Aluminium Hydroxide Ultrafine Powder Extracted from Fly Ash

Abstract

Al(OH)3 ultrafine powder was extracted from fly ash with the method of dispersing agent-carbonizating. Fly ash is activated by the method of sintering with limestone, so the inert mullite can be convert into C12A7 which can be dissolved in Na2CO3 liquor. The conversion of β-C2S to γ-C2S is accompanied by an increase in volume and results in the self-pulverization of the sintering feed, and the diameter of the self-pulverized powder is below 1μm. Na2CO3 liquor was used to leach Al2O3 in the form of NaAlO2 from the self-pulverized powder. High performance dispersing agent is added in the carbonation process to control the crystal and aggregation of Al(OH)3, and the ultrafine powder of Al(OH)3 is prepared, which diameter is less than 0.4μm.