Patent ID: 9428402
Filing Date: 2016-08-30
CPC Classification: B82Y,C01G,C01P,C09C,Y10T

Claim Text:
1. A process for the production of finely divided haematit having a particle size of less than or equal to 100 nm and a specific BET surface area of 40 m 2 /g to 150 m 2 /g, measured in accordance with DIN 66131, the process comprising: a) adding dilute nitric acid to a mixture of metallic iron and water at a temperature of 60 to 120° C. to produce a reaction mixture, wherein the dilute nitric acid is added at a rate sufficient to raise the temperature of the reaction mixture to a temperature of 105 to 160° C., producing an aqueous suspension of finely divided haematite, and b) separating the aqueous suspension of finely divided haematite from any unreacted, metallic iron.