purpose of designing a ventilation system which could dilute and/or remove the toxic gases to maintain an acceptable pollutant level. The program consisted of two parts. The first part was field measurement during which the concentrations of pollutants and wind velocities were measured at various points inside the tunnel to acquire basic data regarding ambient air quality, piston effects for the different types of trains, and existing ventilation conditions. Weather data (temperature, humidity, atmospheric pressure, wind direction and velocity) were gathered at many stations, both on the surface and inside the tunnel. The amount of pollutants released by each type of locomotive for various conditions were also measured. The second part of this study involved establishing mathematical models for predicting the air quality of the various proposed ventilation systems. Three different models were used for this work. The first one is a piston effect model which assumes that the gases and air undergo immediate mixing inside the tunnel. The second one is also a piston effect model which assumes that the diffusion ability of the gases is zero. The third one is a conventional ventilation model which was used for natural and mechanical ventilation conditions. From the result of field measurement and mathematical model studies, a ventilation system was chosen with consideration of both ventilation effects and construction costs.

Jan 1, 1987

The Mining Foundation of the Southwest (MFSW), located in Tucson, AZ, will hold its 16th annual American Mining Hall of Fame Awards Banquet Saturday, Dec. 5,1998. The Hall of Fame recognizes outstanding contributions to the mining industry by selected individuals and industry partners. Each year, one living award recipient and up to two mining history honorees are chosen by the , Hall of Fame Committee and the Board of Governors of the Mining Foundation. In 1989, the Mining Foundation initiated a Medal of Merit to recognize outstanding individual, technical and professional contributions to the mineral industry. In 1995, an award was created to recognize contributions made by companies and organizations in partnership with the mining industry. This year's inductee, guest of honor and featured speaker will be Charles G. Preble, president and chief executive officer of Southern Peru Copper Corp. He is being recognized for outstanding performance as an executive of an American company operating under difficult circumstances in a foreign country. The Hall of Fame will induct H. Myles Jacob, former chairman and CEO of Inspiration Copper Co., for innovation and farsightedness in matters pivotal to the cop- per industry of his time. In addition, John Cromwell Lincoln, former president and chairman of Bagdad Mining Co., will be inducted for his outstanding contributions to the American mining industry. These contributions include metallurgical research and development of the Bagdad Mine as well as pioneering innovation in the electrical industry. Medals of Merit will be awarded to David N. Skillings, editor and publisher of Skillings Mining Re- view, for his dedication and support of mining interests. J. Ruben Velasco Rodriguez will also receive a Medal of Merit. He is economic geologist, professor and former secretary of the board of directors and secretary general of Compania Minera de Cananea. His medal is for fostering excellent relations between Mexico and the , United States in mining geology and management and for advancing the professional development of others in the field of earth science. An Industry Partnership Award will be presented to Stephen Bechtel and the Bechtel Corp. in recognition of Bechtel's 100th anniversary and the company's outstanding service to the mining industry. The banquet will be held at the The Westin LaPaloma in Tucson beginning with cocktails at 6:30 p.m. Tickets are available from Clare A. Roscoe, manager, Mining Foundation of the Southwest 520-577-7519, fax 520-577-7073.

Jan 1, 1998

By Roger L. Baer

Introduction Brief Review -SEC mission & history -Development of SEC mining disclosure guidelines -Principles of good public company ‘disclosure’ SEC staff views of alternative approaches to mining company disclosure -SME Resource & Reserve Committee – April 2003 Food for thought

Jan 1, 2003

By Charles D. Litton

Introduction The successful performance of a mine-wide fire detection system depends upon its ability to detect the presence of a fire rapidly and reliably. It should be sufficiently rapid so that there remains enough time to either safely evacuate a mine or successfully extinguish and control the fire or both. It should be reliable so that false alarms are minimized without sacrificing sensitivity or time response. Systems should also be durable enough to withstand the mine environment over long periods of time while maintaining a high degree of re1iability. Maintenance and calibration of the system should be simp1 e and not require the expenditure of excessive time and manpower to keep it operational. Sensitivity, reliability, and durability of mine fire sensors and their electronic support systems have been the subject of significant Bureau research within recent years. The bulk of this type of information, along with the reports from which the remainder of this paper is derived, can be found in the Bibliography. It suffices to say that there exist commercially available systems for use in mines. This paper addresses a strategy for the use of such sensors and systems. Many factors influence the design of a mine-wide fire detection system, such as the potential sources and modes of ignition, the types of combustibles involved and the quantities avai1able for fire growth and flame spread. Mine air ventilation influences the growth and spread of a fire and also serves to transport the products-of-combustion to other areas of a mine remote from the fire. Fire sensor alarm thresholds place limits on the sizes of fires that can be detected. The time to respond to a detected fire, either in terms of evacuation or control and extinguishment, place additional time constraints on the design of fire detection systems. These factors interact with each other, often in complex ways, and it is the definition and understanding of these factors and their interactions that hold the key to the design of adequate and re1iable fire detection systems. Our level of understanding of the problem has increased dramatically within recent years and it is the intent of this paper to discuss the progress that has been made and how the information can best be used to improve the level of fire detection in underground mines.

Jan 1, 1986

By Peter W. Scott

Feldspars have major uses in glass manufacture and in ceramic products. About 6 million metric tons (6.6 million short tons) are used annually. Feldspars are desirable because of their high aluminum and alkali contents. Na feldspars are favored for glass, while K feldspar is often preferred in the pottery and tile industries. Economic deposits occur in a variety of geological environments. Most are in granites or granite-like bodies, pegmatites being a common source worldwide. Alkali granites, particularly those some- times called alaskites, are mined directly as a source of feldspar and associated minerals. Some other igneous bodies, such as aplites, rhyolites, and partly altered granites (for example china stone) provide alternative feldspar-rich products. Nepheline syenites and phonolites are other sources of feldspar and contain higher amounts of alkalis. Feldspar-rich (arkosic) sediments derived from the weathering of pegmatites and granites are widely extracted and processed for use in ceramics. The present study reviewed the various sources of feldspars throughout the world. Data on the quality of products has been taken from literature, and samples have been obtained from a large number of producers. The mineralogy and chemistry of the samples has been determined and, as far as possible, have been related to the geology of the source area. Feldspar products show a wide range of chemical and mineralogical compositions. Some are pure Na feldspar (albite), others are made up entirely of K feldspar (microline and orthoclase), but many are mixtures of Na and K feldspars. Significant quantities of quartz are often present, and many products contain mica and kaolinite. Fe203 con- tents are very low, typically less than 0.1 percent. Detailed mineralogical studies show that four groups of products can be recognized on the basis of feldspar mineralogy. These are albite, albite with microcline, microcline with orthoclase, and orthoclase with albite. Products containing microcline and orthoclase together are mostly sedimentary in origin. Those with albite only, or albite with microcline have a pegmatitic or granite origin. Those containing orthoclase as the dominant K feldspar are derived from aplites or rhyolites. There does not appear to be any relationship between the feldspar mineralogy and the quartz content. Peraluminous S- type granites and pelite-dominated high-grade metamorphic rocks, in which there is a significant volatile component, are likely to be the most important feldspar sources. Partial kaolinization of feldspar-containing rocks often improves minability, decreases crushing costs, reduces iron content, and increases the K2O/Na2O ratio.

Jan 1, 2001

By A. K. Ghose, S. Chakraborti

The research work outlined in this paper examines the utility of index tests for evaluating the strength of coal, both in the laboratory and in-situ. For routine evaluation of strength and deformation properties of coal seams, as inputs for design in stability analysis and equipment selection, the index tests are cost-effective and also make less demand on time and manpower. Four index tests, namely Protodyakonov Index, Cone Indenter Index, the Point Load Strength Index and Schmidt Rebound Hammer, were evaluated for 13 coal samples and correlated to fundamental strength and deformation properties such as uniaxial compressive strength, Brazilian tensile strength and modulus of elasticity of the same coal stratum. The index tests, barring Point Load Index, showed relatively low percentage scatter compared to the fundamental strength and show marked advantages for routine estimation of coal seam strength.

Jan 1, 1986

By Chen Bing Ching

Hsikwangshan mine is located at Lengshuijiang city of Hunan Province. It is a stibnite deposit. The orebody is gently inclined; its ore run is about 3 km in length and extends about 1.2 km along the direction of dip. The thickness of the ore body is non-uniform and varies from 1.5 to 20 m. The orebody is mined by room and pillar and cementation filling. The nine levels at the ore top have been mined out. At present, the mining operations are at the eleventh level. The mine ventilation system consist of three main fans which are installed in different shafts and are ventilated in parallel. The main fans can be connected to each other through comprehensive return air drifts. Two of the fans are located underground and the other on the surface. The general configuration of the ventilation system is shown in Figure 1. Because the operating areas are scattered and vary frequently as well, it is difficult to bring about air flow control. If the air flow cannot be varied with the variation of production in time, the air quantities are not sufficient in some areas and are excessive in others. However, it is also a problem to coordinate the three main fans with one another to obtain the optimum economic cost of operation. In order to make the air delivery fit the variation of production continuously to satisfy the ventilation requirement of the working faces and to reduce power consumption, we have made a great effort over five years to install an automatic control system for mine ventilation at the Hsikawangshan mine. The key part of this system is a microcomputer. The whole system consists of a console, which is located at the surface; the circuit network that is provided for signal transmission; air doors and ventilators at the working face; the scale air doors which are installed at the main branch airways; main fans and their speed regulating devices, as well as the sensors used for observing pressure, air quantities, temperature and the concentration of carbon monoxide, etc. This system can continuously telemeter the air quantities and carbon monoxide concentration in the main branch airways, air pressure, air quantities, electric current, the temperature of the bearings of the main fans, etc. According to the production air requirements, the system controls the ventilators or air doors which are located at the working faces and regulates the air quantity in the main branch airways. It can also choose the optimum mode of operation automatically, and regulate the rotating speed of the main fans to guarantee the least total power consumption while satisfying the total air quantity requirements. If abnormality of the observed results is discovered, the audible and flashing light alarm signal starts up automatically. The operating mode of ventilation equipment also feeds back to the control room and displays on the console. The configuration of control the system is shown in Figure 2.

Jan 1, 1987

By Douglas J. Cork

Biohydrometallurgica1 processes in the areas of coal desulfurization (Hoffman, M.R., et al., 1981) and recovery of metals from metal sulfide ores (Lundgren, D.G. and Malouf E.E., 1983) are well known. In addition other areas of potential interest to the mining industries have been outlined (Spisak, J.F., 1979). For instance, scientists involved in this interdisciplinary field have endeavored to apply microorganisms to the problem of effluent sulfate disposal. This chapter assesses the feasibility of utilizing a particular two stage anaerobic microbial process to convert effluent sulfate to orthorhombic sulfur. Strong emphasis is given to the possibility of substituting this bioprocess for alternative gypsum synthesis and disposal methodologies commonly practiced by companies which emphasize sulfuric acid or ammonium sulfate leaching processes.

Jan 1, 1985

By Werner Hofmann

INTRODUCTION The attempt to interprete lung cancer incidence caused by inhaled radon decay products in items of radiation dose raises the question of the relevant dose. The various dosimetric approaches published by now are characterized by an increasing complexity in the structure of the models used. Ranging from organ doses to microdosimetric specific energy distributions in the cells at risk, a significant trend from the macroscopic to the microscopic scale can be observed. Since tumors originate preferentially in the basal cells of the lobar and segmental bronchial epithelium, these cells are regarded as the critical target for inhalation carcinogenesis. The evaluation of basal cell doses is, therefore, the main objective of lung dose assessments. Various dosimetric models have been published in the past (Altshuler, Nelson and Kuschner, 1964; Haque and Collinson, 1967; Harley and Pasternack, 1972; Hofmann, Steinhäusler and Pohl, 1979, 1980; Jacobi, 1964; Jacobi and Eisfeld, 1980; James , Greenhalge and Birchall, 1980). Due to incertainties of physical and biological parameters involved and the application of different anatomical and physiological models the claculated doses are varying up to one order of mangitude. Independent of the choice of these dosimetric models applied to the calculation of lung doses, deposition, clearance and resulting dose are affected essentially by the properties of the inhaled aerosol as well as by personal characteristics. Both the properties of the exposed individual as well as of the inhaled environmental atmosphere have to be considered in radiation protection. It is the main objective of this paper to illustrate the influence of both parameter sets on basal cell doses by varying the above parameters. PERSONAL CHARACTERISTICS Though it might be more convenient for radiation protection calculations, the biological "man" cannot be represented by a uniform standard man. In Tab. 1 these personal characteristics which cause the variability of man are listed together with the region of their effectiveness. In the following the influence of these parameters will be discussed with regard to lung dose assessments. Besides these factors the great biological variability of all anatomical and physiological parameters involved as well as pathological alterations due to lung diseases cause additional variations in lung dosimetry. [ ] Age Age can be considered as the most important personal factor influencing the anatomical structure of the lung between birth and about 15 years of life. This period is characterized not only by an enlargement of already existing respiratory units but also by structural changes. Besides these anatomical alterations deposition is strongly dependent also on respiration parameters, such as tidal volume (TV) and respiratory frequency (RF). Whereas RF decreases with progressing age in an exponential manner, TV increases significantly resulting finally in a growth of the respiratory minute volume (RMV). Also mucus clearance in the infant might be more effective than in the adult, though no reliable experimental data are available. Superposing all these age-dependent changes mean basal cell doses are higher for children by about a factor of 2 than for adults living in the same radioactive environment (Hofmann, 1981). In the adult the following alterations of respiration standards with age are reported: total lung capacity diminishes with age, functional residual capacity is unchanged or increases with age and the dead space rises slightly with age (ICRP, 1975). The influence of these lung capacities on deposition, however, can be regarded as insignificant. Due to the ageing process mucus velocities my be considerably smaller in older people. This effect can also be superposed by the simultaneous influence of ciliatoxic effects of cigarette smoke and air pollutants or other bronchial diseases. Since the lower age limit for occupational exposure is about 18 years, age can be disregarded in the uranium mining industry for the determination of radiation doses, though lung cancer induction is significantly dependent on age.

Jan 1, 1981

By N. Colvin, J. W. Gulyas

HISTORY The Surigao Nickel Refinery of Marinduque Mining and Industrial Corporation is located on Nonoc Island off the northwestern coast of Mindanao in the Philippines. Nonoc Island is part of the Surigao Mineral Reservation which had been identified as early as 1912. Initial interest in these deposits was due to their iron content, and their value as a nickel deposit was not seriously entertained until the late 1950's. The Philippine government undertook extensive test pitting and sampling programmes at that time and in the early sixties Marinduque became involved in helping to establish firmer ore reserves. Evaluations of the test pitting programme indicated reserves of 75,000,000 tonnes of ore averaging 1.22% Ni, 0.1% Co and 38.5% Fe. The Philippine government called for bids on the reservation in 1962 and Marinduque and Sherritt Gordon carried out some feasibility studies for the recovery of nickel from the deposit. However, it was not until 1968 that Marinduque was granted proper authority to exploit the Surigao deposits. Marinduque and Sherritt then entered into an agreement which allowed Marinduque to utilize a process developed by Sherritt for treating lateritic ores. During 1968, a 25 st/d pilot plant was erected in Fort Saskatchewan, Alberta for the purpose of modelling all process steps. A 10,000 tonne ore sample was sent from Nonoc as feed stock for the pilot plant.

Jan 1, 1979

By Weixiang Meng, Zhao Song, Ming Guo, Zhigao Liu, Shoubao Zhang

"There are many multi-layer coal reserves in China which account for nearly 20 to 25% of the existing proven reserves. When the coals are mined in a descending order using the fully mechanized long wall mining method, they usually have roof collapse with cavity and air leak in roadways and long wall stopes; this is especially relevant when the thickness of the rock between two coals is less than 5.0 m, as the roof stability of lower seam would be greatly reduced. At the Wuhushan Mine, such abnormal strata behavior occurs, including abnormal support stress, irregular period roof pressure, and roof falls in the face. The main reasons for these behaviors include smaller roof thickness, lower rock strength, and mining influence of upper coal; these reasons were determined by analyzing the in situ conditions. A mechanics-based model of the mine geometry was set up to study the sources of stress, the stress evolution of coal, and the discriminant method of roof stability; to obtain the smallest safe thickness of roof between two coal layers, numerical modeling was applied to analyze the relations between the roof thickness and its displacement distribution. Based on the above research, the No.1001 face was divided into easy roof caving zone (ERCZ), roof caving transition zone (RCTZ), and unlikely to roof caving zone (URCZ). In the ERCZ, comprehensive grouting to reinforce the roof was implemented; in the RCTZ, local grouting to reinforce the roof was implemented. Furthermore, a face stability control index and its range were developed in a fully mechanized face combined with mine pressure observation. After implementing this strategy, there have been no unexpected roof caving or other serious strata behaviors.INTRODUCTIONChina is the country with the largest coal production in the world, and the conditions for its coal seams are particularly complicated. For example, in China’s Datong, Wuda, Pingdingshan, and Qinshui mining areas, there are a large number of multi-layer coal seams. The thickness of these coal seams ranges from 1.3 m to more than 10 m, and the spacing between layers is from under 1.0 m to over 30 m. A common problem with these coal seams is that one layer of mining has a large impact on other coal seams, which are customarily referred to as close-distance coal seams. According to statistics, close-distance coal seams account for about 20–25% and 15–18% of China’s coal reserves and production, respectively.From the reference research of Huang (1999, 2002, 2018) and Tu (2010, 2011) we can learn that in the mining process of close-distance coal seams, downward mining is mainly used. When the upper-layer coal is mined, it has a huge mining disturbance effect on the floor (that is, the roof of the lower coal). The mining disturbance increases the mining fissure in the rockmass and weakens the strata strength. The mining problem formed by this issue is that when the lower coal is mined, problems such as difficulty in roadway support, collapse of stope roof, and difficulty in ventilation are often encountered. Especially for the mining of medium-thick coal seam groups with a layer spacing of less than 5.0 m, there has been a large-scale roof collapse accident with a fall height of more than 10.0 m. In response to such problems, domestic and foreign scholars and engineers such as Tan, Zhao, and Xiao (2010), Xie et al. (2017), and others have also carried out targeted theoretical and practical research."

Jan 1, 2019

By D. Malhotra

Gold and silver ores are generally leached in weak cyanide solutions for recovery of precious metals. However, pretreatment of refractory ores requires flotation to concentrate the precious- metal minerals. Also, flotation is a common concentration technique for recovering precious metals as byproducts in sulfide-mineral flotation circuits. The present paper reviews current plant practice and future challenges for precious metal recovery.

Jan 1, 1999

By J. D. Miller, C. L. Lin

A PC, image-based, on-line instrument for measuring coarse particle size on a conveyor belt is under development. The hardware and software required to implement such a system are discussed, including the interface for the special image-acquisition hardware. The system concept is given with examples to illustrate the step-by-step procedure for the implementation of image-processing algorithms.

Jan 1, 1994

By C. Klauber, H. G. Linge, W. G. Jones

The carbon-in-pulp process for gold processing depends on the adsorption of dissolved Au(CN)2- from solution onto activated carbon. Our work shows that coconut and peat based carbons have the same mechanism and kinetics of adsorption. There is no contribution to the bonding from carbon-oxygen functionalities on the carbon surface, as has been invariably supposed in all previous theories for the mechanism of the reaction. It is shown that Au(CN)2- is reversibly adsorbed intact on, and parallel to, the graphitic planes of the carbon. The physiochemical basis of the measurement of carbon reactivity for gold adsorption is discussed.

Jan 1, 1989

By G. Oswald

The fatty acid flotation process has been used to produce phosphate for decades, yet the chemical mechanism involved has never been thoroughly investigated. A basic knowledge of the process is lacking, and as such, industry has had to develop their own guidelines for the design and operation of conditioning and flotation equipment. These guidelines are the result of many trial and error attempts, and are not by any means universally endorsed. There are almost as many opinions about how to operate a plant as there are practitioners of the art. This paper covers the currently recommended rules for design as viewed by one practicing phosphate metallurgist.

Jan 1, 1993

By D. M. Muir

Thiosulfate offers a nontoxic alternative to cyanide for processing gold ores. The mechanism of leaching gold using ammoniacal thiosulfate solution is driven by the Cu(II)-Cu(I) redox couple and is complicated by competing ligands such as NH3 and S2O32; It is shown that an understanding of the copper speciation and sulfur speciation is required to optimize this system. This paper presents Eh-pH and speciation diagrams for varying concentrations of Cu(II), S2O32- and NH3 and discusses the conditions under which various copper and sulfur species are stable.

Jan 1, 2002

By Robert F. Conley

This paper describes attrition milling as exemplified in rotary and vibratory mills for ultrafine grin¬ding application Without attempting to narrate the differences between various devices, generalized differences between the broad categories of rotary and vibratory milling are presented and compared with the ball mill Applications of these mills for coal, limestone, kaolin, mica, talc and iron oxides are described giving specific differences of the mineral properties that affect their behavior in the grinding mills Where applicable, specific recommendations are provided for ultrafine grinding of various industrial minerals

Jan 1, 1983

By G. Barbery

A review is given of the present applications of random sets and integral geometry in fragmentation and liberation models of ores and minerals. Although attempts have been made in the past to apply such mathematical techniques to the comminution of solids, it is shown that it would not result in major progress. In liberation modeling, it is demonstrated that the approach can lead to fruitful results. Following a recent paper by Davy (1984), a model of liberation prediction is developed that can be calibrated for ore texture and breakage using image analyzers. The model is demonstrated for the case of a Poisson polyhedra ore texture and monodisperse fragment size. The model enables prediction of the complete composite particle distribution and thus is valuable for integration of ore breakage models with minerals separation models.

Jan 1, 1988