GB/T 7731.12-2008Ferrotungsten - Determination of sulfur content - Infrared absorption method and combustion titration method (English PDF)

3.1 Principle

A high frequency induction furnace to sample the combustion heating oxygen flow, the oxygen produced by the sulfur dioxide contained in the measuring chamber to the infrared analyzer dioxide

S absorption of a specific wavelength of infrared energy absorbed is proportional to its concentration can, according to the detector to accept the change in energy can be measured sulfur content.

3.2 Reagents and materials

3.2.1

Magnesium perchlorate anhydrous particles.

3.2.2

asbestos caustic soda, granular.

3.2.3

glass wool.

3.2.4

tungsten particles, sulfur content is less than 0.0002%, particle size 0.8mm ~ 1.4mm.

3.2.5

tin particles, the amount of carbon is less than 0.0003%, particle size of 0.4mm ~ 0.8mm.

3.2.6

pure iron purity of more than 99.80%, sulfur content less than 0.002%, particle size 0.8mm ~ 1.68mm.

3.2.7

oxygen purity of more than 99.95%, if other levels of oxygen to obtain a low and consistent blank, can also be used.

3.2.8

power source gas, nitrogen and compressed air, the impurities (water and oil) content of less than 0.5%.

3.2.9

ceramic crucible, u00d8 × h (mm), 23 × 23 or 25 × 25, and at more than 1200 °C high temperature furnace burning 4h or through burning oxygen

Till the blank is the lowest.

3.2.10

crucible tongs.

3.3 instruments and equipment

3.3.1 Sulphur infrared absorption analyzer (sensitivity of 1 × 10-6)

Its apparatus shown in Figure 1.