Overview
ISO 6230:1989 - "Manganese ores - Determination of size distribution by sieving" specifies standardized procedures for determining particle size distribution of manganese ores (natural or processed such as pellets, sinters and agglomerates) using one or more sieves. The standard defines the principle of sieve analysis, sample types (lot, consignment, increment, subsample, gross sample, test sample, size sample), and the requirement that, when used for comparative purposes, producer and consumer agree on detailed methods to avoid disputes.
Key topics and technical requirements
- Scope and applicability: Applies to natural or processed manganese ores and to size determination by dry or wet sieving.
- Sieving principle: Size distribution is expressed as percentage mass passed or retained on selected sieves (sieve analysis).
- Sampling and sample preparation: Defines sample types and references ISO sampling standards (e.g., ISO 4296 series) for increment, subsample and gross sample handling.
- Sieve media & frames: Requires square apertures per ISO 565 and compliance with ISO 3310-1 / ISO 3310-2 technical requirements; avoid mixing perforated plate and woven wire sieves within a determination.
- Sieve preparation & maintenance: Cleaning and verification procedures (e.g., degreasing, brushing for apertures ≥ 500 µm, careful washing for finer sieves); maintain traceable records and discard sieves that fail verification.
- Drying & moisture control: Drying equipment should hold 105 °C ± 5 °C for moisture determinations (see ISO 4299 for moisture).
- Weighing accuracy: Scales must permit precision to at least 0.1% of rated capacity and report to one decimal place.
- Wet sieving considerations: For apertures