Search Documents

By Philip Barnhard, Lyman G. Bahr

By recording the arrival time of a pipe wall at evenly spaced intervals in a plane perpendicular to the pipe axis, application of the equations of motion permits calculation of the pressure of the explosive acting to accelerate the pipe wall. Data observed from various non-ideal explosives are presented, together with values of pressure to be expected from thermodynamic calculations.

Jan 1, 1981

By R. P. King

A new device, called the dual impact load cell, has been developed and built at the Comminution Center to measure fracture energy and damage accumulation in brittle particles that are subject to impact. The results show that damage accumulation during impact is not a significant factor in determining the fracture energy or the particle strength. However, predamage induced by thermal pretreatment of the particles has a significant effect on both fracture energy and particle strength.

Jan 1, 1995

By Lei Pan, Roe-Hoan Yoon

"Direct force measurement for bubble-particle interaction has been difficult due to bubble deformation, which makes it difficult to know the separation distances between the two macroscopic surfaces. In the present work, we have developed a method of monitoring the deformation accurately, while directly measuring the interaction forces. In effect, we can ‘see’ bubbles interacting with mineral surfaces under different hydrodynamic and chemical conditions and determine both the hydrodynamic and surface forces involved. In the present work, a high-speed camera has been used to record the optical interference fringes of a thin liquid film (TLF) of water formed on a mineral surface. The recorded fringes are then used to reconstruct the spatiotemporal profiles, from which one can determine the hydrodynamic pressure using the Reynolds lubrications theory. From the forces directly measured in the present work and the hydrodynamic pressures obtained from the fringes, we have determined the disjoining pressure. The results show that air bubbles interacting with hydrophilic surfaces form stable TLFs with zero contact angles. The TLF formed on a hydrophobic surface thins fast, form a ‘pimpled’ film, and ruptures to form a finite contact angle. The new information obtained in the present work may be useful to better understand the role of hydrodynamic and surface forces affecting bubble-particle interactions."

Jan 1, 2014

By S. Assemi

Interaction forces between a hydrophilic silica particle and an air bubble were measured by atomic force microscopy using simplified model systems with deionized water and dilute KCl solutions. Contributions from the hydrodynamic force were minimized by using a low piezo speed. Particle-bubble separation distance and the bubble spring constant were calculated from linear regression of the piezo extension versus cantilever deflection. The bubble surface potential was then estimated from fitting the AFM-measured forces to the Hogg-Healy-Fuerstenau (HHF) model, using the surface element integration (SEI) method. Surface potentials obtained for the bubble at a low applied force were comparable with the literature data, suggesting that the simplified model used here can give a reasonable estimation of the bubble surface potential under moderate applied forces. Interaction forces between a silica particle and an air bubble were also measured at different locations on the air bubble surface. The force curves obtained at the edges of the bubble fitted very well to the theoretical force curves regardless of the applied force, while curves obtained at the center and halfway to the center, were more difficult to fit, in particular at higher applied forces (> 13 nN), suggesting that force curves obtained at the edges of the air bubble might be less prone to deformation effects.

Jan 1, 2008

By J. A. Finch, Zhenghe Xu

The competitive adsorption of xanthates on sulphide minerals in a binary mineral system (pentlandite and pyrrhotite) was studied using the pseudo-in-situ technique of attenuated total-reflectance FTIR spectroscopy. The minerals were placed in the same collector solutions, either separated by a glass wall or in direct contact with each other before magnetic separation and separate analysis. The effect of mineral interaction on xanthate adsorption was clearly demonstrated spectroscopically for the first time. At low concentrations of xanthate, its adsorption on pentlandite was activated by physical contact with pyrrhotite; the effect may be attributed to the enhancement of electron transfer through electrical contact between the two minerals. The results emphasise the need for caution in extrapolating results obtained from single-mineral studies to flotation practice

Jun 18, 1905

By S. E. Khalafalla

A method for preparing ferrochromium alloys containing less than 2 pct carbon has been devised in a single vacuum furnace reactor. This method can conserve chromium and should reduce the capital and energy requirements relative to chromite electrothermal reduction. Reduced products containing less than 2 and as low as 0.01 wt pct carbon were obtained by reacting pellets of chromite and carbonaceous reductant mixtures at pressures of 0.1 to 1 ton and temperatures of 1,230° to 1,320° C. The extent of reduction increased with increased temperature and decreased pressure; however, operating conditions were limited due to the onset of significant chromium vaporization at higher temperatures and lower pressures. Foundry coke, anthracite, and carbon black were found to be superior to graphite as reductants. The reduction of chromite to metallics was found to proceed via the carbide intermediates Fe3C or Cr3C2. Lime accelerates the. rate of solid state reduction of chromite and can shorten the furnacin1r time at 1,3000 C under vacuum from 13 hours to less than three hours. Additional lime and silica are added to the hot reduced chromite after releasing the vacuum and raising the furnace. temperature to 1, 700° C. Soaking the charge for about 20 minutes gave a button of low carbon ferrochromium alloy beneath a well-defined slag layer.

Jan 1, 1985

By Tong Qin, Jinxia Zhang, Fusheng Niu, Limei Bai

"The interaction between a deformable bubble and a rigid particle in viscous liquids under microgravity conditions is studied by direct numerical simulation via an Arbitrary-Lagrangian-Eulerian (ALE) method. Due to the microgravity, the bubble will stay as a sphere in the fluid without external forces and its deformation is caused by the moving particle. In this study we assume the flow field is axisymmetric and the motion of the gas inside the bubble is neglected. The particle equations and the Navier-Stokes equations for the fluid are solved in a unified finite element framework. The particle obtains an impact velocity by an external force and the impact velocity is varied over a wide range. A ‘critical time scale’ T0 was identified for the interaction process. For successful contacts between particle and bubble, the time scale of their relative motion must be less than T0.INTRODUCTIONThe particle-bubble interaction is an important process in many applied industrial domains such as water treatment, froth flotation and liquid steel purification. It is a complex three phase process in that it embraces many research areas: fluid hydrodynamics, interfacial forces, particle and bubble behaviour and solution chemistry.Derjaguin and Dukhin(1961) clarified the particle-bubble interaction by introducing three-zone model for small and medium size particles. When the particle is far away from the bubble surface, the hydrodynamic forces are dominant. The particle is driven toward the bubble surface by the particle inertial and gravity. This region is regarded as Zone 1 and the interaction in this zone is a collision subprocess. As the particle gets close to the bubble, it exits a zone where the liquid flow around the bubble surface creates a tangential stream from the upper surface of the bubble toward the rear of the bubble. This is Zone 2 which is called the diffusiophoretic zone. In Zone 3, the particle is very closed to the bubble, surface forces like van der Waals, electrostatic and structural forces are considered. Contrast to Zone 1, Zone3 can be regarded as an attachment subprocess."

Jan 1, 2016

By Andre Thess, Oleg Zikanov

"Direct numerical simulation methods are applied to study the influence of a constant magnetic field on turbulent flows of liquid metals. The flow is assumed to be homogeneous and the problem is reduced to the classical case of the turbulent flow in a 3D box with periodic boundary conditions. The main subject of the study is the anisotropy developing in a liquid metal flow affected by constant magnetic field.To investigate the long-time evolution of initially isotropic flow the large-scale forcing is applied to maintain the flow energy at a statistically steady level. It is found that the flow evolution depend strongly on the magnetic interaction parameter (Stuart number). In the case of small Stuart number, the flow remains three-dimensional, turbulent, an approximately isotropic. At large Stuart number (strong magnetic field) the turbulence is suppressed rapidly and the flow becomes two-dimensional and laminar. Very interesting is the intermittent flow evolution at moderate Stuart number. Long periods of almost two-dimensional, laminar behavior are interrupted by strong turbulent three-dimensional bursts.The influence of a constant magnetic field on scalar transport properties of liquid metal turbulence is investigated using the simplified formulation of homogeneous flow driven by an imposed mean temperature gradient. Such a flow consists primarily of two turbulent antiparallel jets providing an effective mechanism for heat transfer. It is shown that the magnetic field parallel to the mean temperature gradient stabilizes the jets and, thus, enhances heat transfer considerably."

Jan 1, 1999

By Lin Li, Xiang Li, Yifang Zheng, Jilai Xue, Jun Zhu

"Al drops and gas bubbles in the anode-cathode space of aluminum electrolysis cell are of great importance for cell operation improvement in metal loss, current efficiency and energy consumption. A direct observation on the Al drop, gas bubble and ultrasound was carried out through a see-through cell. The Al drop immersed into the cryolitic melt was found moving up and down irregularly in the anode-cathode space without electrolysis, which was then completely dissolved into the melt. During electrolysis, the Al drop came to the anode area and reacted with the gas bubbles generated on the anode. Under ultrasound, the gas bubbles were removed from the anode surface while the Al drop was kept on the side of anode. The observed phenomena were useful for technology improvement in reducing the anode-cathode distance or lowering the energy consumption in aluminum electrolysis.IntroductionDuring aluminum electrolysis, aluminum metal drop and anodic gas bubble are in close contact each other within the anode-cathode space, and the interaction between them can produce significant impact on metal loss, current efficiency and energy consumption. The motions of the Al drop and the gas bubble are also related to the dissolution of aluminum metal into cryolitic melt and the cell voltage drop due to the bubble layer covering the anode surface.A number of studies have been carried out using different types of see-through cells, where the dissolving process of metal Al into cryolitic melts (metal fog) in the anode-cathode space was directly observed and photographed [1, 2]. With the similar method, some direct observations on the anodic bubble behaviors with and without ultrasound were performed during aluminum electrolysis [3-6]. However, to our best knowledge, there is no published work on direct observation on the behavior of Al drops and anodic gas bubbles staying together within the same anode-cathode space, as well as the motion and interaction of them in cryolite-alumina melts."

Jan 1, 2011

By S Natsui, Y Goto, S Kawanishi, J Takahashi, H Nogami

The demand for copper increases yearly, and further improvements in copper smelting efficiency using flash furnaces are required. This study was conducted to understand and promote the interfacial reaction associated with the collision of silica flux and iron oxide particles, ie the formation reaction of fayalite slag, in the reaction shaft of the flash furnace. High-temperature microscopy was used to observe the reaction behaviour of a 2 mm granular SiO2 reagent in contact with micrometreorder- sized FeO reagents in situ. When the amount of FeO was lower than the stoichiometric amount with SiO2, the molten slag formed at the interface between FeO and SiO2 diffused into the SiO2 particle before dissolving the remaining FeO particles. It did not contribute to the subsequent reaction, and despite having the lowest amount of FeO among the samples in this study, many unreacted FeO particles remained on the surface of the samples after testing. On the other hand, under conditions with high FeO content and close to the eutectic composition of the FeO-SiO2 system, a liquid phase formed from low temperatures, gradually increasing in volume and eventually completely dissolving the 2 mm SiO2 grain. These results indicate that the early-stage slag is essential in increasing the interfacial area between FeO and SiO2 and facilitating the supply of FeO to SiO2. In other words, the FeO/SiO2 determines the amount of liquid phase and significantly influences the subsequent interfacial reaction rate between FeO and SiO2. Therefore, the local FeO/SiO2 of the particles falling down the reaction shaft should also be optimised to ensure early slag formation. Meanwhile, the time required for 2 mm SiO2 to complete the reaction for the temperature history employed in this study was significantly longer than the particle residence time in the reaction shaft. Further detailed investigation of the effects of silica flux particle size, composition, and reaction temperature on the reaction time will help find the conditions under which the reaction of silica flux can be completed in the reaction shaft. These kinetic approaches could contribute to future innovations in the copper smelting process using flash furnaces.

Jun 19, 2024

By Edward B. Hughes, Frank G. Norris

OXIDATION is characteristic of all processes for making steel from pig iron. This thought has been aptly expressed by H. W. Graham13 in the most recent Howe Memorial Lecture, "The process of steel-making consists of using iron oxide to reduce the carbon content of the pig iron to the desired level." Direct oxidation refers to the reaction that results from introducing oxygen either alone or mixed with other gases directly into the steel bath. In working a heat, oxygen in some form is added to the steel to remove the undesirable constituents as oxides. There are two general methods of supplying this oxygen to the open hearth bath. The method in which the oxygen is added as a, compound such as C02-or iron ore is designated an indirect method because the steel bath must first decompose the compound to attain oxygen in a usable form. The other method in which oxygen is added to the bath in the elemental or gaseous form, more or less diluted by other gases such as nitrogen, is a direct, method because no decomposition is necessary before the oxygen reacts with iron to form FeO which is dissolved in the bath in a usable form. Bubble formation (at least of a macroscopic size) presents no problem in case of direct oxidation because the reacting agent (oxygen) is in the form of bubbles when entering the metal. Regardless of whether oxygen is introduced into the bath directly or indirectly, several reactions proceed concurrently. In the presence of the bath of molten iron, FeO is formed either by oxidation of iron by oxygen or reduction of oxides by iron. This FeO dissolved in the molten iron is the source of oxygen for the oxidation of manganese, carbon, silicon, and phosphorus if these are present. The oxidation of carbon from steel is the controlling steelmaking reaction. The introduction of oxygen into the bath, its reaction in the elimination of impurities, and its control by the use of de-oxidizing additions have been subjects of importance since steel was first made by the bessemer process. Direct oxidation is, in a sense, an application of the bessemer principle to the open hearth process. Graham13 states: "The use of oxygen or air jets introduced into the metal bath is essentially an effort to approach in the open hearth the turbulence, rapid interface reaction, and high production rate per hour that exists in the bessemer process." The general subject, "Oxygen in Steelmaking," was given new life by the studies of Herty and associates starting about1925. The current interest in elemental oxygen is intimately related to the large scale production of oxygen developed during the war period. Some of the first applications were made during the early summer of 1946 at the Steel Co. of Canada using oxygen with the fuel. Such a use is of considerable interest and importance in contributing to faster heats but is not the subject of the present discussion which deals entirely with the introduction of elemental oxygen directly into the open hearth bath. A recent article12 reviewing the current

Jan 1, 1948

By You-Hai Wen, Yinkai Lei, Tian-Le Cheng

A phase field model is developed to simulate the performance of SOFC electrodes. By solving the conduction equations on both the electrolyte and electrode phases, and incorporating the three-dimensional microstructure and reaction front at triple phase boundaries, the current-voltage relation of an electrode is directly simulated. By further coupling it to our recently developed coarsening model, we are able to investigate the effect of initial microstructure on the performance degradation in SOFC electrode. This model is applied to LSM-YSZ cathodes with different LSM volume fraction. The volume fraction effect on the electrode performance and its degradation rate has been analyzed and discussed.

Mar 1, 2018

By Nozomu Kotake, Rakshya Shrestha, Ralph Griffin, Stefanos Papadopulos, Jeff Fippin, Sushil Kafle

Direct Power Compaction (DPC) is a deep Vibro-compaction method used for liquefaction mitigation. In DPC, H-beams are used as vibrating rods penetrating deep into the ground, and a vibrating force is applied directly to the tip of these H-beams to densify the loose ground. A characteristic feature of DPC is the use of a flapping plate installed at the base of the H-beam to enhance the compaction efficiency during penetration. In addition, 2-rod and 4-rod type equipment have been developed to improve productivity and enable rapid construction. DPC was selected as the most suitable and cost-effective technique to mitigate liquefaction hazards in two projects in the San Francisco Bay Area, one on Alameda Island and another on Treasure Island. Both sites were capped with hydraulically placed sand fills. Liquefaction analyses indicated excessive liquefaction-induced settlements and large lateral spread without ground improvement. Densification using DPC was performed up to depths of 42 ft to reduce the liquefaction potential of the sand fill to acceptable levels and to allow planned improvements. Cone penetration tests were conducted before and after DPC to evaluate its performance. This paper describes the equipment and process involved in DPC and discusses its application in terms of subsurface conditions and geotechnical design considerations.

Sep 8, 2021

By Hui-gang Wang, Mei Zhang, Min Guo

Metal-doped Ni–Zn ferrite with spinel structure was directly synthesized from treated zinc-containing electric arc furnace dust (Zn-containing EAFD) by solid state reaction method, realizing the transformation of Zn-containing EAFD from solid waste to high value-added material. A certain mass of NiCl26H2O was added to the treated Zn-containing EAFD before calcination. Then the effects of the mass ratio of treated Zn-containing EAFD to NiCl26H2O (RTZE/N, g g−1) and calcination temperature on the synthesis and magnetic properties of as-synthesized samples were systematically investigated by X-ray Diffraction, Raman Spectroscopy and Physical Property Measurement System. It is indicated that RTZE/N and calcination temperature had important influences on the synthesis of single-phase spinel ferrite and their magnetic properties. Pure metal-doped Ni–Zn ferrite, which exhibited good magnetic properties of higher saturation magnetization (Ms, 60.5 emu g−1) and lower coercivity (Hc, 49.8 Oe), was obtained when the calcination temperature was controlled at 1100 °C for 2 h with RTZE/N of 1:0.9.

Mar 1, 2017

By António Fiúza, Anthony Danko, Patrícia Leitão, Aurora Futuro, Cristina Vila, Lurdes Dinis

The average global recovery rates for processing scheelite ores by physical methods are normally in the range 50 to 70%, and it is problematic to attain a minimum grade of 60% WO3 in the concentrates without penalizing further this yield. Direct hydrometallurgical processing of low-grade concentrates or medium- to high-grade ores may become an interesting global economic alternative as it allows increasing the recovery rate, avoiding major penalizations due to the grade of the concentrate and increasing the added value of the final product. Leaching of scheelite by sodium carbonate presents several advantages such as its selectivity regarding the dissolution of troubling metals like iron and aluminium, allowing for a simple and flexible process diagram. However, it has the disadvantage that it is performed at high temperature and pressure with a high consumption of reagents. The feasibility of leaching is appraised by the extraction yield and selectivity, but also by the operating cost. Considering these aspects, a relevant objective of the research was to transform alkaline pressure leaching into a feasible processing alternative directly applicable to both medium- and high-grade ores and simultaneously to low- and high-grade concentrates produced by physical methods. The research used ore samples and low-grade concentrates from a typical skarn orebody as well as high-grade concentrates from a chalcopyrite-scheelite orebody. Different operating conditions were tested. Temperature, pressure and reagent concentration showed to be fundamental, but not exclusive, in determining the leaching behaviour. The operating conditions are milder than the ones generally proposed in the literature or currently in use in industry, but with higher carbonate consumptions. The research was oriented towards potential industrial implementation allowing for the application of optimization methods and straight scale-up to pilot-plan design and project.

By Weir D. R, Doyle B. N

The Sherritt Zinc Pressure Leaching Process is based upon the direct pressure leaching of zinc sulphide or lead-zinc bulk sulphide concentrates to produce zinc sulphate in solution and elemental sulphur in the leach residues. The zinc sulphate solution is compatible with conventional purification and electrowinning technology. The pressure leach residues can be treated for the recovery of elemental sulphur, lead and silver. With the conversion of sulphur to the elemental form, zinc pressure leaching allows zinc winning to be independent of sulphuric acid production. Direct pressure leaching of zinc sulphide concentrates was started commercially in October 1980. Continuing research and development studies have defined various pressure leaching configurations for integration with existing roast-leach operations, for grass roots plants, or for plants which are to have the roast-leach section completely replaced. These studies have included the treatment of zinc concentrates from various Australian producers and the development of process flowsheets for potential applications in Australia.

Jan 1, 1989

By George Weaton

Two years ago the general features of the St. Joseph Lead Company's zinc-smelting process were described.1 At that time the discussion was limited to a description of the production of high-purity electrothermic zinc oxide. The present paper will describe the commercial production of electrothermic zinc metal. Since a fairly complete description of the plant of the Josephtown smelter was given in the earlier paper, the brief recapitulation given here will be limited to mention of additional equip-ment recently installed and a bare outline of the preparatory process. The raw material is zinc sulphide concentrate received from the com-pany's mines in St. Lawrence County, New York. An average dry-weight analysis of this material is: Zn, 58.28 per cent; Pb, 0.56; insoluble, 1.6; Si02, 1.12; Fe, 6.4; CaO, 0.47; MgO, 0.27; S, 31.9; Cd, 0.1; Cu, 0.06; Mn, 0.24. Moisture content is usually about 3 per cent. Three 21-ft. 6-in. diameter, 12-hearth Nichols-Herreshoff furnaces roast the concen-trate to a calcine of average composition (first 10 months of 1938) : Zn, 67.69 per cent; Pb, 0.06; insoluble, 1.75; Si02, 1.26; Fe, 7.24; CaO, 0.47; MgO, 0.36; S, 1.88; Cd, 0.1; Cu, 0.07; Mn, 0.27. The sulphur dioxide gas, after passing through a waste-heat boiler, proceeds through a recently redesigned low-resistance gas-purification assembly to the contact sul-phuric acid plant, of which the capacity is 200 tons of concentrates per day. The calcine is mixed with a portion of returned furnace residues and sintered on 42-in. by 44-ft. Dwight-Lloyd sintering machines, gas-fired. Wind-box gases pass through air coolers before filtering in a 1440-bag Dracco unit, and thence to stack. The Dracco fume is mixed with Cottrell dust, from roaster gas cleaning, and sent to the leach plant, where it is roasted (SO2 to acid plant) and leached with sulphuric acid to recover, as end products, lead sulphate, zinc sulphate and cadmium.

Jan 1, 1939

By Takeshi Azakami

By combining the iron reduction process with the usual rotary kiln process, the direct production of metallic zinc from EAF dust is proposed. After thermodynamic estimation and desk-top experiments it is confirmed that the process is hopeful under suitable conditions. In order to get some practical test data the enlargement of the process scale was planned and the bench scale tests were carried on successfully. In these experiments a zinc ingot of PW grade was produced from EAF dust.

Jan 1, 2003

By L. M. Abrantes, A. P. Paiva

"A brief review of some innovative methods for the direct recovery of metals from loaded organic phases is presented; emphasis is given to electroreductive stripping and cementation, which are described and illustrated by examples: of current research. The recovery of silver using a two-phase electrolysis - by direct application of an electrical potential to a mixture of a metal loaded organic phase· containing Cyanex 471X, obtained by solvent extraction, and a stabilized sodium thiosulfate solution - is more extensively discussed. The overall efficiencies are analyzed and compared with data obtained by conventional stripping procedures. Some preliminary results achieved for the recovery of the precious metal using galvanic stripping, applied directly to similar organic solutions and involving zinc and iron powders as reducing agents, are also evaluated.Introductory ReviewThe application of hydrometallurgical methods to the recovery of metal values from ores and concentrates has been receiving a growing interest, either from researchers or from the mining industry [1].For the concentration / purification of the relatively low concentrated metallic solutions resulting from the leaching of those raw materials, solvent extraction (SX) is a well established technique [2]; the loaded organic solvent is then conventionally contacted with a suitable aqueous solution, the metal in its final form being usually recovered from this solution by electrowinning.As an efficient and / or selective stripping is sometimes difficult to achieve, depending on the specific characteristics of the system under consideration, some alternative procedures have been analyzed in order to overcome this problem. One of the chosen routes, mainly developed by Hirai and Komasawa, is to promote the reduction of the desired metal species in the organic phase, in such a way that the stripping stage becomes feasible; for the selective stripping of vanadium from a solvent containing a mixture of vanadium and molybdenum, the authors successfully used reductive [3], electro-reductive [4,5] and photo-reductive [6] techniques. The two latter methodologies have also been applied to the recovery of europium from a solvent containing europium, samarium and gadolinium [7,8].However, further processing is necessary to recover the metal in its solid state; therefore, methods causing the direct reduction of the metal species in the organic phase to their fmal metallic form would be of interest, as an intermediate step would be avoided"

Jan 1, 1997

By E. V. Redin, B. A. Dubrovsky, E. V. Knyazev, A. I. Starikov

"Ti-V magnetite is one of the most abundant composite ore resources in the world. This ore cannot be fully processed via blast furnace technology because of high content of Ti02. According to the investigations carried out in the USA and Japan ITmk3 RHF (Rotary Hearth Furnace) technology is a breakthrough in Ironmaking. Reduction, melting and slag removal can be achieved in just 10 min. The main objective of the investigation is to establish optimum operation conditions for the production of iron nuggets from Ti-V magnetite ore via the ITmk3 by means of the lab scale testing. Samples of ore from the Maly Kuybas deposit (Southern Ural), carbon reductant and fluxes were chemically analyzed. Green pellets were processed via a lab chamber furnace to simulate RHF conditions. The nuggets and slag were chemically analyzed. This preliminary test work provides valuable information which may be used for large-scale testing in a commercially sized RHF.IntroductionThe ITmk3 process upon which this paper focuses was developed by Kobe Steel in its research facilities [l]. After pilot testing at Kobe Steel's Kakogava Works in 1999-2004 the pilot demonstration plant was built and operations were successfully carried out by Mesabi Nugget joint venture in 2002-2004. Steel Dynamics put into operation the commercial plant at the Mesabi Nugget site in Hoyt Lakes (Minnesota) in 2010. Results were consistent with nugget characteristics confirming ITmk3' s flexibility with respect to raw material inputs. At the same time, no research in the field of nugget from the Ti-V magnetite bearing ore with high content of Ti02 and Alz03 has been done. It is well known, if a lot of Ti02 and Alz03 enter the blast furnace, slag becomes viscous. The viscous slag is obstacle for stable operation of the blast furnace. Besides, high content of Alz03 raises the melting temperature of gangue minerals disturbing the coalescence of reduced iron to the nuggets."

Jan 1, 2013