抄録
Dissolution behavior of high purity α-alumina particles and adsorption of Mg2+ ions onto α-alumina surface were studied in 5vol% solid suspensions containing polyacrylic ammonium (PAA). The amount of alumina dissolved was higher in acidic suspensions than in neutral or basic suspensions. The solubility of alumina in the wide pH range from 2.5 to 9.3 decreased with the addition of PAA. The amount of Mg2+ ions adsorbed onto alumina surface depended on two factors of pH and PAA content of suspensions. Negatively charged alumina surface in the pH range from 7.6 to 9.3 adsorbed Mg2+ ions of 17.5μmol/m2-alumina surface. Positively charged alumina surface adsorbed little Mg2+ ions in acidic suspensions. The amount of Mg2+ ions adsorbed onto alumina surface increased in acidic or neutral suspensions and decreased in basic suspensions by addition of PAA.
