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| 2. |
- Alexandrova, L., et al.
(författare)
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Thin film studies in mixed cationic-anionic surfactant system
- 2003
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Ingår i: Proceedings of the XXII International Mineral Processing Congress. - Marshalltown, South Africa : South African Institute of Mining and Metallurgy. - 0958460922 ; , s. 838-846
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Konferensbidrag (refereegranskat)
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| 3. |
- Berglund, Gun, et al.
(författare)
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Influence of different gases in flotation of sulphide minerals
- 1989
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Ingår i: Advances in Coal and Mineral Processing Using Flotation. - Littleton, Colo : Society for Mining, Metalurgy and Exploration. - 0873350871 ; , s. 71-76
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Konferensbidrag (refereegranskat)abstract
- Sulfide mineral flotation is known to be affected by oxidation-reduction conditions in the pulp, although there is some doubt as to whether it is the oxidizing environment or the type of oxidant which influences flotation. Variations in the oxidizing conditions of the pulp and their subsequent effect on flotation were examined for two types of natural sulphide ore, a galena-sphalerite ore and a complex pyrite ore. Different gas mixtures ranging from pure nitrogen to pure oxygen were used to control the oxidizing conditions. Zinc recovery increased with a more oxidizing environment, and nitrogen gas acted almost as a depressant for sphalerite in the flotation of the Pb-Zn ore. For the complex pyrite ore, the selectivity between chalcopyrite and both gangue and pyrite improved when the environment was oxidizing, resulting in higher Cu recovery in the copper rougher concentrate.
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| 4. |
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| 5. |
- 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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| 6. |
- Das, A., et al.
(författare)
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Surface chemical and adsorption studies using Thiobacillus ferrooxidans with reference to bacterial adhesion to sulfide minerals
- 1999
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Ingår i: Biohydrometallurgy and the Environment toward the Mining of the 21st century. - : Elsevier. - 0444501932 ; , s. 697-707
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Konferensbidrag (refereegranskat)abstract
- Adhesion of Thiobacillus ferrooxidans to pyrite and chalcopyrite in relation to its importance in bioleaching and bioflotation has been studied. Electrokinetic studies as well as FT-IR spectra suggest that the surface chemistry of Thiobacillus ferrooxidans depends on bacterial growth conditions. Sulfur-,Pyrite- and chalcopyrite-grown Thiobacillus ferrooxidans were found to be relatively more hydrophobic. The altered surface chemistry of Thiobacillus ferrooxidans was due to secretion of newer and specific proteinaceous compounds. The adsorption density corresponds to a monolayer coverage in a horizontal orientation of the cells. The xanthate flotation of pyrite in presence of Thiobacillus ferrooxidans is strongly depressed where as the cells have insignificant effect on chalcopyrite flotation. This study demonstrate that:(a)Thiobacillus ferrooxidans cells can be used for selective flotation of chalcopyrite from pyrite and importantly at natural pH values.(b)Sulfur-grown cells exhibits higher leaching kinetics than ferrous ion-grown cells.
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| 7. |
- Deo, N., et al.
(författare)
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Biodegradation of some organic reagents from mineral process effluents
- 1999
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Ingår i: Biohydrometallurgy and the Environment toward the Mining of the 21st century. - : Elsevier. - 0444501932 ; , s. 687-696
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Konferensbidrag (refereegranskat)abstract
- The utility of a soil microbe, namely Bacillus polymyxa, in the removal of organic reagents such as dodecylamine, ether diamine, isopropyl xanthate and sodium oleate from aqueous solutions is demonstrated. Time-bound removal of the above organic reagents from an alkaline solution was investigated under different experimental conditions during bacterial growth and in the presence of metabolites by frequent monitoring of residual concentrations as a function of time, reagent concentration and cell density. The stages and mechanisms in the biodegradation process were monitored through UV-visible and FTIR spectroscopy. Surface chemistry of the bacterial cells as well as the biosorption tendency for various organics were also established through electrokinetic and adsorption density measurements. Both the cationic amines were found to be biosorbed followed by their degradation through bacterial metabolism. The presence of the organic reagents promoted bacterial growth through effective bacterial utilization of nitrogen and carbon from the organics. Under optimal conditions, complete degradation and bioremoval of all the organics could be achieved
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| 8. |
- F., Su, et al.
(författare)
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Computer estimation of flotation kinetic model parameters
- 1998
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Ingår i: 2Papers presented at the APCOM '98 conference, organized by the Institution of Mining and Metallurgy and held in London, United Kingdom from 19 to 23 April, 1998. - London : The Institution of Mining and Metallurgy. - 1870706366 ; , s. 513-524
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Konferensbidrag (refereegranskat)abstract
- The effect of chemical variables on the kinetic parameters of apatite flotation from magnetite has been investigated. The two common first-order kinetic models reported in the literature, i.e., the model with rectangular distribution of floatabilities and the model with fast and slow-floating components (F-S model) have been applied in the evaluation of flotation results. The models are evaluated by fitting the flotation results from batch flotation tests. The results although indicate that both models describe the apatite flotation kinetics well in a wide range of kinetic parameters, the F-S model is found to be better in the goodness of fit to the results from every flotation test and also to describe the flotation performance adequately. The kinetic parameters of the F-S model are varied with a change in chemical variables. In particular, the rate constants ratio Kf/Ks is found to be an important parameter for achieving selectivity between apatite and magnetite, and the effect of reagents dosages on the ratio is discussed. The effect of particle size on the apatite flotation kinetics is also illustrated by analysing the froth products at each flotation time in different size classes.
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| 9. |
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| 10. |
- Forssberg, Eric, et al.
(författare)
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Computer-assisted calculations of thermodynamic equilibria in the chalcopyrite-ethyl xanthate system
- 1984
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Ingår i: Reagents in the Minerals Industry. - London : The Institution of Mining and Metallurgy. - 0900488786 ; , s. 251-264
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Calculations show that thermodynamic data can be used to construct pulp chemistry models that satisfactorily describe events in mineral pulps. The usefulness of such models can be enhanced by the insertion of kinetic restrictions derived from analyses of mineral pulps from commercial-scale operations. A number of interesting findings concerning the chalcopyrite-ethyl xanthate system are demonstrated. As it is possible to calculate an operating line for any given flotation system, the calculation results can be compared at all times with practical experience and measurements of flotation processes.
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