转炉除尘污水磁分离净化规律的研究

LAW OF PUKIFICATION OF CONVERTER DUST SEWAGE BY MAGNETIC SEP AKATION:ITS STUDY

转炉炼钢厂除尘污水常用沉降法净化，由于尘粒微细（多数小于２０μｍ），沉降缓慢，沉淀池比负荷低。考虑到废水中悬浮固体物粒度细、磁性强的特点，本研究采用复合絮凝（絮凝－磁凝）预处理工艺，有效增加了尘粒的表观粒度，强化了沉降过程；用具有磁力－重力综合力场的磁滤法取代只有重力场的沉降法，强化了分离过程。根据预处理和分离过程某些规律，提出了力比（磁／阻）的分离数学模型，可作为预测分离指标和调整工艺参数的判据。

In a steel mill, converter dust sewage is usually purified by settlement.However,dust particles settle very slowly due to their fine sizes(mostly less than 20 μm),leading to lowspecific load of a precipitation tank.In the light of such characteristics as fine size and goodmagnetic behaviours of suspended solids in the sewage,a pretreatment process, namely,acompound flocculation process(flocculation-magnetic flocculation)is used to increase theirapparent sizes, intensifying their settlement process. To this end, magnetic filtration process,with a comprehensive force field of magnetic force-gravitational force,should be used,instead ofthe settling process only with gravitational field.According to some laws of the pretreatment andseparation process,the authors give a mathematic model of force ratio (between magnetic forceand resistance)for separation as a basis for predicting separation indexes and adjusting technicalparameters.