颗粒级配法制备高固相含量低黏度氧化铝料浆

PREPARATION OF ALUMINA SLURRIES WITH LOW VISCOUS AND HIGH SOLID LOADING BY DIFFERENT PARTICLE SIZE MIXING METHOD

以平均粒径分别为0.97μm(CQ)和2.18μm(HNXY)的2种Al_2O_3粉体为原料采用级配混合的方法,分别添加离子型分散剂柠檬酸铵或高聚物型分散剂聚丙烯酸,制备了适合胶态成型的高固相含量、低黏度的料浆。讨论了胶态成型中粒度分布,以及分散剂的种类和各自不同的用量对悬浮体流变学特性的影响。当粉体CQ和HNXY的级配质量比为1:2时,其混合粉体粒度分布最接近于Dinger模型理论分布,此时可以得到黏度最低的料浆,当固相含量为65%(体积分数)时,料浆的黏度仍然在1 Pa·s以下;与分散剂柠檬酸铵相比,在相同的固相含量和级配比例下,采用聚丙烯酸的料浆流动性更好。

Low viscosity alumina slurries with high solid content were prepared by the colloidal formation process and using mixed alumina powders with different particles sizes. Two commercial alumina powders with different particle size distributions （the average particle sizes were 0.97 μm and 2.18 μm） were blended in different proportions, and the rheological behavior of the aqueous slurries was analyzed. The effect of various contents of dispersant on the rheological properties of alumina slurries stabilized with static dispersant or polymeric dispersant was studied. The results show that the viscosity of the slurries is lowest when the particle size distribution is closest to the ideal Dinger distribution. The viscosity of the slurries increases when there is too little or too much dispersant. The polymeric dispersant is more effective in reducing the viscosity of high solid loading slurry.