Overview
ISO 10081-1:2003 - Classification of dense shaped refractory products - Part 1: Alumina‑silica specifies a standardized system for classifying and designating dense shaped refractory products in the alumina‑silica series. The standard defines product types, classification groups based on alumina (Al2O3) and silica (SiO2) content, principal raw materials, raw‑material state, and bonding systems. It excludes products with >5% of any metallic oxide (other than alumina, silica, iron oxide) and products with >1% carbon, carbides, nitrides or related materials.
Key topics and requirements
- Scope & exclusions
- Applies to dense shaped alumina‑silica refractory products.
- Excludes products with significant additional metallic oxides (>5%) or carbon/carbonaceous content (>1%).
- Five classification criteria
- Product type (HA, FC, LF, SS, SL)
- Classification group (based on Al2O3 and/or SiO2 content)
- Principal raw material(s)
- State of raw material(s) (naturally occurring raw/calcined, synthetic calcined, fused)
- Nature of the bond
- Product types and group ranges
- High alumina (HA): groups such as HA 98, HA 95, HA 85, HA 75, HA 65, HA 55, HA 45 (group defined by Al2O3 percentage ranges)
- Fireclay (FC): FC 40, FC 35, FC 30
- Low alumina fireclay (LF): LF 10 (10% ≤ Al2O3 < 30% with SiO2 < 85%)
- Siliceous (SS): SiO2 85% ≤ SiO2 < 93%
- Silica (SL): SiO2 ≥ 93%
- Chemical analyses are carried out on calcined test products.
- Bonding classifications
- Ceramic bond - sintering during firing (>800 °C)
- Inorganic chemical bond - chemical reaction at ambient or below 800 °C (may be tempered)
- Fusion cast - formed by total fusion of the product
- Designation
- Product designation lists the five criteria (e.g., “HA 75, based on fused mullite, ceramic bond”).
Applications and users
- Who uses ISO 10081-1:2003
- Refractory manufacturers and product developers
- Specifiers and procurement teams in steel, cement, glass, ceramics, petrochemical and non‑ferrous industries
- Furnace builders, refractory installers and maintenance engineers
- Materials testing laboratories and quality assurance personnel
- Practical uses
- Standardizing product descriptions in specifications and contracts
- Selecting appropriate refractory types for high‑temperature furnaces and linings
- Guiding raw‑material selection, quality control and acceptance testing
- Facilitating interchangeability and procurement across international markets
Related standards
- ISO 10081 series: Part 2 (basic products with
