How to manufacture iron oxide?
Iron oxide, also known as iron trioxide, has a chemical formula of Fe2O3.
There are two preparation methods (wet and dry):
1. Wet method:
FeSO4+2NaOH=Fe（OH）2+Na2SO4
4Fe（OH）2+O2+2H2O=4Fe（OH）3
4FeSO4+4H2O+O2=2Fe2O3↓+4H2SO4
Fe+H2SO4=FeSO4+H2↑
A certain amount of 5% ferrous sulfate solution is rapidly reacted with excessive sodium hydroxide solution (0.04-0.08g/ml of alkali excess is required),
At normal temperature, air is introduced to make it all turn into red-brown iron hydroxide colloidal solution, which is used as the crystal nucleus for depositing iron oxide. more than
The crystal nucleus is used as a carrier, ferrous sulfate is used as a medium, air is introduced, and ferrous sulfate reacts with air at 75-85 DEG C in the presence of metallic iron.
Iron oxide (iron red) generated by the action of oxygen in gas is deposited on the crystal nucleus, and sulfate in solution reacts with metallic iron to regenerate. Ferrous sulfate, ferrous sulfate is oxidized by air into iron red and continues to be deposited, so that it is circulated to the end of the whole process to generate red oxidation Iron.
2. Dry method:
Nitric acid reacts with iron to produce ferrous nitrate, which is cooled, crystallized, dehydrated and dried. After grinding, it is calcined at 600-700 ℃ for 8-10 hours,
The iron oxide red product is prepared by washing, drying, and crushing.
4Fe（NO3）3→2Fe2O3+12NO2↑+3O2↑
Fe2O3·nH2O→Fe2O3+nH2O
Iron oxide yellow can also be used as the raw material and calcined at 600-700 ℃ to obtain iron oxide red.
