Methods of producing a titanium product
A method ( 500 ) for producing a titanium product is disclosed. The method ( 500 ) can include obtaining TiO 2 -slag ( 501 ) and reducing impurities in the TiO 2 -slag ( 502 ) to form purified TiO 2 ( 503 ). The method ( 500 ) can also include reducing the purified TiO 2 using a metallic reducing agent ( 504 ) to form a hydrogenated titanium product comprising TiH 2 ( 505 ). The hydrogenated titanium product can be dehydrogenated ( 506 ) to form a titanium product ( 508 ). The titanium product can also be optionally deoxygenated ( 507 ) to reduce oxygen content.
1. A method for producing a titanium product, comprising:
obtaining TiO 2 rich material as a purified TiO 2 having at least 70% by weight TiO 2 ;
reducing the purified TiO 2 by combining with a metallic reducing agent and a molten salt at a temperature and a pressure to produce a hydrogenated titanium powder product comprising TiH 2 and optionally elemental titanium;
heat treating the hydrogenated titanium powder product under a hydrogen atmosphere to coarsen the powder so as to reduce pore size and specific surface area to form a heat treated hydrogenated titanium powder product, wherein the hydrogen atmosphere is maintained during at least one of heating and cooling; and
deoxygenating the heat treated hydrogenated titanium powder product to reduce residual oxygen to less than 0.2 wt % to form a deoxygenated hydrogenated titanium powder product.
2. The method of claim 1 , further comprising reducing impurities in the TiO 2 rich material to produce the purified TiO 2 .
3. The method of claim 2 , wherein the TiO 2 rich material is a TiO 2 -slag having a TiO 2 content from 70 wt % to 90 wt %.
4. The method of claim 3 , wherein the UGS has a TiO 2 content greater than 90 wt %.
5. The method of claim 2 , wherein the TiO 2 rich material is upgraded TiO 2 -slag (UGS).
6. The method of claim 2 , wherein the reducing impurities includes alkaline roasting the TiO 2 rich material to remove impurities from the TiO 2 rich material and produce intermediate products including alkaline leached TiO 2 rich material.
7. The method of claim 6 , wherein alkaline roasting comprises:
combining NaOH with the TiO 2 rich material at a second temperature to transform TiO 2 into sodium titanate and to transform impurities into salts; and
washing the sodium titanate with water to remove the salts and produce derivatives of sodium titanate.
8. The method of claim 7 , wherein the second temperature is between about 450° C. and about 650° C.
9. The method of claim 7 , wherein the reducing impurities further comprises desilicating the alkaline roasted and water washed TiO 2 rich material to lower silica content prior to reducing.
10. The method of claim 9 , wherein the desilicating is accomplished using a silica gel and a flocculant.
11. The method of claim 2 , wherein the reducing impurities further comprises pre-leaching the TiO 2 rich material using an aqueous NaOH solution to remove silica.
12. The method of claim 2 , wherein the reducing impurities further comprises:
hydrolyzing the TiO 2 rich material to form a titanic acid; and
calcining the titanic acid to form a coarse purified TiO 2 as the purified TiO 2 .
13. The method of claim 12 , wherein the coarse purified TiO 2 has a specific surface area from 10 m 2 /g to 100 m 2 /g, and an average particle diameter from 1 μm to 100 μm.
14. The method of claim 1 , wherein the purified TiO 2 has greater than about 99 wt % TiO 2 .
15. The method of claim 1 , wherein the purified TiO 2 has greater than about 99.5 wt % TiO 2 .
16. The method of claim 1 , wherein the purified TiO 2 is purchased commercially.
17. The method of claim 1 , wherein the metallic reducing agent comprises at least one of Mg, MgH 2 , and CaH 2 .
18. The method of claim 1 , wherein the molten salt comprises at least one of a mono chloride, binary chloride salt and a ternary chloride salt.
19. The method of claim 1 , wherein the reducing occurs in a hydrogen atmosphere and the metallic reducing agent is Mg and MgH 2 .
20. The method of claim 1 , wherein the specific surface area of the heat treated hydrogenated titanium product is from about 0.01 m 2 /g to 0.5 m 2 /g.
21. The method of claim 1 , wherein the deoxygenating is accomplished by heating a molten calcium salt in the presence of solid calcium and the titanium product to a temperature below the melting point of calcium.
22. The method of claim 21 , wherein the molten calcium salt includes CaCl 2 and at least one of KCl and LiCl.
23. The method of claim 1 , wherein the method is free of chlorination and electrolysis.
24. The method of claim 1 , wherein the molten salt includes MgCl 2 .
25. The method of claim 1 , further comprising removing MgO from the hydrogenated titanium product prior to deoxygenating.
26. The method of claim 1 , wherein the deoxygenating is accomplished using CaH 2 .
27. The method of claim 1 , wherein the deoxygenating occurs under one or both of Argon and hydrogen atmosphere.
28. The method of claim 1 , further comprising leaching impurities including MgO from the deoxygenated hydrogenated titanium product.
29. The method of claim 1 , wherein the heat treating includes:
heating the hydrogenated titanium product where the hydrogen atmosphere is controlled to maintain a hydrogen content of the hydrogenated titanium product; or
heating the hydrogenated titanium product under an argon atmosphere and then switching to the hydrogen atmosphere during a cooling phase.