稀土精矿冶炼炉窑的高温烟气资源化利用研究

Research of resource utilization for high-temperature flue-gas in the smelting furnace of rare earth concentrate

中文关键词: 有色金属  稀土精炼  炉窑烟气  余热利用  资源回收

英文关键词: nonferrous metals  rare earth refining  furnace flue gas  waste heat utilization  resource recovery

中文摘要:

      稀土精矿冶炼炉窑是稀土生产工艺的核心装备,会产生大量含氟酸性高温烟气,其中氟化物0.81%,硫酸雾1.06%,二氧化硫0.23%,同时温度达300℃以上,烟气余热丰富,烟气成分的复杂性和特殊性为余热及资源回收利用带来挑战。本文介绍一种新的稀土精矿冶炼炉窑的高温烟气余热利用技术及其现场中试情况。首先根据物质流、能量流守恒计算了烟气流量、温度、组分浓度以及余热量,分析了余热回收的可行性和技术难点；然后提出了新的烟气干法余热回收工艺,依据能源梯级利用原则,通过余热锅炉实现烟气分级降温和余热回收,同时回收高浓度冷凝酸并副产余热蒸汽；最后该工艺在稀土精矿冶炼炉窑系统进行了现场中试,采集并分析72小时中试数据,取得良好资源回收效果。

英文摘要:

      The smelting furnace of rare earth concentrate is the main equipment of rare earth production process. A large number of acidic high-temperature flue gas will be produced, containing 0.81% fluoride, 1.06% sulfuric acid fog, and 0.23% sulfur dioxide, and its temperature is up to 300℃. It means there is lots of waste heat. But the complexity and particularity of the flue gas compositions bring great challenges to the recovery of heat and resource. This paper introduced a new waste heat utilization technology of high-temperature flue gas of rare earth concentrate smelting furnace, and the real situation of the field pilot-scale test. Firstly, the flue gas flow rate, temperature, component concentration and waste heat were calculated according to the conservation of material flow and energy flow. The feasibility and technical difficulties of the waste heat recovery were analyzed. Then, a new dry process of waste heat recovery of the flue gas was proposed. According to the cascade utilization principle of energy, the flue gas was grading cooled and the waste heat was used by the waste heat boiler. Moreover, high concentration condensed acid was gathered and the steam was produced by side. Finally, the field pilot-scale test of the new technology was demonstrated, and the data of 72 hours were collected and analyzed. The field pilot-scale test shows a good effect on resource recovery.