硫化钠法处理SO_2烟气的吸收液脱砷研究

STUDY ON REMOVAL OF ARSENIC IN THE PROCESS OF ABSORBING SO 2 FLUE GAS USING Na 2S SOLUTION

研究了在采用硫化钠吸收低浓度二氧化硫烟气制硫磺粉的工艺过程中吸收液除砷的工艺条件，包括反应时间、反应温度、溶液ｐＨ值以及沉降条件等因素对除砷率的影响．结果表明，当反应时间为５０ｍｉｎ，反应温度为３０～５０℃，溶液ｐＨ值在２～５范围内时，可以达到除砷的目的．同时，还确定了以聚合硫酸铝为絮凝剂的沉降分离方法，当聚合硫酸铝的用量（质量分数）为５×１０－６～１０×１０－６时，可加快沉降速率，提高脱砷率．

The removal of arsenic in Na 2S solution, used for absorbing flue gas with low content of SO 2, was studied. A practical removal rate of As can be obtained under the optimum conditions: reaction time about 50 min, temperature from 30 to 50 ℃, pH from 2 to 5. Meanwhile, an effective separation method using polyaluminium sulphate as flocculant was adopted, and the dosage of the flocculant is from 5×10 -6 to 10×10 -6 .