Experimental Study on Red Mud Dealkalization by Repeatedly Leaching with Low Concentration Acid

10.6919/ICJE.202205_8(5).0069

Wei Wang

Red Mud ； Leaching ； Low Concentration Acid ； Dealkalization

International Core Journal of Engineering

8卷5期（2022 / 05 / 01）

538 - 547

英文

The strong alkalinity of red mud limits its comprehensive utilization in many fields. In order to solve this problem, this paper takes the red mud provided by the Bayer aluminum oxide plant as the research object and proposes a repeatedly leaching and dealkalization scheme with low concentration of acid, that is, the neutralization reaction mechanism of red mud with low concentration of organic acid is used to achieve the dealkalization. During the experiment, the influence of organic acid concentration, leaching times and liquid-solid ratio on the dealkalization rate were investigated. Meanwhile, the red mud before and after dealkalization was analyzed by XRD phase analysis and electron microscope scanning analysis. The results showed that under the conditions of 0.5mol/L oxalic acid concentration and 4:1 liquid to solid ratio, more than 80% of the alkali could be removed after two times of leaching. The pH of the red mud after dealkalization was about 8.1, which could be used as soil for agricultural application.

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