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By G. H. Shefelbine

DISCOVERED during the time of the Spaniards, the Namiquipa silver-lead-zinc mines in Chihuahua, Mexico, remained idle until 1916, when mining claims were first denounced. About 1922 a Japanese company, the Santo Domingo Mining Co., was formed to mine the oxide silver ore. The company built a 75-tpd cyanide plant and mined in the area for a number of years. Because of an error in surveying in one of the company's mines situated in another district, mining was carried over into a claim owned by General Marcel Caraveo, at that time governor of Chihuahua. Santo Domingo Mining Co. lost the resulting lawsuit and consequently had no capital to continue operating at Namiquipa. Later, Ray Brown and Eugenio Caballero formed a company to operate the mine, shipping crude ore to the American Smelting and Refining Co. smelter at Avalos, Chihuahua. The cyanide plant was changed to flotation with a capacity of 75 tons per 24 hr. In 1936 the property was again closed owing to labor trouble, a drop in the price of silver, and increased water in the mine.

Jan 10, 1957

By E. P. Chartkoff, W. P. Sykes

In 1926 one of the authors published researches on the determination and description of the iron-tungsten and iron-molybdenum systems,' including the equilibrium diagrams. In 1929, further work was carried on, including the examination by X-rays, which is recorded here. Meas-urements were made of changes in lattice parameters in the solid solutions. Precipitation from the solid solution and the accompanying changes in hardness were studied as well as the formation of the intermetallic com-pound phases upon sintering a mixture of metal powders. Materials All the specimens were prepared from the same quality of metals and by the same methods as were described in the determination of the constitutional diagrams. The metal powders as mixed and pressed were sintered or fused in a hydrogen atmosphere and subsequently treated as indicated in the titles of the figures. The formation of the iron-rich solutlon in the solid was accomplished by sintering in hydrogen for a period of 20 to 30 hr. at a temperature 25' to 50' C. below the melting point of the eutectic. The tungsten-rich and molybdenum-rich solid solutions of iron were prepared by adding the iron as a solution of iron ammonium oxalate to the oxide of tungsten or molybdenum, followed by a hydrogen reduction. This method results in a homogeneous alloy after sintering the pressed metal powder for 20 to 30 hr. at a temperature slightly below that of the peritectic reaction in the system involved. For X-ray examination the specimens were variously prepared, depending on the nature of the sample and what it was desired to show. For example, the iron containing tungsten or molybdenum in solid solution was cut with a file, the chips were put through bolting cloth, and this powder of filings formed the specimens for comparative study. The

Jan 1, 1930

By H. Hejny

The minerals industry, comprising producers and users of industrial minerals and metals, aggregates and ornamental or dimensional stone, oil, gas and derivates as well as coal and by-products, provides vital inputs to Europe's economy and social well-being. Because of their great diversity, minerals and their derived products are necessary for almost every aspect of life. The European Technology Platform on Sustainable Mineral Resources (ETP SMR) unites hundreds stakeholders from industry, the re-search community, public authorities, the financial community, regulators, consumers and civil society around the major technological challenges to the sector, in order to jointly act towards a common vision. The Platform will contribute to strengthening one of the fundamental pillars of the European economy and society. The Strategic Research Agenda (SRA) of the ETP SMR is designed to act as a realistic and inspirational guide to defining a comprehensive research programme that will mobilise stake-holders and ensure that European competences are at the forefront of science & technology worldwide. It will help to stimulate investment in research and provide guidance for policy options. The SRA shows the way the mineral industry has to proceed in forthcoming decades if it is to serve European society in the way necessary. Without a strong European minerals industry, the future development of the EU economy risks to be curbed significantly.

Jan 1, 2006

By G. Brooks, M. Hamed, S. Nightingale, K. Coley

The Marangoni effect plays a significant role in slag line corrosion of refractories. Previous experimental studies for various refractory /slag systems and mathematical models are reviewed and show that Marangoni flow is important in slag line corrosion under static conditions. Recent work by the authors is presented which also shows significant slag-line corrosion of MgO refractory in SiO2-CaO-FeOx-MgO slag. The rate of attack of the MgO was marginally slower in the case of slags containing alumina. A semi-empirical model developed by Hrma based on mass transfer control described reasonably well the observed progression of corrosion with time. Further work is proposed to evaluate this model.

Jan 1, 2004

By J. Frenzel

The computation of hydrometallurgical equilibria is very difficult because of the many complex species in solution, the precipitates, condensed species, or solids, and the activity coefficient corrections necessary to non-ideal thermodynamics. Our objective was to tryout recently developed genetic algorithms to minimize free energy and solve the equilibrium computation. We selected test problems that were seemingly unsolvable with more traditional algorithms, and we applied genetic algorithms to them. We were pleased to find that genetic algorithms succeeded where other algorithms did not. We concluded that they are an effective tool for hydrometallurgical equilibria.

Jan 1, 1992

By C. P. Lawhon, J. P. Simpson, W. M. Evans

Data obtained under controlled test conditions using a microbit drilling machine showed that oil emulsified in water muds may either increase or decrease the drilling rate, depending upon drilling conditions. A low-viscosity oil such as diesel fuel can give drilling rates in limestone almost equal to that of water. Data obtained for water emulsified in oil muds showed little decrease in the drilling rate in water-saturated cores as the water percentage of the mud was increased above the 5- to 10-percent range. Changes in drilling rate were found to be dependent upon the oil or water concentration of the mud and upon the type of formation drilled. Changes in static filtration on paper (API filtrate) did not correlate with filtration while the mud was circulated across rock. INTRODUCTION Oil additions to water muds have been reported to increase drilling rates, provide hole stability and improve filtration control. Eckel' showed that water-base emulsion muds used in the West Texas area increased drilling rate with increasing oil concentration up to 15 percent oil by volume, but drilling rate decreased at a concentration of 20 percent by volume. Based on laboratory tests using water muds to drill shale, Cunningham and Goins' reported that drilling rates increased and tendency for the bit to ballup decreased with the addition of oil. Percentage increase in drilling rate varied with the particular formation. They showed oil additions to improve drilling rates ap proximately 75 percent in Vicksburg shale and as much as 150 percent in Miocene shale. Each investigation showed an optimum oil content for the particular formation. Most data that indicated improved filtration control due to oil additions were based on static API Eltrates through paper rather than dynamic filtration through permeable rocks. Some types of dynamic test give a better representation of filtration down-hole while drilling and might be more likely to show some correlation with drilling rate. Static filtration would be important, of course, in relation to hole stability and formation damage. This laboratory's drilling tests, conducted on water-raturated Berea sandstone, indicated that improvements in drilling rate were not evident with increasing oil concentration in water-base muds. Investigation also showed similarity between oil-emulsion (water-in-oil) muds and water-emulsion (oil-in-water) muds while drilling these formations. In Lueders limestone high concentration of water-in-oil muds and high concentration of oil-in-water muds provided the same relative drilling rates. In Berea sandstone there was a large reduction in relative drilling rate with both the oil and water muds that contained low percentages of emulsified fluid. Dynamic filtration rates of water muds on rock did not always decrease with increasing oil percentages even though the static API filtration rates on paper did decrease. Data observed in laboratory drilling of limestone and sandstone indicate that improvements in field drilling operations when water- or oil-emulsion muds are wed may not be the result of increased drilling rates but of improved hole conditions. In some cases, actual drilling rates might be slower but improved hole conditions will result in less total time on the hole. DEFINITIONS Mud pressure—Pressure of drilling fluid as measured after leaving the drilling chamber. This is considered as the approximate mud pressure just past the bit and at the face of the formation. Terrastatic pressure—Pressure representing weight of overburden. Formation pressure—Pressure of formation fluid as measured at outlet of drilling chamber. This is considered as approximate pressure of fluid in the pores of the formation. Differential pressure—Difference between the mud pressure and formation pressure. Relative drilling rate, percent—Drilling rate with experimental fluid divided by drilling rate with water times 100 equals percent. LABORATORY EQUiPMENT AND TESTING PROCEDURES The drilling equipment has been described in previous publications The microbit drill is a closed system (capacity, approximately 7 gal) that can be pressurized to 15.000 psi and heated to 500F. Main components are a drilling chamber, filter-heater, rotary-drive and variable-speed cir-

By P Moarefvand, M Osanloo

The anticipated economic life of the mine, which defines the rate of mine production, is dictated initially by the design capacity of the mill/concentrator and the production capacity of the mine relative to the grade and tonnage of ore that can be encompassed by the pit design. A small pit will result in smaller investment and cash flow; in contrast, a larger size of pit will increase capital investment and annual revenue. Since open pit mine design and long-term production sequencing are essentially based on three-dimensional block models, changes in block dimensions leads to different mine sizes, and therefore changes in the mine life. The physical characteristics of the deposit, such as reserve tonnage and ore grade, affect the expected future revenues from the mining project, and consequently they affect the life of the mine. Large blocks will increase the recoverable ore reserves and production rates and hence increase the mine life. This paper discusses the effects of the block dimension on the commercial ore reserve, grade-tonnage curve and its effect on the production rate, ultimate pit size, mining cost and consequently the mine life. The result shows that block height is the most effective parameter governing the economical life of the mine.

Sep 26, 2011

By Heribert Wiedemeier, Ali Khan

The tetnperature-conposition phase diagram of the syste,n MnS-CdS has been investigated over a range fro)n 600° to 1000° C. The small degree of solid solution on the MnS rich slde cornpared to the large CdS rich single-plzase region could be esplained by the difference in strzrctures of the cotnponents and the relative sizes of the metal ions. The change in lattice parameter as a function of cot)zposition is linear atzd jollous Vegavd's rule within experittzental limits of error. Mns and CdS have gained considerable attention in recent years because of their interesting solid state properties. In order to investigate such properties and thermodynamic quantities of mixed compositions of transition metal chalcogenides, it is necessary to establish their phase diagrams. Two earlier publications are concerned with the MnS-CdS system. Schnaase' found complete miscibility when MnS and CdS were co-precipitated in aqueous solutions at room temperature. However, there is evidence that the mixed crystals were not stable over the entire range of composition. roger's' investigation of the ternary system ZnS-CdS-MnS at 900" C indicates a solution of 48 mole pct MnS in CdS. During the course of this work which covers a temperature range from 600" to 100O° C, emphasis has been placed on the use of high-purity materials and well-defined modifications of starting products. EXPERIMENTAL Starting Materials. The stable green modification of MnS with NaCl structure was prepared by direct fusion of the elements and by chemical transport reaction. Stoichiometric amounts of manganese of 99.99+ pct purity and of sulfur of 99.999 pct purity from Gallard-Schlesinger Corp. were sealed in an evacuated quartz tube at a pressure of 10"5 mm Hg and annealed for 48 to 60 hr at 800°C. The quartz tubes used throughout this work were outgassed under high vacuum at a temperature of 90OU to 1000° C for 12 to 18 hr. For the synthesis of MnS by chemical transport3 stoichiometric ratios of elemental manganese and sulfur and small amounts of iodine were sealed under vacuum in a quartz tube, which was placed in the temperature gradient, 900/800-C, of a two zone furnace. Single crystals of MnS in form of platelets and octahedra were deposited at the cooler end of the tube. The manganese content was determined by EDTA titratin. A typical result of several analyses was 63.05 pct Mn which agreed well with the computed value, 63.14 pct. Commercially available CdS of 99.9+ pct purity, a mixture of the cubic and hexagonal forms, was converted into the hexagonal high-temperature modification by annealing CdS under vacuum in quartz tubes at 700° C for about 36 hr. As a second method, cadmium sulfide was transported in a temperature gradient, 70O° /650" C, with in vacuo sublimed iodine from the hot to the cooler zone of the tube. Large sized crystals in form of hexagonal columns and some platelets were obtained. An average result of the cadmium analysis by EDTA titration4 was 77.93 pct in good agreement with the computed value, 77.81 pct. Only the NaCl modification of MnS and the wurtzite modification of CdS were used for the solid solutions. Preparation of Solid Solutions. Finely powdered MnS and CdS samples were thoroughly mixed in molar ratios and compressed into pellets of about 6 mm diam and 2 mm in height at a pressure of approximately 13,500 atm.

Jan 1, 1969

By S. Gallagher, C. A. Hamrick, A. G. Mayton, R Sonier, R. L. Unger

Introduction Industrial safety professionals recognize that adequate illumination is essential to a safe and productive work environment. The need for effective, lighting in underground coal mines is even greater.1 Designing appropriate lighting systems for these mines is no easy [ ] task because of the unique environment and work procedures encountered in underground coal-mining operations. Miners must depend totally on artificial lighting systems to see. Moreover, the working face is a low-reflectivity and low-contrast environment and is continually advancing or retreating.2 Laboratory mock-ups have been a major part of the process lighting equipment manufacturers must under- go to design an underground machine-mounted lighting system. The mock-ups often have taken considerable time. Furthermore, modifications to a lighting system (using different luminaires with an existing configuration or changing a luminaire's location, orientation, etc.) could require more time with additional mock-ups and laboratory measurements. Understanding the need to improve this situation, the US Bureau of Mines has developed an alternate method for facilitating lighting system mock-ups. A PC-Program (CAP),* with the latest software technology enables users to design, alter, and evaluate under- ground machine-mounted illumination systems. Lux levels and distance are measured as the luminaire is moved incrementally through angular traverses about horizontal and vertical axes. The measurements and angles subsequently are entered into the model. From this input data, three-dimensional isolux or isofootcandle profiles are constructed for luminaires that can be placed at various locations and orientations on a mining machine. As an example, Figure 1 shows a computer display of 21.5 Ix or 2.00 fc profiles for luminaires mounted on a simulated mine-shuttle car. Using this information, the model allows the user to determine the lux level at different locations in space about the shuttle car. How the model calculates illumination During initial development of the CAP model, the isolux profile of the luminaire was determined using the inverse square law (ISL) .3 The method of gathering data comprised recording a single measurement of distance at 21.5 ± 1.21x (2.00 ±11 fc) for angular traverses following 0.09 rad (5 degree) increments. This data was then used to find the illumination in space for any other distance at a given azimuth and elevation using the ISL. Limitations, however, exist with this method.4 The main one is that the ISL assumes a luminaire is a single point source of light, so long as the distance is greater than five times the 1al;gest dimension of the luminous area of the luminaire.5 Also, by using a single measurement to calculate the illumination for a given luminaire in the CAP model a large error could result from an inaccurate measurement.

By James Ballard, Charles H. Dowding

Recent Office of Surface Mining regulations have called for pre-blast surveys of residences within one-half mile of blasting. Unless lighting effects and the multiple origins of cracks are recognized, hurried (lowest bid price) pre-blast surveys may be more harmful than beneficial. Unrecorded, but pre-existent, cracks can be noticed by homeowners during blasting under special lighting conditions. This paper discusses important factors to note during pre-blast surveys, presents data collection forms and discusses the importance of photographic technique in recording cracks (both present and previously patched).

Jan 1, 1979

By Takeshi Yoshikawa, Kazuki Morita, Yuichi Kato

"A composite composed of carbon fiber and a Cu-Si alloy is a promising candidate for next generation brake disc materials used in high-speed trains. The composite can be prepared by vacuum infiltration of the Cu-Si alloy into the fibrous carbon matrix. The activity of Si in the alloy plays an important role in controlling the formation of SiC; this formation is attributed to the reaction between the Si in the alloy and the carbon fiber during the infiltration process. Because Fe has strong affinity with Si, the addition of Fe is expected to decrease the activity of Si in the alloy. In the present work, the variation in the activity of Si in the alloy with the addition of Fe has been investigated by equilibrating a Cu-Fe-Si alloy with solid SiO2 and graphite under controlled CO partial pressure. The first-order and second-order interaction parameter of Fe on Si in molten Cu was determined to be -16 and 160, respectively. The negative value of the first-order interaction parameter clarified the addition of Fe to the Cu-Si alloy is effective in decreasing the activity of Si in the alloy.IntroductionIron-based materials have been commonly used for brake discs in high-speed trains. It becomes critical for brake disc materials to withstand high thermal loads with an increase in the maximum speed of high-speed trains. The fabrication of high heat-resistant, light-weight brake disc materials is then crucial for their use in next-generation high-speed trains. Carbon fiber is known to be a light-weight, high-strength material, and is considered to be a promising matrix material for use in brake discs. The Cu-Si alloy exhibits high thermal conductivity. The composite in which the Cu-Si alloy is added to the carbon fiber matrix is expected to be a high performance material for brake discs. The composite can be prepared by the infiltration of the Cu-Si alloy into the carbon fiber matrix at a temperature higher than 1700 K."

Jan 1, 2012

By C. I. Pierce

The Bureau of Mines used an electrolytic tank model to investigate the response of guard electrodes of different dimensions under different simulated reservoir conditions. Sandstone disks from the Berea and Connellsville Formations were used as resistive beds in the model, and agar gel or water was used as conductive beds. In the experiments, bed thickness, hole diameter, mud resistivity, and bed resistivity were varied. The guard electrode is an excellent tool for determining true bed resistivity in the thin-bedded oil reservoirs of the Appalachian area. Vertical resolution and resistivity values are good when there is little or no invasion. Resistivity values are near true bed resistivity in beds thicker than about six hole diameters when the electrode-to-hole-diameter ratio is close to 1. However, low-resistivity muds cause false peaks to appear on the logs near bed boundaries in thick beds, and for resistive beds having a thickness approximately three to five times the hole diameter, apparent resistivities tend to be excessively high when mud resistivity is low.

Jan 1, 1966

By S. Frimpong

Cable shovel requires continuous monitoring through excavation to achieve reliability, longevity and economic usage. The operating environment and the stress and deformation fields on the front-end assembly must continually be monitored to avoid random fatigue failure. In this paper, the authors advance frontiers of cable shovel reliability through real-time stress and deformation monitoring during excavation. Cable shovel boom stress and deformation analysis are developed using a combination of flexible and rigid body approach. A virtual prototype is developed to simulate the cable shovel excavation in oil sands and to examine the motion, stress and local deformation of the boom. A numerical example is used examine cable shovel boom durability using stress and deformation fields simulation. The results show that stress and deformation are large around the joint between the upper body and the boom. The simulation of the effect of material properties on boom deformation shows that the deformation is larger in hard formation than in soft formation. The study provides a solid foundation for further study of failure life analysis of the cable shovel components.

Jan 1, 2006

By Manuel Estrada

"El presente texto señala un breve estudio sobre el aspecto técnico y de ingeniería de La Planta Sacracancha del Banco Minero del Perú. Dicha planta se encuentra a 4 600 m.s.n.m. en la zona denominada Sacracancha del distrito minero de Morococha, perteneciente a la provincia de Yauli, departamento de Junín. Se utiliza la planta Flow Sheet y los minerales tratados son los sulfuros de plomo, cobre, zinc y planta. Asimismo se describe el proceso de producción de la planta, procedencia, operación de la planta y servicios auxiliares como los laboratorios, almacenes, talleres, etc. "

Aug 20, 1965

By G. Johnston, J. Greenly, R. G. Buchheit, D. C. McIntyre, R. Muenchausen, D. J. Rej, R W. Stinnett

"Rapid thermal treatment of materials using high energy, high flux, pulsed ion beams can produce modified surface layers with unique microstrutures and properties. High energy ions loose their energy during the slowing down process in the workpiece and thus deposit their energy continuously over a depth of a few microns. The deposition of energy can lead to melting and in some causes ablation of the heated layer. Because the pulse duration of the ion beams is typically only 50-200 ns, steep thermal gradients generated during heating facilitate rapid cooling (107K/sec-108K/sec) of the treated layer by thermal diffusion into the underlying material. Rapid heating and cooling of materials can generate surface layers with non-equilibrium amorphous or nano-crystalline microstructures that exhibit increased hardness, wear resistance, and corrosion resistance. Pulsed ion beam treatment can also lead to surface smoothening or can be used to mix thin « 1 11m thick) coatings into underlying substrates. Pulsed ion beams can be generated using existing ""flashover"" ion source technology which is capable of producing single shot, mixed C, H, and O ion beams with beam cross sections of approximately 100 cm2 and energy fluxes up to 100 J/ cm2. Recent advances in repetitive high energy pulsed power technology and development of magnetically confined anode plasma ion sources have facilitated the development of ion beam systems that generate single species beams that pulse continuously at 120 shots/second. These capabilities will allow rapid treatment of large surface area workpieces at low cost.IntroductionThe rapid solidification of liquid materials can create unique materials and material microstructures that often have properties that can lead to enhanced performance. Rapid solidification processing of the surfaces of materials using continuous and pulsed laser beams (laser glazing) has been explored for over 20 years (1-5). Advances in high energy, pulsed electron and ion beam technologies over the past decade have provided rapid thermal treatment techniques that may be less expensive to impliment than laser surface treatment for many surface modification applications (6). High energy pulsed ion beams have recently been used to harden aluminum(7), copper(8) and tool steel surfaces (6,9), increase corrosion resistance of Al alloys (6), mix coatings into underlying substrates (10), and create amorphous films (11,12)."

Jan 1, 1994

By Jan Visman, James W. Parkinson

GENERAL INTRODUCTION Sample collection, preparation and analysis are all steps in a single process designed to provide information about a much larger amount of material than the sample itself. For example, information about the ash content of a unit train load of coal may be derived from a single, relatively small sample of perhaps a few hundred pounds (liters) extracted from the entire shipment. These three steps can be thought of as links in a chain, allowing the simple analogy that the strength of the chain, or, in other words, the value of the information is only as strong as the weakest link. Sample collection, discussed in Part 1 of this chapter, is critical because analytical procedures can do no more than reveal the characteristics of the sample presented to the laboratory. If that sample does not properly represent the population to be characterized, neither will the analysis of that sample. Sample preparation is also a critical part of the chain. Any change in the nature of a sample between the time it is collected and the time it is analyzed will appear to reflect the nature of the population. For example, sample preparation procedures that allow air to partially dry the coal sample before reaching the laboratory will cause the sample analysis to indicate a lower moisture content than the sample originally had. Other changes can be more subtle. Second only to moisture loss, oxidation reactions generally cause the greatest problems. Oxidation of a coal sample can alter surface properties, changing flotation response. In extreme cases, combustion parameters, such as caking or agglomerating properties or mineral composition, such as pyrite content, can change. Water samples can also be altered by oxidation. For example, ferrous iron can oxidize to ferric iron, possibly changing water quality parameters such as pH. Sample analysis, the subject of Part 2 of this chapter, is the final link in the chain. Obviously, no laboratory procedure can correct for problems created by improper sample collection and preparation. At the same time, poor analytical techniques will create incorrect information about the total amount of coal from which the sample was extracted (the population) in the same manner as improper sample collection and preparation. The key to gaining correct information about the population is to view these three steps as parts of a single process. Following proper techniques through only one or two steps of the process will not produce accurate information.

Jan 1, 1991

By W. F. Watts

In 1980 the Bureau of Mines developed the Mine Inspection Data Analysis System (MIDAS). MIDAS is a computerized, industrial hygiene data base capable of statistically analyzing environmental data collected in coal and noncoal mines and mills by Mine Safety and Health Administration (MSHA) inspectors or mine operators. The objectives of this report are to describe the current contents of MIDAS, to report analyses of coal and noncoal mine respirable dust samples collected by MSHA inspectors and to evaluate the proposed change in the metal and nonmetal respirable dust standard from a formula based upon the percentage of quartz identified in the sample to 100 µg/m3 of respirable quartz. Based on samples collected by MSHA inspectors, changing the noncoal respirable dust standard would result in 4 pct fewer samples with dust concentrations exceeding the standard. Analysis of respirable coal dust data collected by MSHA inspectors showed that mines with longwall plows or shears had the highest geometric mean concentrations (1.64 and 1.29 mg/m3, respectively). Mine operations using continuous rippers out-numbered longwall mine operations about 10 to 1 and had a geometric mean concentration of 0.66 mg/m3.

Jan 1, 1987

Peru has become an established mining country. The industry and industry-related businesses account for a significant amount of the country´s revenue, on state and local levels. But like other countries with thriving mining industries, Peru has seen its mining industry revenues fall off in recent years due to a lackluster global economy. And the mining industry in Peru must also deal with increasing concerns about mining?s environmental impacts, local community and other social issues, as well as a regulatory environment that has placed more restrictions on what miners can do. That said, the Peruvian government is beginning to realize how important mining and natural resource development is to building the nation?s economy, improving its infrastructure and lifting its population out of poverty. The government support was evident during the Perumin 2013 mining convention, held in September in Arequipa. In addition to Peru?s President Ollanta Humala speaking at the closing ceremony, the country?s ministers of Energy and Mines, and Economy and Finance participated in the event, as well as numerous other federal and state authorities. Perumin is put on by the Instituto de Ingenieros de Minas del Peru (IIMP, or Peruvian Institute of Mine Engineers). The 31st edition of the convention, billed as the ?world?s largest mining convention? by the IIMP, this event was led by Abraham Chahuan CEO of Antamina and Romulo Mucho (SME member) as president of IIMP, attracted about 118,000 participants from more than 48 countries. This was more than the anticipated 75,000 attendance and well past the 51,000 people who attended the 2011 convention. The last edition of PERUMIN was led by the CEO of Compañía Minera Antamina, Abraham Chahuan and Rómulo Mucho (SME member) and representative of the IIMP. The event attracted more than 1,000 journalists from all over the world, the IIMP said. A total of 2,213 booths from equipment and machinery supplying companies from the five continents were present at the Mining Technology Exhibition (Extemin), including companies from the United States, Canada, China, South Africa, Germany, Australia, Brazil and Chile, among others. The convention has grown so large in recent years, that the IIMP shifted its location from Tecsup vocational school in Arequipa to the Cerro Juli Convention Center. The venue is 116 percent larger than Tecsup, the IIMP reported, covering about 20 ha (40 acres). It was reported by Latinomineria magazine that about 10 million Peruvian soles were invested in the new venue to create a world-class events center. It was also estimated that the event generated more than 234 million soles to Arequipa?s economy.

Feb 1, 2014

By W. J. Campbell

This report by the Federal Bureau of Mines Particulate Mineralogy Unit recommends mineralogical definitions and identification-characterization concepts for selected silicate minerals and their asbestiform varieties. Precise definitions acceptable to mineral analysts, regulatory personnel, and medical scientists are essential because of the present lack of conformity in terminology concerned with measuring and controlling asbestiform particulates and their related health effects. Because of the complexity and variability of crystal morphology in different mineral groups, the descriptive terms are generally explained by illustration rather than by numerical values. Applications and limitations of several analytical techniques for particulate identification and characterization are discussed.

Jan 1, 1977

By M. Scaggs

"Respirable dust in underground coal mines has long been associated with lung diseases, and regular dust sampling is required for assessing occupational exposures. At present, respirable dust concentration and crystalline silica content are commonly determined, but considering recent and yet unexplained increases in the incidence of lung disease amongst miners in specific geographic regions, more information about specific dust characteristics is urgently needed. While particle-level dust analysis is ideal, it is impractical for large numbers of dust samples because it is both time and cost intensive. Thermogravimetric analysis (TGA), however, is an alternative option, which offers the ability to determine the total coal to mineral mass ratio in a dust sample – analogous to proximate analysis of bulk coal samples for determining ash content. Here, preliminary development of a TGA method for this purpose is presented. The method is being developed to evaluate dust collected on mixed cellulose ester (MCE) filters using approved permissible sampling equipment. INTRODUCTION Based on the particle size, airborne mine dust can be classified in three categories: inhalable dust (< 100 µm in size), thoracic dust (< 25 µm in size), and respirable dust (< 5 µm in size) (Ramani et al., 2003). The World Health Organization (WHO, 1999) defines inhalable dust particles as those which can be breathed into the nose and mouth, and thoracic dust particles as those which can penetrate airways of the head and enter the airways of the lung. On the other hand, respirable dust particles can penetrate beyond the terminal bronchioles into the gas-exchange regions (alveoli) of the lungs (WHO, 1999). Hlavay (1992) reported that the seriousness of the damage in the lungs and respiratory tract is based on amount of dust remaining in these organs, and the amount of dust depends on the extent of dust exposure, the size distribution of the dust particles, and the capability of the body for dust elimination. Inhalation of respirable coal dust by miners can cause a disabling and potentially fatal lung disease which is called coal worker’s pneumoconiosis (CWP). Silicosis is another fatal lung disease caused by inhalation of respirable silica dust. In CWP and silicosis, dust particles deposit in the lungs, damage the lung tissue, and ultimately cause scarring which cannot be reversed (Colinet, 2010). While overall incidence occupation-related lung disease amongst coal miners in the US has been declining for over 40 years, it appears that there has been a recent increase in specific locations in Central Appalachia (CDC, 2006; Pollock et al. 2010; Suarthana et al., 2011). Although this trend is yet unexplained, one theory is that particular dust characteristics in these locations may be a factor (Hassan and Lau; Page & Oraniscak 2002). For example, several studies have indicated that different coals may generate different amounts of respirable dust (e.g., see Page, 1993 and Litton and Page, 1994), and the surrounding geology may also play a role in terms of the types of dust particles generated. Although respirable dust concentration and crystalline silica content are commonly determined as part of regulatory compliance sampling, more information about specific dust characteristics (e.g., size, shape and composition) is urgently needed."

Jan 1, 2015