The Study On The Removal Of Sulfate From Circulating Water Of Mineral Processing Of Chengchao Iron Mine

The floatability of minerals is affected in some extent by high concentration of sulfate.Therefore, the recovery and economic benefits of mineral processing are influenced, which willcause the loss of valuable mineral resources.In this paper, the removal of sulfate from circulating water of mineral processing ofChengchao iron mine was studied using coagulation precipitation process, ion exchange methodas well as reverse osmosis respectively. Influencing factors of each method were investigated.The feasible operating conditions were obtained and used for the treatment of circulating waterof mineral processing taken from Chengchao iron mine. Meanwhile, technique characteristics,treatment effiency as well as investment and running cost of each method were analyzed. Themain results achieved were as follows:(1)The effect of pH value and dosage of aluminum chloride on coagulation precipitationprocess was significant. The concentration of sulfate from800m~3circulating water was reducedto63mg/L under the optimum conditions, which could achieve water quality standard forindustrial uses. Nevertheless, the concentration of chloride and total dissolved salts (TDS)couldn’t meet the standard.(2)The effect of operating conditions on ion exchange method was minor. Removal rate ofsulfate from800m~3circulating water reached90.8%under the optimum operating conditions.The concentration of sulfate, pH value and so on in the effluent could achieve water qualitystandard for industrial uses, while the concentration of chloride and total dissolved salts (TDS)couldn’t meet the standard.(3)The effect of operating conditions on reverse osmosis was minor. The concentration ofsulfate from synthetic wastewater after the treatment was steadily at below90mg/L, but thepermeation flux of reverse osmosis membrane changed greatly. The53m Dajing circulatingwater was treated under the optimum operating conditions. Each water quality index of theeffluent could achieve water quality standard for industrial uses, which could meet therequirement of water reuse.(4)Compared with coagulation precipitation and ion exchange method, the automatic degreeand stability operation of reverse osmosis method were fine, and the effluent of it was close topure water. In order to decrease investment and running cost, only10%of the total amount ofwastewater per day should be treated with investment of5.935million and running cost of0.80元/m~3. In addition, relevant measures were proposed to avoid problems of reverse osmosis.