Preparation of nano-crystalline magnetic ferric oxide powder comprises adjusting the pH of a solution mixture by adding an alkaline solution, heating the mixture and separating the magnetic particles from the mixture by centrifugation

摘要

Preparation of nano-crystalline magnetic ferric oxide powder with an average particle size of 15 nm from an aqueous solution by cyclic precipitation comprises adjusting the pH value of a solution mixture containing ferric and ferrous salts (in a molar ratio of 1-2 and with total concentration of 0.4-1.3 mol/l) to 6.5-7 by adding an alkaline solution; again adding the ferric and ferrous salt to the precipitated mixture; heating the mixture for 5-30 minutes to terminate the reaction and separating the magnetic particles by centrifugation process.