Effect of ethylene diamine phosphate on the sulfidization flotation of chrysocolla

Abstract

In this study, ethylene diamine phosphate (EDP) was employed as an activator to improve the sulfidization and flotation of chrysocolla. The micro-flotation experiment results indicated that EDP could greatly increase the flotation recovery of chrysocolla. BET and TEM measurements confirmed that the porous structure of the chrysocolla’s surface would lead to large amounts of the reagents. ICP-AES analysis revealed that the addition of EDP caused more active Cu sites formed on the chrysocolla’s surface, enhancing the adsorption of S2- on its surface. Meanwhile, a redox reaction occurred between the S2- and [Cu(en)2]2+ ions causing the Cu, S, and N in the solution to counter-adsorb onto the chrysocolla’s surface by forming new complexes. During this reaction, the Cu(II) species reduced to Cu(I) species and the sulfide ions in the form of S2-, S22-, Sn2-, and SO42- appeared on the mineral surface. The zeta potential measurements further revealed that the EDP-activated chrysocolla surfaces adsorbed more sulfide species and xanthate species, thereby improving the floatability of the chrysocolla.