铜渣氢气还原过程中的物相转变

对铜渣进行氢气还原处理，分析了还原温度和时间对还原前后铜渣物相组成和微观形貌的影响，并对还原过程的物相转变进行了讨论. 结果表明，铜渣氢气还原产物为金属Fe和玻璃态SiO2，二者的产出量随还原温度升高和还原时间延长而增加，950℃还原6 h铜渣中铁还原率比800℃时高47.4%，随反应时间延长铜渣中铁还原率增长速度变慢；原渣中狭长或树突状的铁橄榄石相还原后转变为不规则颗粒状或片状金属Fe相，随还原时间延长和温度升高，颗粒表面变得更加致密；铜渣氢气还原制备金属Fe催化剂时还原温度900~950℃、还原时间3~5 h为宜.

Phase Transformation during the Reduction Process of Copper-containing Slag with Hydrogen

The experiment of copper-containing slag reduction with hydrogen was carried out. XRD, FT-IR and SEM/EDS were used to examine the effects of temperature and reduction time on phase composition and surface morphology of the slag before and after reduction. The analysis results show that the reduction products of slag are metallic Fe and vitreous SiO2. The production of Fe and SiO2 increases with increasing of temperature and retention time. The iron conversion rate at 950℃ for 6 h is increased by 47.4% in comparison with that at 800℃ for 6 h. The iron conversion rate is highest at the early stages and decreases as time proceeds until the end of the reduction. The fayalite phase in the initial slag with the morphology of dendritic growth and long-narrow crystal is transformed to metallic Fe phase with the morphology of irregular grains and flakes. With the increase of temperature and retention time, the surface of metallic Fe grains becomes more compact. The optimum reaction conditions for production of metallic Fe catalyst from the slag reduction with hydrogen are temperature 900～950℃, and retention time 3～5h.