manufacture also has the potential to benefit from using industrial byproducts from the waste stream. These include in particular: Slag Fly ash (from power plants) Silica fume (from steel mills) Synthetic gypsum (from desulfurisation) See also References External links World Production of Hydraulic Cement, by Country Alpha The Guaranteed Portland Cement Company: 1917 Trade Literature from Smithsonian Institution Libraries Cement Sustainability Initiative A cracking alternative to cement Aerial views of the world's largest concentration of cement manufacturing capacity, Saraburi Province, Thailand, at CDC – NIOSH Pocket Guide to Chemical Hazards Further reading Cement Concrete English inventions Limestone Cement Building materials 19th-century inventions de:Zement#Portlandzement