Sustainable solvent extraction of gold and other metals with biomass chemicals

Abstract

This paper presents the basis for an industrial gold purification process using an organic phase made from biomass derived organic chemicals is presented. The use of a sustainable kerosene (a biodiesel) as a diluent in a solvent extraction experiment is important as it allows the solvent extraction of metals to be done without petroleum kerosene. A chemical change in the organic phase which reduces the gold distribution ratio has been observed and rationalized with XANES/EXAFS, this change offers path towards more sustainable flowsheets for gold. A second process is also presented using biomass derived diluent, the parameters required to calculate the ratio of the activity functions of chloride and the tetrachloroaurate(III) complex in choline chloride media are within this paper. Additionally solvent extraction experiments using the new sustainable diluent for lithium and alkaline earth elements together with proof of principle experiments with stable lanthanides, ^99mTc, ¹⁵²Eu, ²³⁸Pu and ²³⁹Pu were performed.