| 摘要 |
The invention relates to a Bayer process for the production of aluminium trihydrate comprising: a) a milling step (B) for the bauxite (10), b) a step of digestion (A) of said bauxite by a sodium aluminate liquor, c) a liquid/solid separation step (C and F), d) a decomposition step (D) for said supersaturated aluminate liquor e) after separation of the precipitated aluminium trihydrate (30), a step of concentration (E) by evaporation of said sodium aluminate liquor for recycling as digestion liquor, said process being characterised in that a calcium based compound (11, 111, 11', 111'), belonging to the group of tricalcinated aluminates, is introduced into said sodium aluminate liquor. The introduction of said calcium compound into the aluminate liquor is carried out between the exit thereof from the decomposition chain and the mixing thereof with the milled bauxite upstream of a heat exchanger. |
