Zinc nitrate hydrate

Add an appropriate amount of water to the reaction kettle, add 60 kg (96% to 99%) of zinc oxide powder under stirring, and adjust into a slurry. Continue to stir and add concentrated nitric acid dropwise at room temperature. When the concentration of the reaction solution is 30-40 °Bé and the pH is 5-6, the reaction is over. Leave it to stand for about 4 hours, take the clear liquid and add nitric acid to adjust the pH to 1 to 2. The material liquid is pumped into the evaporator, concentrated to 60 °Bé, cooled, crystallized and centrifuged for dehydration, and directly put into an iron drum lined with plastic at a temperature below 50 °C to obtain the finished product. Add a certain amount of water to the reactor, add industrial concentrated nitric acid while stirring, and add zinc oxide (content ≥ 70%) at the same time, the ratio of the two ingredients is 1.6:1. Stop the reaction when the pH value of the reaction solution reaches 3.5-4.0, let it stand for 24 hours, pump the clear solution into a refined water tank, and dilute to 30-36 °Bé with water. Adjust the pH to 3 with nitric acid. Put in an appropriate amount of zinc powder and stir for a few minutes to replace the Ca2+ and Pb2+ ions in the solution and make them precipitate Ca and Pb. After the reaction material is clarified, a clear liquid is obtained by suction filtration. Add nitric acid to adjust the pH to 1-2. It is sent to the evaporator and evaporated to 60～63 °Bé under reduced pressure. Cool and crystallize in a crystallization tank, and then pack the finished product.

This product is used to galvanize mechanical parts and make it into steel phosphating agent. It can also be used as mordant in fabric dyeing.