废SCR脱硝催化剂中钨和钒的浸出是实现其回收的关键.采用碳酸钠混合焙烧-稀硫酸浸出法,对废SCR脱硝催化剂中金属钨和钒的浸出实验进行了研究,考察了焙烧温度t_1(℃)、焙烧时间t_2(h)、硫酸浓度c(v/v)、液固比w、浸出温度t_3(℃)、浸出时间t_4(h)、Na_2CO_3与催化剂的质量比m(Na_2CO_3)/m(催化剂)等因素对钨和钒浸出率的影响.结果表明,在t_1为800℃、t_2为3 h、c为2%、w为8:1、t_3为80℃、t_4为4 h、m(Na2CO3)/m(催化剂)为1.2的反应条件下,废SCR脱硝催化剂中钨和钒的浸出率可分别高达99.08%、98.49%,为后续钨和钒的高效提取与回收提供了有利的条件.
the leaching of tungsten and vanadium,which was the key process to recover the metalsfrom spent SCR catalyst,was investigated using the method of roasting the mixture of sodium carbonate and catalyst-sulfuric acid. The influences of roasting temperature t_1,roasting time t_2,sulfuric acid concentration c,liquid to solid ratio w,leaching temperature t_3,leaching time t_4 and the amount of Na_2CO_3 on the leaching rate were investigated during the roasting and leaching processes. The results show that the leaching rates of W and V reach as high as 99.08% and 98.49%,respectively,when the catalyst particles were roasted at 800 ℃ for 3 h after adding 1.2 Na_2CO_3,m( Na_2CO_3) /m( catalyst). The agglomerate was then dissolved in 2%( V/V)sulphuric acid at 80 ℃ for 4 h and the liquid to solid ratio was 8∶1. This study could provide a good basis for the further studies of tungsten and vanadium recovery.