关键词: 碳化硅浇注料, 硅溶胶, 酸性环境, 硝酸, 强度

Abstract: To investigate the performance evolution of silicon carbide castables in acidic environments,silica sol-bonded silicon carbide castables were prepared using silicon carbide,α-Al₂O₃ micropowder,and silica sol as the main raw materials.The physical properties,microstructure,and phase composition of the castables after immersion in nitric acid of different concentrations (0,5%,10%,15%,and 20%,by mass) were studied.The results show that:(1)the surface of the dried specimens after acid immersion remains intact,without pulverization,peeling,or corrosion;(2)with the increase of the nitric acid concentration,the strength of the specimens improves,while the linear shrinkage and mass loss rate increase;(3)after immersion with 20% nitric acid,the phase composition does not change significantly,the bonding between surface particles becomes tighter,and the morphology becomes more even and orderly.It can be concluded that the silicon carbide castables have excellent acid corrosion resistance and can be used stably for a long time in various industrial acidic environments.

Key words: silicon carbide castables, silica sol, acidic environment, nitric acid, strength