| 摘要 |
PURPOSE:To manufacture high-purity metallic Cr minimal in oxygen content, by forming a Cr2O3 powder into a green compact together with a carbonaceneous reducing agent by means of a binder material and by subjecting the above compact to vacuum reduction in a high-temp. vacuum furnace and successively to gaseous reduction under reduced pressure in a reducing-gas atmosphere. CONSTITUTION:A powder of a high-purity carbonaceneous reducing agent such as carbon black, artificial graphite, petroleum, coke, etc., is mixed, as a reducing agent, with powdery Cr2O3 of <= about 32 mesh by the stoichiometric amount necessary for the reduction of Cr2O3, 50-120%. And organic high polymer substance such as synthetic resin, starch, dextrin, etc., is added, as a binder material, to the above powder mixture by 1-20% based on the total amount of Cr2O3 and reducing agent, and the resulting mixture is compacted. This green compact is charged into an atmospheric heat-treatment furnace, where the compact is heated up to >=1,200 deg.C and subjected to carbon reduction in a vacuum atmosphere of 0.05-50mmHg and then to gaseous reduction under reduced pressure in a reducing-gas atmosphere of H2, etc., of 1-100mmHg pressure. In this way, high-purity metallic Cr minimal in respective content of O2, N2, H2, S, etc., can be obtained.
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