高純度金属バナジウムの新製造法の開発
Development of New Production Process of High Purity Vanadium Metal
1Department
Akihiko
Resources and production
Confirmed reserve
Vanadium?
ⅢB
ⅣB
ⅤB
ⅥB
ⅦB
ⅧB
ⅠA
ⅡA
ⅢA
ⅣA
ⅤA
ⅥA
ⅦA
Hydrogen
H
2
Lithium
3
Li
Sodium
11
Beryllium
Be
4
K
20
Rb 38 Sr
Caesium
13
Scandium Titanium
Ca 21 Sc
Rubidium Strontium
Barium
Yttrium
39
Y
Lutetium
Cs 56 Ba 71 Lu
Francium
87
22
Vanadium Chromium Manganese
Ti
23
Zirconium
40
24
103
Lr
104
Iron
Cobalt
Nickel
Copper
B
Zr
Zinc
Tantalum
Hf 73 Ta
Tungsten
74
C
6
7
Silicon
Al
14
N
Oxygen
Si
P
15
O
8
Phosphorus
Gallium Germanium Arsenic
Silver
Cadmium
Nb 42 Mo 43 Tc 44 Ru 45 Rh 46 Pd 47 Ag 48 Cd
41
Nitrogen
Sulfur
16
S
Selenium
Fluorine
9
F
Neon
10
Chlorine
17
W
Rhenium
75
Osmium
Iridium
Re 76 Os
77
Ir
Platinum
78
Gold
Pt
79
Mercury
Indium
49
In
Tin
50
Thallium
Au 80 Hg
81
Tl
Antimony
Sn 51 Sb 52 Te
Lead
82
Tellurium
Bismuth
Pb
83
Bi
Polonium
Cl
18
Bromine
84
I
Ne
Ar
36
Kr
106
107
54
Astatine
> 105
105 ～ 104
104 ～ 103
103 ～ 102
102 ～ 101
108
(Fe-V-Al (l))
U.S.A
12.4 %
Element
20.1 %
15.2 %
V metal
Amount of production
Price
(103 ton / year)
($ ・ kg-1)
Element
V
Fe
Al
Cu
Ni
Zn
・ Average abundance of vanadium in the earth’s crust;
120ppm. (cf. Common (or base) metals such as
Ni: 84ppm, Cu: 60ppm, Zn: 70ppm, Pb: 14ppm).
Experimental
58
1,100,000
29,000
15,000
1,600
11,000
Others
1.1 %
Catalyst
12.9 %
Binder
It is important to develop
a new production process
of pure vanadium metal
and vanadium alloy.
Total
Steel
3
6.42×10 t
86.0%
(pure V)
Preform reduction process (PRP)
Mixing / casting
Feed preform
Tcal. = 873 K
→ 1173 K
tcal. = 2 hr
Calcination
Ca
-15
V
-25
1173 K
Leaching and rinsing
Liquid
Solid
Waste
solution
Vacuum drying
V metal powder
900
1000
m.p.(V2O5)
963 K
Standard Gibbs energy of formation, DGﾟf / kJ mol-1
Reduced preform
1100
Temperature, T / K
1273 K
1200
Casting
1300
Reaction
temperature
0
1173 K
-200
1273 K
Stainless steel
reaction vessel
-400
Feed preform
(V2O5, Flux)
-600
CaO
Appearance
JCPDS # 77-2010
Ca2V2O7 JCPDS # 72-2312
MgO
JCPDS # 77-2364
Mg2V2O7 JCPDS # 70-1163
Stainless steel holder
70
Reductant (Ca, Mg)
calcination. The obtained feed preform has a mechanical
-1200
Ti sponge getter
strength at elevated temperature and suitable for
handling during processing.
1100
1000
Temperature, T / K
900
1200
1300
Current status
Weight change of the samples
Table
Ex. #
X-ray fluorescence spectrometry
Experimental condition and mass of samples after each step.
Reductant
Flux
Table
Mass of preform, Mass of reductant, Mass of sample Mass of sample Mass of sample
wpre / g
wR / g
after calcination, after reduction, after leaching,
V2O5 + 3CaO
Ca
w1 / g
w2 / g
w3 / g
V2O5 + 3MgO
Mg
Analytical results of vanadium powder obtained by PRP.
Composition of sample (mass%)
Ex. # Reductant
Fe
Cr
3.976
3.474
3.642
1.805
ex.1
Ca
CaO
79.0
20.4
－
0.1
0.4
ex.2
Ca
MgO
4.226
4.906
3.670
3.955
0.981
ex.2
Ca
MgO
85.4
13.0
－
0.3
0.5
ex.3
Mg
CaO
4.478
2.573
3.604
4.435
1.071
ex.3
Mg
CaO
86.0
2.4
10.6
0.2
0.5
ex.4
Mg
MgO
4.158
3.345
3.937
5.086
0.729
ex.4
Mg
MgO
99.7
－
0.2
0.01
0.03
ex.1 Flux : CaO, Reductant : Ca
ex.4 Flux : MgO, Reductant : Mg
(1) After calcination
(1) After calcination
Intensity, I (a.u.)
CaV2O4
V
CaO
MgO
Ca2V2O7
Mg2V2O7
(2) After reduction
(2) After reduction
40
60
Angle, 2θ (degree)
80
・Temperature :1273 K, Time : 6 hr
・When using Mg vapor as a reductant, pure
vanadium metal was obtained. The purity of the
obtained vanadium powder was 99.7 mass%.
・When using Ca vapor as a reductant, Ca2V2O7 in
thepreform was reduced to CaV2O4 after reduction.
At this stage, vanadium metal was not obtained.
The feasibility of the preform reduction
process (PRP), based on the thermal
reduction of V2O5, was demonstrated.
・ Complex oxide containing V2O5 was
synthesized by the calcination process in
order to increase the mechanical strength of
feed preform.
・ Vanadium powder with 99.7 mass% purity
was obtained by magnesiothermic reduction
of feed preform.
Future work
・ Investigation of residual oxygen concentration,
and evaluation of total vanadium yield.
・ Development of production process of Ti-V
alloys.
(3) After leaching
(3) After leaching
20
by XRF ; value excludes carbon and gaseous elements.
Condition for reduction
・ Calcined sample maintained its shape form.
→ This can be used as a feed preform for
reduction experiment.
Mg
4.537
The calcination temperature was raised from 873 K
synthesized after calcination.
Ca
CaO
Condition for calcination
・ Complex oxides (Ca2V2O7 or Mg2V2O7) was
V
Ca
Angle, 2θ (degree)
to 1173 K during 2 hr of calcination period.
Flux
ex.1
80
synthesize complex oxides (CaxVyOz, MgxVyOz) during
-1000
X-ray diffraction pattern
60
The melting point of vanadium pentoxide (V2O5) is
low (963 K), and it is difficult to fabricate mechanically
strong solid preform. Reduction has to be carried out
at temperature higher than 1173 K to maintain
enough vapor pressure of Ca or Mg.
CaO or MgO was added to feed preform in order to
-800
aDetermined
50
PRP is simple and low-cost process
for high purity products.
Problem
TIG welding
Reduction process
X-ray diffraction pattern
40
Reduction
by reductant vapor
Stainless steel cover
-1400
800
Calcination process
30
Forming
Ellingham diagram of oxides
Results
20
Preform
Ti
-20
Features
◎ Suitable for uniform reduction
◎ Flexible scalability
○ Possible to control the morphology of the powder
by varying the flux content in the preform
○ Possible to prevent the contamination from the
reaction container and to control the purity
○ Amount of waste solution is minimized.
○ Molten salt as a flux can be reduced in comparison
with the other direct reduction process.
× Difficult to produce reductant and to control its vapor
Fe
Sintered preform
Reduction
MxOy＋ Flux ＋ Binder
-10
-30
800
Tred. = 1273 K
tred. = 6 hr
V2O5 + 5 R → 2 V + 5 ROx
Mg
-5
Development of simple and
low-cost process for high purity
vanadium metal or alloys
(Ref. Matsushita Electric Industrial Co., Ltd)
-4
Vapor pressure log p° (atm)
V2O5
Aim of this study
Vapor pressure of metals
0
◎ Simple and economic process
○ First batch type process with rich scalability
× Difficult to control the purity
× Repeated removal of Al by the electron
beam melting for some applications
Vanadium has high hydrogen storage ability. Ti-V alloy
draws attention as a negative electrode material of nickel
hydride battery, and has a potential to be used for
lower-cost and higher-capacity battery.
Thermodynamic analysis
Flowchart of our process
Electron
beam melting
Features
Ti-V hydrogen storing alloy
Vanadium production
in Japan
39
0.06
3
7
40
3
(Fe－V－Al (l))
Fe－V alloy
15 ～ 25 mass% Al
(Ref. Iron and Steel Institute of Japan)
Total
3 South
40.1 % 36.6×10 t
(pure V) Africa
30.5 %
Australia
14.2 %
Table Amount of production and price of
some metal elements in 2007.
V－Al (l)
Alloying
process
V metal
Other
43.9 %
elements .
Reductant
(Ca, Mg)
China
Total
46.0×103 t
Russia
(pure V)
14.9 %
South Africa
・ The 20th largest crustal abundances among the all
Flux
China
Slag
V2O5 (s)
+ Al (s)
( + Fe (s))
Fe-V production
Other
6.7 %
Japan
2.0 %
・ Low density(6.11 g/cm3) and high melting point (2188 K).
Intensity, I (a.u.)
39.1 %
V2O5 production
109
Feature of vanadium
20 % HCl aq.,
Distilled water,
Isopropanol,
Acetone
23.0 %
→ 6 V (in Al (l)) + 5 Al2O3 (s)
High thermal stability and tensile strength
Po 85 At 86 Rn
Hg, Ag, Pd, Se
Pt, Au, Rh,・・・
50 %
CH3COOH aq.,
South Africa
3 V2O5 (s) + 10 Al (s) (+ Fe (s))
Hassium Meitnerium
・
・
・
10-1 ～ 10-2
10-2 ～ 10-3
Total 31.1 %
56.3×103 t
(pure V)
South Africa
Xe
O, Si
Al, Fe, Ca, Na, K, Mg
Ti, H, P
V, Mn, S, C, Cl,・・・
Cu, Ni, Zn, Nb, Co, Pb,・・・
・
・
・
26.8 %
Radon
Table Abundance of elements in the earth’s crust.
Crustal abundance (ppm)
Total
38.3 %
6
13.0×10 t
(pure V)
Aluminothermic process
In the primary use, vanadium is consumed as an alloy
element of steel.
China
Russia
Xenon
Rf Db Sg Bh Hs Mt
105
China
Krypton
Iodine
53
38.3 %
Argon
Cr 25 Mn 26 Fe 27 Co 28 Ni 29 Cu 30 Zn 31 Ga 32 Ge 33 As 34 Se 35 Br
Niobium MolybdnumTechnetium Ruthenium Rhodium Palladium
Hafnium
72
V
Radium Lawrencium
RutherfordiumDubnium Seaborgium Bohrium
Fr 88 Ra
Carbon
Aluminium
Na 12Mg
19
55
5
Magnesium
Potassium Calcium
37
Boron
Russia
He
Intensity, I (a.u.)
1
Helium
Special steel
Other
3.0 %
ⅧA
Commercial production process
Application
Ores production
Other
0.4 %
The periodic table of the elements
ⅡA
Toru H.
2
Okabe
of Materials Engineering, Graduate School of Engineering, The University of Tokyo;
2Institute of Industrial Science, The University of Tokyo.
Introduction
ⅠA
1
Miyauchi ,
20
40
60
Angle, 2θ (degree)
80
The reason for incomplete reduction when using
・ Analysis of reduction mechanism by utilizing
Ca vapor is not well understood. The difference of
the results between Mg and Ca reductant is partially
the chemical potential diagram for the system
due to the difference of their vapor pressure. The
involving oxygen, calcium, magnesium, and
vapor pressure of Mg (0.458 atm) is 26 times larger
vanadium.
than Ca (0.018 atm) at 1273 K.