Synthethic process of manufacturing micronised pure magnetic grade ferric oxide Fe2O3

摘要

Pure Ferric Oxide is used to produce Ferrite for electronic industries. It is also known as an important pigment in the name of Red oxide. Synthetic pure Ferric Oxide is generally manufactured by chemical reaction with iron scrap and inorganic acid like Sulfuric or Hydrochloric Acid and other processes for manufacturing Ferric Oxide are also known, but Nitric acid is not used to manufacture Ferric Oxide due to passivation problem with iron scraps. The passivation problem is responsible for very slow speed reaction with Nitric acid and iron and it ultimately stops. This invention is a process to avoid passivation problem and to create tremendously vigorous chemical reaction with Nitric acid and iron scrap. With the help of oxygen, heating process and application of small pressure, the speed of the chemical reaction suddenly become vigorous when iron turns into hydrated Ferric Oxide Fe2O3.H2O dispersion in acid-water media. Acidity of the dispersion is reduced by passing through series of similar reactors packed with iron scraps under same condition of that reactor. The resultant product is followed by mechanical purification and after that sent to spray drying roaster to get 98% pure Ferric Oxide Fe2O3 of micron size. The exit gases mainly Nitrogen Dioxide (NO2) can be sent to Nitric acid plant for reuse in the reaction or NO2 can be absorbed in suitable chemical absorbent to get its nitrate. This Ferric Oxide is magnetic grade and thus suitable for the production of Ferrite in electronic industries. This is also a pigment in the name of Red Oxide.