Overview
EN ISO 21079-2:2008 (ISO 21079-2:2008) specifies wet chemical analysis methods for AZS refractories - materials containing alumina (Al2O3), zirconia (ZrO2) and silica (SiO2) - with 5 % to 45 % ZrO2. Issued by CEN/ISO, this part provides traditional (wet) analytical procedures as an alternative to X‑ray fluorescence (XRF, ISO 12677) for the chemical analysis of finished refractory products and raw materials. It is explicitly not applicable to MgO‑based refractories.
Key Topics
The standard defines laboratory methods, calibration and result reporting for the major oxide constituents commonly monitored in AZS refractories. Key technical topics include:
- Scope and applicability for AZS refractories (5–45 % ZrO2) and exclusions (MgO‑based refractories).
- Wet chemical techniques for major oxides and trace elements, including:
- Silicon(IV) oxide (SiO2): molybdenum‑blue and combined dehydration/coagulation + molybdenum‑blue methods.
- Aluminium oxide (Al2O3) and iron(III) oxide (Fe2O3) determinations.
- Titanium(IV) oxide (TiO2), calcium oxide (CaO), magnesium oxide (MgO).
- Sodium oxide and potassium oxide (Na2O, K2O) by flame photometry.
- Chromium(III) oxide (Cr2O3) by diphenylcarbazide method.
- Zirconium oxide (ZrO2) (including hafnium) by mandelic‑acid gravimetric method.
- Calibration, calculation and expression of results, and content required in the test report.
- Cross‑references to related parts: ISO 21079‑1 (apparatus, reagents, dissolution) and ISO 21079‑3 (FAAS and ICP‑AES).
Applications
This standard is designed for practical use in:
- Quality control and incoming raw‑material testing at refractory manufacturers producing AZS bricks, monolithics and castables.
- Analytical and research laboratories performing wet chemical analyses when XRF is unavailable or when independent verification of XRF/ICP results is required.
- Specification compliance and acceptance testing in industries using high‑temperature refractories (metallurgy, glass, ceramics).
- Training and method validation for laboratory analysts performing chemical determinations on alumina‑zirconia‑silica refractories.
Who Should Use It
- Laboratory chemists and QA/QC engineers in refractory production
- Materials scientists and R&D teams evaluating AZS compositions
- Third‑party inspection and testing laboratories
- Standards and compliance officers comparing XRF and wet chemical results
Related Standards
Keywords: chemical analysis, refractories, AZS, alumina, zirconia, silica, ZrO2, wet chemical analysis, molybdenum blue, mandelic acid, flame photometry, EN ISO 21079-2:2008, XRF alternative.
