| 1. |
- Abramov, A.A., et al.
(författare)
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Chemistry and optimal conditions for copper minerals flotation : theory and practice
- 2005
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Ingår i: Mineral Processing and Extractive Metallurgy Review. - : Informa UK Limited. - 0882-7508 .- 1547-7401. ; 26:2, s. 77-143
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Tidskriftsartikel (refereegranskat)abstract
- Reliable information on the surface state of sulphide copper minerals and regularities of sulphidization and flotation of oxidized copper minerals, the composition of sorption layer on the mineral surface forming during its interaction with xanthate or dixanthogen, and the influence of collector forms sorption on the copper minerals floatability and on the optimal conditions for these minerals flotation and depression has been obtained at present. The determined physicochemical models in the form of quantitative equations have been derived for the optimal conditions of flotation and depression of copper minerals under changing pH value and of sodium sulphide, lime, cyanide, zinc–cyanide complexes additions. The equations derived were proven in the laboratory and industrial scale and can be used both in automatic control systems at plants and for improvement of technological processes of selective flotation of copper containing ores.
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| 2. |
- Alexandrova, L, et al.
(författare)
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Three-phase contact parameters measurements for silica-mixed cationic-anionic surfactant systems
- 2009
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Ingår i: Colloids and Surfaces A. - : Elsevier BV. - 0927-7757 .- 1873-4359. ; 348:1-3, s. 228-233
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Tidskriftsartikel (refereegranskat)abstract
- The stability and interactions in thin wetting films between the silica surface and air bubble containing (a) straight chain C10 amine and (b) cationic/anionic surfactant mixture of a straight chain C10 amine with sodium C8, C10 and (straight chain) C12 sulfonates, were studied using the microscopic thin wetting film method developed by Platikanov [D. Platikanov, J. Phys. Chem. 68 (1964) 3619]. Film lifetimes, three-phase contact (TPC) expansion rate, receding contact angles and surface tension were measured. The presence of the mixed cationic/anionic surfactants was found to lessen contact angles and suppresses the thin aqueous film rupture, thus inducing longer film lifetime, as compared to the pure amine system. In the case of mixed surfactants heterocoagulation could arise through the formation of positively charged interfacial complexes. Mixed solution of cationic and anionic surfactants shows synergistic lowering in surface tension. The formation of the interfacial complex at the air/solution interface was confirmed by surface tension data. It was also shown, that the chain length compatibility between the anionic and cationic surfactants system controls the strength of the interfacial complex. The observed phenomena were discussed in terms of the electrostatic heterocoagulation theory, where the interactions can be attractive or repulsive depending on the different surface activity and charge of the respective surfactants at the two interfaces.
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| 3. |
- Cui, Jirang, et al.
(författare)
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Characterization of shredded television scrap and implications for materials recovery
- 2007
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 27:3, s. 415-424
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Tidskriftsartikel (refereegranskat)abstract
- Characterization of TV scrap was carried out by using a variety of methods, such as chemical analysis, particle size and shape analysis, liberation degree analysis, thermogravimetric analysis, sink-float test, and IR spectrometry. A comparison of TV scrap, personal computer scrap, and printed circuit board scrap shows that the content of non-ferrous metals and precious metals in TV scrap is much lower than that in personal computer scrap or printed circuit board scrap. It is expected that recycling of TV scrap will not be cost-effective by utilizing conventional manual disassembly. The result of particle shape analysis indicates that the non-ferrous metal particles in TV scrap formed as a variety of shapes; it is much more heterogeneous than that of plastics and printed circuit boards. Furthermore, the separability of TV scrap using density-based techniques was evaluated by the sink-float test. The result demonstrates that a high recovery of copper could be obtained by using an effective gravity separation process. Identification of plastics shows that the major plastic in TV scrap is high impact polystyrene. Gravity separation of plastics may encounter some challenges in separation of plastics from TV scrap because of specific density variations.
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| 4. |
- Cui, Jirang, et al.
(författare)
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Recycling of consumer electronic scrap
- 2006
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Ingår i: Proceedings, International Seminar on Mineral Processing Technology. - New Dehli : Allied Publishers Ltd. - 8184240120 ; , s. 14-19
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Konferensbidrag (refereegranskat)
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| 5. |
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| 6. |
- Forssberg, Eric
(författare)
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Energy in mineral processing
- 2009
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Ingår i: Proceedings of the XIII Balkan Mineral Processing Congress. - Petrosani : S.C. FOCUS Grafiserv S.R.L., www.focusprint.ro. - 9789736771590 ; , s. 62-66
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Konferensbidrag (refereegranskat)
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| 7. |
- Forssberg, Eric, et al.
(författare)
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Recovery of metals from shredded television scrap
- 2008
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Ingår i: Proceedings of XXIV International Mineral Processing Congress. - Beijing : American Science Press Inc.. - 9787900249548 ; , s. 3461-3468
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Konferensbidrag (refereegranskat)
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| 8. |
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| 9. |
- He, Mingzhao, et al.
(författare)
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Influence of slurry rheology on stirred media milling of limestone
- 2006
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Ingår i: Advances in Comminution. - Littleton, Colo : Society for Mining, Metalurgy and Exploration. - 0873352467 ; , s. 243-260
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper reviews the influences of solids concentrations and dispersants with a range of molecular weights on the flowability of limestone slurries as well as the effects on wet ultrafine grinding in order to reduce energy cost and increase the fineness of a product. Sodium pofyacrylate with a molecular weight of 5,500 (i.e., Dispersant S40) appears most effective for the grinding due to the effective reduction of apparent viscosities and the maintenance of steady flowability. Optimal solids concentration exists at a certain beads load for the effective wet ultrafine grinding of limestone, and a rheological explanation is presented.
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| 10. |
- He, Mingzhao, et al.
(författare)
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Influence of slurry rheology on stirred media milling of quartzite
- 2007
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Ingår i: International Journal of Mineral Processing. - : Elsevier BV. - 0301-7516 .- 1879-3525. ; 84:1-4, s. 240-251
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Tidskriftsartikel (refereegranskat)abstract
- The role of slurry rheology in stirred media milling of quartzite has been investigated by varying important grinding parameters such as media bead density and size, addition of chemicals, solids concentration, stirrer rotational speed as well as the combined effect of these factors. Media bead density has an evident but complex effect on stirred milling performance, depending on stirrer rotational speed and solids concentration. The effect of media bead size on the ultra-fine grinding of quartzite is relevant to the feed size. Optimal ratio of media bead size to the median size of a feed is between 150 and 200. The combined effect of grinding bead size and stirrer speed or solids concentration is insignificant. The addition of Dispersant S40 or a lower solids concentration results in better grinding performance (i.e., a higher energy efficiency and a smaller median size) due to the maintenance of lower viscosities at shear rates investigated during grinding. Stirrer rotational speed interacts with solids concentration. For a given solids concentration, an optimal stirrer speed exists. The observed phenomena can be explained by the interaction of slurry rheology and the stress intensity of individual grinding bead. In addition, an empirical particle size-energy model provides a good fit (R2 > 0.904) to the grinding results under the experimental conditions investigated. Furthermore, the wear of grinding media beads is involved. ZrO2 beads have a lowest wear rate whereas the wear of SiO2 beads is most serious. The wear rate of Al2O3 beads is related to bead size.
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