Sulphur for Fertilisers and Sugar Sulphitation: Which Grade to Use

Two of the biggest users of sulphur in western India are fertiliser blenders and sugar mills. They use the same element in completely different ways, and that changes which grade and form they should buy. This guide explains both.

Sulphur as a crop nutrient

Sulphur is one of the nutrients crops need in fairly large amounts — it is part of proteins and oils, which is why oilseeds, pulses and onion and garlic respond well to it. Intensive cropping and the use of high-analysis fertilisers without sulphur have made sulphur deficiency more common in Indian soils.

Plants take sulphur up as sulphate. Elemental sulphur first has to be oxidised to sulphate by soil bacteria, which makes it a slow-release source:

• Finer particles convert faster because bacteria work on the particle surface. Powder releases sulphate sooner than coarse granules.
• Warm, moist, aerated soils speed up the conversion.
• Oxidation produces a little acidity, so elemental sulphur is also used to help lower the pH of alkaline soils.

Fertiliser makers blend sulphur into products such as sulphur-enriched fertilisers and sulphur–bentonite granules, where the clay helps the granule break up into fine particles in the soil.

Sulphur in sugar mills: sulphitation

Most Indian sugar mills that make plantation white sugar use the sulphitation process. Sulphur is burned in a sulphur burner to produce sulphur dioxide (SO₂), which is absorbed into the limed cane juice. Together, lime and SO₂ clarify the juice and reduce its colour, giving whiter sugar.

Because the gas goes into a food process, mills look for:

• High purity — 99.5% min. sulphur.
• Low ash and impurities, so the burner runs cleanly and does not choke.
• Consistent quality from lot to lot.

That is why mills generally choose bright virgin refinery sulphur, in granules or powder depending on their burner.

Which grade and form to use

For the full difference between the two grades, read virgin vs by-product sulphur.

Packing, storage and safety

• We supply sulphur in 25 kg and 50 kg bags and jumbo bags.
• Sulphur is a flammable solid (UN1350, Class 4.1). Keep it away from flames, sparks and hot surfaces; burning sulphur gives off toxic sulphur dioxide outside the burner.
• Fine sulphur dust can ignite — avoid dust clouds, earth equipment and keep storage areas clean.
• Store bags dry, ventilated and away from oxidising chemicals such as chlorates and nitrates.

Supply from Ankleshwar

We deliver virgin sulphur (IOCL, Nayara and Reliance makes) and by-product sulphur powder from our Ankleshwar warehouse — the same day in Ankleshwar and Panoli; the same or next day to Bharuch, Dahej, Surat and Vadodara; in 1–2 days to Navsari, Vapi and Ahmedabad; and in 2–3 days to Morbi and Rajkot. Tell us your application, form, quantity and packing through our quote form and we reply within 24 hours.

IOCL, Nayara and Reliance are trademarks of their respective owners. Aethon Chemicals is an independent supplier and stockist of genuine material and is not affiliated with these companies.