A new route of ferric ions rejection in a synthetic nickel leach solution

Abstract

A new route of impurity rejection to remove ferric iron from a synthetic nickel leach solution was introduced, which simulated the chemical composition of a typical acid leach solution of nickel laterites under atmospheric pressure. The synthetic solution underwent a stepwise neutralization process, with each step adopting different pH value-temperature combinations. In a conventional nickel atmospheric leach (AL) process, the nickel loss could be as high as 10wt%, which was a longstanding issue and prevented this process from commercialization. The new impurity rejection route is the first step towards resolving this issue. The results show that, the best neutralization performance is achieved at the nickel loss of 3.4wt% in the neutralization scheme that employs ethylenediaminetetraacetic acid as a nickel stabilizer (pH: 1.3–3.5; temperature: 95–70°C)

Keywords

nickel laterite / acid leach / iron removal / impurity rejection / neutralization

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