Influence of composite magnesia types ratio on the performance of large area repair materials
A new type of large-surface repair material with good high-temperature fluidity,high structural strength and simple production process was developed.Sintered magnesia and fused magnesia were properly proportioned,and silicon micro-powder and active α-Al2O3 micro-powder were introduced as composite binders,sodium carboxymethyl cellulose as a dispersant,and sodium lignosulfonate as a water reducer to prepare special raw materials for converter repair.After high-temperature calcination at 1 100 ℃ and 1 500 ℃,the influence of different magnesia types and proportions on the bulk density,apparent porosity,water absorption,pressure resistance,and flexural strength of the converter large-area repair material was analyzed.The results show that when 98％fused magnesia with a particle size of 5～1 mm accounts for 35％and 95％sintered magnesia with a particle size of 1～0.5 mm accounts for 18％,the sample morphology is relatively dense and fine voids are evenly distributed after sintering at 1 500 ℃,and the best comprehensive properties are obtained.At this time,the bulk density of the sample reaches 2.8 g/cm3,the apparent porosity is 16.3％,the water absorption is 5.8％,the linear change rate of reheating is-0.32％,the flexural strength is 7.5 MPa,and the compressive strength is 19.7 MPa.
sintered magnesiafused magnesiarepair material performance
万方数据
维普
