Abstract: The grades of copper and sulfur in a low-grade copper-sulfur ore are 0.45% and 18.26%， respectively. The main sulfides are chalcopyrite，covellite，pyrite，pyrrhotite，etc.，and the content of mud⁃ ding gangue minerals is as high as 21.00%，which belongs to low-grade complex refractory copper ore.In or⁃ der to reduce production costs，improve resource utilization efficiency，and reduce environmental pollution， based on the study of ore properties，a low-alkali copper separation process is used for experimental re⁃ search.The results show that the copper concentrate with copper grade of 18.14% and copper recovery of 89.64%，the magnetic sulfur concentrate with sulfur grade of 31.96% and sulfur recovery of 28.68%，and the floating sulfur concentrate with sulfur grade of 48.39% and sulfur recovery of 62.32% are obtained by the whole process closed-circuit test of low-alkali copper separation process. The total sulfur recovery is 91.00%，which is similar to the technical index of high-alkali copper-sulfur separation process in the field. The dosage of lime and sulfuric acid is significantly reduced，and the cost of beneficiation reagents and the risk of safety and environmental protection are reduced，which provides a technical basis for the transforma⁃ tion of clean and efficient copper-sulfur separation process.

Key words: copper sulfide ore, pyrrhotite, low alkali flotation, recovery rate, safety and environmen? tal protection