Decontamination of Zincate Solutions Using Calcium Hydroxide in a Fluidised Bed Reactor

SUMMARY This article deals with the decontamination and utilisation of waste water. The effectiveness and conditions for the removal of Zn(II) from diluted alkali zinc electroplating bath solutions in flow-rate regime have been investigated. A cheap and simple decontamination route is proposed using the fluidised bed reactor with Ca(OH)2. The advantage of this method is that up to 98% of Zn(II) can be precipitated as a fine crystalline recyclable material—CaZn2 (OH) 6 2H2O with small amount of ZnO. The industrial scheme of this process using lime is proposed.