BUILDING CEMENT In the 1750s John Smeaton, rediscovered hydraulic cement and the early 1800s patents were issued to several individuals. Joseph Aspdin of Leeds, patetend Portland cement in 1824, taking the name from the Island of Portland, where the stone resembled the new material. Apart the Portaland cement also special cements can be divided into three main categories: Those which are produced by adding other materials to Portland cement Those which are produced in a similar manner to Portland cement, that is calcining a mixture of materials such as bauxite; slag etc., then grinding with appropriate  additives to produce the finished product. A category that could  be best classed as all the rest, including such as thermoplastic cements and dental cements.  (Source: Graham Ellicot, IndMin Magazine). WE SUPPLY TO THIS INDUSTRY MAINLY PIGMENTS AS ADDITIVES FOR COLOURING AND SHADE CORRECTORS. GREEN CHROME OXIDE; IRON OXIDES; NAFTIL GREEN; HK PIGMENTS RANGE