v 2 o 5 ( s ) + al ( s ) ( + fe ( s ))
DESCRIPTION
(1) After calcination. V. Others 1.1 %. MgO. Japan 2.0 %. Other 6.7 %. Other 0.4 %. Other 3.0 %. Mg 2 V 2 O 7. Catalyst 12.9 %. Element. China 15.2 %. Crustal abundance (ppm). China 20.1 %. China 31.1 %. Russia 26.8 %. Russia 38.3 %. U.S.A 12.4 %. China 38.3 %. - PowerPoint PPT PresentationTRANSCRIPT
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 MetalAkihiko Miyauchi1, Toru H. Okabe2
1Department of Materials Engineering, Graduate School of Engineering, The University of Tokyo; 2Institute of Industrial Science, The University of Tokyo.
Introduction
Experimental
Results Current status
Future work
V2O5 (s)
+ Al (s)
( + Fe (s))V - Al (l)
(Fe - V - Al (l))
Slag
Electron beam melting
Alloying process
Fe - V alloy
V metal
Flux V2O5
1273 K
Vanadium?
Resources and production Application
Flowchart of our processThermodynamic analysis Preform reduction process (PRP)
Reduction process
Sintered preform
Mixing / casting
Feed preform
Calcination
Reduction
Reductant (Ca, Mg)
Reduced preform
Leaching and rinsing
Solid
Vacuum drying
Waste solution
V metal powder
Special steel
In the primary use, vanadium is consumed as an alloy
element of steel.
High thermal stability and tensile strength
Ti-V hydrogen storing alloy
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.
It is important to develop
a new production process
of pure vanadium metal
and vanadium alloy.
Commercial production process
◎ 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
Features
Aluminothermic process
3 V2O5 (s) + 10 Al (s) (+ Fe (s))
→ 6 V (in Al (l)) + 5 Al2O3 (s)
(Fe-V-Al (l))
Reduction by reductant vapor
MxOy + Flux + Binder Preform
Casting Forming
V2O5 + 5 R → 2 V + 5 ROx
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
PRP is simple and low-cost processfor high purity products.
Stainless steel reaction vessel
Ti sponge getter
Feed preform(V2O5, Flux)
TIG welding
Stainless steel cover
Stainless steel holder
Reductant (Ca, Mg)
Problem 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.
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.
・ Investigation of residual oxygen concentration,
and evaluation of total vanadium yield.
・ Development of production process of Ti-V
alloys.
・ Analysis of reduction mechanism by utilizing
the chemical potential diagram for the system
involving oxygen, calcium, magnesium, and
vanadium.
Calcination process
Liquid
Binder
Vapor pressure of metals
(Ref. Iron and Steel Institute of Japan)
(Ref. Matsushita Electric Industrial Co., Ltd)
Sta
ndar
d G
ibbs
ene
rgy
of fo
rmat
ion,
G゚
f /
kJ m
ol-1
2 Ca + O2 = 2 CaO
3/2 Fe + O2 = 1/2 Fe3O4
Ti + O2 = TiO2
2 Mg + O2 = 2 MgO
4/5 V + O2 = 2/5 V2O5
Temperature, T / K
-1400
-1200
-1000
-800
-600
-400
-200
0
800 900 1000 1100 1200 1300
-30
-25
-20
-15
-10
-5
0
800 900 1000 1100 1200 1300
Vap
or p
ress
ure
log
p° (
atm
)
Mg
Ca
Fe
Ti
V
Temperature, T / K
1173 K
CaO or MgO was added to feed preform in order to
synthesize complex oxides (CaxVyOz, MgxVyOz) during
calcination. The obtained feed preform has a mechanical
strength at elevated temperature and suitable for
handling during processing.
X-ray diffraction pattern Appearance
・ Complex oxides (Ca2V2O7 or Mg2V2O7) was
synthesized after calcination.
・ Calcined sample maintained its shape form.
m.p.(V2O5)
963 KReaction
temperature
-4
1273 K
Condition for calcination
The calcination temperature was raised from 873 K
to 1173 K during 2 hr of calcination period.
Weight change of the samples
X-ray diffraction pattern
Development of simple and
low-cost process for high purity
vanadium metal or alloys
Aim of this study
20 % HCl aq.,Distilled water,
Isopropanol,
Tred. = 1273 K
tred. = 6 hr
1173 K
Ⅰ A Ⅱ A ⅢB ⅣB ⅤB ⅥB ⅦB Ⅰ A Ⅱ A ⅢA ⅣA ⅤA ⅥA ⅦA ⅧAHydrogen Helium
1 H 2 HeLithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
3 Li 4 Be 5 B 6 C 7 N 8 O 9 F 10 NeSodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
11 Na 12Mg 13 Al 14 Si 15 P 16 S 17 Cl 18 ArPotassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
19 K 20 Ca 21 Sc 22 Ti 23 V 24 Cr 25 Mn 26 Fe 27 Co 28 Ni 29 Cu 30 Zn 31 Ga 32 Ge 33 As 34 Se 35 Br 36 KrRubidium Strontium Yttrium Zirconium Niobium MolybdnumTechnetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
37 Rb 38 Sr 39 Y 40 Zr 41 Nb 42 Mo 43 Tc 44 Ru 45 Rh 46 Pd 47 Ag 48 Cd 49 In 50 Sn 51 Sb 52 Te 53 I 54 XeCaesium Barium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury Thallium Lead Bismuth Polonium Astatine Radon
55 Cs 56 Ba 71 Lu 72 Hf 73 Ta 74 W 75 Re 76 Os 77 Ir 78 Pt 79 Au 80 Hg 81 Tl 82 Pb 83 Bi 84 Po 85 At 86 RnFrancium Radium LawrenciumRutherfordiumDubnium Seaborgium Bohrium Hassium Meitnerium
87 Fr 88 Ra 103 Lr 104 Rf 105 Db 106 Sg 107 Bh 108 Hs 109 Mt
The periodic table of the elementsⅧB
Ellingham diagram of oxides
→ This can be used as a feed preform for
reduction experiment.
V metal・・・
Crustal abundance (ppm) Element
> 105 O, Si
Al, Fe, Ca, Na, K, Mg
Ti, H, P
V, Mn, S, C, Cl, ・・・ Cu, Ni, Zn, Nb, Co, Pb, ・・・
Hg, Ag, Pd, Se Pt, Au, Rh, ・・・
105 ~ 104
104 ~ 103
103 ~ 102
10-1 ~ 10-2
102 ~ 101
10-2 ~ 10-3
・・・
15 ~ 25 mass% Al
Feature of vanadium
・ Low density(6.11 g/cm3) and high melting point (2188 K).
・ The 20th largest crustal abundances among the all
elements .
・ 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).
Table Abundance of elements in the earth’s crust.
Total6.42×103 t (pure V)
Steel
86.0%
Catalyst
12.9 %
Others1.1 %Amount of production Price
(103 ton / year) ($ ・ kg-1)
V 58 39
Fe 1,100,000 0.06
Al 29,000 3
Cu 15,000 7
Ni 1,600 40
Zn 11,000 3
Element
Table Amount of production and price of some metal elements in 2007.
Vanadium production
in Japan
China
31.1 %
South Africa
39.1 %
Russia
26.8 %
Other3.0 %
Total56.3×103 t(pure V)
China
38.3 %
South Africa
23.0 %
Russia
38.3 %
Other0.4 %
Total13.0×106 t (pure V)
China
20.1 %
South Africa
43.9 %
Russia
14.9 %
U.S.A
12.4 %
Japan
2.0 %
Other6.7 %
Total46.0×103 t (pure V)
China
15.2 %
South Africa30.5 %
Australia
14.2 %
Other
40.1 %
Total36.6×103 t (pure V)
Ores productionConfirmed reserve
V2O5 production Fe-V production
Tcal. = 873 K → 1173 Ktcal. = 2 hr
50 %
CH3COOH aq.,
Acetone
20 30 40 50 60 70 80
Angle, 2θ (degree)
MgO JCPDS # 77-2364
Inte
nsity
, I
(a.u
.)
Mg2V2O7 JCPDS # 70-1163
Ca2V2O7 JCPDS # 72-2312
CaO JCPDS # 77-2010
20 40 60 80Angle, 2θ (degree)
V
MgO
Mg2V2O7
(1) After calcination
(2) After reduction
(3) After leaching
Inte
nsity
, I (
a.u.
)
ex.1 Flux : CaO, Reductant : Ca
Inte
nsity
, I (
a.u.
)
Ca2V2O7
CaO
(1) After calcination
(2) After reduction
(3) After leaching
CaV2O4
20 40 60 80Angle, 2θ (degree)
ex.4 Flux : MgO, Reductant : Mg
X-ray fluorescence spectrometry
Table Analytical results of vanadium powder obtained by PRP.
Table Experimental condition and mass of samples after each step.
aDetermined by XRF ; value excludes carbon and gaseous elements.
Condition for reduction
・ 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 reason for incomplete reduction when using Ca vapor is not well understood. The difference of the results between Mg and Ca reductant is partially due to the difference of their vapor pressure. The vapor pressure of Mg (0.458 atm) is 26 times larger than Ca (0.018 atm) at 1273 K.
ex.1
Mass of sample
after leaching,
w3 / g
Mass of sample
after reduction,
w2 / g
Mass of reductant,
wR / g
Ca
Mg
ex.2
ex.3
3.642
5.086
3.976
3.345
4.906
2.573
3.955
4.435
1.805
0.729
0.981
1.071
Reductant
Ca
Mg
Ca
Mg
Flux
CaO
MgO
MgO
CaO
Ex. #
Mass of preform,
wpre / g
V2O5 + 3CaO
V2O5 + 3MgO
4.537
4.158
4.226
4.478
Mass of sample
after calcination,
w1 / g
3.474
3.937
3.670
3.604
V Ca Mg
79.0 20.4 -
99.7
86.0 2.4 10.6
85.4 13.0
0.2
Ex. #Composition of sample (mass%)
ex.1
-ex.4
ex.3
ex.2
Reductant
Ca
Mg
Ca
Mg
Flux
CaO
MgO
MgO
CaO
Fe Cr
0.1 0.4
0.50.3
0.5
0.01 0.03
-
0.2
ex.4