Ferrous nitrate is an inorganic substance with the chemical formula of Fe(NO3)2, light green rhombic crystal system and flaky crystal. The melting point is 60.5℃. Soluble in water. The aqueous solution is heated to become basic ferric nitrate. It is moist and stable when it is cold. It is prepared by reducing ferric nitrate solution with silver. Iron filings can also be dissolved in dilute nitric acid with density lower than 1.05g/cm3 at low temperature, and then cooled for crystallization. Centrifugal separation. It can also be prepared by double decomposition reaction of ferrous sulfate and barium nitrate. Used for manufacturing ferric nitrate nonahydrate and other ferric salts. It is prepared by the reduction reaction of ferric nitrate solution and silver. It can also be obtained by dissolving iron filings in dilute nitric acid with the density below 65438±0.05g/cm3 at low temperature, cooling and crystallizing, and centrifugal separation. It can also be prepared by double decomposition reaction of ferrous sulfate and barium nitrate.
Patent: Waste acid from titanium dioxide production by sulfuric acid method is mixed with excess ferrous hydroxide to generate ferrous sulfate; Filtering the reaction solution to obtain filtrate mainly containing ferrous sulfate; Adding excessive barium nitrate into the filtrate mainly containing ferrous sulfate, reacting to generate ferrous nitrate and barium sulfate, filtering the reaction solution, and separating the ferrous nitrate and barium sulfate solution; The barium sulfate precipitate is washed, dried and crushed to obtain a barium sulfate product; A small amount of ferrous sulfate is added to the ferrous nitrate solution to neutralize barium nitrate, and then it is sent to an alkali pressure distiller for vacuum distillation to obtain a ferrous nitrate supersaturated solution, which is cooled, crystallized and dried to obtain a ferrous nitrate product.