硝酸型PCB退锡废水回收利用工艺研究

摘要

PCB退锡废水含大量锡、铜、铁等重金属以及硝酸等有机、无机酸,具有强腐蚀性,是多年来严重污染环境的废水之一,本文设计了一种硝酸型PCB退锡废水综合回收利用工艺,研究了相关工艺参数对该类废水中主要成分锡的回收率的影响。实验结果表明：锡与碱用量为1∶4（mol/mol）,反应温度在98～105℃,反应时间为80 min时,锡的转化率、回收率最高可达98.5%以上。%Spent tin stripper from printed circuit board（PCB） industry was one of the difficultly treated waste water producing serious environmental pollution because of its significant amounts of metals,such as tin,copper,iron,organic acid and inorganic acid（nitric acid）,and it was corrosive.The nitric PCB spent tin stripper recycling process was designed.The effect of the process parameters in each step to recovery rate of tin was studied.The experimental results showed that the separating rate can be higher than 98.5% when the process conditions were as follows,the sodium hydroxide and tin mol ratio 4,slight boiling 100~110 ℃,and time 2 h.