SHS转炉补炉料的物相组成及显微结构特征

利用自蔓延高温合成(SHS)原理,选择工业铝粉作为发热剂,菱镁矿为供氧剂,通过铝热反应,研制出了一种以镁砂为骨料,以镁铝尖晶石和炭质材料作为结合相的新型SHS转炉补炉料.对不同环境温度下补炉料的物相组成及显微结构进行了研究,并对合成尖晶石的固相反应原理及SHS产物相的烧结机制进行了探讨.结果表明补炉料中颗粒状的骨料方镁石与SHS反应产物尖晶石、非晶质碳、少量刚玉相和硅酸盐玻璃相共同构成含有气孔的交织结构,形成尖晶石、碳桥和陶瓷相与方镁石骨料的多重结合;SHS反应过程分碳酸盐矿物的分解反应、铝热氧化还原反应(即SHS反应)和合成尖晶石的固相烧结反应三步进行,其烧结受扩散机理控制.

Phase composition and microstructure characteristic of SHS converter fettling material

A new kind of SHS converter fettling material,which is made up of periclase occurring as aggregate,and spinel as well as amorphous carbon phase as bonding phase, is developed by using Self-propagating High-temperature Synthesis (SHS) principle. The industrial aluminium powder is used as the reducing agent and carbonates of magnesite is used as the oxidizer. The phase compositions and the microstructure of SHS lining materials at different environmental temperatures are studied,and the principle of solid reaction of synthesizing spinels and the sintering mechanism are also discussed. The results are as follows:1) the granular periclase is interwoven together with SHS products of spinels,amorphous carbon phase,and a small amounts of corundum and silicate glass to form the interwoven microstructure;2) the whole sintering process of SHS can be divided into three steps: the first step is the decomposition reaction of carbonates,the second step is SHS reaction,i, e.,thermite reaction,and the third step is the solid reaction of forming spinels, controlled by diffusion mechanism.