Abstract: To address the issue of low recovery of associated gold in traditional high-alkalinity flotation processes,this
study proposes a novel depressant based on flotation system under low-alkalinity conditions. By comparing the performance of
different depressants (CB,WY289,WY289-1),CB was identified as the most effective in a low-alkalinity environment (pH=
9. 0),achieving a copper recovery of 88. 39% in roughing and significantly increasing gold recovery to 74. 09%. Further optimization
of the lime-to-CB ratio (1 500 g/ t lime + 8 g/ t CB) in closed-circuit tests yielded a concentrate with a copper grade
of 19. 84%,copper recovery of 84. 12%,gold grade of 2. 75 g/ t,and gold recovery of 57. 26%. Compared with the traditional
high-alkalinity process (pH=10. 1),gold recovery increased by 6. 24 percentage points. The study demonstrates that the lowalkalinity
depressant CB has significant potential for improving associated gold recovery,providing both theoretical and practical
insights for optimizing low-alkalinity flotation processes.

Key words: low-alkalinity flotation,depressant,recovery for associated gold,copper ore,closed-circuit test