Porous Clinker Refractory Castable

Porous clinker refractory castable is a lightweight refractory castable with excellent properties and is widely used in large coke ovens, blast furnaces, steel rolling heating furnaces, ammonia synthesis plants, and other fields. This article analyzes the raw materials, mix ratio, and molding process of porous clinker refractory castables, summarizes the key technical measures to improve its performance, and compares the performance of ordinary porous clinker refractory castables and high-strength porous clinker refractory castables.

1. Raw materials and characteristics of porous clinker refractory castables

Porous clinker is a synthetic material with the characteristics of small bulk density, high cylinder pressure or particle strength, high refractoriness, and low thermal conductivity. There are many varieties, usually porous pyrophyllite or siliceous clinker, porous clay or high alumina clinker, porous mullite or corundum clinker, porous zirconium-containing and alumina clinker, etc. In China, porous clinker refractory castables have been formulated from porous clay, high alumina, and mullite clinker, with a volume density of 1.0~1.8g/cm³ and a service temperature of 1300~1600°C.

2. Preparation process and performance optimization of porous clinker refractory castables

The mix ratio and molding process of porous clinker refractory castables have a significant impact on their performance. First, the amount of cement should be reduced as much as possible and the amount of high-aluminum powder should be increased so that there is enough powder to wrap the porous clinker aggregate; secondly, the proportion of large particles should be appropriately increased, or the maximum particle size should be increased to 10mm; Finally, among castables of the same material, if the porous clinker has a larger accumulation volume, the bulk density will increase and the strength will also increase. However, it should be noted that increasing thermal conductivity will reduce thermal insulation performance.

3. Research and application of high-strength porous clinker refractory castables

When the volume density of high-strength porous clinker refractory castable is similar, its compressive strength after drying and burning at 1200°C is significantly higher than that of ordinary porous clinker refractory castable. By using high-quality refractory aggregates, reducing the amount of cement, increasing bauxite clinker powder, and adding additives such as soft clay and kyanite, the performance of porous clinker refractory castables can be significantly improved. At the same time, by introducing admixtures such as water-reducing agents, the water consumption of the pouring material is reduced from 17% to 25%. The cost is not increased much, but the performance is greatly improved.

Conclusion: Porous clinker refractory castables have broad application prospects in the field of lightweight refractory castables. By optimizing raw materials, mix ratios, and molding processes, its performance can be further improved to meet the needs of different fields. High-strength porous clinker refractory castables have obvious advantages in performance and are an important development direction for lightweight refractory castables in the future.