草浆碱回收绿液悬浮物特性与绿液预处理

The properties of insoluble matter and pretreatment of green liquor from alkali recovery process

为了有效去除绿液悬浮物,提高碱回收白泥白度,探讨了绿液悬浮物特性及绿液预处理工艺.研究结果显示,利用自然沉降可以使绿液悬浮物含量降低至200mg/L,但沉降时间需要约24h.硅酸钙对悬浮物吸附沉降不能有效控制固体废弃物的产生量,PAC不适合用于绿液预处理.氧化钙对绿液悬浮物的反应吸附沉降是一种有效去除悬浮物的方法.对于实验用的绿液而言,氧化钙的反应吸附沉降的较佳用量为0.8%(对绿液体积),在此用量下,悬浮物可以在15min后基本沉降结束,悬浮物含量约240mg/L,且可以实现91.6%的清液回收率.

In order to effectively remove the insoluble matter from the green liquor and en- hance the brightness of lime mud, the properties of insoluble matter and the pretreatment of green liquor was discussed. The results showed that the content of insoluble matter can be reduced to 200 mg/L by using natural sedimentation, but the sediment time is approximate 24 hours. The adsorption sedimentation used calcium silicate cannot effectively control the discharge of solid waste. PAC is inadaptable to the pretreatment of green liquor. It is effec- tive method to remove the insoluble matter from the green liquor that executed the reactive adsorption by using CaO. For the experimented green liquor,when the usage of CaO is 0.8 %（ vs. the volume of green liquor）, the sediment time is approximate 15 minutes, the content of insoluble matter is about 240 mg/L and the clear liquid recovery is about 91.6%.