GB/T 4699.6-2008 Ferrochromium and silicochromium - Determination of sulfur content - The infrared absorption method and the combustion-titration method
WARNING: Persons using this part shall be familiar with normal laboratory practice. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.
1 Scope
This part specifies the determination of sulfur content of ferrochromium and silicochromium by infrared absorption method and combustion-titration method.
This part is applicable to the determination of sulfur content of ferrochromium and silicochromium. The determination range (mass fraction) of infrared absorption method and combustion-titration method is 0.0050% ~ 0.070% and 0.0050% ~ 0.120% respectively.
2 Normative references
The following normative documents contain provisions which, through reference in this part, constitute provisions of this part. For dated references, subsequent amendments (excluding corrections) to, or revisions of, any of these publications do not apply to this part. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document applies.
GB/T 4010 Ferroalloys sampling and preparation of samples for chemical analysis
3 Method I — Infrared absorption method
3.1 Principle
The test portion is heated and burned in oxygen flow in the high-frequency induction furnace. The generated sulfur dioxide is carried by oxygen to the measuring chamber of an infrared analyzer. Sulfur dioxide absorbs infrared energy at a specific wavelength, and its absorption energy is proportional to its concentration. The sulfur content can be measured based on changes in the energy received by the detector.
3.2 Reagents and materials
3.2.1 Magnesium perchlorate: anhydrous, granular.
3.2.2 Soda asbestos: granular.
3.2.3 Glass wool.
3.2.4 Tungsten particles: sulfur content less than 0.0002%, particle size 0.8 mm ~ 1.4 mm.
3.2.5 Tin particles: carbon content less than 0.0003%, particle size 0.4 mm ~ 0.8 mm.
3.2.6 Pure iron: purity greater than 99.8%, sulfur content less than 0.002%, particle size 0.8 mm ~ 1.68 mm.
3.2.7 Oxygen: purity greater than 99.95%. Other grades of oxygen may also be used if low and consistent blank values can be achieved.
Foreword i
1 Scope
2 Normative references
3 Method I — Infrared absorption method
4 Method II — Combustion-titration method
5 Test report
