固体碳直接还原钢铁厂含锌固废的理论与实践

 钢铁厂内的含锌固废数量巨大，同时富含铁、碳等元素，是可循环再利用的二次资源。通过固体碳直接还原ZnO和FeO的热力学分析，发现在非标准状态下，ZnO的还原条件要优于FeO。为此，在实验室条件下设计了含锌固废在不同温度和时间下的还原试验，发现在还原温度为1 423 K、还原时间为15 min以上时，脱锌率可达到90%，而铁的金属化率需要在1 573 K时才能接近90%；在还原温度低于1 423 K时，还原时间对脱锌率的影响较大；在还原温度高于1 473 K时，还原温度对脱锌率影响较小，同时脱锌率可达到95%。这些结果对国内当前处理含锌固废主要工艺(回转窑、转底炉)的操作制度设置具有重要的参考价值，也为如何选择合理的工艺路线，以低投入、低运营成本实现含锌固废的再利用提供了理论依据。

Theory and application on solid carbon direct reduction #br# of zinc bearing waste in steel plant

 The amount of zinc dust in steel plants is huge，and it is rich in iron，carbon and other elements which is a secondary resource that can be recycled. Under the non standard condition，the reduction tendency of ZnO has an advantage to the one of FeO according to thermodynamic analyzed results. To this end，reduction experiments of the zinc containing solid waste at different temperatures and times are designed under laboratory conditions. It is found that the dezincification rate can reach 90% when the reduction temperature is 1 423 K and the reduction time is more than 15 min，but the metallization rate of iron can close to 90% and required to under the condition of 1 573 K；when the reduction temperature is lower than 1 423 K，the reduction time has a greater impact on the dezincification rate；when the reduction temperature is higher than 1 473 K，the reduction temperature has little effect on the dezincification rate，and the dezincification rate can reach 95%. The reference value of temperature and time are benefit to choosing the optimized operation parameters of the main process to dispose the solid waste combined with ZnO，like as Rotary Kiln (RK) and Rotary Hearth Furnace (RHF). And it also benefits to reuse solid waste contained with ZnO when the more reasonable process with lower investment cost and lower running cost could be chosen.