Industrial minerals
Gypsum & Anhydrite — Cement Set Retarder, Plasterboard & Agricultural Grade
FOB Black Sea / MENA · CFR/CIF worldwide on request
Indicative price
USD 16–20 / MT
Indicative range, firm quote on request
Key parameters
Full product details
Product overview
Natural gypsum (calcium sulfate dihydrate, CaSO4·2H2O) and anhydrite (CaSO4) are the principal calcium sulfate minerals used to control Portland cement setting time, feed plasterboard calcination lines and supply slow-release calcium and sulfur in agriculture. Our export grade delivers 90% minimum combined CaSO4 with crystal water in the 18–21% range on hydrated material, matching the retention curves cement mills specify when grinding clinker with 3–5% gypsum addition.
Material is quarried from sedimentary evaporite beds at Black Sea and MENA sites, primary-crushed to 0–50 mm lump and screened to remove clay bands and carbonate stringers. White to grey rock appearance confirms low organic contamination; moisture capped at 12% keeps pneumatic discharge and grab unloading predictable at mill jetties. Anhydrite parcels are offered for plants that prefer water-free sulfate feed or plasterboard lines operating high-temperature kettle calciners.
Typical buyers include integrated cement groups replacing depleting captive gypsum quarries, independent grinding stations blending set retarder on arrival, plasterboard manufacturers securing lump feed ahead of housing construction cycles, and agricultural distributors supplying calcium sulfate for sodic soil reclamation and oilseed sulfur nutrition. HS codes 2520.10 (gypsum) and 2520.20 (anhydrite). MOQ from 1,000 MT on FOB, CFR or CIF terms.
Full specification
| Calcium sulfate (CaSO4, combined) | 90% min (dry basis, XRF) |
| Crystal water (gypsum grade) | 18–21% (thermogravimetric on as-received sample) |
| Sulfur trioxide (SO3) | 40% min |
| Calcium oxide (CaO) | 30% min |
| Moisture | 12% max at loading |
| Insoluble residue | 5% max (acid-insoluble, mainly silica and clay) |
| Chloride (Cl) | 0.1% max (cement-grade limit) |
| Particle size | 0–50 mm crushed lump; finer ground grades on request |
| Bulk density (loose lump) | ≈ 1.0–1.3 t/m³ |
| Appearance | White to grey crystalline rock, low clay staining |
| HS code | 2520.10 (gypsum) / 2520.20 (anhydrite) |
Loading ports & logistics
Calcium sulfate rock is a non-hazardous bulk solid under IMSBC Code — the main logistics risk is moisture pickup and fines generation during multiple handling transfers. We coordinate three principal delivery modes depending on parcel size and receiver equipment.
Open-hold bulk carriers and coastal barges move parcels of 1,000–20,000 MT from quarry-adjacent jetties on the Black Sea and Arabian Gulf. Handysize and supramax tonnage suit cement plants with grab unloaders; self-discharging barges cover short-sea legs to inland grinding stations.
1-tonne jumbo bags on flat-rack containers hold approximately 24–26 MT per FEU and suit plasterboard calcination plants and agricultural blenders without deep-water berth access. Bags are UV-stabilized polypropylene; lump size is pre-screened to limit bag puncture during ocean transit.
Road tipper trucks and rail hopper wagons cover short-haul routes from quarry face to coastal transhipment or direct delivery within 400 km of load point. FOB loading at exporter-nominated stockpile or jetty with draft survey; CFR and CIF quotes include vessel freight, marine insurance and discharge-port equipment survey. Typical lead time 10–22 days from contract execution to first loading window.
Packaging & documentation
Cargo ships as crushed lump in open vessel holds, 1-tonne jumbo bags on flat-rack containers, or loose in tipper trucks — bagged form is standard for containerized export. Each lot is accompanied by a quarry certificate of analysis showing CaSO4, crystal water, SO3, moisture and chloride, safety data sheet (SDS) per GHS, commercial invoice, weight certificate, bill of lading and certificate of origin.
Crystal-water content is confirmed by thermogravimetric analysis on the COA for gypsum grades; anhydrite lots report combined sulfate without hydration water. Third-party inspection (SGS, Bureau Veritas or equivalent) at load port can be arranged on buyer request — covering hold cleanliness, moisture verification and representative lump sampling. Phytosanitary certificates issued where destination customs require them for bagged mineral shipments.
FAQ
When should a cement plant buy natural gypsum instead of anhydrite?
Natural gypsum (CaSO4·2H2O) releases crystal water during grinding and provides predictable set retardation in Portland cement clinker without raising kiln SO3 above emission limits. Anhydrite (CaSO4) suits plants with dedicated grinding circuits and higher SO3 tolerance, or plasterboard lines that calcine feedstock in-board. We quote both grades against your mill retention-time and free-lime targets.
How is bulk gypsum shipped to cement and plasterboard mills?
Crushed lump gypsum moves in open-hold bulk carriers, self-discharging barges or 1-tonne jumbo bags on flat-rack containers. Parcels from 1,000 MT suit coastal jetties with grab unloaders; larger cement-plant contracts above 5,000 MT load on handysize bulkers at quarry-adjacent berths. Moisture is capped at loading to prevent hold caking; CFR and CIF quotes include discharge-equipment compatibility review.
What moves the indicative gypsum and anhydrite price per tonne?
FOB quotations track CaSO4 purity, crystal-water content for gypsum grades, lump size and crushing cost at quarry, inland haul to load port, and vessel or barge freight to your mill berth. The USD 16–20/MT band reflects current natural gypsum and anhydrite differentials from Black Sea and MENA deposits; firm pricing is confirmed against a signed specification sheet.
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