Intensified Alkiline Leaching Pretreatment of Refractory Gold Ore at Ambient Temperature and Atmosphere Pressure

The arsenic containing refractory gold ore (or concentrate) is pretreated with the physical and chemical synthetic separation process in a ultra-fine grinding-leaching tower mill The ore (or concentrate) is ultra-fine ground to 91%～99% -35μm, then is intensively leached with NaOH solution in a forced agitator tank with the pulp concentration of 40% at ambient temperature (-4～35℃) and atmosphere pressure The arsenic and some sulfide minerals are selectively oxidized, and the gold minerals are exposed, then the gold is effectively recovered by cyanide leaching The 11 sorts of typical refractory gold ores in China are pretreated by the new process, the gold leaching rates by cyanide are increased from 8%～20% before pretreatment to 93%～98% A pretreatment pilot plant of refractory gold concentrate with 10t/d capacity is successfully built and operated Another 30t/d production system is going to be built