17 08 02

EWC 17 08 covers gypsum-based materials arising from construction and demolition, principally plasterboard (drywall) waste and plaster coatings. The chapter also encompasses industrially-derived gypsum streams classified under C&DW routes when managed at construction sites — including synthetic gypsum from FGD power station scrubbing, and specialised variants such as red gypsum from TiO₂ manufacture and phosphogypsum from fertiliser production.

Red gypsum is a distinctive iron-bearing calcium sulphate by-product arising from the sulphate-process route to titanium dioxide (TiO₂) production. Ilmenite ore reacts with sulphuric acid, generating iron(II) sulphate (copperas, FeSO₄·7H₂O) as a co-product. Neutralisation of the acid waste liquor with limestone or lime precipitates a reddish-brown calcium sulphate dihydrate rich in iron oxides — hence the name "red gypsum". Huntsman Pigments (Teesside, UK) and Kronos (Germany, Belgium) are the principal European producers, generating approximately 400,000–600,000 tonnes per year of red gypsum between them.

Plasterboard CDW requires source-segregated collection to achieve the 85%+ gypsum purity needed for wallboard manufacturing re-entry. Mixed CDW gypsum contaminated with paper, insulation and metal fixings is downgraded to soil amendment, cement retarder or landfill cover material. The EU Construction Products Regulation (CPR) and Circular Economy Action Plan push member states toward mandatory separate collection of CDW gypsum streams by 2027, following Denmark and Germany which already have operational collection networks.