高磷矿氢气还原过程的原位研究

通过原位观察的方法,研究了H₂气氛、不同温度下高磷矿还原过程的矿相结构演变规律和温度对金属铁析出形态的影响.高磷矿的鲕状结构在还原过程中未被破坏掉;随着温度的提高,矿相结构的演变加快,温度较高时Fe发生明显偏聚,金属铁从赤铁矿相中加快析出.还原温度对高磷矿中金属铁的析出形态影响显著:在700℃时金属铁析出在矿石颗粒表面形成致密铁层;800℃时析出的金属铁形貌复杂化,铁层致密度下降,出现孔洞,同时有少量的短小铁晶须;900℃时铁晶须数量明显增多,同时伴随着大量多孔海绵铁的析出.因此,可以通过调节还原温度和时间,使得气基还原过程避免黏结失流,同时高效还原高磷矿. 

In-situ research on the H2 based reduction process of high-phosphorous iron ore

Based on in-situ observation,mineral evolution in high-phosphorous iron ore during the reduction process was investigated in the H₂ atmosphere at different temperatures,and the influence of temperature on the morphology of iron was discussed. During the reduction process,ooliths in the iron ore remain. The mineral phases evolve faster with rising temperature,and so does the precipitation of iron from hematite phase. Significant segregation of iron happens at a higher temperature. Temperature has significant impact on the precipitation morphology of metallic iron. At 700℃,the precipitation of metallic iron forms a dense layer on the surface of particles. At 800℃,the precipitation morphology of metallic iron is complex,the density of the iron layer decreases,little holes appear while a small number of short iron whiskers are found. But at 900℃,the number of iron whiskers significantly increases with abundant porous sponge iron. Therefore,by adjusting the temperature and time,the sticking problem during the gas-based reduction process can be avoided,and meanwhile,efficient reduction of high phosphate iron ore is achieved.