Granular sulfur is mainly used to make sulphuric acid, the most produced industrial chemical in the world. Most of that acid goes into phosphate fertilizers, and a growing share into extracting copper, cobalt and nickel from ore. Smaller amounts of granular sulphur are used directly as a fertilizer, in rubber and chemicals, and in agriculture.
For specifications and supply, see our sulfur granular page.
1. Sulphuric acid
Sulphuric acid plants burn molten sulphur to make sulphur dioxide, convert it to sulphur trioxide and absorb it in water. Granular sulphur is the usual feedstock for plants that are not next to a refinery, because it ships and stores easily and is melted on arrival.
The acid then goes mainly into:
- Phosphate fertilizers: phosphate rock is dissolved in sulphuric acid to make phosphoric acid, the base for DAP, MAP and TSP. Single superphosphate is made with sulphuric acid directly.
- Metal leaching: acid dissolves copper, cobalt, nickel and uranium from ore. Nickel processing in Indonesia and copper-cobalt production in Central Africa have become major buyers of sulphur.
- Chemicals and industry: detergents, fibres, pigments, oil refining, batteries and water treatment.
That is why the largest sulphur importers include phosphate producers such as Morocco, Brazil and India, and mining countries such as the Democratic Republic of the Congo, Zambia and Indonesia.
2. Fertilizers
Why sulfur is important in fertilizer
Sulphur is the fourth major plant nutrient after nitrogen, phosphorus and potassium. Plants need it to make proteins and oils, and crops short of sulphur cannot use nitrogen properly. Sulphur deficiency has become more common as cleaner air has cut the sulphur that used to fall in rain, and as high-analysis fertilizers carry less sulphur than older products.
Elemental sulphur products
- Sulphur bentonite (often sold as “sulphur 90”): about 90% elemental sulphur mixed with bentonite clay in pastilles or granules. In moist soil the clay swells and breaks the granule apart, and soil bacteria gradually oxidise the sulphur to plant-available sulphate.
- Sulphur-enhanced fertilizers: NPK, MAP or other granules with fine elemental sulphur built in.
- Soil acidification: elemental sulphur lowers soil pH over time, used for acid-loving crops and on alkaline soils. Our guide to soil pH and fertilizer explains how pH affects crops.
Elemental sulphur acts slowly because bacteria must convert it first. Sulphate fertilizers, such as ammonium sulphate and SOP, act faster. Many programmes use both.
3. Rubber and chemicals
- Vulcanisation: sulphur cross-links rubber, making tyres and other products strong and elastic.
- Carbon disulphide and other chemicals: used for fibres, cellophane and agricultural chemicals.
- Other uses: dyes, pharmaceuticals and matches use small quantities, usually of higher-purity grades.
4. Agriculture beyond fertilizer
Sulphur is one of the oldest fungicides, used against powdery mildew in grapes, fruit and vegetables. These products use fine, wettable or dusting sulphur rather than coarse granules, and are regulated as plant protection products.
What buyers in each sector check
| Sector | Key requirements |
|---|---|
| Sulphuric acid and phosphates | Purity, low ash, low carbon and acidity, low moisture, reliable bulk supply |
| Metal leaching | Purity, consistent supply to inland sites, packaging for rail or road |
| Fertilizer blending | Granule size and hardness, low dust, sometimes bentonite products |
| Chemicals and rubber | Higher purity, low impurities such as arsenic and selenium |
Buying granular sulfur from Agromer
Agromer supplies sulfur granular to corporate direct buyers with an LOI only. Send a recent LOI on your company letterhead with the end use, specification, quantity, destination port and delivery terms. We work with established producers and arrange independent inspection at loading.
Frequently asked questions
What is granulated sulfur used for?
Mainly to make sulphuric acid for phosphate fertilizers and metal leaching. It is also used in sulphur fertilizers, rubber, chemicals and agriculture.
Why is sulfur important in fertilizer?
Plants need sulphur to make proteins and oils and to use nitrogen efficiently. Many soils are now short of sulphur.
What is sulphur 90?
A fertilizer made of about 90% elemental sulphur and 10% bentonite clay, which breaks down in moist soil so bacteria can convert the sulphur to sulphate.
Can granular sulfur be applied directly to soil?
Elemental sulphur can be used as a slow-release sulphur source and to lower soil pH, but sulphur bentonite or sulphate fertilizers usually work better for crop nutrition.
What is the main use of sulfur in industry?
Making sulphuric acid, which is used in fertilizers, metal processing and many chemical industries.
What are five common uses of sulfur?
Sulphuric acid, phosphate fertilizers, metal leaching, rubber vulcanisation and fungicides.