Abstract: In order to solve the scaling problem of the high salinity mine water reverse osmosis system,aprocess of " chemical softening + ion exchange softening" was used to remove calcium,magnesium andsilicon synergistically from the reverse osmosis concentrated water with a total hardness of 2 800 mg /L.The results showed that the optimum dosages of Ca( OH) 2 and Na2CO3 were 550 mg/L and 3 500 mg/L,respectively. The optimum reaction time was 30 minutes. Under the above conditions,the effluent hard-ness was 188 mg /L and the total hardness removal efficiency was 93.29%. The optimum resin modelwas D402 and the optimum flow rate was 15 m/h. Under the above conditions,the effluent hardness wasnot detected. The silica content was decreased to 1.61 mg /L,and the corresponding removal efficiencywas 92.3% by the collaborative process. Close-