直接还原回转窑协同处理含锌固废技术及应用

研究了直接还原回转窑实现含锌固废协同处理的工艺技术。对固废中的含锌化合物的还原及分离理论进行了研究，在回转窑内，只要满足温度T＞1 500 K、气氛还原φ(CO)＞70%条件，就能实现锌从废渣中还原分离出来，同时废渣中的铁也能够被还原，得到回收利用。在某海绵铁生产厂的回转窑上进行了试验验证，得到含锌20%(质量分数)的富锌灰，锌渣中95%(质量分数)以上的铁作为副产物进入到海绵铁中。试验结果表明，协同处理在不影响直接还原生产海绵铁工艺的前提下，实现了含锌固废的综合利用，此次试验中烟气的含硫量成为限制环节，含锌固废的最大配加量以2%为宜。

Technology and application of cooperative disposal of zinc #br# solid waste by direct reduction rotary kiln

 The process of cooperative treatment of solid waste containing zinc by direct reduction rotary kiln was invesigated. The reduction and separation theory of zinc containing compounds in solid waste was studied, which showed in the rotary kiln, when temperature and atmosphere reduction conditions were satisfied(usually T＞1 500 K, φ(CO)＞70%), Zn can be reduced and separated from the waste. Also, the iron in the waste can be reduced and recycled. Experiments were carried out on the rotary kiln of a sponge iron factory, the enriched zinc ash(contains 20% zinc)was obtained, and more than 95% of iron in the zinc slag was added into the sponge iron as a by product. This study showed that, the comprehensive utilization of zinc solid waste was realized without affecting the direct reduction production of sponge iron. In this experiments, the sulfur content in the flue gas became the limiting link and the maximum dosage of zinc slag was 2%.