Applicable to products having a content, expressed as sulphur trioxide, equal to or more than 0.1 % (m/m). Bases on alkaline fusion of a test portion with a mixture of sodium carbonate and boric acid. Extraction of the fused mass with perchloric acid solution and precipitation of the sulphate ions with barium chloride in an acidified medium. Filtration on a fine-texture, ashless filter paper (pore diameter approximately 0.4 to 1.0 m). Calcination after drying in an electric oven at (850 20) °C. Weighing of the residue.
Status: PublishedPublication date: 1977-11
Edition: 1Number of pages: 3
Technical Committee: ISO/TC 226 Materials for the production of primary aluminium
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|std 1 38|
|std 2 38||Paper|