Abstract: A copper oxide ore in Republic of Congo contains 3.61 % copper,mainly in the presence of free copper oxide,and is prone to argillization.According to the ore property and the results of exploratory tests,the process of direct flotation prior to sulfuration flotation is decided to separate copper,and the effect of dispersant,collector and activator on copper flotation index is investigated.The results show that with the decided optimal test conditions,the closed-circuit test obtained the copper concentrate with copper grade 27.12 % and copper recovery rate 83.25 %,indicating good flotation index.