The material

An inert white salt with a four-century history.

Sodium sulphate (Na₂SO₄) is a non-hazardous, free-flowing crystalline salt. It was first described by the chemist and pharmacist Johann Rudolph Glauber in 1625 — and is still known to many as Glauber salt.

In essence.

Sodium sulphate is a stable inorganic salt that dissolves readily in water and behaves predictably across a wide range of industrial processes. It is non-hazardous, well understood, and produced to consistent specifications by European producers.

The material exists as two main mineral forms. Thenardite is the anhydrous crystal; mirabilite (Glauber salt) is the decahydrate, which loses its water on drying to become thenardite. Glauberite is a related natural calcium and sodium sulphate.

How it is produced

Two complementary routes.

Natural sources

Extracted from sulphate-rich saline brines or lakes — particularly in Spain and Turkey — through mining, evaporation and crystallisation of evaporite minerals.

~60% of European output
Industrial co-product

Recovered from viscose fibre production, chemical processes, lead-battery recycling and other value chains — turning by-products into a valuable raw material.

~40% of European output
Circular by nature

A material that fits a circular economy.

When sodium sulphate is co-produced during viscose fibre manufacture, an incidental output becomes a value-adding co-product. It enters new industries as a secondary input, keeping resources in productive loops — a defining principle of the circular economy.