摘要
用流化床热模型对几种铁精矿进行了流化还原过程的试验,其目的是为预还原流化床的最佳操作参数的选择提供依据。实验结果指出,在一定范围内,提高还原温度和流化床床层线速可以改善流化还原过程。在降低成本的前提下,应当尽量提高还原气体中的 H_2及 CO 浓度,尽量降低 CO_2含量。影响流化床粘结失流的主要因素有还原温度、流化床床层线速、还原度及矿粉粒度,添加5%的 MgO 可以基本消除粘结现象。试样藏量和精矿种类对流化还原也有十分重要的影响。对于鞍山精矿,在还原温度为800℃,床层线速为0.6米/秒的条件下,还原30分钟其还原度可达70%,可以满足后续工艺的要求。
Several kinds of iron ore concentrates was studied with a laboratory fluidized-bed。The purepose was to determine the optimal operation para- meters for the pre-reduction.According to the test results obtained,it is possible to improve the fluidizing reduction by increasing the reducing temperature and the gas velocity in a certain range.For reducing the cost,it is necessary to increase the concentration of the H_2 and CO and to decrease the percentage of CO_2.The particale sticking phenomenon in the fluidizing-bed are effected by reduction temperature,gas velo- city,degree of reduction and particale-size of ore concentrates.It is effi- cient to prevent the failure of fluidization by adding 5% MgO.The char- ging weights of test sample and the kind of ore concentrate also bave influence to the reduction process.At 800 ℃ and the reductant gas linear velocity of fluidized-bed is 0.6m/sec.With a period of 30 minutes,the 20% reduction degree of Anshan iron ore concentrate could be reached, and satisfies the successive process.
关键词
熔融还原
铁精矿
流态化
预还原
Smelting Reduction
Fluidization
pre-reduction