Removal of F-From Leaching Solution of Zinc Oxide Dust By CaF 2 Precipitation Method

The removal of fluorine from leaching solution of zinc oxide dust using CaCO3 ,CaO , Ca(OH)2 and CaAl2 O4 respectively as Ca source and Al2 (SO4 )3 · 7H2 O as assistant was investigated . The effects of temperature ,time ,concentration of sulfuric acid ,dosage of assistant on defluorination were examined .The experimental results show that the content of fluorine can be reduced from 0 .736 g/L to 0 .351 g/L under the optimum conditions of assistant dosage of 5 g/L ,CaAl2 O4 dosage of 10 g/L ,reaction temperature of 50-55℃ ,reaction time of 2 h ,the solution pH of 5 .4 .