公开(公告)号：US3615810A

公开(公告)日：1971-10-26

申请号：US3615810D

申请日：1969-06-13

Applicant: BAYER AG

Inventor： HOLZNAGEL WILHELM ,  HUND FRANZ ,  GERLACH GOTTFRIED

IPC: C09C1/24

CPC classification number: C09C1/24 ,  C01P2006/37

Abstract: Process for the production of a temperature-stable solid black pigment of high tinting strength consisting essentially of mixed oxides of iron and manganese, by calcining an intimate finely divided mixture of oxidic or oxide-forming starting materials of iron and manganese, e.g., Fe3O4, Fe(OH)3, FeOOH and active Fe2O3 and MnCO3, Mn2O3, MnOOH and pyrolusite (i.e., MnO2), in a ratio by weight corresponding to 25-90 parts of Mn2O3 to 75-10 parts of Fe2O3, at a temperature of about 800*-920* C. in an atmosphere having an oxygen content of about 7-20 percent by volume, optionally in the presence of an alkali metal salt, e.g., NaC1, or boron oxide, as mineralizer; and the corresponding pigment thereby produced.