Analytical Method: Silicon (total) in iron oxide powder

Instruments and Reagents:

Cat.No. 173016 Spectroquant^® VIS Spectrophotometer Prove 100 or
Cat.No. 173017 Spectroquant^® UV/VIS Spectrophotometer Prove 300 or
Cat.No. 173018 Spectroquant^® UV/VIS Spectrophotometer Prove 600 or
Cat.No. 109748 Spectroquant^® Photometer NOVA 30 or
Cat.No. 109751 Spectroquant^® Photometer NOVA 60 or
Cat.No. 173632 Spectroquant^® Colorimeter Move 100
Cat.No. 114946 Rectangular cells 10 mm and/or
Cat.No. 114947 Rectangular cells 20 mm and/or
Cat.No. 114944 Rectangular cells 50 mm
Cat.No. 114794 Spectroquant^® Silicate (Silicic Acid) Test
Cat.No. 100716 Sulfuric acid 25% for analysis
Cat.No. 106495 Sodium hydroxide for analysis
Cat.No. 109533 MColorpHastTM pH-indicator strips pH 5 - 10
Cat.No. 116754 Water for analysis

Iron oxide powder with an average size of particles of 0.2 - 0.3 mm is used for the production of ferrite cores. Mineral and oxidic admixtures or contaminations are decisive for the quality of the endproduct.

Sample preparation:
In a nickel melting-pot mix 100 mg of the sample, dried to constant weight at 105 °C, with 8 sodium hydroxide tablets (1.5 g). Directly with the gas burner heat the covered melting-pot to weak red glow for 30 minutes. After cooling dissolve the content of the melting-pot in water for analysis. For that purpose put the melting-pot with the cover into a glass beaker as well as 30 - 50 ml water for analysis warm on a bath of water, until the melting cake has dissolved. Adjust the suspension to a pH-value of 7 - 8 with sulfuric acid 25%, quantitatively transfer it into a 250-ml standard volumetric flask and fill up to volume with water for analysis. After mixing let the insoluble parts settle and filter the supernatant solution through an ash-free, acid washed filter. A blank reading analysis must be considered, produced with the used reagents according to the procedure above.

Analysis:
Determine with the above-mentioned test kit.