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- Ikumapayi, Fatai, et al.
(author)
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Recycling process water in complex sulfide ore flotation : Effect of calcium and sulfate on sulfide minerals recovery
- 2015
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In: Mineral Processing and Extractive Metallurgy Review. - : Taylor & Francis. - 0882-7508 .- 1547-7401. ; 36:1, s. 45-64
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Journal article (peer-reviewed)abstract
- The influence of major components of calcium and sulfate ions in process water on xanthate collector adsorption and flotation response of pure chalcopyrite, galena, and sphalerite minerals was investigated by Hallimond tube flotation, zeta-potential, FTIR, and XPS spectroscopy studies, while bench scale flotation tests were also carried out using complex sulfide ores. Marginally lower recoveries of chalcopyrite and galena in process water and in the presence of calcium and sulfate ions in both deionized and process waters using potassium amyl xanthate as collector were observed in Hallimond tube flotation, whereas sphalerite floatability is a little increased in process water using isobutyl xanthate as collector. Zeta-potential results show the adsorption of calcium ions on the minerals. FTIR and XPS studies revealed the presence of surface oxidized sulfoxy species and surface calcium carbonates and/or calcium sulfate on chalcopyrite and galena in the presence of process water and water-containing calcium ions at flotation pH 10.5, and these surface species influenced xanthate adsorption. Surface-oxidized sulfoxy and carbonate species were seen on sphalerite surface in the presence of deionized water, process water, and water-containing calcium and sulfate ions at pH 11.5, but the surface species does not influence xanthate adsorption. Bench scale flotation using two different complex sulfide ores showed that chalcopyrite, galena, and sphalerite recoveries are higher in process water than tap water and general decrease of the minerals floatability at temperatures lower than 22°C in either tap water or process water
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| 2. |
- Karlkvist, Tommy, et al.
(author)
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Flotation selectivity of novel alkyl dicarboxylate reagents for apatite-calcite separation
- 2015
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In: Journal of Colloid and Interface Science. - : Elsevier BV. - 1095-7103 .- 0021-9797. ; 445, s. 40-47
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Journal article (peer-reviewed)abstract
- The investigation aims to demonstrate the conceptual thoughts behind developing mineral specific reagents for use in flotation of calcium containing ores. For this purpose, a series of dicarboxylate-based surfactants with varying distance between the carboxylate groups (one, two or three methylene groups) was synthesized. A surfactant with the same alkyl chain length but with only one carboxylate group was also synthesized and evaluated. The adsorption behavior of these new reagents on pure apatite and pure calcite surfaces was studied using Hallimond tube flotation, FTIR and zeta potential measurements. The relation between the adsorption behavior of a given surfactant at a specific mineral surface and its molecular structure over a range of concentrations and pH values, as well as the region of maximum recovery, was established. It was found that one of the reagents, with a specific distance between the carboxylate groups, was much more selective for a particular mineral surface than the other homologues. For example, out of the four compounds synthesized, only the one where the carboxylate groups were separated by a single methylene group floated apatite but not calcite, whereas calcite was efficiently floated with the monocarboxylic reagent, but not with the other reagents synthesized. This selective adsorption of a given surfactant to a particular mineral surface relative to other mineral surfaces as evidenced in the flotation studies was substantiated by zeta potential and infra-red spectroscopy data.
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