| 摘要 |
A wet caustic aluminate process that comprises digesting a bauxite at a low temperature in caustic aluminate liquor to extract the alumina trihydrate, separating the supersaturated caustic aluminate liquor of low Fe2O3 content from the mud, digesting the mud or a mixture of mud and bauxite at a higher temperature in caustic aluminate liquor to extract the majority of the remaining monohydrate and trihydrate, separating the supersaturated caustic aluminate liquor of higher Fe2O3 content from the residue, precipitating alumina hydrate from the two supersaturated caustic aluminate liquors, recyling spent caustic aluminate liquor to digestion and calcining alumina hydrate to alumina with a Fe2O3 content less than 0.03%.
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