The formation of belite phase by using phosphogypsum and oil shale

This investigation aims at gaining in-depth knowledge for the cement clinke r production by utilizing phosphogypsum (PG) and oil shale (OS) as raw mate rials. The raw mixtures (Raw Mix I and Raw Mix IT) were burnt in a muffle f urnace and then analyzed by X-ray diffraction (XRD) to observe the phases o btained. While fluorellestadite (Ca-10(SiO4)(3)(SO4)(3)F-2) and akermanite (Ca2MgSi2O7) phases were observed with the Raw Mix I composed of 51.43% PG, 16.59% OS, 8.23% stone coal (SC) and 23.75% kaolinite clay (KC) in N-2 atm osphere at the temperature range of 1200-1300 degrees C, the mineralogical phase belite (beta-C2S) of Portland cement (PC) was formed even at 1200 deg rees C by using the raw mixtures (Raw Mix II) composed of 35.84% PG, 11.56% OS, 5.73% SC, 16.55% C and 30.32% CaO. The intensity and the amount of bel ite peaks were increased with increasing burning temperature. (C) 2000 Else vier Science Ltd. All rights reserved.