A production method of basic zinc carbonate, comprising the following steps:
(1) secondary zinc oxide is added in the sulfuric acid solution, and the stirring reaction produces the zinc sulfate solution;
The chemical equation for the reaction between zinc oxide and sulfuric acid is:
ZnO+HSO=ZnSO+HO
During this reaction process, some by-products are generated, and the chemical equation of the reaction is:
PbO+HSO=PbSO↓+HO (PbSO is precipitated in the form of precipitation)
FeO+HSO=FeSO+HO
CuO+HSO=CuSO+HO
CdO+HSO=CdSO+HO
MnO+HSO=MnSO+HO
(2) adding potassium permanganate and zinc powder to the zinc sulfate solution for impurity removal, obtaining impurity removal zinc sulfate solution;
The addition of potassium permanganate can remove divalent iron ions and divalent manganese ions in the reaction solution, that is, remove FeSO and MnSO in the reaction solution. The reaction equation is:
2HO+3MnSO+2KMnO=KSO+5MnO↓+2HSO
14HO+6FeSO+2KMnO=KSO+6Fe(OH)↓+5HSO+2MnO↓
MnSO reacts with potassium permanganate to form manganese dioxide precipitate, which removes manganese ions; FeSO reacts with potassium permanganate to form iron hydroxide precipitate, which removes iron ions;
(3) Add sodium carbonate aqueous solution to the impurity-removing zinc sulfate solution, and stir the reaction until the pH of the solution is 6.5-7.5 at a temperature of 50-55° C., and then continue at a temperature of 45-65° C. Stir the reaction for 0.5-1h;
The chemical equation for the reaction of zinc sulfate and sodium carbonate is:
3ZnSO+3NaCO+3HO=ZnCO·2Zn(OH)·HO+3NaSO+2CO↑
When the pH of the solution reaches 6.5-7.5, then continue to stir and react for 0.5-1h at a temperature of 45-65°C, so that zinc sulfate and sodium carbonate can be fully mixed for reaction;
(4) Filter the reaction solution, wash the filter cake with purified water until the filtrate does not contain sulfate ions, dry the filter cake and pulverize to obtain basic zinc carbonate. Because basic zinc carbonate is insoluble in water, washing the filter cake with water can remove impurities soluble in water, that is, remove sulfate radicals.