Separating Nanoclay Minerals via Electrophoretic Deposition

摘要

This paper presents the possibility of separating nanoclays from aqueous synthetic slurry of two clays by EPD. Na-Montmorillonite (NM) from Southern Clay Products and kaolinite(K) from Source Clays Repository were used to prepare single-component clay slurries and synthetic slurries. Effect of applied potential and electrode gaps on the yield and on the NM/K ratio of the EPD deposit was investigated. ANOVA of two-factor fixed effect Model was employed with F-test at 5% significance level.NM slurry and synthetic slurry were found to have negative bulk potential with high pH while kaolinite slurry have positive bulk potential with low pH. NM slurry and synthetic slurry have higher bulk conductivity than kaolinite slurry. The distinct slurry properties of the single-component clay slurries could lead to the differential electrophoresis of NM and kaolinite in the synthetic slurry during EPD. High potential- low electrode gap had the highest yield of EPD deposit. NM/K ratios of the deposits were compared to the original clay ratio of the synthetic slurry. High potential-high electrode gap showed highest NM/K ratio at an average of 5.2 :1 from 2:1. This showed that the interaction of applied potential and electrode gap on the yield and on the NM/K ratio of the EPD deposit was significant. This means Na-MMT was successfully separated from kaolinite from aqueous synthetic clay slurry by EPD at specific applied potential - electrode gap combination.