Verfahren und System zur Herstellung von Aluminiumoxid aus Bauxiterz

Details

Veröffentlichungs-Nr.

EP3656881

Aktenzeichen

EP18208387

Anmeldetag

26. November 2018

Veröffentlichung

14. Juni 2023

Erteilung

14. Juni 2023

Rechtsraum

EP

IPC

C22B21/00C01F7/14

Abstract

The invention provides a process for producing alumina from bauxite ore in a continuous steady-state manner comprising (a) preparing a bauxite slurry by mixing the bauxite ore with at least a part of an Al-depleted liquid fraction (S100), (b) separating the bauxite slurry into at least a first bauxite slurry portion and a second bauxite slurry portion (S200); (c) mixing the first bauxite slurry portion with an alkaline substance to obtain a first bauxite alkaline mixture (S300); (d) holding the bauxite alkaline mixture within a first temperature range for a first period of time such as to obtain a first reaction product comprising a first solid fraction and a first liquid fraction (S400); (e) separating the first solid fraction from the first liquid fraction (S500), (f) mixing the first liquid fraction with the second bauxite slurry portion such as to obtain a second bauxite alkaline mixture (S600), (g) holding the second bauxite alkaline mixture within a second temperature range for a second period of time and above ambient pressure, such as to obtain a second reaction product comprising a second solid fraction and a second liquid fraction (S700); (h) separating the second solid fraction from the second liquid fraction prior to reducing the pressure of at least the second liquid fraction to ambient pressure (S800); (i) reducing the pressure of the second liquid fraction, and optionally additionally the pressure of the second solid fraction, to ambient pressure (S900); (j) precipitating Al-compounds from the second liquid fraction after reducing the pressure thereof such as to obtain solid Al-compounds and an Al-depleted liquid fraction (S1000); (k) drying the solid Al-compounds such as to obtain alumina (S1100), wherein the first temperature range is lower than the second temperature range, and wherein the first period of time period is shorter than the second period of time.

Anmelder

Firmen

Alunorte -Alumina do Norte do Brasil S.A.
Norsk Hydro ASA

Land

🇧🇷 Brasilien

Fachgebiete