Overview
ISO 13543:2016 - "Copper, lead, zinc and nickel sulfide concentrates - Determination of mass of contained metal in a lot" specifies a reproducible method to calculate the mass of contained metal in a lot of sulfide concentrate. The standard defines how to combine wet mass, moisture content, and dry-basis metal content to determine contained metal and how to estimate the variance and confidence intervals of that mass. It is targeted at users needing traceable, auditable metal mass reporting for commercial and technical purposes.
Key topics and requirements
- Inputs required: wet mass of the lot, moisture content (percent of wet mass), and metal content on a dry basis (percent for major metals; g/t for precious metals).
- Wet mass measurement methods: static scales, belt scales or draft surveys - static scales are recommended because of superior precision.
- Dry mass calculation: dry mass = wet mass × (1 − moisture% / 100). The standard also defines a moisture factor F = 1 − M/100 to simplify formulas.
- Contained metal calculation:
- Major metals (Cu, Pb, Zn, Ni): mass of metal = dry mass × (dry-basis metal % / 100).
- Precious metals (Ag, Au): mass of metal (kg) = wet mass × F × (grams per tonne) / 1000 (standard expresses precious metal content in g/t).
- Uncertainty and variance estimation: variance of the contained-metal mass is derived by propagation of errors using partial derivatives with respect to wet mass, moisture factor and metal content. The formula aggregates variance contributions from:
- wet mass measurement precision,
- moisture determination precision,
- chemical analysis and sampling precision.
- Practical guidance: the standard notes the dominant contributors to uncertainty (e.g., poor mass measurement precision when using draft surveys) and shows worked examples illustrating how increased sampling or analysis reduces uncertainty.
Applications and who uses it
- Mining companies and concentrate producers for inventory accounting and shipment documentation.
- Assay and analytical laboratories for reporting contained metal mass and associated uncertainty.
- Traders, commodity buyers/sellers and port operators for contract settlement and commercial reconciliation.
- Quality assurance, auditors and regulators requiring standardized, auditable mass and uncertainty reporting.
- Metallurgical engineers and logistics teams tracking payable metal and shipment reconciliation.
Related standards
Normative references and complementary ISO documents include:
- ISO 10251 (moisture determination by drying)
- ISO 12743 (sampling procedures)
- ISO 12744 (precision checking of sampling)
- ISO 12745 (precision and bias of mass measurement techniques)
Additional assay and analysis methods are cited in the bibliography (e.g., ISO methods for copper, gold and silver determination).
Keywords: ISO 13543:2016, contained metal, sulfide concentrates, copper, lead, zinc, nickel, moisture content, dry basis, lot mass, variance, confidence intervals, sampling, static scale, draft survey.