Abstract: Based on mineralogy study on a copper oxide ore from Indonesia，research on process conditions of sulphidizing flotation has been carried out.The reseach results indicated that synchronous flotation of copper oxide and copper sulfide was a effective way to process this ore.A close circuit test showed that with a raw ore assaying copper grade of 1.69% and silver grade of 64.88 g/t， a copper concentrate assaying copper grade of 18.64%，silver grade of 843.00 g/t with coppe and silver recovery of 77.86% and 91.86% respectively ,was obtained by using flow sheet of one roughing,one cleaning and three scavenging and sequential return of middlings.

Key words: Copper oxide ore, Sulphidizing flotation, Synchronous flotation, Comprehensive utilization