November 2001 Ž . Materials Letters 51 2001 281–284 www.elsevier.comrlocatermatlet Inorganic wastes in manufacturing of glass-ceramics: slurry of phosphorous fertilizer production and oil shale ash A.V. Gorokhovsky a, ) , V.A. Gorokhovsky b , D.V. Mescheryakov b , J. Mendez-Nonell a , J.I. Escalante-Garcia a , M.I. Pech-Canul a , G. Vargas-Gutierrez a a Department of Engineering Ceramics of CINVESTAV-IPN, Unidad Saltillo-Monterrey, km 13.5, Apartado Postal 663, CP 25000, Saltillo, Coahuila, Mexico b Department of Building Materials of SaratoÕ State Technical UniÕersity, SaratoÕ, Russia Received 3 July 2000; received in revised form 19 February 2001; accepted 21 February 2001 Abstract The use of bicomponent raw material mixtures of industrial wastes to produce pyroxene glass ceramics was investigated. It is shown that oil shale ash from heat power stations can promote the production of crystalline phases and the slurry from phosphorous fertilizer production can provide sufficient concentration of nucleating agents. Mechanical and chemical properties, as well as the structure and crystallization mechanism were characterized. An increase of phosphorous oxide and fluorine concentrations leads to a change of the crystallization mechanism. q 2001 Elsevier Science B.V. All rights reserved. Keywords: Waste utilization; Glass-ceramics; Oil shale ash; Phosphorous slurry; Structure 1. Introduction The pyroxene type of glass-ceramics, based on diopside–hedenbergite–augite–enstatite solid solu- tions, is one of the more promising materials to produce different types of facing materials for the construction industry, taking into account its high mechanical and chemical properties and low manu- wx facturing cost 1 . There are many publications considering different wastes as a source of raw materials for the manufac- ) Corresponding author. Tel.: q 52-84-881-019; fax: q 52-84- 881-300. E-mail address: alexande@saltillo.cinvestav.mx Ž . A.V. Gorokhovsky . w x turing of glass-ceramics 1–5 . Nevertheless, the ap- plication of the different types of waste, produced either within a single industry or by several indus- tries located within a small region, can represent a complex problem for their reutilization. Oil shale ash is a by-product from many heat power stations in Russia, Estonia, China, Germany and Mexico. Its chemical composition is very close to glass-ceramics of the pyroxene type. However, such compositions normally require the introduction of special admixtures, as catalysts, in order to pro- w x mote the crystallization process of glasses 1,2,6 ; their introduction can be achieved by the use of an additional type of waste. The analysis of this situation has shown that the manufacturing of phosphorous fertilizers is usually located close to heat power stations, and some of the 00167-577Xr01r$ - see front matter q 2001 Elsevier Science B.V. All rights reserved. Ž . PII: S0167-577X 01 00314-7