A method for the production of aluminum from bauxites containing aluminum
monohydate of the diaspore or boehmite type which may contain more than
1.5% by weight of calcium carbonates. The ore is digested by producing
feeding a suspension produced from milled bauxite ore and concentrated
aluminate liquor to a plant with a series of autoclaves and a series of
regulators supplying tubular reheaters across the autoclaves with steam.
The suspension first travels across the series of autoclaves, and on
exiting, the digestion of the ore is practically complete, and the
suspension then travels across the series of regulators. The condensation
water from the steam coming from the regulator and feeding the reheater
is collected in a purge pot. Within the series of regulators, the
suspension is diluted on entering a regulator with the water coming from
the condensation of the steam from one or several upstream regulators.