Product Overview:
Alkali-resistant brick is made by low aluminum refractory clay through pelletizing and milling, mixing as per certain ratio, pressing molding and burning under high-temperature. The product is featuring alkali erosion resistance characteristic in the cement kiln system. It can generate liquid phase of high viscosity with alkali metal oxide under high temperature, forming a layer of glazed protective layer, covering on the brick surface, plugging surface porosity, preventing permeation and corrosion of alkali metal liquid melt and thereby realizing the objective of alkali erosion resistance. It can be divided into such three grades as general type, high-strength type and heat-insulating type as per physical and chemical indexes. It’s mainly used at cement kiln preheaters, calciners, tertiary air ducts, rotary kilns and other parts.
Physical and chemical indicators:
Item | General type | High-strength type | Heat-insulating type |
PNJ | GNJ | GRNJ | |
Al2O3 % | 25~40 | 25~40 | 25~40 |
Fe2O3 % ≤ | 2 | 2 | 2 |
Volume density g/cm³ | ≥2.1 | ≥2.1 | ≤1.65 |
0.2MPa load softening starting temperature ℃ ≥ | 1350 | 1300 | 1250 |
Apparent porosity % ≤ | 21 | 19 | |
Ambient compression strength Mpa ≥ | 30 | 60 | 15 |
Thermal shock resistance (1100°C, water cooling) time ≥ | 10 | 25 | |
Alkali resistance | Qualified | Qualified | Qualified |