Comparison of Copper Scavenging Capacity between Two Different Red Mud Types

Materials

Yingqun Ma¹  Chunhua Si¹ 

[1] Centre for Ecological and Environmental Technologies, South China Agricultural University, Guangzhou 510642, China; E-Mails:

关键词: alumina;    bauxite;    red mud;    calcite;    alkaline;    copper;    boehmite;    atacamite;    metal immobilization;   

DOI  :  10.3390/ma5091708

来源: mdpi

【 摘 要 】

A batch experiment was conducted to compare the Cu scavenging capacity between two different red mud types: the first one was a highly basic red mud derived from a combined sintering and Bayer process, and the second one was a seawater-neutralized red mud derived from the Bayer process. The first red mud contained substantial amounts of CaCO₃, which, in combination with the high OH⁻ activity, favored the immobilization of water-borne Cu through massive formation of atacamite. In comparison, the seawater-neutralized red mud had a lower pH and was dominated by boehmite, which was likely to play a significant role in Cu adsorption. Overall, it appears that Cu was more tightly retained by the CaCO₃-dominated red mud than the boehmite-dominated red mud. It is concluded that the heterogeneity of red mud has marked influences on its capacity to immobilize water-borne Cu and maintain the long-term stability of the immobilized Cu species. The research findings obtained from this study have implications for the development of Cu immobilization technology by using appropriate waste materials generated from the aluminium industry.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.