Study On The Separate Treatment And Reuse Of Wastewater From High-phosphorus Hematite Mineral Processing

For a long time, many problems have exsited in our national industry of hematite mineral processing such as serious environmental pollution and high quantity of exhausting and effluent. In this paper, the treatment of wastewater from weight-magnetic beneficiation process and flotation process was studied separately and the technology of coagulation-flocculation precipitation was used to treat these two kinds of wastewater.And then the effect of inevitable components in reused water and effluent as reused water on the mineral processing index was analysed.At last the paper studied the benefit of the craftwork at the angle of ecnomics.The results showed that the treated water could be reused and did not have adverse influence on the mineral process. It was very important that the technology made cleaner production come ture in hematite mineral processing.The results showed that the turbidity and total phosphorus of the wastewater from weight-magnetic beneficiation processing did not meet the requirements for industrial reuse.The total phosphorus of the wastewater was 3.5mg/L and the turbidity was between 42.2NTU and 86.3NTU.The optimum parameters of the coagulation-flocculation precipitation has been got to treat the wastewater. Aluminium chloride was the better coagulants to treat the wastewater.The scheme was that the dosage of Aluminium chloride was 9.75mg/L.7.54 was used as the pH of the interaction which was the pH of the original wastewater. According to the waterpower condition by orthogonal experiment,the turbidity and total phosphorus of the wastewater were reduced to 0.17NTU and 0.32mg/L separately. The quality of effluent meet the requirements for industrial reuse.The turbidity,total phosphorus and CODcr of the wastewater from flotation processing did not meet the requirements for industrial reuse.The turbidity,total phosphorus and CODcr is 126000NTU,1540.24mg/L and 2094.86 mg/L. Two better ways were used to the wastewater. The one was that the dosage of calcareousness was 1500mg/L and the dosage of HF-1 was 20mg/L. According to the waterpower condition by orthogonal experiment, the turbidity,total phosphorus and CODcr of the wastewater were reduced to 2.1NTU,0.43mg/L and 12.35mg/L separately.The other way used the technology of coagulation-flocculation precipitation by two stages.The first stage was that the dosage of CFA was 400mg/L; The second stage was that the dosage of ferric chloride was 40mg/L and the dosage of HF-2 was 0.25mg/L. According to the waterpower condition by orthogonal experiment, the turbidity,total phosphorus and CODcr of the wastewater were reduced to 0.63NTU,0.47mg/L and 95.41 mg/L separately.The results of flotation indicated that the effluent took no adverse effect on the flotation index on the whole and could be reused.The paper studied the effect of inevitable components on the flotation.The research results showed that SO42- had greatly bad effect on the flotation index. And other inevitable components just badly affected the flotation index while the concentration of them was heavy to some extent.If the dosage of the coagulation is controlled strictly, the bad effect will be avoided effectively.The paper studied the economic benefit of the craftwork at last. The scheme by using Aluminium chlorid could make the profit be 22942.53 Yuan RMB which was used to treat and reuse 18000 ton wastewater from weight-magnetic beneficiation processing monthly.In order to treat and reuse 18000 ton wastewater from flotation processing monthly,the scheme by the combined use of calcareousness and HF-1 could make the profit be 289136.64 Yuan RMB.While the scheme by the use of coagulation-flocculation precipitation of two stages could make the profit be 285950.64 Yuan RMB.The craftwork will improve the utilization rate of water resouce,reduce effluent,solve social problems caused by wastewater and promote the development of economic, environment and society.