Alumina Silica Refractory Brick

Updated: 2026-09-15

Overview

Alumina Silica Refractory Brick is a ceramic material engineered to withstand extreme temperatures and corrosive environments. Composed mainly of alumina (Al₂O₃) and silica (SiO₂), it is classified by its alumina content, ranging from semi-silica (15–30% Al₂O₃) to high-alumina (over 45% Al₂O₃). Its microstructure ensures low porosity and high mechanical strength, making it indispensable in industries requiring thermal insulation and structural integrity. Developed in the early 20th century, these bricks revolutionized high-temperature processes by replacing traditional fireclay bricks. Today, they are standardized for global industrial use, with grades tailored to specific thermal and chemical demands.

Physical and Chemical Properties

The brick's performance hinges on its alumina-to-silica ratio. Higher alumina content (e.g., 70%) enhances refractoriness (up to 1800°C) and alkali resistance, while higher silica improves thermal shock resistance. Typical density ranges from 2.3 to 2.8 g/cm³, with compressive strength exceeding 50 MPa. Its low thermal conductivity (1.0–1.5 W/m·K) minimizes heat loss. Chemically, it is inert to acids and slags but may react with strong alkalis or molten metals. The brick's porosity (10–20%) affects insulation and erosion resistance, with dense variants used in direct contact with molten materials.

Main Applications

These bricks are widely used in metallurgy (blast furnaces, ladles), cement (rotary kilns), and glass (tank furnaces) industries. In steelmaking, they line hot blast stoves and tundishes, enduring temperatures up to 1600°C. The cement sector relies on them for sintering zones, where abrasion and thermal cycling are severe. Specialized variants serve niche roles: low-iron bricks for glass contact, and high-purity types for silicon production. Their adaptability also extends to incinerators and petrochemical reformers, where corrosion resistance is critical.

Safety and Storage

Handle with dust masks and gloves to avoid respiratory or skin irritation from fine particles. Broken bricks may have sharp edges, requiring cut-resistant gloves. Storage demands dry conditions to prevent hydration of binders, which weakens the brick. For disposal, used bricks are often recycled as aggregate in new refractory products. Avoid dumping in landfills unless inertness is confirmed, as some grades may leach trace metals at high pH.

B2B Procurement Guide

Key specifications include Al₂O₃ content (e.g., 48%, 65%), dimensions (standard: 230×114×65 mm), and thermal shock resistance (measured by cycles before failure). Verify manufacturer certifications like ISO 9001 and MSDS for hazardous substances. Bulk orders (20+ tons) often qualify for discounts, but test samples first. Lead times vary from 2 weeks (stock items) to 8 weeks (custom shapes). For kiln linings, prefer bricks with pre-installed expansion joints to minimize onsite labor.