Experimental study on the interaction between peat, lignite and germanium-bearing solution at low temperature

摘要

The interaction between peat, lignite and germanium(Ge)-bearing solution with an initial Ge concentration of 5 mg/L was studied at 25-100℃ and at pH 2.96-12.08. The results show that the apparent transfer ratios of peat and lignite for Ge in the solution were positively correlated with temperature in acid environment (initial pH=2.96), and the ratios (up to 86.5%) of lignite were obviously higher than those (up to 58.5%) of peat, but the organic transfer ratios of lignite were lower than those of peat. The activation energy values for interaction between peat, lignite and Ge-bearing solution are 30.96 and 15.67 kJmol~(-1), respectively. The strong acid (initial pH=2.96) and the strong alkaline (initial pH=12.08) environment contribute to the transfer of Ge in the solution. At 4 < pH < 10, the influences of pH on the interaction between peat and Ge-bearing solution are not significant, while weak acid environment (initial pH=6.38) conduces to the transfer of Ge into lignite. The interaction between peat, lignite and Ge-bearing solution are mainly attributable for the complexation of Ge with organic substrate. The experimental results from this study provide direct experimental evidence for the hydrothermal sedimentary genesis of abnormal enrichment of Ge in coal.