Overview
ISO 4296-2:1983 - "Manganese ores - Sampling - Part 2: Preparation of samples" specifies standardized methods for preparing manganese ore samples for chemical composition and moisture content determination. Applicable to both natural and processed manganese ores, it complements ISO 4296-1 (increment sampling) and links to ISO 4299 (moisture determination). The standard also includes an annex with detailed specifications for the riffle divider used in sample splitting.
Key topics and technical requirements
- Scope and sample types: Defines increment, subsample, gross sample, divided sample, moisture sample, sample for chemical analysis and final sample.
- Separation of tests: Moisture and chemical-analysis samples must be prepared separately; moisture determination should be done immediately and samples stored in airtight containers to avoid evaporation.
- Protection and handling: Increments and gross samples must be protected from contamination and weather during preparation.
- Division methods: Permitted methods include coning and quartering, riffle divider, increment division, and mechanical dividing apparatus. The chosen method should minimize bias and meet prescribed precision.
- Equipment requirements: Crushers and grinders (avoid overheating and moisture loss), test sieves (ISO 565), dividing apparatus, drying ovens (105–40 °C control range), and technical balances.
- Particle size and comminution: Typical workflow shows staged crushing (examples in the standard: to –22.4 / –20 / –10 mm, then –5 mm, –1 mm, –0.5 mm) and final grinding to –0.1 mm for chemical analysis.
- Final samples: From prepared samples, four independent final analysis samples (50 g or more each) are produced - for seller, purchaser, arbitrator and reserve (reserve retained for 6 months).
- Riffle divider specifics (annex): Dimensions and number of riffles, even-number requirement, receiver fit to avoid spillage, smooth internal surfaces, and a maximum chute angle (≤ 60°) to reduce bias.
- Precision goal: Designed to achieve sample-preparation precision within ±0.7% (absolute manganese or moisture percentage) with 95% probability.
Applications and users
- Mining and ore-processing companies preparing consignments for sale or internal QC
- Assay and analytical laboratories performing chemical and moisture analyses
- Quality assurance, purchasing departments, and trade arbitrators resolving disputes
- Logistics and shipping teams compiling certificates of analysis for consignments
Related standards
- ISO 4296-1: Manganese ores - Sampling - Part 1: Increment sampling
- ISO 4299: Manganese ores - Determination of moisture content
- ISO 565: Test sieves - woven wire cloth, perforated plate and electroformed sheet
Keywords: ISO 4296-2, manganese ores sampling, sample preparation, riffle divider, moisture determination, chemical analysis, increment sampling, sample division methods.