RI 3256 Progress Reports – Metallurgical Division – 8. Studies in Zinc Metallurgy

"During the year which has passed since the last progress report on reduction of zinc by natural gas,3 the laboratory experiments on this investigation have been completed. In this concluding report, the whole subject will be reviewed and additional data presented.Chemical ReactionsIn a thermodynamic study of zinc smelting, Maier 4 discussed the use of methane for reducing zinc oxide, and predicted equilibria at various temperatures for the sore important reactions. The study has been extended to include the following list.Maier predicted that 870°C. would be the critical temperature above which reaction (1) would take precedence over reaction (2) and that reaction (1) at equilibria would be substantially complete at or above 927°C. A subsequent papers described experimental verification of these predictions and gave data on reaction rates under various conditions.It methane is passed through a heated bed of zinc oxide at a low enough rate reactions (1), (3), and (4) reach an equilibrium which can be expressed by reaction (10). The equilibrium concentrations for the products of this reaction in the temperature range 900° to 1100°C. were calculated by applying the thermodynamic constants to the stoichiometric relations. 6 The results of these calculations are listed in table 1 and shown graphically in figures 1, A and B. These data have major importance, and experimental work has shown that they are subtantially correct."