Production of Carbonates from Industrial Wastes Using CO₂ Fine Bubbles and Conversion to Inorganic Phosphor

Abstract

To build the effective carbonation process for social implementation, the improving the yield and crystal quality of carbonates are essential during the reactive crystallization between CO₂ in exhaust gas and Ca･Mg in industrial wastes.

In the case where CO₂ fine bubbles are applied to the reactive crystallization of Ca･Mg carbonates, Ca²⁺ and Mg²⁺ accumulate because of the negative charge on the fine bubble surface, and the CO₃^2– concentration becomes higher due to the acceleration of the CO₂ mass transfer caused by minimizing the bubble diameter. Hence, the local supersaturation regions near the minute gas-liquid interfaces can be utilized to the enhanced production and the quality control of Ca･Mg carbonates. Additionally, the Ca･Mg carbonates which controlled crystal quality are convertible to inorganic phosphors with superior luminescent properties for upgrading.