Optimization of Re solvent extraction from molybdenite roasting dust leaching solution and the performance evaluation of extraction in a multi-stage mixer–settler

Separation of Re from roasting dust leaching solution of molybdenite using a multi-stage mixer–settler extractor was studied. Systematic solvent extraction tests were performed using TBP as an extractant diluted in kerosene. The optimum extraction conditions were as follows: pH=0, temperature 25°C, 500rpm agitation rate, 6min contact time and 40% v/v TBP. The results showed that the extraction reaction is exothermic. A flow sheet was developed for the process. Three different extraction ways were studied in a laboratory size mixer–settler: Namely, counter-current, cross-current and co-current. The results showed that counter-current was the best. In addition, it was found that 2h of continuous operation was necessary to reach a steady state condition for the process. Extraction as high as 95.43% was obtained. •We optimize the effective parameters on Re solvent extraction in the mixer–settler.•Re extraction from leach liquor by TBP is an exothermic reaction.•Three different ways of extraction are studied at a phase ratio of 1.•A flow sheet is developed to separate Re from aqueous solution.•The final E value for the counter-current four-stage extraction is 95.43%.