沉淀法白炭黑颗粒在水介质中的解聚与分散研究

Disaggregation and Dispersion of Precipitated Silica Particles in Water Media

由沉淀法制备的白炭黑粉体因颗粒微细、比表面积大和表面羟基间的结合作用而形成多次团聚体,严重影响其填充补强等性能的发挥。对沉淀法白炭黑进行了颗粒聚集行为和在水介质中的解聚、分散试验研究。结果表明,采用搅拌磨对白炭黑进行湿法研磨,并添加分散剂可使白炭黑颗粒解聚并有效分散,在研磨时间1.5 h、球料比5∶1、浆体质量分数10%、分散剂用量6%等试验条件下对白炭黑解聚分散,白炭黑颗粒D50由25.2μm降为11μm。

Silica powder prepared by precipitation method had formed among multiple aggregates because of its particles fining, large surface area and interaction among the hydroxyl groups in particls surface. So, its reinforcing properties of filling were seriously affecting. The research on the aggregation behavior of precipitated silica particles and its disaggregation and dispersion in aqueous medium were carried out. The results showed that the wet grinding of silica in stirred mill and adding dispersant can make silica particles be effectively dispersed and disaggregaed, and D50 of silica particles reduced by a 25.2 μm to 11 μm after disaggregation and dispersion with follow conditions ： grinding time 1.5 h, the ball feed ratio 5∶1, slurry concentration of 10%, the amount of dispersant 6%.