Compsn. of fly ash, calcium oxide or hydroxide, and calcium sulphate - for stabilising soils and treating effluents

摘要

The mixt. contains (A) 60-75% silico-aluminous fly ash; (B) 15-35% CaO or Ca(OH)2 and (C) 5-15% CaSO4. In soil treatment the following mixts. are pref:- clay soils 65% (A), 23-25% (B) and 10-12% (C); for alluvial soils 70% (A), 18-20% (B), and 10-12%; and for sandy soils 75% (A),10-15% (B) and 10-15% (C). For (C) plaster may be used or plaster oven dust contg. anhydrite, plaster, a gypsum. It reinforces the mechanical resistance of soils combining the effects of lime and cement treatment presently used in a single operation. In treating industrial and urban effluent, it provides a combined action of flocculation, neutralisation and fixation.