title: Use of industrial byproducts as alumina sources for the synthesis of calcium sulfoaluminate cements.
abstract: Calcium sulfoaluminate (CSA) cements show some desirable environmentally friendly features that include the possibility of using several industrial byproducts as raw materials in their manufacturing process. Alumina powder, from the secondary aluminum manufacture, and anodization mud, from the production process of anodized aluminum, have proved to be suitable as partial or total substitutes for an expensive natural material like bauxite. CSA clinker generating raw mixtures, containing limestone, natural gypsum, bauxite, and/or one of the alumina-rich byproducts, were heated 2 h in a laboratory electric oven at temperatures ranging from 1150 to 1300 °C. Conversion of reactants into 4CaO·3Al(2)O(3)·SO(3) (the key component of CSA cements), evaluated using X-ray diffraction (XRD) analysis, increased with an increase of both burning temperature and byproduct concentration. When examined through differential thermogravimetric and XRD analyses, a synthetic CSA clinker (made from the raw mixture incorporating alumina powder as a total replacement of bauxite) mixed with 20% gypsum showed a hydration behavior almost similar to that of an industrial CSA cement containing the same amount of gypsum.
authors.affiliation: Dipartimento di Ingegneria e Fisica dell'Ambiente, Università degli Studi della Basilicata, Viale dell'Ateneo Lucano 10, 85100 Potenza, Italy.
authors.forename: Maria Lucia
authors.initials: ML
authors.lastname: Pace
authors.forename: Antonio
authors.initials: A
authors.lastname: Telesca
authors.forename: Milena
authors.initials: M
authors.lastname: Marroccoli
authors.forename: Gian Lorenzo
authors.initials: GL
authors.lastname: Valenti
mesh_terms: D017607:Aluminum Compounds / Q000138:chemical synthesis*; D000537:Aluminum Oxide / Q000737:chemistry*; D017610:Calcium Compounds / Q000138:chemical synthesis*; D006358:Hot Temperature; D008956:Models, Chemical; D013457:Sulfur Compounds / Q000138:chemical synthesis*; D013818:Thermogravimetry; D014866:Waste Products / Q000032:analysis*; D014961:X-Ray Diffraction
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D013457:Sulfur Compounds; D014866:Waste Products; C529583:calcium sulfoaluminate; D000537:Aluminum Oxide