ISO 23201:2015

Overview

ISO 23201:2015 specifies a wavelength dispersive X‑ray fluorescence (WDXRF) spectrometric method for determining trace elements in aluminium oxide (alumina) primarily used for aluminium production. The method is designed for smelting‑grade alumina and reports analytes as oxides (for example Na2O, SiO2, Fe2O3, TiO2). Sample preparation uses fusion into a borate glass disc (fused bead) and analysis on a wavelength dispersive X‑ray fluorescence spectrometer.

Key topics and technical requirements

• Analytical technique: Wavelength dispersive X‑ray fluorescence (WDXRF) with vacuum path instrumentation verified for precision (see AS 2563).
• Sample preparation: Fusion of alumina sample into a borate glass disc using lithium tetraborate / lithium metaborate flux; use of platinum/platinum‑alloy crucibles and moulds; strict cleaning to avoid contamination (silica is a common contaminant).
• Calibration & QA:
  • Two‑point regression calibration with synthetic standards from high‑purity chemicals.
  • Use of a certified reference material to verify calibration.
  • Intensity measurements corrected for spectrometer drift.
• Scope of analytes and concentration ranges (expressed as oxides, on an un‑dried basis):
  • Na2O: 0.10–1.00%
  • SiO2, Fe2O3: 0.005–0.05%
  • CaO: 0.01–0.10%
  • TiO2, V2O5, ZnO, MnO, K2O, CuO, Cr2O3, NiO: 0.001–0.010% (varies by element)
  • P2O5: 0.001–0.050%
  • Ga2O3: 0.001–0.020%
• Reagents & apparatus: Specifies high‑purity oxide chemicals for standards, flux composition, platinum crucibles/moulds, furnaces (1100–1200 °C), vibratory mills with non‑contaminating parts, and precautions for fusion (use oxidizing flame to avoid Fe reduction/alloying).
• Performance verification: Instrument performance and method precision assessed according to referenced normative documents.

Applications and users

This standard is intended for:

• Alumina producers and quality control laboratories for routine analysis of smelting‑grade alumina.
• Primary aluminium smelters requiring incoming material certification and process control.
• Independent testing labs, instrument vendors and R&D groups validating WDXRF methods for trace elements. Practical uses include supplier qualification, batch release testing, process troubleshooting, and compliance with metallurgical specifications where trace impurities affect smelting performance.

Related standards

• ISO 802 - Preparation and storage of test samples (alumina)
• ISO 2927 - Sampling of aluminium oxide for aluminium production
• AS 2879.7–1997 - Basis for this method (Australian Standard)
• AS 2563 - Instrument precision verification (WDXRF)

Keywords: ISO 23201:2015, aluminium oxide, alumina, WDXRF, wavelength dispersive X‑ray fluorescence, trace elements, smelting‑grade alumina, fused bead, calibration, quality control.