煤矸石与废盐酸制备PAC的节能环保工艺分析

Analysis of Energy Saving and Environmental Protection Process for Preparing PAC from Coal Gangue and Waste Hydrochloric Acid

煤矸石是煤矿开采过程产出的伴生物,属于一般固废,而废盐酸主要来源于各种工业生产活动,属于工业危废。本文提出了一种综合处理一般固废和工业危废的节能环保工艺方案。将煤矸石进行焙烧活化处理,产生高温烟气和活化煤矸石。活化煤矸石与废盐酸用于制备聚合氯化铝(PAC)。在余热锅炉中,高温烟气经过热量交换转化为低压蒸汽和中温烟气,供酸浸工艺和烘干工艺使用。低温烟气脱硫脱硝后无害排放,同时得到副产品硫酸铵和硝酸铵。

Coal gangue is an associated organism produced in the coal mining process and belongs to general solid waste,while waste hydrochloric acid mainly comes from various industrial production activities and belongs to industrial hazardous waste.This paper proposes an energy-saving and environmental protection process scheme for the comprehensive treatment of general solid waste and industrial hazardous waste.The coal gangue is roasted and activated to generate high temperature flue gas and activated coal gangue.Activated coal gangue and waste hydrochloric acid are used to prepare polyaluminum chloride(PAC).In the waste heat boiler,the high-temperature flue gas is converted into low-pressure steam and mediumtemperature flue gas through heat exchange,which are used in the acid leaching process and the drying process.After desulfurization and denitrification,low-temperature flue gas is harmlessly discharged,and by-products ammonium sulfate and ammonium nitrate are obtained at the same time.