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Sökning: L773:0371 9553 OR L773:1743 2855 > Luleå tekniska universitet

  • Resultat 1-10 av 17
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1.
  • Abdel-Khalek, N.A., et al. (författare)
  • Effect of starch type on selectivity of cationic flotation of iron ore
  • 2012
  • Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 121:2, s. 98-102
  • 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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2.
  • Andersson, Charlotte, et al. (författare)
  • The need for fundamental measurements for a sustainable extraction of metals
  • 2011
  • Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 120:2, s. 199-204
  • 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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3.
  • Gao, Ming-Wei, et al. (författare)
  • Simulation of batch grinding of iron ore
  • 1990
  • Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 99, s. 142-146
  • 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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4.
  • Hosseini, S.H., et al. (författare)
  • Smithsonite flotation using mixed anionic/cationic collector
  • 2009
  • Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 118:3, s. 186-190
  • 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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5.
  • Hosseini, S. H., et al. (författare)
  • Smithsonite flotation using potassium amyl xanthate and hexylmercaptan
  • 2006
  • Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 115:2, s. 107-112
  • 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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6.
  • Hosseini, S. H., et al. (författare)
  • Studies on selective flotation of smithsonite from silicate minerals using mercaptans and one stage desliming
  • 2011
  • Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 120:2, s. 79-84
  • Tidskriftsartikel (refereegranskat)abstract
    • The separation of oxide zinc mineral from silicate minerals in smithsonite mineral, associated silicate minerals and oxide zinc ore samples was assessed using methyl mercaptan (CH3SH), ethyl mercaptan (C2H 5SH) and hexyl mercaptan (C6H13SH; HM) as collectors. The optimal flotation conditions were defined through Hallimond tube, contact angle and batch flotation and the results were applied to a natural Angooran oxide zinc ore. The microflotation and artificial mixture flotation results showed a maximum of 78% flotation recovery using HM. Selective flotation of oxide zinc ore was also accomplished by using an HM collector at pH 9. The flotation recovery was 55% without desliming. When the initial feed was deslimed before bench scale flotation tests, the recovery increased from 55 to 75%with 22·5%zinc content in the concentrate.Whenmethylmercaptan or ethyl mercaptan was used, lower zinc recoveries and grades compared to HM flotation were achieved
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7.
  • Jelkina Albertsson, Galina, et al. (författare)
  • Effect of basicity on chromium partition in CaO-MgO-SiO2-Cr 2O3 synthetic slag at 1873 K
  • 2014
  • Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 123:2, s. 116-122
  • 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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8.
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9.
  • Lennartsson, Andreas, et al. (författare)
  • Thermodynamic process modelling of black copper addition to a Peirce-Smith converter: effect on the distribution of antimony and bismuth
  • 2014
  • Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 123:3, s. 157-164
  • Tidskriftsartikel (refereegranskat)abstract
    • The effect of adding black copper, originating from treating waste electrical and electronic equipment (WEEE), to a Peirce-Smith converter has been investigated by using a thermodynamic process model. The model was formulated, by the authors, in an earlier publication and expanded, in the present work, to include the minor elements antimony and bismuth. The results show that the model describes the distribution of Bi well, whereas the distribution of Sb is not described as well and should only be used for trends. Addition of black copper lowers the removal of Bi and Sb compared to a converter cycle without addition. To maintain a good removal of Bi and Sb, black copper should be added as early as possible during a converter cycle.
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10.
  • Minz, Friederike, et al. (författare)
  • Particle-based Sb distribution model for Cu–Pb flotation as part of geometallurgical modelling at the polymetallic Rockliden deposit, north-central Sweden
  • 2017
  • Ingår i: Mineral Processing and Extractive Metallurgy. - : Taylor & Francis. - 0371-9553 .- 1743-2855. ; 126:4, s. 212-223
  • Tidskriftsartikel (refereegranskat)abstract
    • The polymetallic Cu–Zn ore of the Rockliden massive sulphide deposit in the Skellefte District in north-central Sweden contains a number of deleterious elements in relevant concentrations. Of particular concern is the amount of antimony (Sb) reporting to the Cu–Pb concentrate. The aim of this study was to compare different model options to simulate the distribution of Sb minerals in a laboratory flotation test based on different degrees of details in the mineralogical information of the flotation feed. Experimental data obtained from four composites were used for the modelling and simulation. The following different simulation levels were run (sorted from least to highest level of detail of their mineralogical information): chemical assays, unsized bulk mineralogy, sized bulk mineralogy and particle information. It was shown that recoveries simulated based on bulk mineralogy are mostly within the error margin acceptable in the exploration stage of the Rockliden deposit. Unexpected high deviation in the simulation using particle information from the original recovery has been partly attributed to the fact that recovery of non-liberated particles cannot be modelled appropriately in the present version of the modelling and simulation software. It is expected that the implementation of full particle information in simulation will improve the Sb distribution model for the mineralogically complex Rockliden deposit.
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