The invention relates to a process for extracting gold from low-grade difficultly-treatable
gold ore containing
arsenic and carbon. The process is characterized in that: the
gold ore has the characteristics of high clay mineral content, large fine ore amount after
grinding, and the like. The process comprises the following steps of:
grinding raw ore to 10 to -30 millimeters; sieving ore through a sample
sieve of 1 to -2 millimeters or washing the ore with water so as to separate fine ore from the ore; floating gold concentrate by using the obtained fine ore; performing direct
heap leaching on ore of +2
millimeter and performing
biological oxidation; performing medium transformation such as
acid washing,
water washing, alkali washing and the like on the biologically-oxidized ore and cyaniding directly so as to extract gold, wherein gold is extracted from the floated gold concentrate by
biological oxidation-cyaniding and carbon soaking-
pressure oxidation-cyaniding and
gold extraction or baking, oxidation and cyaniding. Due to the adoption of the process, the problem of permeability of
gold ore is solved and the gold extracting rate is effectively increased from 2 to 5 percent during direct
heap leaching and cyaniding to 55 to 65 percent. The process has the advantages of simple process, high gold extracting rate, low
pollution, high benefit and the like.