ISO 12315:2010

Overview

ISO 12315:2010 provides a clear, industry-aligned method for calculating and reporting the Al2O3 content of smelter-grade alumina. The standard defines procedures to derive Al2O3 (%) on either a dried (300 °C) or ignited (1 000 °C) basis by combining mass-loss determinations with trace-element analysis. It is intended for laboratories, producers and quality teams involved in primary aluminium production and alumina specification.

Key points:

• Al2O3 content is expressed as a percentage (mass fraction).
• Calculation uses the results from ISO 806 (loss of mass at 300 °C and 1 000 °C) and AS 2879.7 (trace elements by WDXRF).
• The standard accounts for both moisture-on-ignition (MOI) and loss-on-ignition (LOI) effects when converting between bases.
• Sulfur from heavy-fuel-oil calcination is to be included as its oxide (reported as SO3) in the sum of impurities ΣI when applicable.

Key Topics

• Calculation principle: The Al2O3 percentage is obtained by subtracting the sum of measured impurities (ΣI) from 100 %, with adjustment factors to correct for MOI (300 °C) and LOI (300–1 000 °C) depending on whether results are reported on a dried or ignited basis.
• Determinations required:
  • Loss of mass at 300 °C (MOI) and at 1 000 °C (LOI) per ISO 806.
  • Trace-element oxides via wavelength-dispersive X-ray fluorescence per AS 2879.7 (or its ISO replacement when published).
  • Sulfur determination where relevant for heavy-fuel-oil calcined alumina.
• Reporting conventions: Typical smelter-grade alumina values are given as guidance: 98.5–98.9 % (dry basis) and 99.4–99.7 % (ignited basis).

Applications

• Quality control and acceptance testing for smelter-grade alumina shipments.
• Specification compliance and product certification for aluminium producers and alumina refiners.
• Laboratory reporting templates and calculation routines used in process control and contractual testing.

Related Standards

• ISO 806 - Determination of loss of mass at 300 °C and 1 000 °C.
• AS 2879.7 - Determination of trace elements by WDXRF (to be replaced by ISO 23201 when published).

Practical value

Implementing ISO 12315:2010 ensures consistent, reproducible Al2O3 reporting across laboratories and supply chains. The standard reduces ambiguity between dry and ignited bases, incorporates trace-element corrections, and lists required test-report information (reference to the standard, sample and test dates, material identification, basis used, and Al2O3 to one decimal place), supporting transparent quality management and contractual clarity.