Overview
ISO 10469:2006 - "Copper sulfide concentrates - Determination of copper - Electrogravimetric method" - specifies an analytical procedure for determining the mass fraction of copper in copper sulfide concentrates in the range 15% to 50%. The method is electrogravimetric: copper is chemically liberated from the concentrate, separated from interfering elements, and electrolytically deposited for gravimetric measurement. Trace copper remaining in solutions and residues is quantified by FAAS (flame atomic absorption spectrometry) or ICP-AES.
Key topics and requirements
- Scope and precision: Applicable to copper sulfide concentrates with copper content between 15 % and 50 %; the standard defines precision reporting and acceptance criteria.
- Principle: Decomposition of a test portion with nitric and sulfuric acids, selective separation of interferents and electrogravimetric deposition of copper in an acidic chloride-containing electrolyte to avoid co-precipitation (molybdenum is not coprecipitated under specified conditions).
- Interferent separations:
- Silver removed as AgCl.
- Arsenic, antimony, selenium and tin removed by fuming with hydrobromic acid.
- Iron (and bismuth/tellurium when present) removed either by copper sulfide precipitation (sodium thiosulfate) or iron(III) oxide hydrate (hydroxide) precipitation.
- Trace analysis: Residual copper in electrolytes, filtrates and precipitates is analyzed by FAAS or inductively coupled plasma atomic emission spectrometry.
- Reagents and calibration: Requires analytical-grade acids (nitric, sulfuric, hydrochloric, hydrobromic), sodium thiosulfate, ammonium iron(III) sulfate, high-purity copper standard, and matrix-matched calibration solutions (A, B, C) prepared per the standard.
- Apparatus and safety: Standard laboratory glassware, analytical balance, fume hood and controlled-temperature bath. A clear safety warning is included - users must follow appropriate health and safety practices for hazardous acids and fumes.
Applications and users
- Laboratories performing metallurgical assays, assay offices, and quality control in mining and concentrate processing.
- Producers and traders of copper sulfide concentrates requiring an accurate, traceable copper assay for contract settlement, process control, and product specification.
- Complementary method where gravimetric accuracy is preferred or where instrumental methods require confirmation.
Related standards
Keywords: ISO 10469:2006, electrogravimetric method, copper sulfide concentrates, determination of copper, FAAS, electrolytic deposition, copper assay, metallurgical laboratory.
