Modification of the Amount of CH4 Supplied for the Efficient CH4 Reduction of SnO2

摘要

The methane reduction (MR) of SnO2 has been proposed as a highly efficient method for recovering Sn from SnO2 containing industrial wastes. The MR of SnO2 also produces a mixture of H-2 and CO, which can be further utilized as a syngas for the production of various fuels through the Fisher-Tropsch process. To optimize the process parameters, we studied the effect of the amount of supplied CH4 (CH4/SnO2 molar ratios of 1, 3, or 5) on the recovery of Sn from SnO2 and the H-2/CO ratio in the produced gas. Through a combination of thermodynamic simulation and experimental confirmation, we found that the recovery rate of Sn, and the molar ratio of H-2/CO in the product gas, increased as a function of the supplied-CH4/SnO2 ratio. We found that the recovery of Sn increased as a function of supplied-CH4 (95.5% at CH4/SnO2=5) however, the purity of Sn was consistent for all studied samples (similar to 99.90%). Our results confirm that 3N quality high purity Sn can be easily recovered from SnO2 containing industrial wastes by direct solid-gas reduction.