Development of an integrated model for cobalt solvent extraction using Cyanex 272

摘要

A model of metal extraction based on pH isotherms was generated and applied to a cobalt solvent extraction (SX) circuit. Cyanex 272 (bis-(2,4,4-trimethylpentyl) phosphinic acid) was used as the organic extractant due to its selectivity for cobalt over nickel in the extraction process. Experiments were conducted for cobalt, nickel and magnesium extraction, with the latter two representing impurity elements in Co SX. The methods for determining metal extraction incorporated the effects of temperature, solution composition and pH on the equilibrium constant k, and hence on the overall extraction extent. This information was applied to a multi-stage mixer-settler model consisting of integrated extraction units. The initial mathematical model for cobalt, which was built in Matlab can be further developed to include the impurity elements and incorporate the scrubbing and stripping units. Future work will focus on using the model for process optimisation.