生石灰对竹浆碱回收白泥白度的影响研究

Effects of Quick Lime on Whiteness of Lime Mud from Bamboo Pulp Alkali Recovery

本文通过石灰与绿液清液的苛化反应制备白泥,探讨了石灰质量对碱回收白泥白度的影响。结果表明,碱回收白泥制备过程中的加料顺序、石灰消化时间、消石灰的粒度对白泥白度没有明显影响;石灰浓度对白泥白度具有明显影响,浓度越高,所制备白泥白度越低。碱回收苛化时,在满足所得白液总碱量的情况下,为获得高白度白泥碳酸钙,应尽可能降低石灰浓度。对于实验用绿液而言,石灰浓度在13%时,所得白液总碱量约为85g/L(Na2O计),所得白泥碳酸钙白度可达94%ISO。石灰质量对白泥的白度具有明显的影响,但与石灰纯度没有明显关系。石灰中的有色杂质是影响白泥白度的主要因素。

In this paper, lime mud was prepared through causticization of green liguor with quick lime. The effect of quick lime quality on whiteness of the lime mud was studied. Results show that the charging sequence, the quick lime slaking time and the slaked lime particle size have no significant effects on whiteness of lime mud. The quick lime concentration should be as low as possible to obtain high whiteness of lime mud under the condition of ensuring the total alkali content of white liquor. For the green liquor used in experiment, when the concentration of quick lime is 13%, the the total alkali content of white liquor is about 85g / L （ as Na20） , and the whiteness of lime mud can reach 94% ISO. The quality of quick lime has obvious effect on the whiteness of lime mud, the main factor is not the quick lime purity, but the dark color impurity in quick lime is.