| 摘要 |
Impure Na oxalate (I), accruing in a pptn. stage in the decomposition of bauxite by the Bayer process, is worked up by drying the pptd. moist (I) together with Al(OH)3 and/or reactive Al2O3, with an Al:Na molar ratio of at least 0.8, with the hot waste gases from a fluidised bed and decomposing the dry prod. in a fluidised bed at 780-1000 deg.C, to form Na aluminate (II). - The dry prod. is decomposed in a circulating fluidised bed, pref. at 850-950 deg.C and an average suspension density of 20-150 kg/cu.m. Drying is carried out by direct contact with the waste gases, pref. by spray drying. The Al:Na molar ratio is max. 1.2.
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