Institute of Industrial Science (IIS) and Okabe Lab.

Size: px
Start display at page:

Download "Institute of Industrial Science (IIS) and Okabe Lab."

Transcription

1 Institute of Industrial Science (IIS) and Okabe Lab. Ryosuke Matsuoka Graduate School of Engineering, The University of Tokyo 1

2 Institute of Industrial Science (IIS) 2

3 About IIS Largest institute of national university s institute. Professors: about 100 Staffs: about 300 Graduate students: about Labs in this Building 8 F Okabe Lab. 50 m 250 m 3

4 Okabe Lab. (Resource Recovery and Materials Process Engineering Laboratory) Future Materials: Titanium and Rare Metals 4

5 Main Titanium Ti Sub 5

6 Okabe Lab. (Resource Recovery and Materials Process Engineering Laboratory) Research works 1. New Ti production process 2. Nb and Ta production process 3. Recycle process 4. Recovery process from wastes okabe.iis.u-tokyo.ac..ac.jp/

7 Iron Removal from Titanium Ore using Selective Chlorination and Effective Utilization of Chloride Wastes Ryosuke Matsuoka 1 and Toru H. Okabe 2 1 Graduate School of Engineering, The University of Tokyo 2 International Research Center for Sustainable Materials, Institute of Industrial Science, The University of Tokyo 7

8 Titanium? Feature of Titanium 1. Light and high-strength 2. Corrosion resistance 3. Biocompatibility 4. Some titanium alloy shape memory alloy super elasticity Japan Aerospace Exploration Agency The JAPAN TITANIUM SOCIETY 8

9 The Kroll process Kroll process : Ti production process Chlorination of Ti ore TiO 2 (+ FeO x ) + C + 2 Cl 2 TiCl 4 (+ FeCl x ) +CO 2 Reduction of TiCl 4 using Mg TiCl Mg Ti + 2 MgCl 2 Electrolysis Electrolysis of MgCl 2 MgCl 2 Mg + Cl 2 Mg & TiCl 4 feed port Mg & MgCl 2 recovery port Metallic reaction vessel MgCl 2 recovery port Sponge titanium Ti / Mg / MgCl 2 mixture Furnace Fig. Reactor for reducing titanium by the Kroll process. 9

10 Upgrading Ti ore for minimizing chloride wastes Others Upgrade FeO x Others FeO x TiO x TiO x Chloride wastes Ti ore (eg. Ilmenite) Up-graded Ilmenite (UGI) Discarded 1. A large amount of chloride wastes (e.g., FeCl x ) are produced in the Kroll process. 2. Chloride waste treatment is costly, and it causes chlorine loss in the Kroll process. Importance 1. Reduction of disposal cost of chloride wastes 2. Minimizing chlorine loss in the Kroll process 3. Improvement of environmental burden 4. Reduction of raw material cost 10

11 Refining process using FeCl x This study 1: Low-grade Ti ore (FeTiO X ) MCl x Selective chlorination (Cl 2 ) 2: FeCl x Ti scrap Chlorine recovery Upgraded Ti ore (TiO 2 ) FeCl x (+AlCl 3 ) Fe TiCl 4 Reduction process Ti Advantages: 1. Utilizing chloride wastes from the Kroll process 2. Low cost Ti chlorination 3. Using low-grade Ti ore in the Kroll process Effective utilization of chloride wastes Development of a new environmentally sound chloride metallurgy 11

12 1. Selective chlorination This study 1: Low-grade Ti ore (FeTiO X ) MCl x Selective chlorination (Cl 2 ) 2: FeCl x Ti scrap Chlorine recovery Upgraded Ti ore (TiO 2 ) FeCl x (+AlCl 3 ) Fe TiCl 4 Reduction process Ti 12

13 Thermodynamic analysis (FeO x chlorination) Ti ore : mixture of TiO x and FeO x. Fe-Cl-O system, T = 1100 K Oxygen partial pressure, log p O2 (atm) Fe 2 O 3 (s) Fe 3 O 4 (s) FeO (s) Fe (s) CaO / CaCl 2 eq. H 2 O / HCl eq. FeCl 2 (l) FeCl 3 (g) MgO / MgCl 2 eq. Chlorine partial pressure, log p Cl2 (atm) CO (g) / CO 2 (g) eq. C (s) / CO (g) eq. Fig. Chemical potential diagram of the Fe-Cl-O system at 1100 K. FeO x is chlorinated using MgCl 2 or CaCl 2 + H 2 O, and high-purity FeCl x can be obtained by controlling deposition temperature. 13

14 Thermodynamic analysis (TiO x chlorination) Ti ore : mixture of TiO x and FeO x. Ti-Cl-O system, T = 1100 K 0 Fe / FeCl 2 eq. Oxygen partial pressure, log p O2 (atm) TiO 2 (s) Ti 3 O 5 (s) Ti 2 O 3 (s) TiO (s) Ti (s) CaO / CaCl 2 eq. Ti 4 O 7 (s) TiCl 3 (s) TiCl 4 (g) MgO / MgCl 2 eq. Chlorine partial pressure, log p Cl2 (atm) CO (g) / CO 2 (g) eq. C (s) / CO (g) eq. Fig. Chemical potential diagram of the Ti-Cl-O system at 1100 K. TiO x is not chlorinated using CaCl 2, MgCl 2, nor CaCl 2 + H 2 O. 14

15 Thermodynamic analysis (Ti ore chlorination) Ti ore : mixture of TiO x and FeO x. Fe-Cl-O and Ti-Cl-O system, T = 1100 K Oxygen partial pressure, log p O2 (atm) CaO / CaCl 2 eq. H 2 O / HCl eq MgO / MgCl 2 eq. Chlorine partial pressure, log p Cl2 (atm) Selective-chlorination potential (TiO x,fecl x are satable) CO (g) / CO 2 (g) eq. C (s) / CO (g) eq. Ti chlorination potential TiCl 4 (g) TiCl 3 (g) Fig. Combined chemical potential diagram of the Fe-Cl-O and Ti-Cl-O system at 1100 K. The selective-chlorination of Ti ore using MgCl 2 or CaCl 2 + H 2 O can proceed. 15

16 Selective chlorination experiment FeO x (s) + MgCl 2 (l)= FeCl x (l) + MgO (s) FeO x (s) + CaCl 2 (l) = FeCl x (l) + CaO (s) Chloride Condenser Vacuum pump (Deposit obtained after exp.) Stainless steel susceptor Graphite crucible Chlorination Reactor (Residue obtained after exp.) Mixture of Ti ore and MCl x RF coil N 2 gas or N 2 + H 2 O gas Fig. Experimental apparatus for selective-chlorination of titanium ore. Experimental condition Quartz tube Ceramic tube T = 1100 K, t = 1 h, Atmosphere : N 2, UGI : 4 g, MgCl 2 : 2 g T = 1100 K, t = 6 h, Atmosphere : Ar + H 2 O, Low-grade ore : 3 g, CaCl 2 : 2 g 16

17 Results (chlorine source: MgCl 2 ) FeO x (s) + MgCl 2 (l) = FeCl 2 (l, g) + MgO (s) XRD analysis Deposit obtained after selective-chlorination. FeCl 2 was generated. Intensity, I (a. u.) : FeCl 2 (JCPDS # ) Angle, 2θ (deg.) Fig. XRD pattern of the deposit in the cooling zone. The sample powder was sealed in Kapton film before analysis. XRF analysis Residue after selective-chlorination. Fe was selective chlorinated. Table Analytical results of titanium ore, the residue after selective chlorination, and the sample after reduction. These values are determined by XRF analysis. Ti Concentration of element i, C i (mass%) Fe Si Al V Ti ore (UGI) After heating residue

18 Results (chlorine source: CaCl 2 +H 2 O) H 2 O (g) + CaCl 2 (l) = 2 HCl (g) + CaO (s) FeO x (s) + HCl (g) = FeCl 2 (l, g) + H 2 O (g) XRD analysis Deposit obtained after selective-chlorination. FeCl 2 was generated. Intensity, I (a. u.) : FeCl 2 (JCPDS # ) Angle, 2θ (deg.) Fig. XRD pattern of the deposit in the cooling zone. The sample powder was sealed in Kapton film before analysis. XRF analysis Residue after selective-chlorination. Fe was selective chlorinated. Table Analytical results of titanium ore, the residue after selective chlorination, and the sample after reduction. These values are determined by XRF analysis. Ti ore (low-grade ore) Ti Concentration of element i, C i (mass%) Fe Si 2.33 Al 1.00 V 0.63 After heating residue n.d

19 2. Chlorine Recovery This study 1: Low-grade Ti ore (FeTiO X ) MCl x Selective chlorination (Cl 2 ) 2: FeCl x Ti scrap Chlorine recovery Upgraded Ti ore (TiO 2 ) FeCl x (+AlCl 3 ) Fe TiCl 4 Reduction process Ti 19

20 Chlorination of Ti Fe-Ti-Cl system at 1100 K Cl 2 (g) FeCl 3 (g) log p Cl2 (atm) FeCl 2 (l) Fe (s) B A TiCl 4 (g) TiCl 2 (s) Ti (s) log a Ti -30 FeTi (s) log a Fe -60 Fig. Chemical potential diagram of the Fe-Ti-Cl system at 1100 K. TiCl 4 can be generated by reacting Ti and FeCl x. 20

21 Thermodynamic analysis (vapor pressure) Vapor pressure, log p i (atm) Ti (s,l) Fe (s,l) TiCl 2 (s) Temperature T, in K FeCl 2 (s,l) TiCl 3 (s) FeCl 3 (s,l) TiCl 4 (l) Reciprocal temperature, 1000 T -1 / K -1 Fig. Vapor pressure of iron and titanium chlorides as a function of reciprocal temperature. The separation of chlorides and the recovery of high-purity TiCl x are possible by controlling deposition temperature. 21

22 Chlorine recovery of FeCl 2 using Ti Ti (s) + 2 FeCl 2 (s, l) = TiCl 4 (g) + 2 Fe (s) (a) Silicone rubber plug Quartz tube Sample mixture Vacuum pump Ar gas Heater (Deposits after experimant) Graphite crucible (b) 5 cm Fig. Experimental apparatus for chlorine recovery of FeCl 2 using Ti. Experimental condition T = 1100 K, t = 6 h, Atmosphere : Ar, Ti: 0.3 g, FeCl 2 : 2 g 22

23 Results (residue) Ti (s) + FeCl 2 (s, l) = TiCl x (g) + Fe (s) XRD analysis Residue after chlorination. Fe generated at heating zone. Before heating Intensity, I (a. u.) Intensity, I (a. u.) : a-ti (JCPDS # ) : FeCl 2 2H 2 O (JCPDS # ) Angle, 2θ (deg.) After heating (residue) : a-fe (JCPDS # ) : FeCl 2 2H 2 O (JCPDS # ) Angle, 2θ (deg.) Fig. XRD patterns of the sample before heating and residue at the heating zone. 23

24 Results (deposit) Ti (s) + FeCl 2 (s, l) = TiCl x (g) + Fe (s) XRD analysis Deposit on quartz tube Unreacted FeCl 2 was deposited. Intensity, I (a, u) : FeCl 2 (JCPDS # ) Angle, 2θ (deg.) Fig. XRD pattern of the deposit in the quartz tube. The sample was sealed in Kapton film before analysis. XRF analysis Table Analytical results of the samples before and after heating and the sample deposited on quartz tube and Si rubber. These values are determined by XRF analysis. Concentration of element i, C i (mass %) Ti Fe Cl Dep. on Si rubber after heating Dep. on quartz tube after heating Residue before heating Residue after heating

25 Conclusions 1. Selective chlorination of titanium ore using MgCl 2 or CaCl 2 + H 2 O was demonstrated, and Ti ore with low Fe content was produced. 2. Chlorine recovery of FeCl 2 using Ti was demonstrated, and Fe-free TiCl x was produced. Low-value material Low grade ore Chloride wastes Ti related scraps A new process by this study 1: Selective-chlorination 2: Chlorine recovery High-value material High grade ore Chlorine free waste Ti feed 25