ISO 2369:1972
Aluminium fluoride for industrial use; Determination of silica content; Spectrophotometric method using the reduced silicomolybdic complex
- Standard No.
- ISO 2369:1972
- Release Date
- 1972
- Published By
- International Organization for Standardization (ISO)
- Status
- 2002-05
- Latest
- ISO 2369:1972
- Scope
- The method can be applied provided the phosphorus pentoxide content does not exceed 0, 02 % (m/m). The principle is based on alkaline fusion of a test portion by means of a mixture of sodium carbonate and boric acid. Solution of the fused mass in excess nitric acid so that the pH of the final solution is between 0, 3 and 0, 5 after being diluted. Formation, in a suitable aliquot portion, of the (yellow) oxidized silicomolybdic complex under clearly defined conditions of acidity, concentration of reagents, temperature and time. Selective reduction in a high acidity sulphuric acid medium and in the presence of tartaric acid. Spectrophotometric measurement at a wavelength of about 815 nm.
ISO 2369:1972 history
- 1972 ISO 2369:1972 Aluminium fluoride for industrial use; Determination of silica content; Spectrophotometric method using the reduced silicomolybdic complex
