Overview
ISO 13545:2000 - Lead sulfide concentrates: determination of lead content specifies a standardized wet-chemistry procedure for measuring lead in lead sulfide (galena) concentrates. The method uses acid digestion, lead sulfate precipitation, and EDTA titration (with xylenol orange indicator) after removing interfering elements. It is intended for concentrates with lead content between 50 % (m/m) and 80 % (m/m) and is not applicable when barium exceeds 1 % (m/m). The standard includes procedural steps, reagent and apparatus requirements, sampling guidance and precision/accuracy information.
Key topics and requirements
- Scope & applicability: Designed specifically for lead sulfide concentrates within the 50–80% Pb range; limitation for high barium content.
- Principle: Acid decomposition (nitric/sulfuric/bromine), removal of As/Sb/Sn, precipitation of lead as lead sulfate, dissolution in ammonium acetate, and titration with EDTA using xylenol orange.
- Reagents & standards: Analytical-grade acids, bromine, ammonium acetate, EDTA volumetric standard solution, and standard lead solutions for EDTA standardization.
- Apparatus: Class A volumetric glassware, analytical balance (0.1 mg), crucibles, pH meter; AAS or ICP is referenced as optional for complementary lead determination.
- Sampling & test portions: Test portions typically 0.25–0.5 g (around 200 mg Pb); advice on air-equilibrated samples and predried portions (Annex A).
- Quality control: Duplicate determinations (repeatability conditions), blank tests, EDTA standardization routine, acceptance flowchart and precision equations (Annexes A–C).
- Safety note: Use appropriate lab safety due to hazardous reagents and operations.
Practical applications and users
Who uses ISO 13545:2000:
- Metallurgical and mineral assay laboratories performing routine concentrate analysis.
- Mining companies and concentrate producers for product specification and quality control.
- Regulatory bodies and contract laboratories verifying concentrate composition for trade and compliance.
- Research groups validating analytical methods for sulfide concentrates.
Practical value:
- Provides a reproducible, validated methodology for accurate lead content determination in galena concentrates.
- Useful for production quality control, shipment certification, metallurgical accounting, and dispute resolution in concentrate trading.
- Complementary use with instrumental methods (AAS/ICP) allows cross-checking and method verification.
Related standards
Relevant laboratory and sampling standards cited within ISO 13545 include:
Keywords: ISO 13545:2000, lead sulfide concentrates, lead content determination, EDTA titration, acid digestion, lead sulfate precipitation, xylenol orange, metallurgical assay.