Utilization of starch graft copolymers as selective depressants for lizardite in the flotation of pentlandite.

This paper investigates the detrimental effect of lizardite surface characteristics on pentlandite flotation. To reduce the effect, two different starch graft copolymers, starch–graft–polyacrylamide (S–g–PAM) and starch–graft–polyacrylic acid (S–g–PAA) were synthesized as depressants for lizardite. The flotation results show that at pH value of 8, where the flotation of lizardite and pentlandite are routinely performed, S–g–PAM and S–g–PAA improve pentlandite recovery efficiently, compared with the traditional depressant carboxymethyl cellulose (CMC). Experimental results demonstrate that S–g–PAM and S–g–PAA disperse the hydrophilic lizardite particles from the pentlandite surface and also flocculate lizardite particles. [ABSTRACT FROM AUTHOR]