To improve the strength and wear resistance of wear-resistant castables, we can start from the selection of raw materials, mix design, construction process control and maintenance, as follows:
I. Selection of raw materials
1• Aggregates: Select aggregates with high hardness and good wear resistance, such as corundum, silicon carbide, etc. At the same time, control the particle size distribution of aggregates, reasonably match aggregates of different particle sizes, make the particles more densely packed, and improve the density and strength of the castables.
2• Binders: Select binders with excellent performance, such as calcium aluminate cement, etc., and add them in appropriate amounts to enhance the strength of the wear-resistant castables. Binders such as silica sol and aluminum sol can also be introduced to improve the high temperature performance and wear resistance of the castable.
3• Additives: Adding active micropowders such as silicon micropowder and alumina micropowder can fill the gaps between particles and improve density. Water reducers can also be added to reduce water consumption without reducing fluidity, thereby improving strength and wear resistance.
2. Mix design
1•Optimize the ratio of aggregate and powder: According to the use requirements and material properties, find the best ratio, generally the aggregate accounts for 60%-75%, and the powder accounts for 25%-40%.
2•Determine the amount of binder: The amount of binder should be moderate, generally 5%-10%. Too much or too little will affect the performance.
3. Construction process control
1•Mixing: Use a forced mixer to ensure that the wear-resistant castables materials are evenly mixed. Strictly control the mixing time and water addition, the mixing time is generally 3-5 minutes.
2•Pouring and vibration: Ensure that the mold is well sealed during pouring, vibrate fully, expel internal air, and increase density.
3•Demolding and finishing: Demolding at the right time, generally 12-24 hours after pouring, and trim the surface in time after demolding.
4. Maintenance and heat treatment
1•Maintenance: Reasonable maintenance after pouring, such as curing for 3-7 days in a humid environment, is conducive to the full hydration reaction of cement and improves strength.
2•Heat treatment: According to the type of castable and usage requirements, appropriate heat treatment is carried out to eliminate internal stress and further improve strength and wear resistance
