某钢铁企业生产废水处理工艺设计

Process Design of Wastewater Treatment of an Iron and Steel Enterprise

深入探讨了某钢铁企业生产过程中产生的6股废水的处理工艺,采用生化工艺处理冷轧废水、软水站废水和除盐水站废水,使得出水水质均满足当地相关标准;采用NF分盐+RO浓缩+蒸发结晶组合工艺处理脱硫废水、水洗废水和煤气冷凝水,出水水质满足《城市废水再生利用工业用水水质》(GB/T 19923-2005)表1中敞开式循环冷却水系统补充水标准,产盐分别满足GB/T 5462-2015《工业盐》日晒工业盐中二级指标和GB/T 7118-2008《工业氯化钾》二级指标,其中纳滤(NF)浓液回流至软化工艺段,在较高pH环境下,使得硫酸根与钙离子结合生成硫酸钙,从而使得整个工艺流程具有较低的投资成本和运行成本。

This paper deeply discussed the process of 6 kinds of wastewater produced in an iron and steel enterprise.Biochemical process is used to treat cold rolling wastewater,soft water station wastewater and demineralized water station wastewater,so that the obtained water could meet the local standards.The combined process of NF+RO+evaporative crystallization was adopted to treat desulfurization wastewater,washing wastewater and gas condensate.The produced water could meet the make-up water standard of open circulating cooling water system in table I of The Reuse of Urban Recycling Water-Water Quality Standard for Industrial Uses(GB/T 19923-2005).The salt could meet the secondary standard in sun exposure of Industrial Salt(GB/T 5462-2015)and the Secondary Standard in Industrial Potassium Chloride(GB/T 7118-2008).NF concentrated water was refluxed to the softening process to combine sulfate with calcium ions to form calcium sulfate in high pH environment,so that the whole process had low investment cost and operation cost.