Sulphur (spelled sulfur in American English) is used mainly to make sulphuric acid. The United States Geological Survey reports that about 90% of the sulphur consumed in the United States in 2025 was consumed in the form of sulphuric acid, and the largest use of that acid is turning phosphate rock into fertiliser. The remainder goes into fertiliser applied directly to soil, rubber vulcanisation, metal leaching, chemicals, pulp and paper, and crop protection.
What is sulphur used for in industry?
The uses fall into two groups: sulphur that is first converted to acid, and sulphur used as the element.
| Use | Form of sulphur used | What it does |
|---|---|---|
| Phosphate fertiliser | Sulphuric acid | Dissolves phosphate rock to make phosphoric acid and superphosphate |
| Metal leaching | Sulphuric acid | Dissolves copper, nickel and uranium from ore |
| Chemicals and pigments | Sulphuric acid | Detergents, resins, dyes, titanium dioxide, textiles |
| Sulphur fertiliser | Elemental sulphur, sulphur bentonite | Supplies sulphur to crops and lowers soil pH |
| Rubber | Sulphur powder, insoluble sulphur | Vulcanisation of tyres and rubber goods |
| Crop protection | Sulphur powder | Fungicide on vines, fruit and vegetables |
| Pulp, paper and food | Sulphur dioxide and sulphites | Bleaching and preserving |
Sulphuric acid: the main use
Sulphuric acid is made by the contact process. Sulphur is burned in air to give sulphur dioxide. The sulphur dioxide is oxidised to sulphur trioxide over a vanadium oxide catalyst. The trioxide is absorbed into concentrated acid and diluted to the strength required. The burning releases heat, which acid plants recover as steam and electricity. That is why a fertiliser complex prefers to buy sulphur and make its own acid.
The share of sulphur that ends up as acid has been high for decades. One encyclopaedic reference gives about 85% for the world in 1989; the USGS figure for the United States in 2025 is about 90%. World production of the acid was estimated at 260 million tonnes in 2022.
Phosphate fertiliser
Phosphate rock does not dissolve in water, so plants cannot use it directly. Treating the rock with sulphuric acid gives phosphoric acid, the intermediate for DAP and MAP, or, with less acid, single superphosphate. This is the largest single use of sulphuric acid. An encyclopaedic reference puts fertilisers at about 60% of acid consumption as of the late twentieth century, with about 20% going to the chemical industry and about 6% to pigments.
The link is direct enough that sulphur demand follows phosphate output. The USGS notes that new sulphur demand from phosphate fertiliser projects is expected mostly in Africa and west Asia. The phosphate products are on our phosphate and potash fertilisers page, and the acid itself on the sulphuric acid page.
Metal leaching
Mines use sulphuric acid to dissolve metals out of ore. Copper oxide ores are leached in heaps, and nickel laterite ores are leached under pressure in high-pressure acid leach plants. The USGS expects the growth of nickel production from high-pressure acid leach projects, which supply battery materials, to add to sulphur demand. Remote mines often build a sulphur-burning acid plant on site, because solid sulphur is easier to ship than acid.
Chemicals
About a fifth of sulphuric acid goes into the chemical industry: detergents, synthetic resins, dyes, pharmaceuticals, petroleum refining catalysts, and viscose and acetate textiles. Titanium dioxide pigment made by the sulphate route is another large consumer. Battery acid for lead-acid batteries is a small, high-purity grade.
What is sulphur used for in agriculture?
Sulphur is a plant nutrient in its own right. Crops need it to form proteins, and oilseeds are the most demanding. Cleaner fuels and lower emissions have reduced the sulphur that once reached fields from the air, so more now has to be applied.
Elemental sulphur does not dissolve in water and plants cannot take it up as it is. Soil microbes first oxidise it to sulphate. That takes time, which makes elemental sulphur a slow-release source, and the oxidation produces acidity, which is why sulphur is also used to lower the pH of alkaline soils.
The practical difficulty is particle size. Fine sulphur oxidises quickly but is dusty and a fire hazard to handle. Sulphur bentonite solves this. It is a pastille of about 90% sulphur bound with bentonite clay. The clay swells when it meets soil moisture and breaks the pastille into fine particles in the ground. Sulphur is also supplied to crops in sulphate form, in ammonium sulphate, single superphosphate and gypsum.
Uses of sulphur as the element
Rubber vulcanisation
Heating rubber with sulphur forms sulphur bridges between the polymer chains and turns a soft, sticky material into an elastic, durable one. The process was patented in 1843 and is still how tyres are made. Rubber compounders use finely ground sulphur powder and, for tyres, insoluble sulphur, a polymeric form that does not migrate to the surface of the uncured rubber.
Crop protection
Dusting sulphur and wettable sulphur are among the oldest fungicides. They are used on grapes, strawberries, many vegetables and other crops.
Pulp, paper and food
Burning sulphur gives sulphur dioxide, from which sulphites are made. Large quantities of sulphites are used to bleach paper and to preserve dried fruit. Sugar mills use sulphur dioxide to clarify juice when making mill white sugar.
Other uses
Sulphur goes into carbon disulphide for viscose and cellophane, matches, skin preparations in pharmacy, and sulphur concrete and sulphur-extended asphalt.
Which form for which use
Acid plants, the largest buyers, melt whatever they receive, so they buy on purity and price. Solid sulphur for them moves as granular sulphur, prilled sulphur or crushed lump sulphur; plants close to a refinery take molten sulphur by tanker. Rubber, agriculture and chemical users buy ground, formed or treated products in bags. Where sulphur comes from and how it is formed is covered in our guide to sulphur production.
How sulphur is traded
Bulk sulphur is sold FOB the load port or CFR the discharge port in vessel parcels, largely from the Middle East, Central Asia and North America to phosphate producers and metal leaching operations. Smaller buyers take jumbo bags and 50 kg bags in containers. The specification covers purity, moisture, ash, acidity, organic carbon and, for formed product, size and fines. Prices move sharply from quarter to quarter; current levels are on our dated sulphur price page.
CBIL brokers sulphur between a named producer or seller and a named buyer, against an independent inspector's certificate, from SGS, Intertek or a similar company, issued at loading.
Request a sulphur quote with the form, quantity, end use and discharge port.