It is one of the leading producers of sodium sulphate in the world, with the most comprehensive range of bulk and packed products. It has annual production capacity of 625,000 tonnes. Minera de Santa Marta exports 80% of its production to more than 40 countries in Europe, North Africa, Asia and South America.

Anhydrous sodium sulphate is obtained from glauberite and thenardite at two mines in Spain located in Belorado (Burgos) and Villarrubia de Santiago (Toledo). It is used in the manufacture of washing powders, glass, paper, textile dyes, animal feed and in the chemical industry in general.