EARTH

[3913-23-09] Rapidly forming tooeleite by controlled multi-jet precipitation and its formation mechanism

Guanshi Zhang¹, Qingzhu Li^1,2, ○Qingwei Wang^1,2, Liyuan Chai^1,2, Mengqing Yue¹, Zhaoyang Li¹ (1. Central South University, 2. Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution)

Chairman: Carlito Tabelin （Hokkaido University）

Keywords:Arsenite, tooeleite, rapid formation, controlled multi-jet precipitation (CMJP)

A novel method was proposed in this study to rapidly form tooeleite, an unique natural ferric arsenite sulfate mineral, by controlling the degree of supersaturation through controlled multi-jet precipitation method. The effects of pH, As(III) concentration, feeding rate and the volume of base solution were systematically studied. The optimized crystallographic tooeleite can be obtained under the condition of pH 2.4, As(III) concentration 0.2 mol/L, feeding rate 1.5 mL/min, and base solution 30 mL. Various characterizations confirm that the precipitate obtained by this treatment was tooeleite with relatively higher crystallinity, compared with that synthesized by current existing method. Tooeleite can be formed in room temperature for 15 min by this method. Furthermore, the FTIR and XRD shows amorphous phase, exists as a precursor, and plays a vital role in the formation of tooeleite. This study provides a method for rapid mineralization of tooeleite, which will make sense in its application to the direct removal of As(III) from contaminated acid.