Search Documents

By T. Stack, C. Roos, M. Drake, P. Conrad

"This paper presents the evaluation Montana Tech completed for the Western Energy Company Rosebud Mine relating to the benefits of survey data collected using novel technologies over traditional methods for topographic surveys. These technologies include Unmanned Aircraft Systems (UAS), photogrammetry, and laser scanning/LIDAR. Utilizing these technologies, large areas such as reclamation areas and cast blasts can be surveyed in a timely manner for use by the mining operation. The areas that were evaluated were the improvements in the safety of employees and the time required to collect data. In addition, there is also a potential cost savings for the operation, all while not affecting the accuracy of the data that is collected. PROJECT BACKGROUND Accurate topographic survey data is critical to successful surface mining operations. It is used for mine planning and design as well as permit compliance. Currently, employees typically collect survey data using GPS equipment or total stations. These methods can be dangerous, as they require employees to work near large operating mobile equipment, edge of high walls, and on piles of stacked steep-sloped loose material. Aerial and satellite photographs, performed by a contractor, can be used to obtain some of this information, but it is expensive and may not be attainable during overcast conditions. Montana Tech, along with the Rosebud Mine, conducted research on the accuracy, cost, and other benefits of survey data collected using novel technologies. Some of the methods studied include, but are not limited to, Unmanned Aerial Systems (UAS) or Vehicles (UAV), photogrammetry, and laser scanning. These methods were evaluated to determine if these technologies provide mining companies with a safer, cost effective, and accurate method to collect data for surface mining operations. The project scope was to evaluate various surveying techniques to determine which techniques would be applicable for the Rosebud Mine and complete a trade-off study comparing the new techniques with currently used methods. The trade-off study included an analysis of the technological differences between the methods, safety and legal considerations for the new techniques, operational limits, and the costs associated with each technique. Working with the Rosebud Mine team, techniques were selected for field trial and accuracy comparison. This paper presents a literature review of applicable technical papers and a summary of the Federal Aviation Administration regulations for UAS, followed by a study comparing conventional GPS topographic surveys with UAS based systems and laser scanning systems. The comparison of the various methods was broken into the following four categories: operator safety analysis, time comparison, survey accuracy, and cost analysis. After all of these portions of comparison were completed a recommendation was provided based on the evaluation that was performed."

Jan 1, 2017

By Kensuke Sassa, Shigeo Asai, Norihisa Waki

"A new method for separating inclusions from a molten metal using a high magnetic field has been proposed. The principle of this method based on the magnetization force has been confirmed in experiments of separating intermetallic compounds imitating inclusions from molten Al-Si-Mn-Fe and Al-Si alloys. In order to measure a magnetic susceptibility, the Gouy's method has been so modified by using a super-conducting magnetic as to work in a high temperature up to 1473K. A theoretical expression for the magnetization force, which is indispensable to evaluate the magnetic susceptibility, has been derived. The magnetization forces acting on intermetallic compounds which were used in the magnetic separation were measured over the range of liquidous to solidous temperatures and the magnetic susceptibilities of the intermetallic compounds were obtained from measured magnetization forces by use of the theoretical expression.I. IntroductionRecent developments in the technology of super-conducting magnets have given rise to the circumstance that a high magnetic field over a relatively large space is readily available without liquid helium. Then, it has been found that a high magnetic field provides magnetic effects to nonmagnetic substances and various interesting phenomena have been reported in the broad science fields of physics, chemistry and biology1). ""A science related to a high magnetic field"" in which many fields are transversally viewed from the standpoint of a high magnetic field2 ) is going to be established. In particular, new phenomena and functions brought by the science related to a high magnetic field are also useful for Material Science and Engineering so that the creation of Materials Science and Engineering related to a high magnetic field"" has been conceived 3).Now, when a substance regardless of being magnetic or nonmagnetic is put in a magnetic field, it feels a magnetization force, which is familiar to such a force that a magnet attracts iron. The force is in proportion to the product of magnetic field strength, its gradient and susceptibility so that a precipitated substance can be separated from a molten metal based on the difference between susceptibilities of a substance and a melt. This is a basic principle of the magnetic separation. So far the application of the magnetic separation has been limited to the separation of ferromagnetic substances from a nonmagnetic medium. A high magnetic field, however, has enabled to separate nonmagnetic substances from a nonmagnetic medium.In this study, a new method to separate inclusions from a molten metal using a high magnetic field has been proposed. The principle of the method was verified by experimental works and the feasibility on the elimination of inclusions in steelmaking processes has been studied"

Jan 1, 2000

By T. Krichler

"Current mine control stations are either single-position systems with high engineering effort or all-in-a-box solutions with low integration possibilities of third-party devices. Above all, both approaches are cost-intensive and not feasible for small companies. This paper shall be an inspiration of how to enhance the productivity and monitoring of an existing mining system in a modular way by introducing a proven technique of the ongoing digital revolution: A Wi-Fi network based on the communication protocol OPC UA. The starter kit consists of a single-board computer, a WLAN access point and any electronic sensor. INTRODUCTION The majority of the European mining industry is run by small and medium deposits (Europe Geology, 2017). This is due to the fact that most ore mines in Europe are widely distributed within the continent, are generally small and additionally they are often steeply inclined. Such ore bodies are normally mined with underground mining methods and must be excavated with high selectivity because of their small thickness. That is why the economy of scales, higher efficiency through bigger machines, cannot be used in most deposits in Europe except for lignite mines. It is important to find an alternative possibility to improve the efficiency of European mines for making them competitive internationally. For cost optimization and profit maximization it is necessary to use the trends of industry 4.0 and to broadcast these into the mining industry to reach a technological advantage. The goals of the EU within the Horizon 2020 funded project are to shorten the actualisation of the mine and block model to hours, improve the communication with Through the Earth (TTE) via very- or ultra-low frequency for long-time monitoring of the abandoned workings, and develop a cost-effective mine control station for optimization of mining processes in Small and Medium Enterprises (SMEs) as well. This paper deals specifically with the new approach for data acquisition, transmission and visualisation of a mine. SCADA AND ERP IN MINING There are already many Supervisory Control and Data Acquisition (SCADA) and Enterprise Resource Planning (ERP) programs on the market, but these are normally not developed for the mining industry. At the moment this leads to three options. • To hire a system integrator, who shall build a complete control station for one mine that requires a high amount of knowledge in programming and cannot be maintained by the mining company itself. • To buy different types of out-of-the-box systems, whereby every system can include some of the used technology. In this case a huge amount of project engineers and operators – at least one per system and shift- is required. • To buy every machine and program from one company including the service contracts."

Jan 1, 2018

By P. Wearden, K. Bryner, K. Vrana, V. Castranova, R. Dey, R. Reist, J. Blackford

"Summary: Fibroblast proliferation and enhancement of collagen synthesis are key steps in the development and progression of pulmonary fibrosis. The current investigation presents a fibroblast proliferation assay to detect the release of competence factors from pneumocytes. The specific objective of this study was to define cell culture conditions for fibroblasts that would allow selective detection of competence factors in test media. The results indicate the following: (a) fibroblasts should be cultured for 2 days in plasma-free medium rather than 2% plasma to assure complete quiescence; (b) 1% plasma was optimum for producing progression activity for the bioassay of a competence factor, while 0.5% plasma did not produce sufficient progression activity (yielding false negatives) and 2% plasma often contained significant competence activity (yielding false positives); and (c) fresh plasma should be used since the progression activity of plasma was adversely affected by freezing and thawing. Under these conditions, this bioassay can be employed with either rat or human lung fibroblasts to detect competence factors such as platelet-derived growth factor (PDGF), at levels as low as 25 ng/ml.Fibrotic lung disease, as a consequence of occupational exposure to silica dust. is characterized by the development of concentric hyalinized nodular lesions in the lung and the progressive loss of pulmonary diffusion capacity. Proliferation of pulmonary fibroblasts and enhanced synthesis of collagen by these pneumocytes have been shown to be key steps in the development of chronic silicosis ( 1 ). The regulation of lung fibroblast proliferation by cytokines released from alveolar macrophages may be an important pathogenetic mechanism in the development of the fibrotic process (2). Some cytokines stimulate fibroblast proliferation by activating specific phases of the cell cycle (3,4). In particular, platelet-derived growth factor (PDGF) promotes fibroblast proliferation by inducing the movement of quiescent (G0 ) cells into the G1 phase of the cell cycle (5). Insulin-like growth factor (IGF) and transforming growth factor-P (TGF-P). on the other hand, regulate the rate of transition of fibroblasts from G 1 into the S phase (5,6). These two classes of cytokines have been termed competence and progression factors, respectively. One approach used to examine the release of cytokines from macrophages is the fibroblast proliferation assay in which quiescent fibroblasts are exposed to culture supematants from macrophages exposed to various stimuli. In most of these assays, the supernatant contains fetal calf serum (FCS), which provides the competence factor(s) necessary to facilitate the proliferation of fibroblasts (7-9). Recently, a fibroblast proliferation assay using platelet-poor .plasma [lacking competence factor(s)] as a substitute for FCS bas been described (I 0, 11 ). In this assay, the release of a competence-inducing PDGF-like growth factor from rat and human macrophages can be distinguished from other cytokines that act as progression factors."

Mar 1, 1992

By N. V. Ramana Murthy

Utilisation of Low-Grade Iron Ore Fines after concentration not only helps in conservation of the mineral wealth, but also substantialsly improves the economics of iron ore mining. There has been need to develop suitable beneficiation process for upgradation of low-grade iron ores towards their rational utilisation. Presently the circuit adopted for processing iron ores has limitations in reduction of alumina. The depletion of high-grade reserves, utilisation of low-grade reserves coupled with in-creasing market pressure for improved product quality necessitates re-examination of the process flow sheets and evaluate alternative or supplemental processing routes. The main objective of the Process amenability studies for utilisation of Low-Grade Iron Ore Fines (-10mm) is to get Pellet grade concentrate with +65% Fe (min), SiO2 1.8% (max), Al2O3 1.8% (max) and other proportionate constituents by adopting suitable beneficiation techniques and to collect the relevant data (Quality and Quantity of the Products) for the process development. In an effort to formulate a conceptual process flow sheet, the Process amenability studies for utilisation of Low-Grade Iron Ore Fines (-10mm), which is lying at a mine site in India, samples were collected and taken up for the study. The efforts of R & D of NMDC are discussed in this paper. Low-Grade Iron Ore Fines (-10mm) sample assayed 60.10% Fe with 3.48% SiO2 Aland 4.48% 2O3from 40 microns to 300 microns. The sample consists of hematite as the chief ore mineral followed by minor amounts of maghemite. The gangue minerals include quartz and ferruginous clay in which quartz occurs as medium grained where as ferruginous clay occurs as fine to sub microscopic size mineral. The economical processing route evolved out of the studies finally could yield a final concentrate constituting 58.63% by weight along with Iron unit?s recovery of 63.51% assaying 65.10% Fe with 1.48% SiO2 and 1.85% Al2O3route that adopted comprises the following operations. Making slurry in a sump pump followed by grinding in close circuit with 48mesh size Screen. The -48 mesh size product was subjected o the Cycloning to remove slimes. The Cyclone Underflow product was subjected to Floatex Density Separation (FDS) to separate fine heavy minerals from the gangue minerals. The FDS Underflow was collected as concentrate. The FDS Overflow product was further subjected with Wet High Intensity Magnetic Separation (WHIMS) to recover more Iron units as magnetics. A conceptual process flow sheet was evolved, which may become the prelude to the subsequent finalisation of the process flow sheet for commercialisation.

Jan 1, 2014

By X. Zhu, L. Chen, R. Guru, M. Peiravi, M. Mohanty, L. Ackah, B. Xu

"The overall goal of this study was to develop a suitable flowsheet to extract rare earth elements (REEs) from coal ash. Only the findings from the first part of this study is being reported at this time. A total of fourteen coal samples of different ranks were examined for REEs concentration. An anthracite coal sample, originating from Pennsylvania having more than 700 ppm (in the coal ash) was selected for the REE extraction tests. The experimental program completed so far included high temperature leaching using nitric acid, followed by the solvent extraction tests. A 4x2x2 experimental design was used to conduct a total of thirty two high temperature leaching tests by varying acid molarity (at 4 levels), solid content (at 2 level) and leaching time (at 2 level). The highest LREE (light REE) recovery of 90% and HREE (heavy REE) recovery of 94% were obtained from the most optimum leaching test condition while maintaining the impurity recovery to the leachate at less than 40%. Solvent extraction experiments were conducted to recover the REE’s from the above leachate solution using a variety of organic extractants including, TBP, Cyanex, D2EHPA and their combinations. D2EHPA was found to be the best extractant during this SX text series providing nearly 99% recovery of REEs. INTRODUCTION The demand for rare earth element and other strategic metals (REM) in the world is rapidly increasing due to their use in a variety of high technology applications. More than 100,000 tons of rare earth oxides (REO) are being used worldwide on an annual basis. However, we have less than 10% of the world reserve of rare earth element (REE) mineral deposits in the US. More than 60% of rare earth oxide (REO) was imported to the US from outside (mostly from China) in the year of 2013. However, China’s institution of export quota has significantly reduced the supply of REMs to the U.S. Hence, new ways of producing REM and/or finding substitutes for those metals for the high-tech applications need to be invented/discovered in a timely manner. Coal Combustion Byproducts (CCBs), which are discarded as waste materials in most cases, are known to contain REEs (in low concentration) that could be extracted using a suitable process flowsheet. This may be a worthwhile route to pursue considering the short supply of REMs and the abundance of coal ash in thousands of ash ponds in the US. On an annual basis, more than 110 million tons of Coal Combustion Byproducts (CCBs) are being produced while satisfying our nation’s need for electricity (ACAA, 2014). However, less than 50% of these CCBs are being successfully used in various applications and the remainder is being dumped as waste materials in the landfills and ash ponds."

Jan 1, 2017

By Charles M. Wilk

"Mass stabilization involves mixing binding agents into marginal or contaminated soil to improve the subject material’s physical and/or chemical properties. This paper concentrates on the principles of soil mixing and benefits and application to new and existing rail right-of-way. Successfully applied in Scandinavia and other European countries, the soil mixing is now being applied in right of way in the northern latitudes of the U.S. and Canada. These regions have significant areas of “peaty” soils that can complicate construction and maintenance of rail and structure foundations. Mass stabilization can be used to improve the bearing strength of these soft soils for subsequent construction of railroads, pipelines, roads, and buildings. In civil engineering, the technology is often used to improve the construction properties such as bearing strength, of a marginal soil. In environmental engineering, stabilization is remediation treatment technology that protects human health and the environment by immobilizing hazardous constituents within the treated material. . The treatment is conducted while the subject material remains in-place (insitu). Mass Stabilization is often used to accomplish both civil and environmental purposes on the same project effectively addressing marginal soil while eliminating the expense of soil removal and replacement. This paper presents the principles of mass stabilization technology, implementation in the field and recent completed railway projects. The example rail projects will present the various benefits that soil mixing provides to railway construction and maintenance. Bench-scale studies and full scale implementation as well as soil construction properties before and after mass stabilization will be discussed. The paper and presentation will include information on the advantages of mixing methods and binding agent delivery systems.INTRODUCTIONNew or existing railroad right-of-ways may cross ground with low bearing capacity. Right of way subgrade undergo deflection (strain) as loads (stress) are applied. The amount of strain or deflection of the subgrade caused by loading of a train is proportional to the stiffness of the subgrade materials. Some soils, such as tamped ballast, are very stiff and resist loads well. Other soils such as soft clay, peat, or loose sand have low stiffness and undergo substantial movement under loads. It is very desirable to have the stiffest possible material in a track subgrade. Stiff subgrade material limits deflection under load, reducing track roughness and occurrence of track defects. Mass stabilization is a geotechnical method that can be used to improve the bearing capacity or stiffness of soil in these right-of-way. Mass stabilization involves mixing binding agents into soil subject to treatment while the soil remains in-place or insitu. Variations in the design or areas subject to treatment can be used to address transmission of vibration to adjacent structures."

Jan 1, 2015

By Q. Zhang

The necessary capability of the gravity transportation pipeline system for cemented coal gangue backfilling at the Suncun Coal Mine, China, is about 74.4 m3?h-1 according to mining production and working times in the mine. It is estimated that the working velocity and maximum pipe length-backfill depth ratio of the backfill system are 3.82m?s-1 and 5.4, respectively and that the probable backfill capability of the system is 110.18m3?h-1. Results of hydraulic calculations for the backfill transportation system show that the designed backfill system is reliable in flowability and sufficient for backfill capability needs.

May 1, 2007

By Charles M. Wilk

"Mass stabilization involves mixing binding agents into marginal or contaminated soil to improve the subject material’s physical and/or chemical properties. This paper concentrates on the principles of soil mixing and benefits and application to new and existing rail right-of-way. Successfully applied in Scandinavia and other European countries, the soil mixing is now being applied in right of way in the northern latitudes of the U.S. and Canada. These regions have significant areas of “peaty” soils that can complicate construction and maintenance of rail and structure foundations. Mass stabilization can be used to improve the bearing strength of these soft soils for subsequent construction of railroads, pipelines, roads, and buildings. In civil engineering, the technology is often used to improve the construction properties such as bearing strength, of a marginal soil. In environmental engineering, stabilization is remediation treatment technology that protects human health and the environment by immobilizing hazardous constituents within the treated material. . The treatment is conducted while the subject material remains in-place (insitu). Mass Stabilization is often used to accomplish both civil and environmental purposes on the same project effectively addressing marginal soil while eliminating the expense of soil removal and replacement.This paper presents the principles of mass stabilization technology, implementation in the field and recent completed railway projects.The example rail projects will present the various benefits that soil mixing provides to railway construction and maintenance. Bench-scale studies and full scale implementation as well as soil construction properties before and after mass stabilization will be discussed. The paper and presentation will include information on the advantages of mixing methods and binding agent delivery systems.INTRODUCTIONNew or existing railroad right-of-ways may cross ground with low bearing capacity. Right of way subgrade undergo deflection (strain) as loads (stress) are applied (1). The amount of strain or deflection of the subgrade caused by loading of a train is proportional to the stiffness of the subgrade materials. Some soils, such as tamped ballast, are very stiff and resist loads well. Other soils such as soft clay, peat, or loose sand have low stiffness and undergo substantial movement under loads. It is very desirable to have the stiffest possible material in a track subgrade. Stiff subgrade material limits deflection under load, reducing track roughness and occurrence of track defects. Mass stabilization is a geotechnical method that can be used to improve the bearing capacity or stiffness of soil in these right-of-way. Mass stabilization involves mixing binding agents into soil subject to treatment while the soil remains in-place or insitu. Variations in the design or areas subject to treatment can be used to address transmission of vibration to adjacent structures."

Jan 1, 2017

By J. H. Nixon

A three phase program evaluated commercial proximity warning devices, developed and designed a microprocessor-based electrostatic field measurement instrument, and utilized this instrument to investigate the electro-static fields about power lines. The Phase I program consisted of test and evaluation of these commercially available proximity devices. The evaluation results were reported in the Phase I report entitled ?Evaluation of Proximity Warning Devices? dated 22 February 1980. The Phase II program resulted in the design and development of a microprocessor-based Distributed Sensor A.C. Electrometer which measures the electrostatic field present at 17 discrete locations along a crane boom. Operator control of the measurement system allows simultaneous electric field measurements from 17 probes, print out of the electric fields measured, and data archiving on magnetic tape for post measurement analysis. Under the Phase III program, electrostatic fields around a crane boom were measured by the instrument at 17 high voltage power lines of various voltages and geometries. The electric field data was processed and plotted versus boom distance from the power line. Analysis of the electric field data indicate that the distances at which a single sensor alarm will activate, vary by a factor of 3 to 1. This is due primarily to variations in boom orientation. The results also indicate that in the case of multiple power lines, a single electrostatic field sensor cannot reliably be used to determine the distance from a power line.

Jan 1, 1982

By Marilia S. de Magalhaes

Keywords: sinter, characterization, agglomeration, iron ore Iron ore sinters are the main burden of blast furnaces for pig iron production. The evaluation of these agglomerates is very important due to their properties affect indirectly the productivity and costs of production of the steel industry. In the sintering plants, the standard procedure of sinter assessment has been carried out by particle size control, bulk chemical analyses, tumbler and/or shatter tests and determination of reduction degradation and reducibility indexes. Microscopy techniques have just been applied to characterize sinters produced in pilot conditions, however, these techniques, the classical ones and the less traditional, allow enhancing the industrial sintering process assessment. For investigation of the phases, microstructures and fabric, reflected-light and scanning electron microscopy(backscattered electrons images) were used; for micro analytical chemical examination, energy-dispersive X-ray spectrometry; for Kikuchi patterns registers, electron backscattering diffraction. In addition to the microscopy techniques, the magnetic behavior was depicted by means of magnetic susceptibility measurements. Iron ore sinters are made up by hematite, magnetite, silicoferrite of calcium and aluminium and silicates. These phases develop either during sintering or, in some proportion, represent remnants of ores and fluxes; this is the case of some hematite and Mg-bearing silicate, respectively. From the magnetic susceptibility results, three different behaviors were determined, which are directly related to the magnetiteproportion in the samples. The phase association and proportion, the sintering conditions andthe quality assessment are some features appraised by such procedures, which reveal themagnitude of this proposal in sintering plants.

Jan 1, 2005

By N. S. Dalal, X. Shi, V. Vallyathan

"INTRODUCTIONThis paper summarizes our recent investigations of the potential role of silicon-oxygen based free radical species in the biochemical mechanism of the lung injury caused by the inhalation of freshly fractured silica. The impetus for this study came from the following observations. Inhalation of crystalline silica is associated with the development of acute and chronic silicosis. Chronic silicosis is characterized by the development of sharply marked concentric fibrotic nodules in the lung. This occurs over a period of several decades with the development of progressive respiratory impairment. In contrast, acute silicosis is manifested by the filling of the alveoli with an amorphous lipoproteinaceous exudate within a short period after exposure, and rapid development of respiratory disability often leading to fatality. Most studies on the pathogenesis of silicosis have focused on the elucidation of cellular mechanisms of cell injury and the development of chronic silicosis. Because pulmonary responses to crystalline silica are distinctly different for · the acute and chronic silicosis, we hypothesized that the acute response is associated with some unique properties of ·freshly formed silica particle surfaces, due to the formation of some reactive chemical species caused by the rupturing or the silicon-oxygen bonds. In occupations involving drilling, tunneling and sandblasting operations acute silicosis can be correlated with this unique surface reactivity of silica. The formation or reactive species was demonstrated, using electron spin resonance (ESR) spectroscopy (Dalal et al., 1986; Fuibini et al., 1987; Hochstrasser and Antononi, 1972). Grinding of quartz crystals under ultra high vacuum (10-10 torr) leads to the formation of Si- and SiO• radicals and these radicals are quenched by exposure to air and other gases (Hochstrasser and Antonini, 1972). ESR signals have also been reported from micronized quartz samples that were evacuated at 413 K (Bolls et al., 1983). In order to find a more direct relationship of such radicals to acute silicosis, we made ESR measurements on quartz dusts freshly ground in ambient air and found- that indeed grinding under ambient environment leads to the formation of the Si• and SiO• type of radicals which decay on storing the dusts in air or in biological buffers (Dalai et al., 1986; Vallyathan et al., 1988). The Si• and SiO radical formation on grinding has also been reported by Fubini et al. (1987). In addition, we recently found that •OH radicals are generated in aqueous suspensions of freshly ground quartz (Dalai et al., 1988; Shi et al., 1988; Vallyathan et al., 1988). We have subsequently carried out detailed cytotoxicity and biological assays on freshly made as well as aged quartz dusts. As summarized below, the results provide new insight into the biochemical mechanism of acute silicosis."

Jan 1, 1988

By Mandeep Singh

The smelting of lead ores has been carried out in southeast Missouri for centuries, and modern smelting practices have generated a variety of waste products. Lead blast furnace slag is one such product, which typically contains 10% zinc, 25% iron and 2% lead. This slag has often been stockpiled on the producing smelter site and accumulations have now reached several million tonnes. It is possible that in the near future these slags will be classified by the federal Environmental Protection Agency as hazardous, and therefore there is considerable interest in possible treatment processes to render the slags non-hazardous by removing the offending metallic elements. To ensure that the overall slag processing costs are kept to a minimum, it is imperative that lead and zinc be recovered in a form suitable for sale or further processing. There are two generic routes for processing blast furnace slags and they involve hydro-metallurgical or pyrometallurgical techniques. With hydrometallurgy, the slags would be leached directly and the metal values recovered from purified leach solution(s) by electrowinning. One problem with processes of this type is that the zinc and lead grades of the slags are low and the iron content is high, and thus the economics of metal production are often not favorable. For pyrometallurgical processing (1), it has been shown that the slags can be fumed to produce an oxide dust containing all the lead and zinc, and representing only a fraction of the weight of the initial slag. The oxide dust may then be processed hydrometallurgical to recover zinc and lead.

Jan 1, 1992

The maximum current density at which conventional copper electrowinning plants will result in satisfactory, adherent, and dendrite·free cathodes is determined by the thickness of the diffusion boundary layer. A decrease in the value of that thickness will permit an increase in the current density. This fact is utilized to develop a high current density cell in which the reduction of the boundary layer thickness is accomplished by means of a specially designed electrolyte circulation system. The high current density cell is used to determine the effect of current density on such process parameters as current efficiency, cell voltage, power consumption, and cathode purity. A number of empirical equations are developed for the purpose of estimating the magnitude of these effects.

Jan 1, 1972

By R. Chryst, R. Kus

In the Integrated IT Systems proposed by Przedsie? biorstwo Robót Geologiczno-Wiertniczych—Geological and Drilling Company (PRGW) a network connects a database with all of the departments of a mining division. A key element thereof is the common graphics environment—Micro Station supplied by the firm, Bentley. PRGW’s SoftMine software and GMSI’s CadsMine that are used to design and schedule mining operate in this environment. The digital form of the design project facilitates the verification of information and the integration of technical solutions with SAP R/3 type financial—accounting systems. The system has been successfully implemented in the Brown Coal Mine in Poland.

Jan 1, 2003

By W. J. Miles

Many years ago, a relationship was established between dust inhalation and pneumoconiosis. Since then, various government agencies have regulated crystalline and amorphous forms of silica material in the workplace. In 1987, the International Agency for Research on Cancer (IARC) classified crystalline silica as a probable carcinogen. With this listing, crystalline silica became a regulated substance under the Hazard Communication Standard. The minerals and chemicals industries have responded in various ways. They have: • developed worker and user training programs and literature; • labeled products with appropriate warnings; • continued to implement dust reduction programs; and • developed meaningful epidemiological studies of workers. • begun development of reliable analytical methods for measuring crystalline silica at the 0.1 % threshold level; Background Silicosis historically has been the major health hazard resulting from exposure to crystalline silica. Silicosis is the scarring of the lung from excessive exposure to crystalline silica. It has been recognized as an occupational disease for more than 2000 years, since early Greek physicians noted the respiratory problems of miners, stonecutters, and quarrymen who were exposed to excessive quantities of mineral dust. During the industrial revolution, the incidence of the disease was greatly increased by the use of machinery that increased dust levels. Subsequently, the need for dust control was recognized and measures were instituted. Silicosis is characterized by progressive breathlessness on exertion and develops over the course of years. Xray images of the lungs show

Jan 1, 1990

By Lloyd L. Farnham

This paper is one of a series describing the mineral resources of the Nation, including location, history, production, ownership, geologic setting, and mining methods for most of the known manganese deposits in New Mexico, With few exceptions these descriptions are the result of field examinations by the writer. Of 32 counties, the 12 which occupy the western half of the State contain all the known manganese deposits, These counties are Catron, Dona Ana, Grant, Hidalgo, Luna, Rio Arriba, Sandoval, Santa Fe, Sierra, Socorro, San Juan, and Taos. (See fig. 1.)

Jan 1, 1961

The Black Hills Mineral Atlas briefly summarizes all important data available on the mines and mineral deposits in the Black Hills that have been explored, developed, mined, or located. The purpose of the atlas is threefold; First, from available data the general potentialities of the Black Hills region can be determined, although it is not possible to calculate actual ore reserves; second, it will provide the necessary basic information regarding a given property or commodity for further detailed study; and third, the compilation is a comprehensive directory of Black Hills deposits.

Jan 1, 1955

The Black Hills Mineral Atlas briefly summarizes all pertinent date available on the mines and mineral deposits in the Black Hills that have been explored, developed, mined, or located. The purpose of the atlas is threefold: First, from available date the general potentialities of the Black Hills region can be determined, although it is not possible to calculate actual ore reserves; second, it will provide the necessary basic information regarding a given property or commodity for further detailed study; and third, the compilation is a comprehensive directory of Black Hills deposits.

Jan 1, 1954

By R. E. Powers, E. H. Kinelski, H. A. Morrissey

A group of 17 American blast-furnace sinters, an American open-hearth sinter, an American iron ore, and a Swedish sinter were used to evaluate testing methods adapted to appraise sinter properties. Statistical calculations were performed on the data to determine correlation coefficients for several sets of sinter properties. Properties of strength and dusting were related to total porosity, slag ratio, and total slag. Reducibility was related to the degree of oxidation of the sinters. THIS report to the American iron and steel industry marks the completion of a 1949 survey of blast-furnace sinter practice sponsored by the Subcommittee on Agglomeration of Fines of the American Iron & Steel Institute. The use of sinter in blast furnaces, sinter properties, raw materials, and sinter plant operation have been reported recently.1,2 After preliminary research and study," test procedures were adapted to appraise the physical and chemical properties of sinter to determine what constitutes a good sinter. During the 1949 to 1950 plant survey each plant submitted a 400-lb grab sample to research personnel at Mellon Institute, Pittsburgh, Pa. A 400-lb sample was also submitted from Sweden. In addition, 2 tons of group 3 fines iron ore were obtained from a Pittsburgh steel plant. The following tests were performed on the iron ore sample and on the 19 sinter samples: chemical analysis; impact test for strength and dusting; reducibility test; surface area measurements, B.E.T. nitrogen adsorption method; S.K. porosity test; Davis tube magnetic analysis; X-ray diffraction analysis for magnetite and hematite; and microstructure. Results of these evaluations are discussed in this paper and supply a critical look at testing procedures used to determine sinter quality. Sinter Tests and Results Each 400-lb grab sample of sinter was secured at a time when it was believed to represent normal production practice at each plant. It was not possible to use the same sampling procedures throughout the survey; consequently samples were taken from blast-furnace bins, cooling tables, and railroad cars. These were very useful for evaluation of test methods, since they were obtained from plants with widely divergent operations. With the exception of Swedish sinter and sinter sample N, which were produced on the Greenawalt type of pans, all survey sinters were produced on the Dwight-Lloyd type of sintering machines. Sinters submitted for test were prepared in identical manner by crushing in a roll crusher (set at 1 in.), mixing, and quartering. To secure specific size fractions for tests, one quarter of the sample was crushed in a jaw crusher and hammer mill to obtain a —10 mesh size. The remainder was screened to obtain specific size fractions. The group 3 fines iron ore was dried and screened and samples were taken from selected screen sizes to be used for various tests. Prior to testing, each ore sample except the —100 mesh fraction was washed with water to remove all fine material and was then dried. This iron ore, a hematitic ore from the Lake Superior region, was used as a base line for comparing results of tests on sinters. The iron ore did not lend itself to impact testing, since it was compacted rather than crushed in the test, and no impact tests are reported. However, the iron ore was subjected to all remaining physical tests to be described. Chemical Analysis: Table I presents chemical analyses performed on the survey sinter samples. Included in this table are data obtained from determination of FeO and the slag relationships: CaO + MgO and total slag (CaO + MgO + SiO, SiO2 + Al2o3 + TiO2). The percentage of FeO was used as an indication of the percentage of magnetite in the sinter. It was believed that slag relationships could be correlated with sinter properties. During initial determination of FeO great disagreement arose among various laboratories, both as to the results and the methods of determining values. Table I lists the values of FeO resulting from the U. S. Steel Corp. method of chemical analysis,' which reports the total FeO soluble in hydrochloric and hydrofluoric acids (metallic iron not removed) with dry ice used to produce the protective atmosphere during digestion. Use of dry ice was a modification required to obtain reproducible results. In this method, the iron silicates and metallic iron are believed to go into solution and are therefore reported as FeO. This is important, for in the study of the microstructure of sinters, glassy constituents suspected of containing FeO as well as crystallized phases of undetermined identity which may also contain FeO have been observed. Strength Test by Impact: In evaluating sinter quality, one of the properties stressed most by blastfurnace operators is strength. This strength may be described as the resistance to breakage during handling of sinter between the sinter plant and the blast-furnace bins. It is also the strength necessary to withstand the burden in the blast-furnace. After

Jan 1, 1955