Technical requirements for construction of refractory castables

Technical requirements for construction of refractory castables

1. Clean water shall be used for mixing refractory castables.

2. The formwork used for pouring shall have sufficient rigidity and strength, the size of formwork shall be accurate, and deformation shall be prevented during construction. The formwork joint shall be tight without mortar leakage. Anti-adhesion measures shall be taken for formwork. Waterproof measures shall be taken for the surface of thermal insulation masonry in contact with castables.

3. The castables shall be mixed with a forced mixer. The mixing time and liquid addition shall be in accordance with the construction instructions. When changing the material brand, the mixer, hopper, weighing container, etc. shall be washed clean.

4. The mixed refractory castables shall be poured within 30min or within the specified time according to the construction instructions. The initially set castables shall not be used.

5. The setting of the expansion joint of the integrally cast refractory lining shall comply with the design provisions. If there is no regulation, the average value of the inner liner expansion joint per meter can use the following data: clay refractory castable is 4~6mm; The refractory castable of high-alumina cement is 6-8mm; Phosphate refractory castable is 6-8mm; The water glass refractory castable is 4~6mm, and the Portland cement refractory castable is 5~8mm.

6. The pouring of refractory material castables shall be continuous. Before the initial setting of the former layer of castable, the pouring of the second layer of castable shall be completed; If the interval exceeds the initial setting time, it shall be treated according to the construction joint requirements. The construction joint should be left on the centerline of the same row of anchor bricks.

7. After construction, the refractory castables shall be cured according to the method specified in the design. During curing, it shall not be subjected to external force and vibration.

8. Formwork removal. Non-bearing formwork can be removed only when the strength of castable can ensure that its surface and edges and corners are not damaged or deformed due to formwork folding. The load-bearing formwork shall not be removed until the castable reaches 70% of the design strength. The thermosetting castables shall be baked to the specified temperature before being folded.

9. The casting lining surface shall be free of peeling, cracks, holes and other defects. Slight mesh cracks are allowed.

10. The prefabricated parts of refractory castables should not be stacked in the open air. Rain-proof and moisture-proof measures shall be taken when stacking in the open air.