| 1. |
- Abbasalizadeh, Aida, et al.
(författare)
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Neodymium extraction using salt extraction process
- 2015
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Ingår i: Mineral Processing and Extractive Metallurgy. - : Maney Publishing. - 0371-9553 .- 1743-2855. ; 124:4, s. 191-198
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Tidskriftsartikel (refereegranskat)abstract
- The present paper deals with the feasibility of the neodymium recovery from spent Nd-Fe-B magnets using molten salt electrodeposition method. The salt bath consisted of a mixture of LiCl- KCl-NaCl corresponding to the eutectic composition. The experimental set-up with its salient features is presented. AlCl3 was used as flux and graphite rods dipped in the salt bath served as electrodes. The voltage for the electrolysis was chosen on the basis of the decomposition potential of NdCl3. The reaction sequence can be described as Iron-free neodymium deposition could be carried out successfully. In view of the proximity of the electrode potentials, the co-deposition of the aluminium and neodymium was observed to occur at the cathode, as revealed by SEM/EDS and XRD analyses of the electrodeposit.
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| 2. |
- Cao, Weimin, 1981-
(författare)
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Using and validation of the DFT method for oxygen adsorbed on the iron (100) surface
- 2010
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 119:2, s. 67-70
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Tidskriftsartikel (refereegranskat)abstract
- Electronic and structural properties of atomic oxygen adsorbed on the iron (100) surface are examined using density functional theory calculations. The oxygen adsorbed on the iron (100) surface is investigated at the three adsorption sites top, bridge and hollow sites respectively. Adsorption energy, work function and surface geometries were calculated, the hollow site was found to be the most stable adsorption site, which is in agreement with the experiment. In addition, the difference charge density of the different adsorption system was calculated to analyse the interaction and bonding properties between Fe and O. It can be found out that the charge redistribution was related to the geometry relaxation. The calculated results are compared with the experimental and other theoretical results.
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| 3. |
- Ge, Xinlei, et al.
(författare)
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Salt extraction process-novel route for metal extraction Part 3-electrochemical behaviours of metal ions(Cr, Cu, Fe, Mg, Mn) in molten (CaCl2-)NaCl-KCl salt system
- 2010
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 119:3, s. 163-170
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Tidskriftsartikel (refereegranskat)abstract
- The present work is Part 3 of a novel salt extraction process towards the extraction of metal values from slag, low-grade ores, etc. The electrochemical behaviour of different metal ions, Cr(III), Cr(II), Cu(II), Fe(III), Mg(II) and Mn(II) was studied using cyclic voltammetry (CV) at 827°C in (CaCl 2-)NaCl-KCl system with a tungsten or glassy carbon electrode. The deposition process of Cr(III) species was found to be consisted of two electrochemical steps, while, in the case of other species, the deposition only involves one step. The deposition potentials and diffusion coefficients were determined from the cyclic voltammetrys. Electrodeposition of chromium was performed using a two-electrode cell under constant voltage, and pure dendrite and nodular-like crystals of chromium were obtained. The present study provides a good understanding of the electrochemical behaviour of these metal ions in molten salts, and thus is helpful to this novel salt process for the recovery of metal values from slag or other materials.
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| 4. |
- Ge, Xinlei, et al.
(författare)
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The salt extraction process : A novel route for metal extraction part 1 - Cr, Fe recovery from EAF slags and low grade chromite ores
- 2010
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 119:1, s. 27-32
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Tidskriftsartikel (refereegranskat)abstract
- The present work is part of an investigation towards the development of a process route for the extraction of metal values from slag, low grade ores and other oxidic materials such as spent refractories using molten salts in the temperature range 800-950uC. The present paper focuses on the recovery of metal values, primarily Cr and Fe, from electric arc furnace slag and chromite ore. The impact of different factors to the dissolution of slag, such as temperature, holding time, flux content and weight ratio of flux/slag was studied. Based on the optimised experimental factors, the salt bath containing metal values extracted from the slag/ore was electrolysed under an applied voltage of 2·8 V. The cathode deposit was subjected to SEM/EDS and XRD analyses, which confirmed the formation of CrFe alloy. The process was also extended towards the production of CrFe alloy directly from chromite ore. The results show that the molten salt extraction process offers a promising route towards the recovery of metal values from slags and low grade ores.
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| 5. |
- Ge, Xinlei, et al.
(författare)
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The salt extraction process - A novel route for metal extraction Part 2 - Cu/Fe extraction from copper oxide and sulphides
- 2010
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 119:2, s. 93-100
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Tidskriftsartikel (refereegranskat)abstract
- The present work is Part 2 of a novel salt extraction process towards the extraction of metal values from slag, low grade ores, etc. The authors describe the extraction of copper/iron from CuO, Cu 2S and CuFeS 2, which provides a green process route to treat the copper ore including both oxides and sulphides. The dissolution properties were investigated with respect to process parameters such as weight ratio of flux/copper ore and temperature. The highest extraction ratio is found at 92% in dissolution of Cu 2S, and residue of salt melt was confirmed to be mainly Al 2O 3. A cell voltage between 1·6 and 2·2 V is introduced for electrolysis, and the cathode products are proved to be pure Cu for electrolysis of CuO/Cu 2S, and Cu/Fe mixture for CuFeS 2 by X-ray diffraction and scanning electron microscopy/energy dispersive spectroscopy analysis. Some sulphur and iron chloride were found to volatilise and were deposited in the low temperature zone. Yield of copper has been estimated to be 52·3% during electrolysis of Cu 2S.
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| 6. |
- Jelkina Albertsson, Galina, et al.
(författare)
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Effect of basicity on chromium partition in CaO-MgO-SiO2-Cr 2O3 synthetic slag at 1873 K
- 2014
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 123:2, s. 116-122
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the present work is to get an understanding of the phase relationships in the CaO-MgO-SiO2-Cr2O3 system with a view to control the precipitation of Cr-spinel in the slag phase. The equilibrium phases in CaO-MgO-SiO2-Cr2O3 slag system at 1873 K (1600°C) have been investigated experimentally and compared with the results from thermodynamic calculations. The Cr2O 3 and MgO contents in the slag were fixed at 6 and 8 wt-% respectively. The basicity (CaO/SiO2) of slag was varied in the range 1·0-2·0. A gas/slag equilibrium technique was adopted to synthesise the slag at a high temperature in air. The samples were heated to and soaked at 1873 K (1600°C) for 24 h in order to achieve the equilibrium state and subsequently quenched in water. The chromium distribution and phase compositions in the quenched slag were studied using scanning electron microscope wavelength dispersive spectroscopy and X-ray diffraction techniques. FactSage software was used for the phase equilibrium calculations. The experimental results obtained from the present work were compared with the calculation results from FactSage software. It was found that the spinel formation at 1873 K (1600°C) is favoured in the slag basicity range 1·0-1·4.
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| 7. |
- Matsushita, Taishi, et al.
(författare)
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Dynamic in situ X-ray observation of a molten steel drop shape change in molten slag
- 2011
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Ingår i: Transactions of the Institutions of Mining and Metallurgy, Section C: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 120:1, s. 49-55
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, the interfacial reactions between molten synthetic slag (Al2O3-CaO-SiO2- FeO) and liquid iron alloy were investigated at 1873 K with the aid of an X-ray radiographic apparatus. The mother slag consists of 40 mass%CaO, 40 mass%SiO2 and 20 mass%Al2O3.FeO was added to this slag at the experimental temperature, and the movement of the droplet and deformation of the droplet shape were monitored in the dynamic mode. The change of the shape of the droplet is discussed based on the reaction and mass transfer at the slag/metal interface. From the movement of the droplet, interfacial velocity of the metal droplet induced by Marangoni flow was estimated and compared with the results obtained in the present laboratory earlier. The importance of surface velocity values on steel refining process simulations is discussed.
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| 8. |
- Morales, R., et al.
(författare)
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Gas-solid reactions towards new frontiers
- 2008
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 117:2, s. 77-85
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Tidskriftsartikel (refereegranskat)abstract
- Reactions between solids and a gas phase have interesting theoretical aspects as well as technological applications. Studies of the decomposition of alkaline earth carbonates have been carried out over the past decade by thermogravimetric analyses, using thin powder beds and isostatically pressed compacts with embedded thermocouples. The investigations revealed the complexity of the reactions and the impact of heat and mass transfer on the reaction kinetics. In the case of BaCO3, the kinetics of decomposition is complicated by the formation of a liquid phase. For SrCO3, the reaction kinetics could be simulated by theoretical modelling. Gas-solid reactions were also employed as a versatile process tool towards the production of alloys and intermetallics involving transition elements by hydrogen reduction of complex oxides involving transition metals. Thin powder beds were employed to examine the microkinetics, whereas fluidised beds were utilised to produce bulk alloys. Preliminary correlations could be drawn between the thermodynamic stabilities of the oxides and the activation energies of chemical reduction. By adjusting the process parameters, nanoscale products could be produced, the structural, mechanical and thermal properties of which were investigated. The potentialities of this method as a green route to produce industrially important alloys and intermetallics with unique properties are demonstrated.
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| 9. |
- Mostaghel, Sina, et al.
(författare)
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Influence of alumina on physical properties of an industrial zinc-copper smelting slag : Part 2 - Apparent density, surface tension and effective thermal diffusivity
- 2013
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 122:1, s. 49-55
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Tidskriftsartikel (refereegranskat)abstract
- Apparent density, surface tension and effective thermal diffusivity of an industrial iron-silicate based slag and mixtures of this slag with 5, 10 and 15 wt-% alumina addition were measured using the sessile drop and the laser flash techniques respectively. A comparison is made between corresponding values obtained from the commonly applied models and the experimental measurements. Results show that increasing the alumina concentration in slag increases the degree of polymerisation of the melt and, consequently, its effective thermal diffusivity. By alumina addition to the system, the surface tension increases progressively from 338 mN m-1, in the reference slag sample, to 488 mN m-1 in the mixture of slag and 15 wt-% alumina addition. The apparent density of the liquid-solid containing slag is continuously decreased due to the increased alumina concentration. However, the effect is more pronounced between 8 and 12 wt-% total alumina content in the slag.
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| 10. |
- Mostaghel, Sina, et al.
(författare)
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Influence of alumina on physical properties of an industrial zinc-copper smelting slag : Part 1 - Viscosity
- 2013
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 122:1, s. 42-48
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Tidskriftsartikel (refereegranskat)abstract
- The rotating cylinder method was applied to measure the viscosities of an industrial iron silicate slag and mixtures of this slag with 5, 10 and 15 wt-% alumina addition, in temperature range 1100-1300 C. The measured viscosities were compared with the predicted values using two of the commercially available software products for viscosity calculations, namely Thermoslag®1·5 and FactSageTM6·2. As the models can only predict viscosities for a solid free melt, obtained values by FactSageTM6·2 were modified using the Einstein-Roscoe equation. Results show that aluminium behaves as a network former cation in this type of slag, and by increasing the alumina concentration, the melt becomes progressively polymerised. Consequently, the viscosity of the slag increases at a given temperature, which is supported by thermodynamic predictions. According to the modified FactSage TM6·2 calculations, the viscosity of the solid containing slag increases from 2·1 to 5·5 poise at the industrial operating temperature (∼1250 C).
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