Cobalt and Nickel Occurrences in Lead Tailings Processed for Heavy Metal Removal

The processing of lead tailings for removal of the heavy metals produces concentrates upgraded in Co and Ni values. Reflected light microscopy, scanning electron microscopy, image analysis, and Vickers hardness measurements were used to identify mineral species, associations, degree of liberation, and distributions to the test products. Siegenite and bravoite were the most common species encountered, but violarite and enriched pyrite and marcasite phases were also identified. Liberation for the Co and Ni minerals contained in the tailings was 20 micrometers or less.