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Solvent extraction behaviour of scandium from lateritic nickel-cobalt ores using different organic reagents

Ferizoglu E., Kaya S., Topkaya Y. A.

Physicochemical Problems of Mineral Processing

2018

Vol. 54, iss. 2

538--545

Scandium is one of the most important and strategic metals that can be recovered as a by-product from lateritic nickel-cobalt ores. In this research, different extractants were investigated to extract scandium from sulphate medium by using solvent extraction method. Generally, the organic extractants are classified as acidic, neutral and basic reagents. Thus, the aim of the present study was to compare scandium extraction efficiencies of some acidic, neutral and basic organic reagents. For this reason, Ionquest 290 (Bis(2,4,4-trimethylpenthyl) phosphonic acid), DEHPA (Di(2-ethylhexyl) phosphoric acid), Cyanex 272 ((Bis(2,4,4-trimethylpentyl) phosphinic acid) which are acidic organophosphorus compounds, Cyanex 923 (Trialkyl phosphine oxide), which is a neutral organophosphorus compound, and Primene JMT, a basic extractant, were used. The extraction efficiencies of these extractants were studied with respect to the extractant concentration at the same pH and O/A (organic/aqueous) phase ratio. As a result of this study, DEHPA and Primene JMT were found to have high scandium extraction efficiencies with lower impurity co-extractions at pH=0.55 with O/A phase ratio 1/1.

Złoża rud niklu w redeponowanych laterytach w Grecji, ich wykorzystanie i zagospodarowanie pogórnicze

Paulo A., Strzelska-Smakowska B.

Przegląd Geologiczny

2016

Vol. 64, nr 3

159--165

The article presents the geological features of rarely described ferruginous nickel ores in carbonate rocks. They are exploited mostly in central Greece, giving about 1% of world production. Geochemical associations of laterite-derived nickel ores and bauxites occurring in carbonate formations of similar age in the not distant area are presented. The deposits formed in several stages starting with the lateritic alteration of nearby serpentinite and redeposition of water-suspended saprolite into karstic forms of Jurassic limestones. Ferruginous clayey material was sealed by transgressive Cenomanian marly sediments and was subject to further transformations in the vadose zone of the uplifted rock massive. Mining geology, environmental and economic aspects of exploitation are analysed. Finally, guidelines for the land use in post-mining areas are provided.