关键词: 二步法, 氧化焙烧, 绿矾

Abstract: This paper studied a two-step method of oxidizing calcination process in order to improve the utilization efficiency of copperas and achieve the energy-saving and environmental production. The analysis of copperas' drying and dehydration curves and TG-DSC (thermogravimetric analysis and differential scanning calarmeutry) curves showed that the best drying temperature was 110℃, and most of the product was FeSO₄·7H₂O. Then the dried products were calcinated at the different temperature. The influences of the calcination temperature on the product recovery, residual sulfur content, the compound morphology of Fe and the distribution of sulfur in the flue gas was investigated. The results showed that when the temperature was 800—900℃, air flow rate was 120L/h, and the constant temperature time was 90min, the amount of residual sulfur in the calcinated product was 0.33% and total Fe was more than 60%. Therefore, the final product could be added into the sinter as iron materials.

Key words: two steps, oxidizing roasting, copperas