| 摘要 |
The present invention relates to a process for the production of aluminum-containing iron oxide crystallization nuclei having an alpha-FeOOH crystal structure with an aspect ratio of 2100 to 3100 by using FeCl2, comprising the steps of a) initially adding an Al component, while stirring, in amounts of 6 to 20 mole % based on total Fe, to an iron II chloride solution with a total Fe content of 20-100 g/l, and a Fe III content of 0.1-10 mole % Fe III (based on total Fe), b) heating this mixture to a precipitation temperature between 30° C. and 60° C., c) adding a precipitating agent with an active constituent content of 2-10 equivalents per liter, preferably 4-8 equivalents per liter, to the mixture, and the molar ratio Fe+Al to precipitating agent is 20%-80% of the stoichiometric amount, d) then oxidizing the precipitated suspension with an oxidizing agent at an oxidation rate of 2-50 mole %/hr. of the iron to be oxidized and the subsequent production of iron oxide red pigments via alpha-FeOOH as intermediate.
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