Applications and Characteristics of Lightweight Alkali-resistant Refractory Castables

Light alkali-resistant refractory castables are composed of lightweight alkali-resistant refractory materials as aggregates, different proportions of alkali-resistant refractory powders as matrix materials, and a certain proportion of binders. It has high strength, good volume stability, and resistance to the alkaline medium is highly corrosive. The lightweight alkali-resistant refractory castable can be used in the construction of flues and chimneys. It can not only resist the erosion of alkaline high-temperature flue gases but also reduce the weight of chimneys and flues. It can also be used in the construction of flues and chimneys. Alkali corrosion in industrial kilns in steel, non-ferrous metals, glass, machinery, petroleum, and other industries, such as the preheater top cover, cylinder, and kiln insulation lining of rotary kilns.

The physical properties of lightweight alkali-resistant refractory castables are as follows: 110℃, 16 hours drying, bulk density 1.5~1.6g/cm3, flexural strength 3~6MPa, compressive strength 30~40MPa: bulk density 1.4~1.5℃, The temperature is 1100℃, after 3h, g/cm3, flexural strength 6.0~6.5MPa, compressive strength 40~45MPa, linear change after combustion -0.3%~0.5%: thermal conductivity is 0.4~0.5℃, temperature is 350 ℃W/(m·K).

Construction requirements for lightweight alkali-resistant casting materials

1. Clean drinking water must be used. The pH value is between 6 and 8. Stirring water should be accurately weighed. The water consumption is as follows: 16%~17% of the total material amount for high-quality products and 18%~20% for first-class products.

2. A forced mixer is recommended. All mixing tools must be cleaned. Stir until the ingredients are uniform.

3. The pouring surface of all molds should be coated with a layer of oil.

4. All embedded metal parts should be coated with asphalt paint before pouring.

5. Use up the lightweight castable within 0.5 hours after mixing. When the pouring thickness is within 200mm, it should be poured to the specified thickness at one time and vibrated until it is completely dense.

6. The maintenance humidity is 100%, and the maintenance humidity is 10-30℃. Demold 24 hours after pouring. Maintenance time is 3~7 days.

7. This material cannot be mixed with or in direct contact with other newly mixed concrete.

During use, it is also necessary to pay attention to the proportion of each batch of castables to ensure that the amount of water used is within the specified range. The proportion of premium products and first-class products needs to be adjusted as required to obtain the best concrete performance. It is best to use a forced mixer for mixing, and all mixing tools should be kept clean to ensure that the materials are fully and evenly mixed.