Overview
ISO 1953:2015 - Hard coal - Size analysis by sieving - defines reference methods for determining the particle-size distribution of hard coal by manual sieving (wet or dry). The standard covers test sieves with nominal aperture sizes between 125 mm and 45 μm, gives guidance on sampling (Annex A) and includes procedural details, apparatus and result reporting. It applies to all hard coals (but not to coke or other manufactured fuels) and notes that for highly pulverized coal the method will only determine the percentage oversize.
Key topics and technical requirements
- Scope and applicability: Reference methods for size analysis of hard coal using manual wet or dry sieving; limitations for pulverized coal and exclusion of manufactured fuels.
- Sieve series and apertures: Recommended sieve series (e.g., 125, 90, 75, 63, 50, 45, 31.5, 22.4, 16, 11.2, 8, 5.6, 4, 2, 1 mm and wire-cloth sizes down to 45 μm). Guidance on supplementary sizes when needed.
- Apparatus: Test sieves (ISO 3310 compliant), receivers, accurate weighing scale (to 0.1 %), trays, brush, vibratory shaker (for mechanical sieving), and for wet sieving: pressure-filter, Buchner funnel, filter paper and controlled oven.
- Sampling and sample mass: Sampling methods per ISO 13909 / ISO 18283 and minimum gross/sample mass requirements (Table 1) to achieve target precisions (1 % or 2%).
- Preparation and division: Drying limits (air-dry ≤ 40 °C) and procedures for dividing samples (mechanical dividers, flattened-heap or strip methods).
- Procedures: Detailed step-by-step for dry sieving (including hand-placing for large fragments) and wet sieving (used when particles agglomerate). Notes on combining wet and dry sieving and the potential influence of soluble clays/shales on wet-sieve results.
- Results and reporting: Express results as percentage mass retained on each sieve, calculation and graphical presentation conventions, and required test-report content.
Practical applications and users
ISO 1953:2015 is used for:
- Quality control in coal preparation plants and screening operations
- Design data and performance checks for crushing and screening equipment
- Yield assessment of run-of-mine coals and product grading verification
- Laboratory particle-size analysis in mining, power generation, and fuel supply chains
Primary users include coal testing laboratories, plant engineers, sampling technicians, equipment manufacturers and consultants involved in coal handling and preparation.
Related standards
Keywords: ISO 1953:2015, hard coal size analysis, sieving, test sieves, dry sieving, wet sieving, coal sampling, particle-size distribution, sieve aperture sizes.
