【提出用】

Future Materials: Titanium, Rare Metals

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OKABE LAB.
LAB.
T.T.OKABE
Future※ 研Materials:
究 室 名 のTitanium,
み 入 力 くRareだ さMetals
いResearch Center for Sustainable Material Energy Integration
Resource Recovery and Materials Process Engineering
Department of Materials Engineering, Graduate School of Engineering

http://www.okabe.iis.u-tokyo.ac.jp/

Turning rare metals into “common metals”!!

Okabe Laboratory is working on the research and development of new smelting processes and environmentally friendly recycling processes forrare metals. Our main focus is "future materials: titanium, rare metals”. We aim to innovate rare metal process technology for the betterment ofsociety.

 Upgrade recycling of Ti
About 14 wt% ofa Boeing 787 consistsof Ti.

Aerospace→High specificstrength

Ti ingot

Fabrication

 Recycling of precious metals
Automotive
catalyst
・Platinum (Pt)・Palladium (Pd)・Rhodium (Rh)Ti scrap suchas turning

Ti productScraps containing precious metals

Titanium (Ti) scrap generated in the Ti ingot fabrication process iscontaminated by oxygen impurities. Therefore, it is difficult torecycle Ti scraps into ingots.

 Deoxidation of Ti using rare earth metals

Oxygen partial pressure, log pO2 (atm)

Ti capNa2O (s)−10Ti crucible−20−30−30

Ti –100 ppm oTi –10 ppm oTi foil+Ti samples
Molten salt
(YCl3−NaCl)
Y metalYCl3 (l)−20−100

Based on thermodynamic calculations, we have developed a novel
deoxidation technology of directly removing oxygen from Ti scrap
using rare earth metals such as yttrium (Y) and cerium (Ce).

 Deoxidation of Ti via gas phase
TiTi

M (g)Ti (s)OREXa (g)M(s, l)Alloys containing
precious metals

To dissolve precious metals intosolution, the process
× requires strong chemicals
× generates a large amount ofhazardous liquid waste
× consists of multiple steps

Electro-refining
Hydrometallurgical process(Dissolution / Purification)★ Environmental-friendly
and highly efficient
process is required.

Precious metals

Chlorine partial pressure, log pCl2 (atm)Ti

Cu bullions

Ti –10000 ppm o
Ti – 1000 ppm o

−40

−60
−40

Alloying /Concentration

YOCl (s)NaCl (l)Y2O3 (s)Y (s)Pyrometallurgicalrefining

Further purification / Separation

Na (g)−50

PCBs・Gold (Au)

Automotive catalysts contain 100–1000 times more PGMs than PGM ore. PCBs
contain around 10 times more Au than Au ore.

Marine Structures→Corrosion-resistant materials
1000 t of Ti is used for the D runwayof the Haneda Airport.

0Electronics

REXa
(l)

REXa (g) + a/b M (g) →RE (on Ti) + a/b MXb
REOcXdRE = Y, La, Ce, Ho...
X = F, Cl, Br, I…
M = Sm, Eu, Tm, Yb,Li, Na, K, Ca…

We have developed a novel deoxidation technology for reducing theamount of deposits on Ti surface and impurities in Ti by supplying
deoxidants and fluxes to Ti through the gas phase.

 Solubilization process
PGMs (M)
Washcoat(Al2O3, CeO2)

Alloying

M–R, R

Vapor etc.

Oxidation orchlorination

Dissolving
separation

M–R–O, R・ Solubility

Substrate

Technology to dissolve precious metals in
non-oxidizing acids (e.g.,hydrochloric acid) and solutions (e.g., sea water) using a pretreatment ofalloying them with reactive metals such as magnesium (Mg) or calcium (Ca)followed by oxidation or chlorination.

 Physical concentration process
Alloying or plating

M–R, RPGMs (M)Washcoat(Al2O3, CeO2)

Vapor or solution

Physical separation
・ Magnetic
・ Flotation
・ Eddy current

Substrate

Technology to selectively add functions (e.g., magnetism, hydrophobicity) toareas of scrap containing precious metals by electroless plating or chemicaltreatment with chloride or sulfide vapors, allowing for the concentration of
precious metals using physical separation.