Abstract: 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.

Abstract: 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 the following steps: a1) a suspension, produced from the milled bauxite ore and the concentrated aluminate liquor is fed to a plant containing a series of n autoclaves and a series of m regulators supplying m tubular reheaters across m autoclaves with steam; a2) the suspension first travels across the series of autoclaves, and on exiting the last autoclave A, the digestion of the ore is practically complete and a3) the suspension then travels across the series of regulators, the condensation water from the steam V coming from the regulator D and feeding the reheater R is collected in a purge pot P. In at least one position in 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.