Overview
ISO 562:2024 - Hard coal and coke - Determination of volatile matter - specifies a standardized, empirical test method for measuring the volatile matter content of hard coal and coke (not applicable to brown coals and lignites). The test determines volatile matter as the loss in mass, corrected for moisture, after heating a prepared test portion out of contact with air under tightly controlled conditions.
Key topics and technical requirements
- Scope: Applies to hard coal and coke; excludes brown coals and lignites. Moisture is determined in parallel for correction.
- Principle: Loss in mass on heating (less moisture loss) at 900 °C for 7 minutes in an oxygen-excluded environment.
- Furnace: Electric furnace maintaining a uniform zone at 900 °C ± 5 °C; temperature recovery after inserting crucibles must be within 4 minutes.
- Temperature control: Unsheathed thermocouple (wire ≤ 1 mm) positioned under crucible; periodic correlation with any permanently sheathed thermocouple is required.
- Crucible and lid: Fused silica cylindrical crucible with well-fitting lid; combined mass typically 10–14 g; lid/crucible horizontal clearance ≤ 0.5 mm; correct fit is critical to exclude air.
- Sample preparation: General analysis test sample prepared to nominal top size 212 µm and in moisture equilibrium with lab atmosphere. Sample preparation procedures reference ISO 13909 series and ISO 18283.
- Sample charge and handling: Typical test portion ≈ 1 ± 0.1 g placed in crucible; for coke, 2–4 drops of cyclohexane are added before heating to reduce oxidation risk.
- Weighing: Analytical balance capable of 0.1 mg resolution for pre- and post-heating mass determinations.
- Expression of results: Volatile matter expressed as percent of mass in the analysed sample after moisture correction.
- Quality: The standard contains sections on precision (repeatability and reproducibility limits) and required test reporting.
Applications and users
- Laboratories performing coal analysis, quality control, or fuel characterization.
- Coke producers, coal preparation plants, utilities and research institutions needing reproducible volatile matter data for:
- combustion performance assessment
- coke quality evaluation
- fuel blending decisions
- regulatory reporting and specification compliance
- Useful where standardized, comparable volatile matter data are required across labs and international markets.
Related standards
Keywords: ISO 562:2024, volatile matter determination, hard coal, coke testing, coal analysis, silica crucible, furnace 900 °C, cyclohexane, analytical balance.
