Overview
EN ISO 4349:2024 - "Solid recovered fuels - Determination of the Recycling Index for co-processing" (ISO 4349:2024) specifies a standardized method to quantify the share of material recovery occurring when solid recovered fuels (SRFs) are used for co-processing (e.g., in a cement kiln). The outcome is the Recycling Index (R‑index), expressed as a mass fraction (%) of dry matter, calculated from the SRF’s ash content (at 815 °C, dry basis) and ash composition.
Key topics and technical requirements
- Scope: Defines the R‑index for SRF co‑processing and the calculation basis (ash content + ash elemental composition).
- Sample handling: Sampling and sample preparation follow ISO 21645 and ISO 21646.
- Ash determination: Ash content determined per ISO 21656:2021 (815 °C, dry basis).
- Elemental analysis methods:
- Method A - wet digestion followed by ICP‑MS or ICP‑OES;
- Method B - fused bead preparation followed by ICP‑OES;
- Method C - pellet preparation followed by XRF analysis.
- Reagents & apparatus: Analytical acids (HNO3, HF, HCl), lithium metaborate, muffle furnace, microwave unit, ICP‑OES/ICP‑MS, XRF spectrometer, platinum crucible and press (as listed in the standard).
- Calculations: Conversion of elemental content to oxide forms (Al2O3, CaO, Fe2O3, SiO2, etc.) and stepwise computation of the R‑index for co‑processing.
- Quality & reporting: Performance characteristics, validation (informative Annex B), and required elements of the test report are specified.
- Informative data: Annex A provides typical SRF ash compositions from mixed municipal/commercial waste.
Practical applications
- Enables consistent, comparable quantification of the material fraction recycled when SRFs are co‑processed in industrial processes (notably cement clinker production).
- Supports lifecycle and circular economy claims by showing how SRF use can replace mineral raw materials as well as fossil fuels.
- Helps cement producers, SRF suppliers and waste managers assess feedstock suitability and optimize blend design for clinker chemistry.
- Provides laboratories and conformity assessment bodies with validated analytical routes (ICP, XRF, fused bead, wet digestion) to determine ash composition and compute R‑index.
Who should use this standard
- SRF producers and auditors
- Cement and co‑processing industries
- Environmental and materials testing laboratories
- Regulators, waste management authorities and sustainability analysts
- Standards developers and certification bodies
Related standards
Keywords: EN ISO 4349:2024, Solid recovered fuels, SRF, Recycling Index, R‑index, co‑processing, ash composition, cement kiln, ICP‑OES, ICP‑MS, XRF.