1 Subject Content and Application Scope
This standard specifies the determination of silicon dioxide content by molybdenum blue spectrophotometric method.
This standard is applicable to the determination of silicon dioxide content in limestone products for chemical industry and the determination range is 0.05%~5%.
2 Normative References
GB 6682 Water for Analytical Laboratory Use - Specification and Test Methods
GB/T 9721 Chemical Reagent - General Rules for the Molecular Absorption Spectrophotometry (Ultraviolet and Visible)
3 Method Summary
Melt the specimen with mixed flux of sodium carbonate - boric acid, and then leach with diluted hydrochloric acid. At pH value about 1.1, ammonium molybdate reacts with silicic acid and generates silicon molybdenum heteropoly acid, which is then restored to silicomolybdenum blue with ammonium ferrous sulfate in oxalic acid - sulfuric acid medium by taking ethanol as stabilizer; and measure the absorbance at spectrophotometer wavelength of 680nm.
1 Subject Content and Application Scope
2 Normative References
3 Method Summary
4 Reagents and Solutions
5 Apparatus
6 Specimen
7 Analytical Procedures
8 Plotting of Working Curve
9 Expression of Analysis Results
10 Allowable Difference
Additional Information
