Abstract:
A gold deposit in Minxian, Gansu, features fine-grained pyrite as the primary gold-bearing mineral, with elevated hazardous arsenic content and gold predominantly occurring as encased gold. To optimize gold recovery from the ores, beneficiation tests of the ores on the southern ore belt were conducted comparing the recovery effects of flotation, gravity separation, carbon-in-leach (CIL), and roasting, both individually and in combination. Results indicate that flotation effectively recovers gold and silver from the ores on the southern ore belt, yielding a gold concentrate grade of 45.41 g/t Au and 134.00 g/t Ag, with recovery rates of 73.76 % Au and 84.05 % Ag. However, due to high average arsenic levels in gold-bearing pyrite and the presence of arsenopyrite, the gold concentrate retains 1.00 % arsenic through the flotation of the ores on the southern ore belt. Exploratory arsenic reduction tests revealed a strong correlation between gold and arsenic, rendering effective separation unfeasible.