Sulfur

 

Analytical control within the sense of the standard STN 65 1091
The sulfur production runs through the Claus process being the most common methods of gas treatment containing a highly toxic hydrogen sulphide. The Claus process for the sulfur production is based on the hydrogen sulphide gas combustion with the air oxygen.
Controlled parameters of sulfur quality
Sulphuric acid

The method is based on the extraction of acid compounds with distilled water followed by a titration of the extract with sodium hydroxide solution.
Organic compounds
The method is based on the gravimetric determination. The content of organic compounds is equal to the difference of residual weight in the dish after annealing at 250 °C and at 800 ± 25 °C.
Ash
The method is based on the gravimetric determination. The ash content is calculated from the residue in the dish after annealing at 800 ± 25 °C.
Water
The method is based on the less of the sulfur mass dried to a constant mass at 70 ± 2°C.
Hydrogen sulphide
The di-isopropanol-amine is added into molten sulfur to decompose polysulphides into hydrogen sulphide. The content of bubbler is purged with gas – nitrogen, and the contained hydrogen sulphide in the sulphur as well as that from the polysulphides is collected in the sodium hydroxide solution. The content of hydrogen sulphide is determined using the potentiometric titration with silver nitrate.