Study On MgO-CaZrO₃-ZrO₂ Self Flow Castables

In order to solve the difficulty of sintering CaZrO₃ powder,the hardship of magnesia castables,self flow molding and the hydration of Ca O due to the incomplete reaction in situ reaction of MgO-Ca O-Zr O2 composites,sintering method of CaZrO₃ powder and self flow molding method of magnesia castable have been studied in this experiment.MgO-CaZrO₃-Zr O2 composites were prepared by self flow molding method,and sintered magnesite,pre-synthesis calcium zirconate and nano zirconia were used as the main raw materials with polycarboxylate superplasticizer JSS as dispersant.The effects of CaZrO₃-Zr O2 mixed powder and CaZrO₃ particles on the composite structures and performances of MgO-CaZrO₃-Zr O2 composites have been characterized by the tests of sintering performance,thermal shock resistance,steel slag erosion resistance and the analyses of XRD and SEM-EDS.The results showed that both MgO and Cr2O3 could promote the sintering of CaZrO₃ powder,sintering performance of which became better with the addition of MgO-Cr2O3 compound additives;The self flow molding of magnesia castable could be realized by the regulation of grain grading and the selection of dispersant JSS;The microstructure of MgO-CaZrO₃-Zr O2 self flow castables was optimized by the moderate introduction of CaZrO₃-Zr O2 mixed powder and CaZrO₃ particles.In addition,the sintering performance,thermal shock resistance and the steel slag erosion resistance of MgO-CaZrO₃-Zr O2 self flow castables were enhanced as well;MgO-CaZrO₃-Zr O2 composites were prepared by self flow molding method and sintered at 1550℃ for 3h,with sintered magnesite as the main raw materia l and JSS as water reducer.MgOCaZrO₃-Zr O2 composites showed excellent structure and performance according to the regulation of grain grading when the introduction of CaZrO₃-Zr O2 mixed powder was 10.8wt%,1⁰mm CaZrO₃ particles was 16wt% and 3¹mm CaZrO₃ particles was 3wt%.Besides,the steel slag corrosion resistance of MgO-CaZrO₃-Zr O2 composites was excellent and the strength rete ntion after 5 times 1100℃^room temperature circular cooling thermal-shocked was 45.92%.