Overview
ISO 616:2021 - "Coke - Determination of shatter indices" specifies a standardized laboratory method to determine the mechanical strength of coke using the shatter test. The shatter index is reported as the percentage of a prepared coke sample that remains on a specified test sieve after a defined dropping procedure. The standard describes sampling, apparatus, test procedure, result calculation and reporting for consistent, repeatable coke strength measurements.
Key topics and technical requirements
- Definition: The shatter index is the percentage of a test portion retained on a sieve of nominal opening x mm after the prescribed dropping test.
- Sampling & preconditioning: Follow ISO 18283 or ISO 13909-6 for sampling. Moisture is checked per ISO 579; if moisture > 5% the sample must be dried before testing.
- Size analysis: Perform sieve analysis in accordance with ISO 728 to prepare size fractions and assemble a representative test portion.
- Test portion: Reconstitute a 25 kg ± 0.1 kg test portion containing all fractions >63 mm in original proportions.
- Apparatus: Shatter test apparatus with base unit (minimum 1 220 × 970 mm base), sample box (internal 710 × 460 × 380 mm) and raising/lowering mechanism. Standard drop positions: bottom of box 1 830 mm above base when raised, and 460 mm when lowered.
- Procedure: Transfer test portion into the sample box, raise to the standard height, release doors to allow free fall onto base plate - repeat for a total of four drops. Recover coke, sieve using ISO 3310-2 compliant test sieves (common sizes listed) and weigh fractions to nearest 10 g (or 0.01 kg during preparation).
- Result calculation: Shatter index Sx = (cumulative mass retained on sieves ≥ x mm) / (total mass after test) × 100. Report to 0.1 percentage unit.
- Validity & precision: Test is valid if total mass after sieving differs from original test portion by ≤ 100 g. Example repeatability limits: duplicate S40 results should not differ by more than 4.0 units; S12.5 by more than 1.0 unit. Reproducibility between laboratories is not quoted due to sample transport breakage risk.
Applications
- Quality control for coke production and blending
- Feedstock assessment for blast furnaces and foundries
- Supplier/contract compliance and material acceptance testing
- Research on coke mechanical properties and coke-making process optimization
Who uses this standard
- Coke producers and quality laboratories
- Steelmakers and foundries specifying coke feed quality
- Independent testing laboratories and material inspectors
- R&D engineers studying coke durability
Related standards
Keywords: ISO 616:2021, coke shatter index, shatter test, coke strength, test sieves, coke testing, ISO coke standards.
