Abstract: The gold in a low grade and refractory gold ore of Guizhou is fine disseminated and mainly occurs in sulfide minerals like pyrite，or occurs as monomer gold.The monomer gold account for 81.34% of total gold，and gold in carbonate and silicate occupies 18.66% of total gold.In order to efficiently develop and utilize this gold ore，experiment of gold flotation was conducted with lime as pulp regulator.The results showed that at the grinding fineness of 96% -0.074 mm，gold concentrate with gold grade of 9.41 g/t and recovery of 86.45% was obtained by adopting the process of one roughing-three cleaning-three scavenging，middles from cleaning collected and processed by one roughing-one cleaning-two scavenging process，and other middles back to the flow-sheet in turn.

Key words: Carlin type gold mine, Pyrite, Regulator, Lime, Flotation