| 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. |
- Abdel-Khalek, N.A., et al.
(författare)
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Effect of starch type on selectivity of cationic flotation of iron ore
- 2012
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 121:2, s. 98-102
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Tidskriftsartikel (refereegranskat)abstract
- Cationic flotation is one of the most widely accepted technologies for upgrading siliceous iron ore using polysaccharides (mainly starches) as depressing agents for iron bearing minerals while floating silica with amines. In this paper, a group of starches are investigated as depressants for haematite. These starches are wheat, corn, rice, potato and dextrin. The role of starch type on the selectivity of the separation process has been studied through zeta potential, adsorption measurements as well as flotation tests. The effects of type of starch and pH of the medium have been studied. The results indicate that the selectivity of the separation process is strongly affected by the type of starch used, where better results are obtained with corn starch or wheat starch in comparison to the other types. Fourier transform infrared spectroscopy measurements indicated that the interaction between starches and haematite surface is intermolecular interaction.
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| 3. |
- Andersson, Charlotte, et al.
(författare)
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The need for fundamental measurements for a sustainable extraction of metals
- 2011
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 120:2, s. 199-204
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Tidskriftsartikel (refereegranskat)abstract
- The increased need for efficient material processing and efficient utilisation of more complex raw materials and the need for recycling or reusing byproduct and waste streams, are all increased challenges in material processing. To cope with these challenges, there is a need for new basic physical and thermodynamic data. The present paper gives four examples, as well as preliminary data, of areas where increased knowledge of fundamental parameters will increase the possibility for a sustainable extraction of metals. The examples include measurement of solubility of pure individual slag minerals, determination of distribution of leachable elements between different mineralogical phases in slag, influence of alumina on liquidus temperature of a copper slag and thermal diffusivity measurements in magnetite based iron ore pellets, all important in different ways to increase the sustainability of the respective materials involved
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| 4. |
- 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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| 5. |
- Gao, Ming-Wei, et al.
(författare)
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Simulation of batch grinding of iron ore
- 1990
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 99, s. 142-146
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Tidskriftsartikel (refereegranskat)abstract
- A batch-grinding process treating a natural magnetite ore was simulated by a population-balance model. Different methods of determining selection and breakage functions for the ore were investigated. Grinding tests were performed with seven monosize fractions in a pilot-scale ball-mill. The back-calculated selection function was compared with experimentally measured values of the selection function, S, and the breakage functions so determined were checked against the results of the simulation. It appears that if the breakage functions of a material are not normalizable, it is necessary to carry out a sufficient number of monosize grinding tests to allow reliable selection and breakage functions to be estimated. Graphs. 8 ref.--AA
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| 6. |
- 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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| 7. |
- 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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| 8. |
- 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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| 9. |
- Hosseini, S.H., et al.
(författare)
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Smithsonite flotation using mixed anionic/cationic collector
- 2009
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 118:3, s. 186-190
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Tidskriftsartikel (refereegranskat)abstract
- The surface interaction and adsorption of the components in a mixture of surfactants are of considerable interest for both practical and theoretical reasons. The flotation behaviour of smithsonite in the presence of sodium sulphide (Na2S) and a mixture of potassium amyl xanthate (KAX) and dodecylamine (DDA) and its adsorption on smithsonite surface at various concentration ratios have been investigated using zeta potential, contact angle, microflotation and diffuse reflectance FTIR studies. The smithsonite mineral has weak response to flotation in the presence of KAX alone as a collector. The presence of KAX enhanced the amine flotation recovery in the presence of sodium sulphide. The flotation results using mixed collectors showed the maximum recovery and contact angle were 95.5% and 104° at pH 12 respectively. The FTIR spectra revealed the coadsorption as amine - xanthate complex when mixed collector is used. The presence of KAX increased the DDA adsorption due to decrease in the electrostatic head - head repulsion between the two adjacent surface ammonium head group cations because the anionic KAX sitting between these two cations screens the electrostatic repulsion and increased the lateral tail-tail hydrophobic bonds.
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| 10. |
- Hosseini, S. H., et al.
(författare)
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Smithsonite flotation using potassium amyl xanthate and hexylmercaptan
- 2006
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 115:2, s. 107-112
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Tidskriftsartikel (refereegranskat)abstract
- The influence of potassium amyl xanthate (KAX) and hexylmercaptan (HM) adsorption on smithsonite surface at various concentrations were investigated through using zeta potential, contact angle, microflotation and diffuse reflectance FTIR studies at different pH. The zeta potential measurements of KAX showed that the adsorption of ionic charge (more negative charge after KAX treatment) takes place on the surface of pure crystalline smithsonite. The charges vary between −38 and −45 mV at pH 10·5. Flotation results using potassium amyl xanthate reveal that the maximum recovery of 81·3% and the maximum contact angle of 98·7° occurs at pH 10·5 at KAX concentration of 2·96 × 10−3M in sodium sulphide (2·6 × 10−2M) and copper sulphate (9·4 × 10−3M) solutions. The highest recovery and contact angle for flotation by means of HM occurs at pH 9 at values of 78·6% and 92·3° respectively with HM concentration 1·1 × 10−2M. The FTIR spectra studies of smithsonite conditioned by KAX confirmed the adsorption of KAX and the presence of CS2 on smithsonite surface. The FTIR spectra in HM studies showed the adsorption of RS− on the oxidised zinc surface and the S-H bond in the mercaptan is destroyed on adsorption. The comparison between the results using anionic collectors showed that the presence of different amounts of reagents on smithsonite surface in two cases confer different degree of hydrophobicity on the smithsonite surface.
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