The method is applicable to products having a silica content between 0.005 % (m/m) and 0.025 % (m/m) provided that the content of phosphorus pentoxide plus vanadium pentoxide does not exceed 0.02 % (m/m). The principle of the method is based on the formation of oxidized molybdosilicate (yellow) under well-defined conditions of acidity, concentration of reagents, temperature and time. Selective reduction of the complex in a highly acidic medium of sulphuric acid and in the presence of tartaric acid. Spectrophotometric measurement of the reduced coloured complex at a wavelength of about 815 nm. - Replaces ISO Recommendation R 1232-1970.
Status: WithdrawnPublication date: 1976-09
Edition: 1Number of pages: 5
Technical Committee: ISO/TC 226 Materials for the production of primary aluminium
- ICS :
- 71.100.10 Materials for aluminium production
ISO 1232:1976Stage: 95.99
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