Mechanism and kinetics of ultrasound-enhanced CaCO3 precipitation for indium enrichment in zinc oxide dust leaching solution

In this study, ultrasound-enhanced calcium carbonate precipitation was used to enrich indium in zinc oxide dust leachate, and the effects of precipitation endpoint pH and ultrasound power on the indium precipitation behaviour were investigated, and the optimal conditions of ultrasound-enhanced precipitation were obtained to be the precipitation endpoint pH of 4.0 and the ultrasound power of 200 W. The precipitation rate of indium under these conditions was 99.79 %. At the same time, the effects of ultrasonication and conventional stirring on the indium precipitation kinetics were compared, which proved that ultrasound can shorten the time for precipitation to reach equilibrium and reduce the amount of calcium carbonate used, and the theory of ultrasonication activation energy was put forward. The activation energy of ultrasonication was E