Study On Preparation Of CeO₂ Polishing Slurry

Recently the need of high-quality CeO2 polishing slurry has been growing.Despite that our country has rich cerium resources and high production of cerium oxide polishing powder,most of the products are low-end.We are still behind developed countries like Japan,US and France in preparation of high-quality CeO2 polishing slurry.Most of the high-quality CeO2 polishing slurry we use depends on imports.So it is of big significance to study on the preparation of high-quality CeO2 polishing slurry.This research mainly adopts the ammonium carbonate precipitation method,with cerium carbonate as cerium source,a certain proportion of ammonium bicarbonate and ammonia water mixture as precipitating agent,through the process of precipitation,fluorination,aging,washing,drying,calcination,finally prepared cerium oxide polishing powder which had a particle size of about 500 nm and used this powder as a main raw material to prepare CeO2 polishing slurry.Through the single factor experiment method to research on the formulation and process of CeO2 polishing slurry,using scanning electron microscope,Zeta potential tester,spectrophotometer and so on to study mainly on the settlement behavior,absorbance,Zeta potential value of CeO2 polishing slurry,discussing different influence factors of suspension dispersant,pH value,dispersing method and preparation temperature to the suspension property of CeO2 polishing slurry;through mixing dispersants experiments to determine the slurry formulation;having a study on the harden problem in the bottom of the slurry,finally getting the optimum formulation and process of CeO2 polishing slurry.The research draws the following conclusions:the main influence factor of dispersion property and redispersibility of slurry is the kinds and usage of suspension dispersant,and the addition of 0.2%sodium polyacrylate(PAAS),1.5%dispersant A,0.2%ternary polymer sodium dispersant(ASH),0.1%polyethylene glycol 20000 can effectively control the agglomeration of particles;The addition of ethanol can significantly influence the settlement of CeO2 slurry,it is of best dispersion effect when water/alcohol weight ratio is 4:1;The dispersion effect of cerium oxide particles is good when pH is 9;Better dispersion method is mechanical stirring and ultrasonic interaction,with dispersion time of 5h and stirring rate of 1500r/min;Temperature effect is little;Accession to lppm polyacrylamide absorbent gel(PAM)and 0.031%cellulose sodium(CMC)can effectively alleviate the hardening problem of sediment layer and improve the the redispersibility of slurry.