Rates of Copper Extraction by LIX65N

Abstract

Extraction rate of copper from aqueous solution by LIX65N-kerosene solution was studied by use of an agitated vessel with a plane interface. The extraction rate was found to increase with repeated regeneration of the LIX solution with sulfuric acid solution. Such behavior is due to impurities contained in commercial LIX65N. They are surface-active substances that participate in a reaction between the extractant reagent and copper ion at the liquid-liquid interface; they are liable to be dissolved out by contacting with diluted sulfuric acid. As a result, the rates of copper extraction by LIX65N are proportional to ([RH]_i/[H⁺]_i)^p. When the reaction is affected by impurities in the extractant, the exponent p was found to be 0.5. When refined LIX solution was used, the value of p was more than unity. Even for the original LIX65N solution, however, the values of p for extraction in a contactor with large interfacial area or from aqueous solution of low pH become more than unity.