STABILIZATION (PRECIPITATION) OF MERCURY FROM PRECIOUS METALS EXTRACTION WASTES UTILIZING TRIMERCAPTOTRIAZINE

摘要

The need for the removal of mercury from theprecious metals extraction circuits may be influenced by process,environmental, as well as by occupational hazard reasons. Inthese circuits mercury is mainly present as cyanide complexes.The effectiveness of any stabilization method will be influencedby the high thermodynamic stability mercury-cyano speciesexhibit in an aqueous solution. In this study, we haveinvestigated the utility of the trisodium salt of trimercapto-s-triazine (TMT) for precipitation of mercury from thecorresponding cyano-complexes. The influence of pH, molarratio of TMT to Hg, coagulant and flocculant additions, excessof free cyanide, as well as the presence of other metal-cyanospecies on the effectiveness of mercury precipitation wereinvestigated in detail Also, a 'teal world" precious metals milleffluent initially containing approx 7 #mu#g /mL (Ppm) of Hgwas treated and it was found that greater than 99.8 percent of themercury was removed from the solution as an insoluble Hg/TMT complex.