Method for recovery of zinc in the form of an oxide from waste zinc electrolytes that contains ions of zinc, magnesium and manganese and free from ions of iron

摘要

This notification concerns the recovery of zinc oxide from zinc waste electrolytes containing zinc, magnesium and manganese ions and iron-free ions including neutralisation in the acid electrolyte. (B) neutralisation of acid by adding a neutralising factor to zinc waste electrolyteego with gaseous CO2 and caSO4 precipitation and caSO4 precipitation separation from solution. Subsequently C) saturation of the aqueous solution NH3 with gaseous CO2 and D) excretion of zinc in the form of Zn(HCO3)2 by mixing portions of the solutions from stage (B) and (C)and then separate the sediment from the solution; then E) the sediment distribution Zn(HCO3)2 to ZnCO3; and F) the thermal treatment of the ZnCO3 sediment with ZnO formation. In addition, the method includes the pre-treatment phase (A) of the neutralising agent by producing grains of a diameter not greater than 1 mm, with the neutralising factor in the stage (A) being calcium.