研究了微波辐照预处理对鲕状高磷铁矿气基还原联合高温熔分除磷提铁工艺的影响。微波预处理采用昆明理工大学研制的功率连续可调MW—HS多功能高温微波反应器。微波预处理样品进行SEM和EDs分析以及热重分析。研究结果表明:微波预处理可以明显改变鲕状高磷铁矿颗粒的显微结构。在颗粒内部中磷灰石和铁氧化物之间产生明显的裂纹,并使鲕粒内部形成众多的微裂和疏松结构。微波预处理对鲕状高磷铁矿的气基还原的后期阶段有促进作用并延缓了颗粒内部烧结现象的发生。管式炉气基还原和高温熔分实验结果表明:微波辐射预处理可以大幅提高铁的回收率,但是同时铁样中的磷略有升高。在1273K,CO气氛和还原时间为2h的条件下,450W功率微波预处理的矿粉最终金属化率可以达到90%,其熔分结果的金属回收率可以达到83%,铁样磷含量为0.48%。
Influence of microwave radiation on newly proposed phosphorus removal process (gaseous reduction and slag/metal separation) is studied. Microwave radiation on the ore fines is carried out using MW-HS multi-function high temperature microwave reactor. The treated ore fines are subjected to examinations of SEM, EDS and TG. TG tests are conducted using thermal analyzer(LINSEIS STA PT 1600). Results show that microwave pretreatment can obviously change the microstructure of the ore fine. After microwave pretreatment, arc cracks develop along the boundaries between phosphorite phase and hematite phase and loose zones in the areas where multi-minerals coexist. Microwave pretreatment has an intesification effect in the late stage of the gaseous reduction of the ore fines. Results of gaseous reduction and melt separation tests indicate microwave pretreatment could greatly improve the metal recovery rate in processing the ore fines using the proposed phosphorus removal method while phosphorus content in the metal sample is slightly increased. Under the condtion that the reduction temperture is 1 273 K, reduction atmosphere full CO and reduction time 2 hours, metallization rate of the sample pretreated using microwave power of 450 W could reach 90% . And in the melting separation process, its metal recovery rate reaches83% with a phosphorus content of 0.48% (mass percent) in the metal sample.