锡铁矿硫化焙烧脱锡

Removal of Tin from Tin-bearing Iron Ore with Sulfidation Roasting

在热力学分析的基础上,结合化学和XRD分析对锡铁矿硫化焙烧脱锡过程进行了研究.结果表明,一定范围内提高焙烧温度和延长焙烧时间有利于锡铁矿脱锡,但焙烧温度高于1473K时,物料中铁酸钙物相发生软熔,包裹未反应固体含锡颗粒,造成锡脱除率下降;黄铁矿和无烟煤用量增加时,脱锡率呈先增加后降低的趋势.优化的脱锡工艺条件为:焙烧温度1473K,焙烧时间60min,黄铁矿添加量5%(ω),无烟煤添加量5%(ω),氮气流量15L/h.此条件下,物料锡含量由0.35%降至0.05%,脱锡率达85.71%,可高效脱除锡铁矿中的锡.

Based on the thermodynamic analysis, the removal process of tin from tin-bearing iron ores was studied by chemical and X-ray diffraction analysis. The results showed that raising roasting temperature and prolonging holding time were beneficial to increasing of the tin removal rate in a certain range. However, when the temperature increased above 1473 K, the calcium ferrite was cohesive, causing the unreacted tin-bearing particles being enclosed and tin removal rate being decreased. With increasing of addition of pyrite and anthracite, the tin removal rate increased first and then deceased. The tin content in the tin-bearing iron ore was decreased from 0.35% to 0.05% under the conditions of holding time 60 min, pyrite addition amount 5%（w）, anthracite addition amount 5%（w）, and N2 flow rate 15 L/h. Tin could be removed effectively from tin-bearing iron ore by sulfidation roasting.