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A simulation of a capper concentrate smelter was built with a capacity of 450,000 tons per year. The system's components to simulate were three : a Reverbetory furnace, a Wiente ' s modified converter ( TMC ) and two cranes. The system was classified as dynamic, stochastic and discrete. In the simulation language choice it was concluded that the most advantageous one was GPSS/H. The model verification was done through the interactive Debugger that the language has and the statistical validation was done through the result variables of sane activities, that as a whole characterize the system (charged matte and charged concentrate to the TMC, skimming white metal and skimning slag). The validation was done comparing the simulation results of these variables with the ones obtained for those variables in a specific month in the smelter. The comparison consisted in a difference of means test and in all cases the equality was accepted with a 95% of confidence. The animation tool was PROOF, a general purpose animator, that is used after processing the simulation.

Jan 1, 1994

By A. M. Thyer

Throughout the history of mining, underground fires or explosions have killed many hundreds or thousands of people. Fortunately, the safety record has gradually improved as a result of many people’s work on improving safety standards and work practices. However, fire and explosion still remains a threat in many situations. As a result the UK Mines Inspectorate commissioned a project to study materials used underground and to develop a fire/explosion risk assessment system. Such a system has been developed, following the study of incidents, specified fire resistance criteria, and fire safety practices. The final methodology uses a series of check sheets to identify potential fuels and ignition sources, preventative measures, fire/explosion mitigation systems, and items for inclusion in emergency plans.

Jan 1, 2003

By Kevin Andrews, SETAREH GHAYCHI AFROUZ

Ground control analysis and groundwater inflow assessments for underground coal mines require in-depth field investigations including, but not limited to, geological and geotechnical core logging, downhole geophysical logging, laboratory rock strength testing, and packer (Lugeon) testing. Field and laboratory data collection are time consuming and expensive, and an initial understanding of the expected trends among various geotechnical and hydrogeological parameters can assist with the planning and optimization of geotechnical characterization studies and grouting plans. In this study, a comprehensive database is analyzed, comprised of important rock mass characteristics (hydraulic conductivity, rock quality designation (RQD), and lithology) for coal-bearing rocks in the Central Appalachian Basin. Statistical analysis of the data is completed to establish an enhanced understanding of geotechnical and hydrogeological conditions expected to be encountered as underground coal mining passes near and beneath streams and rivers. The results of the study provide valuable reference material for the coal mining industry for completion of shaft installations, mine stream crossings, environmental assessments, and grouting and mine dewatering designs.

Jul 1, 2023

By Bowen Li, Matthew D. Andriese, Jiann-Yang Hwang, Zhiwei Peng

"Magnetic iron sulfide ore particles heat rapidly by microwave (MW) irradiation generating plasma during oxidation of surfaces. The high temperatures produced by the exothermic event decompose local portions of samples forming a differentiated flux of partially melted silicate (si-mt) with entrained metal-sulfide (sul-mt) droplets. The si-mt forms crystals of olivine (01) in Ca-rich pyroxene (Cpx) melt that resorbs a portion of iron sulfide (Po). The immiscible sul-mt droplets of (Fe,Ni,Cu)1-xS contain magnetic subsolidus Ni-pyrrhotite (Ni-Po) with Cr-bearing ferrospinel (Mag). Sub-micron sized flecks of Au are found on the surface of a sul-mt droplet with scanning electron microscope (SEM).IntroductionSulfide ore deposits supply the world's mineral resource in the production of non-ferrous metals. Particularly, Cu-Ni deposits are chemically enriched in metals from high sulfur saturation during magmatic formation that creates the proper geochemical environment for metals enrichment [1, 2]. The sulfur and oxygen fugacity control redox conditions of a differentiated silicate/sulfur magmatic melt with the concentration of iron playing a dominate role in the chemical partitioning of metals in sulfide liquid [3, 4]. The initial magnetic crystallization of (Fe,Ni)i-xS monosulfide solution (mss) from metal-sulfide liquid has an exclusive effect on the fractionation of mineral assemblages (zoning) [5].Phase equilibria of sulfide melt (sul-mt) components are related by a miscibility gap with mss forming Ni-rich pyrrhotite (Ni-Po) followed by the crystallization of (Fe,Cu)1-xS intermediate sulfide solution (iss) [6]. Precious metals form stable chacogenides and are retained in solution until the final liquid solidifies. The redistribution of metals now occurs by subsolidus cooling of mss and iss that exsolve low-temperature Fe-Cu-Ni bearing mineral assemblages [7]. The proper interpretation of ore genesis increases processing capabilities by isolating chemically enriched zones during extraction and should be used to aid in sustainable mine site development [8-11]."

Jan 1, 2013

By A. S. Azman

The mining workforce experiences high rates of hazardous noise exposure and hearing loss. However, previous studies have identified specific behavioral and attitudinal barriers that keep miners from effectively acting to prevent their own hearing loss. NIOSH has developed several new hearing loss prevention tools and interventions that specifically target these barriers to prevention. The NIOSH Hearing Loss Simulator addresses motivation to take action and knowledge about the consequences of noise exposure. The QuickFit earplug test device and QuickFitWeb online hearing protection tester address barriers to effective earplug and earmuff use by verifying at least 15 decibels of protection. The NIOSH Roll-Pull-Hold technique helps miners obtain better protection through an easy-to-remember set of steps that improves attenuation by 9 decibels. The ?Inquiring Ears Want to Know? fact sheet helps miners to understand audiograms and to use them to maintain their hearing health. Each of these interventions can be used within the context of a comprehensive hearing loss prevention program.

Jan 1, 2010

By AIME AIME

AN enthusiastic crowd, cheerfully confident that the upturn in the oil industry has arrived, gathered in Los Angeles on Sept. 29 for a Petroleum Division meeting arranged by the Southern California Section. The assembly room of the California Oil and Gas Association was the place of meeting. H. Norton Johnson was in the chair for the morning session, with about eighty members and guests present. Four papers were presented before lunch and a fifth, on electrical coring, was withdrawn as the work on which it was based is still confidential. Joseph Jensen read his contribution on the "Kettleman Hills Middle Dome Unit Plan" and, as he had an active part in framing the plan, his outline and discussion of it was authoritative and informing. J. H. Woods asked concerning the operation of the casing-head gasolene plant under the plan and was informed that one company would operate the plant and royalties would be paid participating companies

Jan 1, 1933

By A. J. de Witte

INTRODUCTION The importance of determining dips of subsurface formations in wells, especially in wildcat wells, is self-evident and need not be enlarged upon. Various dipmeter instruments have been described in technical literature1,2,3,4 over the years. The introduction of the continuous dip-meters3,4 has made the earlier types obsolete. Continuous dipmeter logs are run by at least two different major service companies. Included as part of the service are a limited number of dip calculations—usually 10—made at different levels from the log. Very frequently this is the total result of a dip survey. It is believed that dipmeter surveys would be of considerably more advantage if geologists and engineers were able to make their own calculations from the original records. Determination of dips from the dipmeter record starts with the correlation of three log curves taken at different sides of the borehole. It cannot be over-emphasized that the quality of the results hinges primarily on this correlation. Nobody should be better qualified to correlate logs than a subsurface geologist or field engineer. The next requirement is to have an easy yet accurate way of computing the dip from the correlated points. Service companies use a mechanical device for this purpose. Directions for a graphical method were given in a recent article by B. 0. Prescotts. This paper describes a different graphical technique which, in our experience, is simpler, faster and at least as accurate. The entire manipulation is carried out on the stereonet in a number of easy moves. The paper is divided into two parts. This first part contains the introductory sections and full explanation of the geometry involved. The second part reviews the reading of data from an actual field log and summarizes the practical rules for computation of dips, the whole process being illustrated by an example. Following the outlined procedure, one could calculate a good many levels in a relatively short time, thus being able in particular to check suspected anomalies such as fault zones or unconformities in as close detail as the log will permit. GENERAL EXPOSITION OF THE METHOD Prnciple of the Dipmeter The position of a plane in space is defined by the location of three points, not on a straight line. Referring to Fig. I, if a borehole traverses a bedding plane, we can determine the strike and dip of the bed by finding three points which are not in line along this plane. Such points as A, B, and C are obtained with the dipmeter. The device consists of three electrodes (or caliper arms)1, 2, and 3 spaced at 120 angles, as schematically indicated, whose readings are separately recorded (Curves 1, 11, 111, to the right). When electrode 1 passes the boundary of the bed, Curve I will kick, etc. From these curves, we know the relative distances of points A, B, C, measured along the axis of the hole. If A is at zero, then B and C are at levels d1 and d2 up the hole,

Jan 1, 1957

By J. Bulina, J. T. Brown

SINCE the inception of vacuum cold-hearth arc melting of high-temperature alloys (about 4 years ago) it has been theoretically reasoned and qualitatively found that better mechanical properties are often obtained from alloys which have been melted by this practice. Mechanical properties are emphasized in this evaluation because of their importance in design. Vacuum-arc melting has an intrinsic advantage in that it creates an ingot grain structure which is easier to forge and thus leads to greater yields for the finished product. The greater yield naturally gives the process an economic basis when the cost per pound of alloy is rather high. However, the question stressed here is, does the process create an alloy with inherently better properties? There are several theoretical reasons for suspecting that it does. One is the vacuum refining which should permit lowering the content of harmful residuals with high vapor pressures. A second is the vacuum process which should preclude the formation of harmful distribution of oxides, nitrides, or carbo-nitrides, by keeping the amount of such constituents formed to a minimum. A third is the vacuum-arc cold-hearth method which prevents the possibility of pick-up of harmful elements from a refractory crucible since none is used. Fourth, the rapid solidification rate, induced by having a cold mold and only small amounts of molten metal at any one time, minimizes the segregation of elements like titanium, aluminum, and molybdenum from the top to the bottom of the ingot. This rapid solidification rate also decreases the tendency of the above elements to form undesirable phases by segregating locally. Another less frequently considered vacuum-arc melting advantage is the inherently finer-grained ingot structure which can be produced. Finer initial grain size leads to better forgeability, and means that after relatively small reductions to billets or final forged products a finer-grained material is obtained, which, by virtue of its finer grain size, would usually have greater stress-rupture ductility.

Jan 1, 1960

By J. R. Linney

Demand for eastern magnetite in 1948 necessitated practically all eastern magnetite industries to operate on a six-day week, with the result that over 11,000,000 long tons of crude ore were mined, and the shipping products amounted to approximately 5,000,. 000 long tons. Reports indicate that operating on a six-day week and doing maintenance work on the seventh day was satisfactory and resulted in excellent continuity of operation. In the Port Henry district, Republic Steel Corp. once again set new all-time records for the production of crude ore and total shipping product; 1,868,000 long tons of crude ore were mined, 945,000 from the Old Bed mine, 408,500 from the Harmony mine, and 514,500 from the Fisher Hill mine. Of the 969,000 long tons of shipping products, 663,800 long tons were sinter, 181,000 lump ore, and 115,200 con¬centrates.

Jan 1, 1949

By C. Dorfling, P. Albertyn

"Hydrometallurgical recovery of metals from printed circuit board waste typically involves multiple leaching stages; conventionally, base metals dissolution by mineral acids is followed by leaching of gold using cyanide or halide based lixiviants. Alternative lixiviants for gold leaching can reduce the potential hazardous nature of operation. The aim of this study was to investigate the feasibility of using thiosulfate as lixiviant for gold leaching from waste printed circuit boards. Batch leaching tests were performed to investigate the effects of thiosulfate concentration (0.1 – 0.2 M), ammonium concentration (0.2 – 0.4 M), pH (9 – 10.5), solids content (25 – 50 g/L), and copper content of the feed material on the gold leaching behavior. The concentrations of metals in liquid samples were determined by means of inductively coupled plasma atomic emission spectroscopy, and high pressure liquid chromatography was used to evaluate thiosulfate degradation/consumption. The ratio of thiosulfate to ammonia was found to have the most significant effect on the extent of gold leaching, with the best gold extraction observed at a ratio of 0.5 mole thiosulfate per mole ammonia. The lower pH range of 9 – 9.5 generally produced better Au leaching, while low copper extraction during the first stage base metal leaching stages has proven to be detrimental to gold leaching from the residue. Thiosulfate degradation/consumption increased and gold extraction decreased with higher residual copper in the feed. An optimum gold extraction of 78.5 % from base metal leach residue was achieved with 0.2 M thiosulfate, 0.4 M ammonia, and 0.02 M cupric ions at 25°C in the pH range 9 – 9.5.INTRODUCTION Background and Aim The recycling of e-waste is becoming increasingly important as it provides certain economic benefits apart from the obvious environmental benefits. Printed circuit boards (PCBs) are found in most forms of e-waste and contain especially high concentrations of base and precious metals. Hydrometallurgical processes are often considered for the recovery of valuable metals from PCBs; these processes normally implement several leaching stages to selectively recover certain metals."

Jan 1, 2018

By Huang Daguang, Paulo Couceiro, Juan Navarro

Mining is typically conducted through a set of interdependent unit-operations, which commonly include drilling, blasting, digging and hauling, in order to deliver the required ore material into the comminution circuit and to remove waste rock with minimum impact in the operation. In such complex environment, the identification of critical paths, and respective interfaces between different unit-operations, are necessary to determine a sustainable long-term operational program. Facing this challenge, adaptive cost optimization strategies are required to increase productivity and revenue while minimizing potential environmental impacts. Since the overall mining efficiency can be strongly impacted by blasting outcomes, an operating method based on the searching of the ideal blast design is required in order to minimize the mine total cost of ownership. The implementation of a consistent continuous improvement program requires specific care in terms of design, control and execution of the different stages of blasting. For that, the application of the most advanced technologies for rock characterization, based on drill monitoring systems, and smart explosive products, allows the improvement and control of blast results by adapting the explosive energy distribution to the rock condition, so as to optimize the performance of downstream stages such as digging, hauling and comminution. This paper describes the application of a heuristic optimization approach, where blast parameters are used as decision variables to evaluate the potential impact of several blasting scenarios on subsequent unit operations, under the continuous ability of modelling, measuring and calibrating operational performances along of the mine cycle.

Feb 6, 2023

By Kenneth S. Johnson

Large reserves of high-purity Permian gypsum crop out and are at shallow depth in three regions of western Oklahoma, Gypsum beds in the Blaine Formation are 10 to 30 feet thick and are generally 95 to 99 percent pure, whereas the massive Cloud Chief Gypsum is 20 to 100 feet thick and is 92 to 97 percent pure. Reserves are estimated at 48 billion short tons. Eight companies in the State currently mine about 1 million tons of gypsum each year for wall- board, for plaster, as a retarder in portland cement, and as a soil conditioner. Future uses, under more favorable market conditions, may be in the chemical industries, largely because of gypsum's potential as a source of sulfur. Three thick sequences of Permian rock salt underlie most of western Oklahoma at depths of 30 to 3,000 feet. Individual salt beds 5 to 30 feet thick are interbedded with thinner layers of shale and anhydrite. Five large salt plains, fed by natural springs of saturated brine constitute additional resources of salt. Reserves, estimated at 20 trillion short tons, are virtually untapped, and, ironically, about 90 percent of the salt used in Oklahoma is imported. Chemical data on the rock salt are lacking, but evaporated salt produced from brines is generally 97 to 99 percent pure. Current production from three solar-evaporation plants is used mainly for stockfeed, recharging water softeners, and deicing roads. Potential uses are in the chemical industries, where salt or brine is a necessary raw material.

Jan 1, 1973

By H. H. Uhlig

IN our study of the mechanism of and the prevention of corrosion in stainless steels, it was considered of fundamental importance to obtain knowledge of the surface structure of such alloys. If corrosion resistance is due to a self-healing oxide layer, which like a paint film protects the underlying metal, it would be obviously relevant were the effort made to make the film less permeable and more adherent; for example, the surface might be expected to respond to an anodizing process, which is found successful in increasing the film thickness and corrosion resistance of aluminum. However, if passivity and corrosion resistance of stainless steels are due to another cause, the attack of the problem would follow another path. One of the most effective techniques for studying passivity and corrosion tendency is the measurement of the electrochemical potential. Not only can one determine by potential measurements whether a metal is active or passive, but also one can determine the degree of passivity and rate of transformation of passivity with time. Chemical media that build up or destroy passivity when in contact with the steel can also be classified by potential measurements. Something can be learned, too, of the effect of alloy additions such as molybdenum to 18-8, known to decrease corrosion of the alloy in chloride solutions. A study of alloys in previous investigations has sometimes included data on the electrochemical potentials. Tammann and Sotter1 measured the electrochemical potentials of alloys of iron-molybdenum and iron-chromium and reported the critical concentration of molybdenum or chromium at which passivity initiates. Strauss2 made similar measure-ments for the iron-chromium system. The electrochemical potential' has also been used to indicate carbide precipitated 18-8. In 18-8, heat-treated to precipitate carbide, active metal exists at the region of the grain boundaries, contrasted with passive metal within the grains, the active metal accounting for a resultant active potential. Several

Jan 1, 1939

By R. A. Williams

The Pascua Lama Project is situated on the border of Chile and Argentina at an elevation of 4,800 m. The ore contains gold, silver and copper, and an initial milling production rate of 33,000 t/d is planned. The mineralogy of this deposit is unusual. The ore is hard and abrasive, and it contains a complex array of sulphate minerals, such as chalcanthite, jarosites and alunites. The sulphides are predominantly enargite and pyrite. A novel flowsheet has therefore been developed, which includes dry grinding and ore washing to remove and then neutralize the soluble salts, prior to flotation, cyanide leaching and Merrill-Crowe recovery of the precious metals. These metallurgical issues and challenges associated with plant design and construction in the high and remote Andes Mountains make this a particularly challenging project.

Jan 1, 2001

By B. Larsen, S. Z. Nascimento, K. Fidje, J. P. M. Amaro, H. Gran

Safe and good operation of Søderberg electrodes is dependent upon high quality electrode paste coupled with correct electrode operating procedures. Good electrode performance depends further on proper melting and densification of the electrode paste. The melted paste should form a dense and viscous layer that prevents gasses from the baking process to move upwards. Both paste cylinders/blocks and briquettes can be used, but the procedures may differ between the various types of paste products. For briquette columns the formation of the important viscous layer is obtained through melting and densification of the briquettes. By basic rheological studies of electrode paste and by laboratory tests of briquette beds at isothermal conditions we have achieved a better understanding of the melting process. The effects of temperature gradients, pressure and friction between the briquettes and the electrode casing have also been evaluated qualitatively in pilot scale experiment and in industrial scale tests. The paper shows that melting and densification starts at a considerable lower temperature than the pitch softening temperature. It is concluded that the formation of a briquette electrode column depends on parameters as temperature, briquette column pressure and the friction. Operating conditions influencing the above parameters should be defined and established for each specific furnace operation. Such factors are e.g., charging and slipping procedures, column heating and electrical conditions.

Jan 1, 2004

By D. J. Hutchinson, M. Lato, M. Diederichs

Light Detection and Ranging (LiDAR)-based applications for geomechanical purposes have recently proven to be a highly reliable and accurate form of remote analysis and documentation. The ability to remotely collect, process and evaluate rockmasses for structural geomechanical applications has benefits ranging from safety to efficiency, and provides a permanent record that can be assessed before and after an excavation has been completed. With the collaboration of Queen’s University and Rio Tinto, the Iron Ore Company of Canada (IOC) mines in Labrador City, Newfoundland and Labrador, evaluated the practical application of the I-Site 4400 LiDAR equipment, in conjunction with the Vulcan geotechnical module for geomechanical purposes. The project provided a comparative analysis between conventional hand-mapping and digital analysis. The analysis indicates that digital mapping could be employed as an active tool within the general geotechnical workflow, where results would be used in pit wall and rockmass support designs. As well, the field work enabled the generation of effective operational guidelines and protocols to maximize scanning efficiency.

Jan 1, 2009

The disadvantages of the present zinc producing methods, RLE and ISP, are high energy consumption and environmental problems. Therefore, efforts have been directed in Outokumpu Zinc towards the development of alternate routes. One interesting pyrometallurgical process to produce zinc is to inject zinc calcine together with a solid reductant into molten iron, saturated with carbon. This process has been studied by thermodynamic calculations, laboratory tests and mini-pilot test runs at Outokumpu Research Oy, Pori, Finland. The results of these tests are presented and discussed in this paper. The mini-pilot tests demonstrated that over 97 per cent evaporation of the zinc was possible using a reactive coal dust as the reducing agent. The recovery of zinc in the metal phase was at best 88 per cent of input zinc, but only part reported in molten lead in the splash condenser. The final metallic zinc contained at best 98 per cent Zn, the main impurities being dissolved lead and coal carried along with the flue dusts.

Jan 1, 1993

By Strathmore R. B. Cooke, Eugene L. Talbot

THE perfluoro acids and derivatives show unusual surface-active properties that qualify them as possible flotation reagents. They lower the surface tension of water from 15 to 20 dynes below that obtainable with the corresponding hydrocarbon compounds.1, 2 Fluorochemicals adsorb very strongly on solid surfaces to give films that exhibit larger contact angles than films of the corresponding hydrocarbons."' * The large contact angles probably result from the terminal —CF3 group. The perfluoro acids are made by electrolysis of the corresponding carboxylic acid in anhydrous hydrogen fluoride.5 From the perfluoro acids many derivatives may be obtained, such as amides, amines, alcohols, xanthates, ethers and esters and others. Since the fluorinated analogues of the conventional hydrocarbon flotation collectors possess enhanced surface properties, a few were selected for testing. Because a survey of all possible minerals and reagent combinations would be out of the question, hematite was chosen to represent a nonsulphide system and pyrite to represent a sulphide system. The fluorinated reagents used in these experiments were prepared in the research laboratories of Minnesota Mining & Mfg. Co. Some were synthesized especially for this research. They are not available cokmercially. Separation of Nonsulphide Ores: The separation of oxides from silica has always been a challenge to the flotation industry because differences in surface properties of the minerals are normally insufficient to produce clean concentrates. Oleic acid," rosin acids,' and amine salts% ave been used to considerable extent to effect separation of metal oxides and silica. The system hematite-silica was chosen to represent the nonsulphides both because of its difficulty of separation and because large tonnages of easily obtainable material are available, such as gravity concentration tailings and nonmagnetic taconites on the Mesabi Range. The wash-ore tailings used here contained approximately 35 pct iron after desliming. Samples of the material used in this work were part of the same lot used by Chang, Cooke, and Huch9 and were prepared in an identical manner. Reagents for Nonsulphide Ores: Since one of the purposes of this investigation was to compare hydrocarbons with fluorocarbons, reagents of known behavior such as oleic acid, and the alkali metal salts of certain resin acids (Dresinates), were established as standards. Hydrocarbons and fluorocarbons of comparable chain length and other experimental fluorocarbons were tried as collectors for hematite. A list of the materials used and the concentrations of their stock solutions are given in Table I. Since silica can be selectively floated from hematite by conventional reagents," a few fluorocarbon reagents were also tried for this purpose. Their composition and concentrations are given in Table 11. Most of these reagents served the dual function of collector and frother. In the case of F-11 flotation did not occur but it served as a frother when F-6 was employed as a collector. Reagent grade sulphuric acid and sodium hydroxide were used to regulate the pH. Deionized water containing less than 0.1 ppm of salts expressed as NaCl was used for all solutions and flotation tests. The pneumatic flotation cell consisted of a 350-ml fritted glass Buechner funnel with a source of filtered air which could be controlled by a needle valve." A 50-g sample of ore and 250 ml of deionized water were added to the flotation cell and stirred slowly. The reagents were added and the pulp was conditioned before air was admitted to the cell. Approximately 15 ml of the pulp were removed for pH determination before flotation was started and were then returned to the system. The pH was again measured after flotation. Air was admitted to the cell until no further flotation occurred or until the character of the float changed markedly. Both the float and the nonfloat products were filtered, dried, weighed. and assayed for iron. The cell was washed in hot water and rinsed with deionized water after each test. Occasionally the cell was cleaned with concentrated hydrochloric acid to remove iron oxide particles from the glass frit. Experimental Results: Above a pH of 8, sodium oleate was an effective collector for hematite. The emulsification of equal parts of heavy fuel oil (20"

Jan 1, 1956

Lower the respirable dust exposure of longwall shearer operators by keeping the dust cloud confined to the face. Approach Change the location of face-side machine cooling, water sprays. How It Works The dust breathed by the longwall shearer operator is usually produced by the shearer itself. The dust cloud originates at the face, and the exposure of the operator depends largely on how quickly this cloud spreads into the walkway. Water sprays on the shearer body can have a large effect on dust cloud spreading. Results to date indicate that sprays can help confine the dust cloud to the face if they are carefully placed. Otherwise they can make dust levels far worse. The worst offenders are often face-side sprays used to discharge cooling water from the cooling jackets of the shearer motors. These face-side sprays set up an air circulation pattern as illustrated in the drawing. Air induced by the sprays to flow towards the face, raises the air pressure in front of the face, which causes the air flow to turn and then move back over the shearer, bringing dust with it into the walkway.

Jan 1, 1981

By Andrey Dmitriev

The solution of set of equations for the bottom zone presented by a condition of a thermodynamic equilibrium, namely, an equilibrium constant of wustite reduction by carbon oxide, material and thermal the balances, supplemented by the equation of the heat balance for the top zone, allows to calculate the base indices of blast furnace smelting. The calculated indices are extreme accessible at the given parameters of charge and blast. Application of actual degrees of the use of gas instead of equilibrium allows the calculations of actual indices of the blast furnace smelting process.

Jan 1, 2006