Recovery of copper and rare earth elements from the processed Alloga carbonaceous shale, Southwestern Sinai, Egypt

Abstract

ABSTRACT The present work is concerned with the recovery of Cu and REEs from the processed Alloga carbonaceous shale (almost free from U) of Abu Zeneima area at Southwestern Sinai using H2SO4 acid agitation leaching method. The working processed sample assays 0.18% Cu and 0.068% REEs. The applied optimum leaching conditions realized dissolution efficiencies of 91.2% for Cu and 99.1% for REEs. For selective separation of Cu, LIX973N diluted in kerosene was used. Cu was regenerated from the loaded organic phase under the optimum stripping conditions of 12% H2SO4 acid with shaking time of 3 min at A/O ratio of 1/1 and then precipitated directly as Cu (OH)2. With respect to REEs extraction, the raffinate solution left behind after Cu recovery and assayed 0.16 g/L of REEs was subjected to Dowex50 W-X8 cation-exchange resin in its hydrogen form realizing loading efficiency of 79.5%. About 99% of eluted REEs was precipitated by the addition of 10% oxalic acid at pH of 1.1. A flowsheet for the preparation of CuO and RE2O3 was proposed.