US 6,248,302 B1 · Process for treating red mud to recover metal values therefrom

Abstract

A method for processing red mud to recover iron, aluminum, silicon and titanium metal values therefrom the method comprising the steps of adding the red mud to a digester containing an acid to provide a mixture of acid and red mud and heating the mixture to dissolve soluble compounds of at least one of iron, aluminum, silicon and titanium to provide a digest containing dissolved salts of the soluble compounds and to provide a gas component. Thereafter, the digest is treated with water to dissolve water soluble salts therein to provide a slurry comprised of a liquid containing water and the dissolved soluble salts and a solid component comprised of silica. The solid component is separated from the liquid and the pH of the liquid is adjusted to form an aluminate and an iron-containing precipitate. The iron-containing precipitate is separated from the liquid to provide an iron-depleted liquid whose pH is adjusted to precipitate aluminum trihydrate which is separated from the iron-depleted liquid to provide an aluminum trihydrate-depleted liquid. The pH of the aluminum trihydrate-depleted liquid is adjusted to form a precipitate comprised of at least one remaining salt in the aluminum trihydrate-depleted liquid to provide a salt-depleted liquid. The salt precipitate is separated from the salt-depleted liquid thereby recovering the metal values from the red mud.

Claims22

Dependent claims

A method for processing red mud to recover iron, aluminum, silicon and titanium metal values therefrom, the method comprising the steps of:

(a) adding said red mud to a digester containing an acid to provide a mixture of acid and red mud;
(b) heating said mixture to dissolve soluble compounds of at least one of iron, aluminum and titanium to provide a digest containing dissolved salts of said soluble compounds and to provide a gas component;
(c) treating said digest with water to dissolve water soluble salts therein to provide a slurry comprised of a liquid containing water and said dissolved soluble salts and a solid component comprised of silica;
(d) separating said solid component from said liquid;
(e) adjusting the pH of said liquid upwardly to form an iron-containing precipitate;
(f) separating said iron-containing precipitate from said liquid to provide an iron-depleted liquid;
(g) adjusting the pH of said iron-depleted liquid to precipitate aluminum trihydrate;
and
(h) separating said aluminum trihydrate from said iron-depleted liquid to provide an aluminum trihydrate-depleted liquid.

6 more elements

Dependencies are inferred from the claim text.

Process for treating red mud to recover metal values therefrom

Life of this patent

Process for treating red mud to recover metal values therefrom

Life of this patent

Abstract

Claims22