Thiosulphate leaching of gold in the presence of carboxymethyl cellulose (CMC)

► Carboxymethyl cellulose (CMC) improves thiosulphate leaching of gold. ► The carboxymethyl and hydroxyl groups of CMC compete with thiosulphate anions. ► CMC reduces leaching passivation and increases dispersion of leach slurry. ► Leaching is satisfactory at low reagent concentrations with the addition of CMC.