HIsmelt熔融还原炼铁用铝铬质耐火材料烧结性能及Cr^(6+)降价机制  

Sintering properties and Cr^(6+)reduction mechanism of aluminum-chromium refractories in HIsmelt reduction of ironmaking

作　　者：李静捷 张寒[1] 赵惠忠[1] 李宇奇[1] LI Jingjie;ZHANG Han;ZHAO Huizhong;LI Yuqi(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081

出　　处：《钢铁研究学报》2024年第10期1336-1342,共7页Journal of Iron and Steel Research

基　　金：湖北省教育厅科学研究计划指导项目(B2023005);辽宁省“揭榜挂帅”科技计划重点资助项目(2022JH1/10800005)。

摘　　要：HIsmelt炼铁工艺具有流程短、原料适用性广、产品纯净度高等特点,是一种高效低碳绿色的炼铁工艺,其炉衬主要使用铝铬质耐火材料。以板状刚玉和铝铬渣为原料,磷酸二氢铝为结合剂,选择硅微粉为添加剂,经150 MPa压力成型和1600℃×3 h烧成后制得HIsmelt熔融还原炼铁用再生铝铬质耐火材料试样,就硅微粉对试样烧结性能及铬元素价态转变的影响开展了研究。结果表明:加入硅微粉可以促进试样的烧结,使铬元素向刚玉中固溶,从而抑制Cr^(6+)化合物的产生。铝铬固溶体晶胞参数随硅微粉加入量的增加而变大。同时,硅微粉可以将Cr^(6+)降价还原为Cr^(3+),降低试样中Cr^(6+)的浓度。加入硅微粉后试样中可原位生成柱状莫来石,从而影响试样的热震稳定性和热膨胀系数,硅微粉的加入量(质量分数)以2%~3%为宜。HIsmelt ironmaking process is known for its short process,wide applicability of raw materials,and high purity of products.It is an efficient,low-carbon and green ironmaking process that utilizes aluminum-chromium refractory materials for furnace lining.Using tabular corundum and aluminum-chromium slag as raw materials,aluminum dihydrogen phosphate as a binder,and silica micropowder as an additive,a sample of regenerated aluminum-chromium refractory material for HIsmelt smelting reduction ironmaking was prepared by forming under 150 MPa pressure and firing at 1600℃for 3 h.The influence of silica micropowder on the sintering performance and chromium valence state transformation of the sample was studied.The results show that the addition of silica micropowder can promote the sintering process and formation of aluminum-chromium solid solution to avoid the generation of Cr6+compounds.The lattice constant of the aluminum-chromium solid solution increases with the addition of silica micropowder.Meanwhile,silica micropowder can reduce Cr^(6+)to Cr^(3+),reducing the concentration of Cr6+in the specimen.A small amount of mullite will be generated in situ after adding silica micropowder,which will influence the thermal shock resistance and thermal expansion coefficient of the specimen.The appropriate amount of silica micropowder is 2-3wt.%.

关 键 词：HISMELT 铝铬质耐火材料 硅微粉 Cr^(6+)降价 铝铬渣 

分 类 号：TB321[一般工业技术—材料科学与工程]