Abstract:One highly efficient mineralized bacterium was isolated and screened from tailing slag of cyanide-bearing gold mine, which was identified as bacillus.sp by 16S rDNA and named JK-2. Heavy metals in gold tailings were solidified by JK-2 induced precipitation of calcium carbonate. Solidification effect of tailings after MICP process and heavy metal fixation rate were investigated. Products of MICP process were analyzed by SEM, XRD, FT-IR and other characterization methods. The results show that JK-2 can effectively solidify gold mine tailings, and unconfined compressive strength of cured body rises with increase of binder concentration, which the highest is up to 0.72 MPa. Lead in fixed gold tailings is transformed into carbonate binding state. Fixed rate of Pb and Cr in tailings is 88.7% and 63.5% respectively. SEM shows that a large number of crystals are formed after curing, and FT-IR spectrum shows that CO32- exists in solidified products. According to XRD, solidification products are mainly calcite and spherical aragonite.