As one of the primary strategic metal, chromium plays an important role in the national economy in China. However, the chromium resource is seriously insufficient meanwhile the chromium pollution is severe in China. This article elaborates the advantages and disadvantages of the current detoxification methods and chromium extraction methods for the chromium-containing residues as well as the bottlenecks they are faced with. It points out that, for developing an effective extraction method for chromium from chromium-containing residues, the micro-structural analysis for the mineral phases of the chromium-containing residues and the thorough investigation on the chemical states, combined forms and distribution of chromium in each mineral phase are crucial. Moreover, this article summarizes the current international research of the micro-structural analysis of chromium-containing residues. This article also introduces the work of our research group that applies the understanding of micro-mechanism of crystal growth and transformation under the surface/interface control on chromium extraction from chromium-containing residue. This new idea and technology are instructional for achieving the combination of detoxification and reclamation for chromium-containing residues. Finally, the potentiality and developing tendency of this idea as well as the technologies of chromium extraction from chromium-containing residue via crystal growth and mineral phase transformation are prospected.
Contents
1 Introduction
2 The current researches on disposal of chromium-containing residue
2.1 Detoxification methods
2.2 Chromium extraction methods
3 Micro-structural analysis of chromium-containing residue
4 Chromium extractions under the guidance of micro-structural analysis
5 Conclusion