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

Abstract

The methane reduction (MR) of SnO 2 has been proposed as a highly efficient method for recovering Sn from SnO 2 containing industrial wastes. The MR of SnO 2 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 CH 4 (CH 4 /SnO 2 molar ratios of 1, 3, or 5) on the recovery of Sn from SnO 2 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-CH 4 /SnO 2 ratio. We found that the recovery of Sn increased as a function of supplied-CH 4 (95.5% at CH 4 /SnO 2 =5) however, the purity of Sn was consistent for all studied samples (~99.90%). Our results confirm that 3N quality highpurity Sn can be easily recovered from SnO 2 containing industrial wastes by direct solid-gas reduction.

Efficient Sn Recovery from SnO2 by Alkane (CxHy=2x+2, 0 ≤ x ≤ 4) Reduction

“…5c,d). However, considering that the alkane reduction would occur under the high alkane partial pressure conditions 20,21 , the highly negative entropic contribution to the Gibbs free energy of binding, −TΔ S , will definitely compensate the positive Δ E of dissociative adsorption (Δ E 1 in Fig. 5c,d) 24,25 , making the Δ G of dissociative C 3 H 8 and C 4 H 10 binding negative (exothermic).…”

“…In our previous report 20,21 , we have designed a methane reduction (MR) method, an ecofriendly and simple versatile process of Sn recovery from SnO x containing industrial wastes, which also can be potentially applied for Sn ore smelting. A direct facile contact between gas phase methane and SnO x improves the efficiency of the reaction.…”