Study On The Erosion Of High Alumina Castables At Ambient Temperature

High alumina castables are commonly used as resistant lining materials for industrial furnaces because their high strength and wear resistance.They are widely used in new energy engineering,environmental protection,electric power,metallurgy,machinery,chemical industry and building materials industries.Precast castables were prepared by changing aggregates/powders composition and size of aggregates.The relationship between the parameters(speed,angle,amount of abrasive particles,etc.)of the abrasive particles and the target parameters(different raw materials,critical particle size,etc.)were established.The high aluminum castables composition model were established for analysis the erosion mechanisms.And the wear resistance test method of refractory at ambient temperature was discussed.The experimental results demonstrated that:1.The erosion process of the original surface of the castables has two stages: the wear rate is highest in the first stage and matrix is the body mainly subjected to particles erosion;the wear rate is gradually reduced in the second stage with the exfoliation of matrix and the exposure of aggregate,and the wear rate is stable at a low level in the last.Castables with larger critical particle size has better wear resistance,which takes more time to enter the stable stage.The internal section surface of castables has a tendency that the volume wear rate decreases with the erosion time and finally stable at a low level.The volume erosion rate of internal section surface of castables have a small range of fluctuations because the position of the component cutting randomly.It causes the structure of the internal section surface to be uncertain.2.The wear resistance of castables will improved with increased critical particle size of aggregate,which due to the coarse aggregate has better wear resistance.In the first stage,matrix have more effect on wear resistance.However,aggregate will be dominate in later period.The wear resistance of castables with appropriate aggregate and matrix is better.3.The volume erosion rate of original surface f the castables was higher than that of internal section at the same erosion condition.The particles of inner part of castables are closely embedded while particles at surface are loosely packed because of coanda effect.The proportion of matrix of the original surface is higher than that of the section.The volume erosion rate of castables were increased with the increased of erosion angle.The erosion mechanisms was dominated by micro-cutting at low angle,while the erosion mechanisms was dominated by brittle fracture at high angle.The abrasive with larger speed has greater impact kinetic energy.