Sulfur vs Sulphur: Names, Forms and Industrial Uses

Is there a difference between sulfur and sulphur?

No. Sulfur and sulphur are two spellings of the same element, symbol S, atomic number 16. Sulfur is the spelling used by IUPAC, the international authority on chemical nomenclature. Sulphur is the traditional British English spelling.

IUPAC’s 2005 recommendations on inorganic nomenclature list sulfur as the approved English name, with no alternative spelling noted. An August 2009 editorial in Nature Chemistry observed that sources disagree on when IUPAC settled on sulfur, giving either 1971 or 1990. The same editorial notes that the word comes from Latin rather than Greek.

Oxford Learner’s Dictionaries records that the Royal Society of Chemistry (RSC) in the UK has also adopted sulfur. Sulphur is still the usual spelling in British, Irish, South African and Indian English, and Canadian, Australian and New Zealand English use both. Cambridge Dictionary lists sulphur as the UK spelling.

Indonesian has its own word. The KBBI dictionary gives belerang as the standard Indonesian term for sulfur, and its chemistry entry for sulfur points back to belerang. That entry describes sulfur as a brittle yellow mass that can also take other forms, such as clear crystals. An Indonesian buyer may therefore meet belerang, sulfur and sulphur for one material.

Which spelling do trade and shipping documents use?

Both appear, often side by side. Chemistry references tend to write sulfur, while shipping and trade documents often write sulphur.

The US Geological Survey (USGS) and the RSC periodic table use sulfur. In the IMDG Code for dangerous goods carried by sea, the proper shipping name for UN 1350 is SULPHUR, with sulfur listed as a synonym. The IMSBC Code schedules for solid bulk cargoes and the industry association The Sulphur Institute also use sulphur.

What forms is commercial sulfur traded in?

Sulfur is traded either as a solid or as a hot liquid. Solid sulfur comes as lumps, as particles formed from molten sulfur, or as fine powder.

The IMSBC Code, the international code for solid bulk cargoes, separates two groups of solids. The first is formed sulfur, which is molten sulfur shaped into prills, granules, pellets, pastilles or flakes. A 2013 summary of the code by the Faroese Maritime Authority describes it as a co-product of sour gas processing or oil refining, bright yellow and odourless. The second group is crushed, lump and coarse-grained sulfur, which has its own schedule.

The ship’s master therefore needs to know which form of sulfur is being loaded (UK P&I Club, 2023), and the carriage status of each cargo follows its cargo documents.

How does handling differ for solid, powdered and molten sulfur?

Solid sulfur is melted or ground before use, depending on the process. Powder needs dust control, and molten sulfur must be kept hot.

Sulfur melts at roughly 113–119 °C, depending on its crystal form. According to the US EPA’s AP-42 guidance, sulfur-burning sulfuric acid plants melt solid sulfur, filter it to remove ash and spray it under pressure into the combustion chamber. For rubber vulcanization, lump sulfur is ground to powder before use.

Dust needs managing with any solid sulfur. The UK P&I Club (2023) notes that bulk sulfur is usually stored in the open and contains some dust, so many authorities require water sprays during handling. With fine powder, the dust can form an explosive mixture with air that static electricity can ignite. A New Jersey Department of Health fact sheet advises vacuuming or wet methods for clean-up rather than dry sweeping.

Moisture and static matter too. Dry sulfur does not react with bare steel, but wet sulfur can be highly corrosive. Flow or agitation can build up an electrostatic charge, and fires can start during loading of dry sulfur when static builds up on the loading pipes (UK P&I Club, 2023).

Molten sulfur needs heated tanks and gas control. In the vapour space of a tank it can form H₂S, SO₂ and SO₃. For storage and safety procedures, use the safety data sheet (SDS) from the producer or shipper.

Where does commercial sulfur come from?

Most commercial sulfur today is recovered from oil refining and natural gas processing. Only a small share is still mined.

The US EPA’s AP-42 defines sulfur recovery as converting hydrogen sulfide (H₂S) into elemental sulfur. H₂S is a by-product of natural gas processing and of refining high-sulfur crude oil. The Claus process accounts for about 90–95% of recovered sulfur.

In a Claus unit, one third of the H₂S is burned with air to SO₂ in a furnace at 980–1,540 °C. The remaining H₂S then reacts with the SO₂ in catalytic reactors at 200–315 °C to form sulfur and water. Liquid sulfur from the condensers runs into a covered pit and is then moved as a liquid or formed into solids.

Britannica records that the Frasch process, which from 1894 melted underground sulfur deposits with very hot water, dominated world supply until about 1970. After that, sulfur from petroleum, natural gas and metal sulfides took a growing share. The Frasch process is still used in Poland and Russia. The RSC now describes modern production as coming almost entirely from removing sulfur from natural gas, oil and tar sands.

What is sulfur used for in industry?

Most sulfur is converted into sulfuric acid. Britannica puts the share at about six-sevenths of the sulfur produced, and names fertilizers, both phosphate and ammonium sulfate, as the main use of that acid.

According to The Sulphur Institute, well over half of the world’s sulfuric acid is made by burning elemental sulfur at the consumer’s own site, so many plants produce their own acid. Most of the rest is recovered at non-ferrous metal smelters and pyrite mines.

Beyond sulfuric acid, sulfur is used to vulcanize rubber and in fungicides. For Indonesian buyers, the uses are covered industry by industry.

• Nickel smelting (HPAL): sulfur is burned to make sulfuric acid for leaching laterite nickel ore.
• Fertilizer: feedstock for sulfuric acid used in phosphate and ammonium sulfate fertilizers.
• Sulfuric acid and chemicals: feedstock for sulfuric acid, sulfites and other derivatives.
• Sugar mills: sulfur is burned into SO₂ gas to clarify cane juice (sulfitation).
• Rubber and tires: vulcanizing agent.
• Pulp and paper: a source of SO₂ and sulfites for pulping.
• Traders and distributors: bought in bulk for resale.

What should buyers ask when comparing sulfur offers?

Compare offers on the same basis. Ask each seller to state the following in writing so the offers line up item by item.

1. Physical form: lump, prills, granules, pastilles, flakes, powder or molten. The form decides how the sulfur is handled and whether it must be melted or ground before use.
2. Purity: the sulfur content in percent, and whether an analysis report backs it.
3. Other parameters: for example ash, acidity and any impurities that matter for your process. In a sulfuric acid plant, feed with hydrocarbon impurities produces more water vapour and acid mist.
4. Packaging: for example jumbo bags or bulk.
5. Volume and timing: tonnes per transaction and the loading window.
6. FOB port: where the goods are delivered on board. Under FOB, the buyer nominates the vessel, arranges insurance and handles import. The ship’s master needs to know which form of sulfur is being loaded.
7. Safety documents: whether the producer’s or shipper’s SDS is available for storage and handling.

What should buyers know when buying sulfur FOB?

Buyers can raise the points above with any FOB sulfur seller, including PT Samudra Rayya Nusantara, a trading company that sells lump sulfur from Oman on FOB terms at Sohar Port. The sulfur has 99.54% purity, comes in jumbo bags and is offered in 500–20,000 tonnes per transaction.

The company holds no stock in Indonesia and does not ship. Goods stay in the country of origin and are delivered on board the vessel the buyer nominates. Sohar is on the Gulf of Oman, outside the Strait of Hormuz. Further specifications come with the offer, and samples and meetings are available to buyers with a clear purchase plan.

Product details are on the lump sulfur page. Sohar’s location is covered in the article on Sohar Port and the Strait of Hormuz.