SEMICONTINUOUS BIOOXIDATION OF THE CHONGYANG REFRACTORY GOLD ORE

The semi-continuous biooxidation of a flotation concentrate of a parti cularly refractory Chinese gold ore was investigated. Without biooxida tion, even after roasting, it was possible to recover only a little mo re than 46% of the gold. The ore contained sulfide minerals, clay mine rals, and carbonaceous material. Approximately 58% of the gold was ass ociated with arsenopyrite, 38% with the clay minerals and about 7% wit h the carbonaceous material. Two different bacterial consortia were st udied for effectiveness at biooxidizing the concentrate. Both were eff ective and arsenopyrite oxidation was rapid. After the biotreatment it was possible to recover about 76% of the gold. Apparently the remaini ng non-recoverable gold is associated with the clays and the carbonace ous material. (C) 1997 Published by Elsevier Science Ltd.