Biocementation of Pyrite Tailings Using Microbially Induced Calcite Carbonate Precipitation

• Published in: Molecules (Basel, Switzerland) Vol. 27; no. 11; p. 3608
• Main Authors: Kang, Bo, Zha, Fusheng, Deng, Weihao, Wang, Runkai, Sun, Xianguo, Lu, Zhitang
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 04.06.2022; MDPI
• Subjects: Acid mine drainage; acid mine drainage (AMD); biochemical and physicochemical reactions; Calcite; Calcium carbonate; Chemical precipitation; Compressive strength; Curing; Fourier analysis; Fourier transforms; Groundwater; Heavy metals; Immobilization; Infrared analysis; Infrared spectroscopy; Leaching; microbially induced calcium carbonate precipitation (MICP); Mine drainage; Mine tailings; Particle size; Permeability; Pollution prevention; Sand; Sand & gravel; Scanning electron microscopy; source control; Sulfides; Sulfur content; Tailings; Thermogravimetric analysis; Toxicity testing; Water resources; X-ray diffraction; acid mine drainage (AMD); source control; microbially induced calcium carbonate precipitation (MICP); biochemical and physicochemical reactions
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27113608

Tailing sand contains a large number of heavy metals and sulfides that are prone to forming acid mine drainage (AMD), which pollutes the surrounding surface environment and groundwater resources and damages the ecological environment. Microbially induced calcium carbonate precipitation (MICP) technology can biocement heavy metals and sulfides in tailing sand and prevent pollution via source control. In this study, through an unconfined compressive strength test, permeability test, and toxic leaching test (TCLP), the curing effect of MICP was investigated in the laboratory and the effect of grouting rounds on curing was also analyzed. In addition, the curing mechanism of MICP was studied by means of Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction spectroscopy (XRD), and scanning electron microscopy (SEM). The experimental results showed that MICP could induce calcium carbonate precipitation through relatively complex biochemical and physicochemical reactions to achieve the immobilization of heavy metals and sulfides and significantly reduce the impact of tailing sand on the surrounding environment.