Using the Modified Tessier Method to Analyze Antimony Speciation in Suspended Solids in Mining Wastewater

The modified Tessier method was used in the present study to analyze the antimony (Sb) speciation in suspended solids in mining wastewater from Ban-po Antimony Mine in Guizhou province. It was found that the residual fraction and the soluble fraction are the highest and the lowest in the five Sb fractions, accounting for 62.5% and 3% of the total respectively. The order of the five Sb fractions is: the residual fraction > the reduced fraction > the oxidation fraction > the acid-extractable fraction > the soluble fraction. The antimony soluble form in aqueous solution is mainly Sb (V), about 90% of the total. The results from the analysis by X-ray diffraction and scanning electron microscopy showed that the major crystalline forms of suspended solids are K-Mg-Fe-Al-Si-O-H2O, Cu3SbS4, 3CaO·2Sb2O5·8H2O, SiO2 and the content of antimony element is approximately 2.55%.