ISO 579:2013

Overview

ISO 579:2013 - "Coke - Determination of total moisture" specifies a standardized laboratory method to determine the total moisture content of coke. Applicable to blast‑furnace coke, foundry coke and other high‑temperature carbonization products, the method quantifies moisture by heating a representative sample and calculating the mass loss on drying. ISO 579:2013 ensures reproducible, comparable moisture results for quality control, trade, and process monitoring.

Key topics and requirements

• Principle: Moisture is measured as the mass loss after heating a prepared coke sample in air until constant mass is reached. Coke is not liable to oxidation under the specified conditions.
• Apparatus:
  • Drying oven able to maintain a uniform zone at 120 °C to 200 °C.
  • Tray ~0.1 m² area, 25 mm deep, made of non‑corrodible material (stainless steel, tinned steel, aluminium).
  • Balance with readability to 1 g.
• Sample preparation:
  • Follow mechanical sampling and division per ISO 13909-6.
  • Crush whole sample to a nominal top size of 16 mm; obtain laboratory portion by dividing.
  • Prevent moisture change during handling (airtight storage, avoid wet contacts and dust loss).
  • Visibly wet samples or those expected >15% moisture must be air‑dried first (air‑dry loss X determined per ISO 13909-6).
• Procedure:
  • Weigh tray empty, add ~1 000 g ± 100 g laboratory sample, weigh, dry at 120–200 °C until mass change ≤ 0.1% mass fraction between successive heats.
  • Calculate total moisture (%) as: moisture (%) = (mass loss on drying / initial sample mass) × 100.
  • For visibly wet samples combine air‑dry loss (X) and residual moisture (M) to obtain total moisture: M_T = X + M × (1 − X/100).
• Precision:
  • Repeatability limit: 0.5% absolute mass fraction.
  • Reproducibility limit: 0.7% absolute mass fraction.
• Reporting:
  • Report mean of duplicate determinations to 0.1% mass fraction and include reference to ISO 579:2013, sample ID and results.

Applications and users

ISO 579:2013 is used by:

• Metallurgical and foundry laboratories for moisture analysis of coke used in blast furnaces and foundries.
• Quality control teams monitoring feedstock condition and combustion performance.
• Traders and inspectors requiring standardized moisture reporting for contracts and acceptance testing.
• Process engineers optimizing coke performance, handling and storage.

Keywords: ISO 579:2013, coke moisture determination, total moisture of coke, blast‑furnace coke, foundry coke, moisture analysis, laboratory procedure, drying oven, precision repeatability reproducibility.

Related standards

• ISO 13909-6 - Hard coal and coke - Mechanical sampling - Part 6: Coke - Preparation of test samples (normative reference used for sampling and air‑drying procedures).