(昆明理工大学 复杂有色金属资源清洁利用省部共建国家重点实验室
冶金与能源工程学院，昆明 650093)
摘 要: 高硫煤对锡铁精矿进行还原硫化焙烧，可实现物料中锡的有效脱除。以热力学和动力学分析为基础，对锡铁精矿的高硫煤硫化焙烧脱锡机理和过程进行了研究。结果表明：在空气气氛下，高硫煤还原硫化锡铁精矿主要通过布多尔反应产物CO的还原作用和气化产物SO2的硫化作用实现。与传统黄铁矿硫化现象不同，高硫煤添加量由0.6增加至1.8，锡铁精的矿深度还原未造成锡脱除率的下降，是由于高硫煤气化产物SO2的气相硫化速率较快，使锡快速挥发，减少了硬头(锡铁合金)的生成；在空气流量10 mL/min、焙烧温度1473 K、保温时间60 min、高硫煤添加量1.8(高硫煤/锡铁精矿质量比)及添加粒度74 μm的条件下，处理后矿样锡含量降至0.066%，经进一步磁选处理物料锡含量最低可降至0.058%，达到高炉炼铁关于锡含量小于0.08%的要求，为高硫煤的清洁利用提供一种新途径。
关键字: 高硫煤；锡铁精矿；还原硫化焙烧；脱锡；动力学
（Faculty of Metallurgical and Energy Engineering, State Key Laboratory of Complex Nonferrous
Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:Through the reduction-sulfidation roasting process using high sulfur coal, tin can be removed efficiently from tin-bearing iron concentrates. According to thermodynamics and kinetics analysis, the mechanism and process of tin-bearing iron concentrates reduction-sulfidation roasting were studied. The results show that, under air atmosphere, the tin reduction-sulfidation is realized mainly through CO and SO2, which are respectively generated from the Boudouard reaction and the high sulfur coal gasification. Being different from the phenomena using pyrite as curing agent, deep reduction of tin-bearing concentrates does not cause tin removal rate decrease with the increase of high sulfur coal addition. The reason may be that curing rate of tin phases by the SO2 is higher, and the formation of iron-tin alloy decreases. Tin content of the concentrates decreases to 0.066% under the conditions of air flow rate of 10 mL/min, roasting temperature of 1473 K, reaction time of 60 min, high sulfur coal addition amount of 1.8 (mass ration of high sulfur coal to tin-bearing iron concentrates) and particle size of 74 μm. It is further reduced to 0.058% after magnetic separation, which can meet the standard of BF iron making, requiring tin content in iron ores less than 0.08%. The work may provide a new approach for the clean use of high sulfur coal.
Key words: high sulfur coal; tin-bearing iron concentrates; reduction-sulfidation roasting; tin removal; kinetics
