Titaniferous ore beneficiation
This invention relates to a process for beneficiating a titaniferous ore. The process comprises calcining the titaniferous ore, at least one alkali or alkaline earth metal salt, and at least one alumina-containing material in the presence of oxygen to form a calcined ore mixture, then leaching the calcined ore mixture with a solution comprising ammonium, sodium or magnesium chloride in the presence of oxygen to form a leached ore mixture, and contacting the leached ore with an acid to form a beneficiated ore.
1. A process for beneficiating a titaniferous ore comprising:
(a) calcining the titaniferous ore, at least one alkali or alkaline earth metal salt, and at least one alumina-containing material in the presence of oxygen to form a calcined ore mixture;
(b) leaching the calcined ore mixture with a solution comprising ammonium, sodium or magnesium chloride in the presence of oxygen to form a leached ore and a first liquid phase; and
(c) contacting the leached ore with an acid to form a beneficiated ore and a second liquid phase.
2. The process of claim 1 wherein the calcining is performed at a temperature from 800° C. to 1000° C.
3. The process of claim 1 wherein the titaniferous ore comprises an ore selected from the group consisting of ilmenite, anatase, ilmenite beach sands, low-grade titaniferous slag, natural rutile, perovskite, and mixtures thereof.
4. The process of claim 1 wherein the alkali or alkaline earth metal salt is selected from the group consisting of bicarbonates, carbonates, hydroxides, and sulfates.
5. The process of claim 1 wherein the alkali or alkaline earth metal salt is selected from the group consisting of NaHCO 3 , KHCO 3 , LiHCO 3 , NaHSO 4 , KHSO 4 , Na 2 CO 3 , K 2 CO 3 , Li 2 CO3, LiOH, NaOH, and KOH.
6. The process of claim 1 wherein the alkali or alkaline earth metal salt is sodium or potassium bicarbonate.
7. The process of claim 1 wherein the alumina-containing material is selected from the group consisting of alumina, aluminum hydroxide, alumina-containing clay, alkali metal aluminates, and mixtures thereof.
8. The process of claim 1 wherein the calcined ore mixture is washed with water prior to leaching step (b).
9. The process of claim 1 wherein the leaching is performed using a solution comprising ammonium chloride.
10. The process of claim 1 wherein the leaching of the calcined ore mixture occurs at a temperature of at least 35° C.
11. The process of claim 1 wherein the solution further comprises 0.5 to 2 wt. % of an oxygen-containing compound selected from the group consisting of methanol, ethanol, acetone, glycol, glycerol, sucrose, glucose, fructose, glyoxal, acetaldehyde, and formaldehyde.
12. The process of claim 11 wherein the oxygen-containing compound is selected from the group consisting of methanol and acetone.
13. The process of claim 1 wherein the solution has a pH in the range of from 3.5 to 4.5.
14. The process of claim 1 wherein air is bubbled through the solution during the leaching step.
15. The process of claim 1 wherein the acid is selected from the group consisting of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, and formic acid.
16. The process of claim 1 wherein the acid is hydrochloric acid.
17. The process of claim 1 wherein the first and second liquid phases are contacted with carbon dioxide gas to recover dissolved aluminum and alkali or alkaline earth metal ions.
18. The process of claim 1 further comprising washing the beneficiated ore with water.