UTILIZATION OF SOLID WASTE OF ALUMINUM SULPHATE INDUSTRY IN THE PRODUCTION OF ACID, SALT AND HEAT RESISTANT MORTAR

Abstract

Geopolymeric binders are produced from a range of various aluminum silicate source materials such as fly ash, blast furnace slag and kaolin. Therefore, Egyptian kaolinite can be used for the preparation of meta kaolinite (MK) as a constituent for geopolymer manufacturing along with Partially de-aluminated meta kaolinite (PDK) as a source of activated silicate. Metakaolinite (MK) was prepared by thermal treatment of raw kaolinite obtained from the kaolin deposits intercalated sedimentary rocks in south Sinai (Egypt) and PDK wastes were obtained from aluminum Sulphate Company of Egypt. Different parameters for complete hydroxylation of kaolinite were tested, such as heating temperature ranged from 200 – 750 ̊C for ninety minutes. The production of metakaolinite from kaolinte was assured by X-ray diffraction and infra-red analysis for the raw kaolinite and metakaolinite. The pozzolanic activity was determined by Chappelle test, the obtained value was 0.74 g Ca(OH)2/g meta-kaolinite which indicated that the prepared meta-kaolinite can be used as pozzolanic material (acts as cementitious material) and as a source of activated aluminum silicate for preparation of Geopolymeric binder. Heating at 700 ̊C for 60 minutes is the optimum conditions for getting activated MK. The geopolymer mortar was produced from byproduct waste as alternative for environmentally green construction and building materials without using Ordinary Portland Cement (OPC). The 30 % PDK /MK mixtures achieved the highest compressive strength (65 MPa). The study showed that the resulting geopolymer has good resistance for acid, salts and heat. So, the PDK wastes that traditionally disposed into landfills can be sustainably used in developing and producing geopolymer mortar with economic and environmental income.