Separation of Vanadium and Titanium Phase from the Vanadium Slag System Utilizing Supergravity - J-Stage
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ISIJ International, Vol. 61 (2021), No. 3, pp. 690–696
ISIJ International, Vol. 61 (2021), No. 3
https://doi.org/10.2355/isijinternational.ISIJINT-2020-333
Separation of Vanadium and Titanium Phase from the Vanadium
Slag System Utilizing Supergravity
Weijun HUANG and Yajing LIU*
College of Materials Science and Engineering, Hebei University of Engineering, Handan, 056038 China.
(Received on June 8, 2020; accepted on November 18, 2020; J-STAGE Advance published date:
January 17, 2021)
To effectively recycle and utilize vanadium and titanium resource from the vanadium slag, the crystalliza-
tion and separation behaviors of V-spinel phase and Ti-spinel phase in the FeO–SiO2–V2O3–TiO2 system as
the main components of vanadium slag were investigated. The results indicated that the suitable tem-
peratures for precipitating V-spinel phase and Ti-spinel phase were chosen as 1 723 K and 1 623 K, respec-
tively. With introduction supergravity at the parameter of G = 700, T = 1 723 K and t = 10 minutes, the
solid V-containing phase was intercepted by the filter to form the V-enriched slag, while the residual melt
went through the filter into the lower crucible to form the Ti-containing slag. And the mass fraction of V2O3
in the V-enriched slag reached about 32.98 wt% and that of TiO2 in the Ti-containing slag reached about
19.41 wt%; the recovery ratios of V2O3 and TiO2 were about 86.50% and 76.80%, respectively. In addition,
the Ti-spinel phase was further separated and concentrated in the Ti-enriched slag from the Ti-containing
slag with the gravity coefficient G = 500 at 1 623 K for 10 minutes. The mass fraction and the recovery
ratio of TiO2 in the Ti-enriched slag could reach 30.83 wt% and 89.80%, respectively. In the whole process,
the comprehensive recovery ratio of TiO2 could reach 68.97%.
KEY WORDS: vanadium slag; V-spinel phase; Ti-spinel phase; supergravity separation; concentrate.
theless, this kind of ore resource has been mainly adopting
1. Introduction
blast furnace iron making process for refining of iron, but
Titanium is reputed as “space metal”, characterized the extractions of vanadium and titanium are inadequate.
by its stable chemical properties, good resistance to high After mineral processing, about 53% TiO2 and 61.62%
temperature, low temperature, strong acid and alkali, as V2O5 in the vanadium-titanium magnetite go into the iron
well as the highest strength-to-density ratio of any metallic concentrate, which transfer into the vanadium-bearing hot
elements.1–4) In a non-alloy state, titanium is as strong as metal and the titanium-bearing blast furnace slag with
some steels, but 45% lighter. Titanium can be alloyed with 20–25% TiO2 that is used to extract titanium material.8)
aluminium, vanadium and other elements to produce strong And the vanadium-bearing hot metal is pre-oxidized in a
lightweight alloys for aerospace, automobile, industrial vanadium-extraction converter (VEC) by blowing oxygen
process, agri-food and other applications.4–6) Vanadium, through it to obtain semi-steel and vanadium-bearing slag
as one of the most important alloying elements, is widely that contains 11–15 wt% V2O3 and 10–14 wt% TiO2.12–15)
used in metallurgy, chemical engineering and aerospace for Then, the vanadium oxides in the vanadium slag are treated
its ability to enhance mechanical properties, such as tensile by wet extraction to obtain V2O5, but TiO2 is discharged
strength, hardness and fatigue resistance.7,8) With the devel- into the waste residue, which not only leads to resource
opment of economy in the 21st century, the requirements of waste, but also causes environmental pollution.14–18) Fur-
titanium and vanadium are rapidly increasing. thermore, the plenty of TiO2 can significantly improve the
Furthermore, it is well known that vanadium-titanium chemical stability of the spinel boundary and reduce the
magnetite resource is a typical multiple-element symbi- conversion rate of vanadium during the salt roasting and
otic composite ore, which contains 59.2–62.3 wt% TFe, leaching.14–16,19–21) Therefore, it is necessary to improve the
5.2–12 wt% TiO2, 0.8–1.02 wt% V2O5.8–10) Meanwhile, the grade of vanadium slag and recycle titanium resource before
vanadium-titanium magnetite is the largest titanium and the vanadium wet extraction process. Thus, the comprehen-
vanadium resource in China and other countries.8,11) Never- sive utilization of vanadium slag has been studied by many
researchers during the vanadium extraction process, but the
* Corresponding author: E-mail: lyj19850518@163.com effects are limited.11–13,16,22–24) In addition, few reports on
© 2021 The Iron and Steel Institute of Japan. This is an open access article under the terms of the Creative Commons
Attribution-NonCommercial-NoDerivs license (https://creativecommons.org/licenses/by-nc-nd/4.0/).
CCBYNCND
© 2021 ISIJ 690
ISIJ International, Vol. 61 (2021), No. 3
the recovery of titanium from Ti-bearing slag, especially supergravity technology in the molten slag with a filter will
the vanadium slag system of the FeO–SiO2–V2O3–TiO2 result in the liquid phase through the filter and the solid
have been successfully applied in industry due to the limi- particles remain in the upper part for realizing V-containing
tations of existing process for treating the complex system. phase or Ti-containing phase enrichment and separation
Therefore, an innovative and efficient method for improving from the molten slag, which will improve the grade of vana-
vanadium slag grade and recycling the titanium element dium in the vanadium slag and recycle titanium resource.
before vanadium wet extraction process are strongly desired. Meanwhile, the separated tailing is mainly composed of
Supergravity is a new technology, which is used to fayalite phase, which can be used as recycled material in
replace the conventional gravity field in industrial produc- metallurgical industry.
tion.25–27) By rotating, a stable and adjustable centrifugal Therefore, thinking about the successful application of
force field is generated, which is used to strengthen the supergravity technology on other types of slag to separate
phase transfer and microscopic mixing for improving the valuable elements in previous studies,25,28,30,31,35–41) this
multiphase reaction and the effective separation.28–30) In this work studied the crystal behaviors of various spinels in
environment, the molecular diffusion and the mass transfer the FeO–SiO2–TiO2–V2O3 slag as the main components
among molecules with different sizes are much faster than of vanadium slag with different treatments to obtain
that of normal gravity field. Gas-liquid, liquid-liquid, solid- the suitable temperatures. And then the separations of
liquid in a porous medium or channel under supergravity V-containing phase and Ti-containing phase from the FeO–
condition can significantly improve the stress difference SiO2–TiO2–V2O3 slag were investigated by supergravity
between two phases to strengthen the relative speed, reduce technology. Meanwhile, the microstructure and recovery
the role of liquid surface tension, and generate a great shear- ratios of V2O3 and TiO2 in the enriched slag were analysed
ing force for stretching or tearing the liquid into micron or and calculated, respectively.
nanoscale liquid membrane and liquid droplets.31–33) Com-
pared with the conventional gravity field, the interphase
2. Experimental
area is greatly increased, the diffusivity of substances is
obviously improved, the phase interface is fast updated, Reagent grade powders of V2O3 ( > 99.50 mass%),
and the micromixing of different phases is accelerated, to FeC2O4 ( > 99.50 mass%), TiO2 ( > 99.50 mass%), and high
greatly enhance the mass transfer of substance. Thus the purity SiO2 ( > 99.99 mass%) were used as raw materials.
supergravity technology has been studied in the following These four kinds of powders were dried at 373 K for 4
metallurgy fields: (a) removal of impurity elements (such as hours in a drying oven to remove moisture, and then were
Fe, Si, and Cu) from molten metals,27,34) (b) enrichment of well mixed in a ball mill in the required proportion accord-
valuable elements (such as Ti, V, RE, and P) from metal- ing to the actual component of vanadium slag as shown in
lurgical slags,25,28,30,31,35–41) (c) separation of non-metallic Table 2. After that, the mixed powders were pressed into
inclusions (such as Al2O3 particle) from molten metal,42–44) tablet samples and heated at 1 823 K for 120 minutes in a
and (d) refinement of the solidification structure of metal magnesia crucible to ensure complete melting for preparing
alloy (such as Al–Cu alloy).28,29,45) The research results pre-melted slag under Ar gas ( ≥ 99.999 vol%) with a flow of
have demonstrated that the supergravity technology is a 400 ml·min − 1. After heating, the sample was rapidly taken
high-efficiency method for purifying the molten metal, out from the furnace and quenched by water to avoid the
recycling the valuable elements, and refining the solidifica- oxidation of elements during the cooling process. In addi-
tion structure according to three selective features (namely tion, during the heating process, the sample was held at 873
selective separating, selective concentrating and selective K for 120 minutes to decarburize FeC2O4.
growing).35–45) After completion of the pre-melting process, 10 g of
Vanadium slag is mainly composed of four oxides, the pretreated slag was put into crucible and heated to
namely FeO, SiO2, V2O3 and TiO2, as shown in Table 1 823 K for 30 minutes under Ar gas in a muffle furnace
1.8,12) Si is mainly existed in the fayalite phase. V and Ti are to ensure fully melting. Thereafter, the melted slag was
mainly concentrated in “dispersed” and “fine” spinel phases sequentially cooled to the target temperatures at a cooling
(FeV2O4, FeTiO3), which is wrapped in silicate phases.8,11,12) rate of 2 K/minute and maintained for 60 minutes. After
Considering that the melting point and density of various heating, the samples obtained in different temperatures
phases in the vanadium slag are about 2 023 K and 4.32 × were water-quenched and measured by X-ray diffraction
103 kg/m for V-spinel, 1 668 K and 4.12 × 103 kg/m for (XRD) and a scanning electron micrograph (SEM) with an
Ti-spinel as well as below 1 573 K and 3.10 × 103 kg/m3 attached energy dispersive X-ray analyzer (EDS) to obtain
for fayalite phase respectively, the suitable temperature and the crystallization behaviors of various spinels with different
holding time are selected to melt Ti-spinel and fayalite or conditions for confirming the suitable temperatures.
fayalite for liquid and promote the growth of solid spinels According to the crystallization experiment results in
(V-spinel or Ti-spinel). As the density difference between Section 3.1, it is known that the suitable treatment tempera-
solid particles and liquid slag,11,35,46) the introduction of
Table 2. Typical chemical composition of the studied slag sys-
Table 1. Composition of typical vanadium slag, wt%. tems, wt%.
FeO SiO2 V2O3 TiO2 MnO Al2O3 MgO CaO Cr2O3 FeO SiO2 V2O3 TiO2
28–36 19–15 11–15 10–13 7–9 4–2 3–1 3–1 3–0 43.00 26.00 17.00 14.00
691 © 2021 ISIJ
ISIJ International, Vol. 61 (2021), No. 3
tures were 1 723 K for the separation of V-spinel phase and ditions were sectioned longitudinally along the center axis to
1 623 K for the separation of Ti-spinel phase. The separation obtain a macrograph. And then, the separated samples were
experiments of V-spinel phase and Ti-spinel phase were measured by XRD and SEM-EDS methods for analyzing the
conducted in a centrifugal apparatus respectively, as shown mineral compositions and microstructures, and the chemi-
in Fig. 1. A counterweight was symmetrically fixed onto a cal components of samples were determined by XRF and
centrifugal rotor in the furnace for generating a stable and ICP-OES. The contents of various oxides in samples were
adjustable supergravity field, which rotated from vertical converted by the mass of the corresponding elements in the
to horizontal once the centrifugal rotor started running. 30 ICP-OES tested results. Conclusively, the recovery ratio of
g of the pretreated slag was ground and put into the upper vanadium and titanium was calculated via Eq. (2).
magnesia crucible with several pores (D = 0.5 mm). And
mM wM1
a carbon felt was embedded on the bottom of crucible as RM 100% .............. (2)
filter with the thickness of 5 mm. Another lower magnesia mS wM0 mM wM1
crucible was used to hold the slag that went through the where, RM is the recovery ratio of elements (V or Ti) in
filter. The sample was heated to 1 723 K in a heating fur- separated slag, mM and mS are the mass of separated slag
nace for 60 minutes, and then the centrifugal apparatus was and tailings, wM1 and wM0 are the mass fractions of oxides
adjusted to angular velocity of 1 583 r/min, namely G = (V2O3 or TiO2) in separated slag and tailings.
700 as calculated by Eq. (1) at 1 723 K for 10 minutes to
separate and concentrate the V-spinel phase. After that, the
3. Results and Discussion
equipment was shut off and the sample was quenched by
water. In addition, the parallel experiment was carried out 3.1. Optimum Crystallization Temperature of Spinels
at 1 723 K for 10 minutes without supergravity treatment. in the FeO–SiO2–V2O3–TiO2 System
During the whole experimental process, Ar gas was injected In order to achieve the purpose of supergravity separation
to avoid the oxidation of elements. of V-containing phase and Ti-containing phase, the suitable
treatment temperature should be first determined to obtain
2
N 2 2r a single crystal (V-spinel or Ti-spinel) phase with suitable
g2 ............ (1) grain size from the molten slag. Therefore, the present work
g 2 ( 2r )2 900
G investigated the crystallization behavior of spinel phases in
g g the vanadium slag.
where N is the rotating speed of the centrifugal apparatus, Combined with the variations in mineral compositions
r/min; w is the angular velocity, rad/s; r is the distance from and microstructures of slag melt with temperature decreas-
the centrifugal axis to the centre of sample, 0.25 m; g is ing as shown in Fig. 2, it was obvious that the fine V-spine
normal gravitational acceleration, 9.8 m/s2. crystals were precipitated at 1 773 K. With temperature
After the separation of V-containing phase (V-spinel decreasing to 1 723 K, the diffraction peak intensity of
phase), the slag was heated to 1 623 K for 60 minutes under V-spinel was obviously increased, and the fine V-spinel
Ar gas, and then the centrifugal apparatus was adjusted to crystals transformed into a larger lump and strip crystals,
angular velocity of 1 338 r/min (namely G = 500) at 1 623 but titanium element remained in slag melt rather than
K for 10 minutes to separate and concentrate the Ti-spinel forming Ti-spinel precipitations. When temperature fur-
phase. After the separation of Ti-bearing phase, the slag was ther decreased to 1 673 K, the diffraction peak intensity of
taken out and cooled by water. V-spinel changed slightly, while a weak diffraction peak of
The samples obtained by supergravity with different con- Ti-spinel started to present and its shape appeared needle as
Fig. 1. Schematic diagram of centrifugal separation apparatus. 1. Counterweight; 2. Centrifugal axis; 3. Base; 4.
Magnesia crucible; 5. Slag melt before centrifugal separation; 6. Resistance coil; 7. Slag melt after centrifugal
separation; 8. Filter; 9. Spinel particles after centrifugal separation; 10. Spinel particles before centrifugal sepa-
ration; 11. Thermocouple; 12. Horizontal rotor; 13. Conductive slipping; 14. Temperature controller. (Online
version in color.)
© 2021 ISIJ 692
ISIJ International, Vol. 61 (2021), No. 3
shown in Figs. 2(c), 2(e). When temperature reached 1 623 3.2. Separation of V-Spinel Phase from the FeO–SiO2–
K, the peaks of Ti-spinel significantly enhanced compared V2O3–TiO2 System
with that of 1 673 K, and the acicular Ti-spinel crystals Figure 3 shows a cross-section of the samples obtained
changed into ribbon and rod. In addition, the fayalite phase by centrifugal enrichment with the gravity coefficient G =
didn’t precipitate from the molten slag at 1 623 K. In addi- 700 at 1 723 K for 10 minutes compared with the parallel
tion, the physicochemical properties of vanadium slag could sample with the normal gravity at same temperature for
be deteriorated when the temperature was below 1 600 K 10 minutes. It is observed from Fig. 3(a) that there was no
according to the literature.8,47) Overall, it is known from the stratification phenomenon presenting in the parallel sample
experimental results that Ti-spinel phase could be precipi- under normal-gravity field, and the whole sample with a
tate when the temperature reached 1 673 K. Meanwhile the uniform structure was obviously blocked by filter. After
suitable size of V-spinel and Ti-spinel could obtain at 1 723 centrifugal separation, two separated samples that went
K and 1 623 K, respectively. through and held above the filter were obtained, which
From above analysis, a single V-spinel phase with means that part of slag went through the filter into the lower
appropriate crystal size could be obtained from the vana- crucible and the significant stratification was presented as
dium slag when the temperature was chosen as 1 723 K. shown in Fig. 3(b).
After separation of V-containing phase, a single Ti-spinel In order to further analyse separated effect, the mineral
phase with appropriate crystal size could be obtained compositions and microstructures with G = 1 for area-A in
from the residual slag when the temperature was 1 673 Fig. 3(a) and G = 700 for area-B and area-C in Fig. 3(b)
K. Therefore, in order to obtain a single V-spinel phase were detected by SEM-EDS as shown in Fig. 4. It can be
or Ti-spinel phase in the crystals from the corresponding seen that the slag in the upper part for area-B as shown in
slag during the subsequent separation experiments, the Figs. 4(b), 4(d) was mainly composed of a large quantity of
experimental temperature should be chosen as 1 723 K and irregular triangle and quadrangle V-spinel phase and glass
1 623 K, respectively. phase, which was defined as the V-enriched slag; and that
in the low part for for area-C as shown in Figs. 4(c), 4(e)
was mainly composed of a large quantity of glass phase and
a few acicular V-spinel phase, which was defined as the
Ti-containing slag. Compared with the separated sample,
the V-spinel phase and glass phase coexisted in the slag
for the parallel sample with the normal gravity as shown
in Fig. 4(a), which means that the vanadium slag didn’t
appear stratified phenomenon under normal-gravity field.
In addition, after the treatment of supergravity technology,
the size of spinel phase was obviously increased and silicate
phase was significantly decreased, which would benefit the
subsequent vanadium extraction process. As the V-spinel
particles were wrapped in silicate phase in the vanadium
slag, larger grain size and higher spinel grade could increase
the exposed area to improve the vanadium oxidation and
yield rates during wet extraction process, which could effec-
tively reduce the required sodium salt dosage and roasting
temperature as well as waste discharge.16–19)
Fig. 2. SEM photographs and XRD patterns of the slag melts with
different temperatures: (a) SEM of 1 773 K; (b) SEM of Fig. 3. Macrographs of the samples after centrifugal separation
1 723 K; (c) SEM of 1 673 K; (d) SEM of 1 623 K; (e) XRD compared with the parallel sample at 1 723 K for 10
patterns. (Online version in color.) minutes: (a) G = 1; (b) G = 700. (Online version in color.)
693 © 2021 ISIJ
ISIJ International, Vol. 61 (2021), No. 3
Fig. 4. SEM photographs of the samples for separating vanadium: (a) SEM of the parallel slag; (b) SEM of the
V-enriched slag; (c) SEM of the Ti-containing slag; (d) EDS of V-spinel; (e) EDS of liquid. (Online version in
color.)
Table 3. Chemical components of the samples after centrifugal gathered in the residue (the upper part) after supergravity
separation, wt%. technology to achieve the separation of vanadium and tita-
Sample FeO SiO2 V2O3 TiO2 nium and improve the vanadium grade in the enriched slag.
Parallel slag 43.00 26.00 17.00 14.00
3.3. Separation of Ti-spinel Phase from the Ti-Containing
V-enriched slag 54.38 5.36 32.98 7.28 Slag
Ti-containing slag 33.84 42.61 4.14 19.41 After the separation of V-containing phase from vana-
dium slag, titanium was enriched and recycled from the
Ti-containing slag with the gravity coefficient G = 1 and
Table 4. Recovery ratio of V2O3 and TiO2 in the stratified samples G = 500 at 1 623 K for 10 minutes. The microstructures
after centrifugal separation (Pct). with different conditions were analyzed by SEM-EDS as
Mass Mass Recovery Recovery shown in Fig. 5. It can be shown that the main phases con-
Sample
(g) Fraction Ratio of V2O3 Ratio of TiO2 sisted of Ti-spinel phase and silicate glass phase, but the
V-enriched slag 13.38 44.59 86.50 – mass fraction of each phase and the size of spinels were dif-
ferent under various conditions. For the parallel sample with
Ti-containing slag 16.62 55.41 – 76.80
the normal gravity G = 1 as shown in Fig. 5(a), fine spinel
particles were uniformly distributed in the glass phase, and
the stratified phenomenon didn’t appear. But with the intro-
Table 3 shows the chemical composition of the strati- duction of supergravity technology, Ti-spinel phase was
fied sample using XRF and ICP-OES with the G = 700, almost separated and stayed in the upper part as shown in
T = 1 723 K and t = 10 minutes. The mass fraction of Figs. 5(b), 5(d), which was defined as the Ti-enriched slag.
V2O3 in the V-enriched slag was up to 32.98 wt%, while And most of silicate phase and few acicular spinel phase
that in the Ti-containing slag was just 4.14 wt%, which went through the filter in the low part as shown in Figs.
presented a clear differentiation phenomenon. The opposite 5(c), 5(e), which was defined as the tailing. Table 5 shows
result appeared on the distribution of TiO2, and the mass the chemical composition of the stratified sample using XRF
fraction of TiO2 in the Ti-containing slag was up to 19.41 and ICP-OES with the G = 500, T = 1 623 K and t = 10
wt%, while that in the V-enriched slag was just 7.28%. The minutes. The mass fraction of TiO2 in the Ti-enriched slag
recovery ratio of V2O3 in the V-enriched slag reached about was up to 30.83 wt%, while that in the tailing was just 4.55
86.50%; and that of TiO2 in the Ti-containing slag was up wt%. The recovery ratio of TiO2 in the Ti-enriched slag
to 76.80%, as shown in Table 4. This means that the solid could reach 89.80% as shown in Table 6. And the com-
spinel particles were effectively intercepted by the filter and prehensive recovery ratio of TiO2 is also used to explain
© 2021 ISIJ 694ISIJ International, Vol. 61 (2021), No. 3
Fig. 5. SEM-EDS photographs of the samples for separating titanium: (a) SEM of the parallel slag; (b) SEM of the
Ti-enriched slag; (c) SEM of the tailing; (d) EDS of Ti-spinel; (e) EDS of liquid. (Online version in color.)
Table 5. Chemical components of the samples after centrifugal as shown in Table 3, which could be used as raw materials
separation, wt%. for vanadium ferroalloy. After two-step supergravity separa-
Sample FeO SiO2 V2O3 TiO2 tion, the content of TiO2 was increased from 14 wt% in the
primary slag to 30.83 wt% in the Ti-enriched slag. And the
Parallel slag 33.84 42.61 4.14 19.41
main components of the Ti-enriched slag were iron oxide,
Ti-enriched slag 39.91 22.60 6.66 30.83 titanium oxide and silicon oxide as shown in Table 5, which
Tailing 25.94 68.65 0.86 4.55 could be used as raw materials for titanium-silicon ferroal-
loy and titanium metal smelting. In addition, the contents
of FeO and SiO2 in tailing reached 25.94% and 68.65%
Table 6. Recovery ratio of V2O3 and TiO2 in the stratified samples respectively, which could be recycled as metallurgical mate-
after centrifugal separation (Pct).
rial in the steel industry.
Sample Mass (g) Mass Fraction Recovery Ratio of TiO2
Ti-enriched slag 16.97 56.56 89.80 4. Conclusions
Tailing 13.03 43.44 –
The crystallization behaviors of V-spinel and Ti-spinel
for FeO–SiO2–V2O3–TiO2 system as the main compo-
nents of vanadium slag were investigated. On this basis,
the final enrichment effect, which could be estimated by the V-spinel phase and Ti-spinel phase were effectively
the recovery ratio of TiO2 in the Ti-containing slag multi- separated utilizing supergravity technology, the following
plied by that of in the Ti-enriched slag. The comprehensive conclusions have been drawn:
recovery ratio of TiO2 could reach 68.97%. (1) For the FeO–SiO2–V2O3–TiO2 system, the fine
According to the above analysis, it is known that vana- V-spinel crystals transformed into a larger lump and strip
dium and titanium were effectively separated from the crystals with decreasing of the temperature from 1 773 K to
vanadium slag after two-step supergravity separation pro- 1 723 K. With further decreasing to 1 673 K, Ti-spinel crys-
cess. The mass fraction of V2O3 was increased from 17.00 tals started to crystallize from the slag. Therefore, in order
wt% before separation to 32.98 wt% in the enriched slag, to adequately precipitate a single V-spinel phase from the
which was effectively improved the quality of vanadium molten slag, the temperature should be chosen as 1 723 K.
slag and decreased the content of other oxides. In the sub- (2) For the FeO–SiO2–TiO2–(V2O3) system, the acicular
sequent vanadium extraction process, it could improve the Ti-spinel crystals changed into ribbon and rod with decreas-
leaching rate of vanadium, decrease the amount of sodium ing of the temperature from 1 673 K to 1 623 K. Meanwhile,
salt and waste discharge. In addition, the main components the fayalite phase didn’t precipitate from molten slag at
of the V-enriched slag were iron oxide and vanadium oxide 1 623 K, so the temperatures should be chosen as 1 623 K
695 © 2021 ISIJISIJ International, Vol. 61 (2021), No. 3
to precipitate Ti-spinel phase from the molten slag. H. Chen: AIChE J., 59 (2013), 541.
15) J. Wen, T. Jiang, Y. Z. Xu, J. Cao and X. X. Xue: J. Ind. Eng. Chem.,
(3) After centrifugal separation at the parameter of G = 71 (2019), 327.
700, T = 1 723 K and t = 10 minutes, the solid V-containing 16) J. Wen, T. Jiang, Y. J. Liu and X. X. Xue: Miner. Process. Extr.
phase was intercepted by the filter to form the V-enriched Metall. Rev., 40 (2019), 56.
17) H. Peng, J. Guo and X. Zhang: ACS Omega, 5 (2020), 17664.
slag, while the residual melt went through the filter into the 18) K. Li, Q. Jiang, L. Gao, J. Chen, J. Peng, S. Koppala, M. Omran and
lower crucible to form the Ti-containing slag. And the mass G. Chen: J. Hazard. Mater., 395 (2020), 122698.
19) R. Deng, H. Xiao, Z. Xie, Z. Liu, Q. Yu, G. Chen and C. Tao: Chin.
fraction of V2O3 in the V-enriched slag reached about 32.98 J. Chem. Eng., 28 (2020), 2208.
wt% and that of TiO2 in the Ti-containing slag reached 20) Z. Qin, G. Zhang, Y. Xiong, D. Luo, C. Li, S. Tang, H. Yue and B.
Liang: Hydrometallurgy, 192 (2020), 105259.
about 19.41 wt%; the recovery ratios of V2O3 and TiO2 were 21) J. Wen, T. Jiang, X. Zheng, J. Wang, J. Cao and M. Zhou: Sep. Purif.
about 86.50% and 76.80%, respectively. Technol., 230 (2020), 115881.
(4) With further separating TiO2 from the Ti-containing 22) H. X. Fang, H. Y. Li and B. Xie: ISIJ Int., 52 (2012), 1958.
23) L. Yu, Y. C. Dong, G. Z. Ye and D. Sichen: Ironmaking Steelmaking,
slag at the gravity coefficient G = 500, T = 1 623 K 34 (2007), 131.
for 10 minutes, the Ti-containing phase was collected in 24) J. Diao, B. Xie, C. Q. Ji, X. Guo, Y. H. Wang and X. J. Li: Cryst.
Res. Technol., 44 (2009), 707.
the Ti-enriched slag. The mass fraction of TiO2 in the 25) F. Q. Wang, J. T. Gao, X. Lan and Z. C. Guo: ISIJ Int., 57 (2017),
Ti-enriched slag was up to 30.83 wt%, while that in the 200.
tailing was only 4.55 wt%. The recovery ratio of TiO2 in the 26) Z. C. Guo, Y. P. Gong and W. C. Lu: Sci. China, Ser. E: Technol.
Sci., 50 (2007), 39.
Ti-enriched slag was up to 89.80%. In the whole separation 27) Y. H. Yang, B. Song, G. Y. Song, Z. B. Yang and W. B. Xin: Metall.
process, the comprehensive recovery ratio of TiO2 could Mater. Trans. B, 47 (2016), 2714.
28) M. R. Rahimipour and M. Sobhani: Metall. Mater. Trans. B, 44
reach 68.97%. (2013), 1120.
29) L. X. Zhao, Z. C. Guo, Z. Wang and M. Y. Wang: Metall. Mater.
Acknowledgments Trans. A, 41 (2010), 670.
30) J. C. Li and Z. C. Guo: Metall. Mater. Trans. B, 45 (2014), 1272.
This work was supported by the National Natural Science 31) J. C. Li, Z. C. Guo and J. T. Gao: ISIJ Int., 54 (2014), 743.
Foundation of China [No. 51804094]. 32) J. Yeon, Y. Ishida, M. Nakamoto and T. Tanaka: Mater. Trans., 59
(2018), 1192.
33) L. Meng, Z. Wang, Y. W. Zhong, L. Guo, J. T. Gao, K. Y. Chen, H.
REFERENCES J. Cheng and Z. C. Guo: Chem. Eng. J., 326 (2017), 540.
34) Z. Wang, J. T. Gao, L. Meng, A. J. Shi and Z. C. Guo: ISIJ Int., 58
1) W. Li, X. X. Xing, N. Gao and P. Wang: Eng. Fract. Mech., 221 (2018), 1175.
(2019), 106705. 35) J. C. Li, Z. C. Guo and J. T. Gao: Ironmaking Steelmaking, 41 (2014),
2) N. Sui, G. B. Mi, M. Q. Yan, J. X. Cao and X. Huang: Rare Met., 710.
37 (2018), 952. 36) J. T. Gao, Y. W. Zhong and Z. C. Guo: ISIJ Int., 56 (2016), 1352.
3) G. Lu, T. Zhang, G. Zhang, W. Zhang, Y. Zhang, Z. Dou, L. Wang, 37) C. Li, J. T. Gao, Z. Wang, H. R. Ren and Z. C. Guo: ISIJ Int., 57
Y. Wang and G. Xie: JOM, 71 (2019), 4600. (2017), 767.
4) S. L. Zhang, Y. J. Ma, S. S. Huang, S. S. Youssef, M. Qi, H. Wang, 38) J. T. Gao, Y. Li, G. L. Xu, F. Q. Wang, Y. Lu and Z. C. Guo: ISIJ
J. K. Qiu, J. F. Lei and R. Yang: J. Mater. Sci. Technol., 35 (2019), Int., 57 (2017), 587.
1681. 39) C. Li, J. T. Gao and Z. C. Guo: Metall. Mater. Trans. B, 47 (2016),
5) J. H. Chen, J. S. Li, B. Tang, Y. Chen and H. C. Kou: Prog. Nat. 1516.
Sci.: Mater. Int., 29 (2019), 50. 40) Y. Lu, J. Gao, F. Wang and Z. Guo: Metall. Mater. Trans. B, 48
6) L. Zhang, L. N. Zhang, M. Y. Wang, G. Q. Li and Z. T. Sui: ISIJ (2017), 749.
Int., 46 (2006), 458. 41) J. Gao, Y. Zhong and Z. Guo: Metall. Mater. Trans. B, 47 (2016),
7) X. S. Li and B. Xie: Int. J. Miner. Metall. Mater., 19 (2012), 595. 2459.
8) D. X. Huang: Vanadium Extraction and Steelmaking, Metallurgical 42) C. Li, J. T. Gao, Z. Wang and Z. C. Guo: Metall. Mater. Trans. B,
Industry Press, Beijing, (2000), 123 (in Chinese). 48 (2017), 900.
9) W. J. Huang, M. Chen, X. Shen, S. Yu, N. Wang and L. Xu: Steel 43) G. Y. Song, B. Song, Z. C. Guo, Y. H. Yang and M. M. Song: Metall.
Res. Int., 88 (2017), 1600324. Mater. Trans. B, 49 (2018), 34.
10) Y. C. Dong, X. R. Wu and L. S. Li: ISIJ Int., 45 (2005), 1238. 44) A. Shi, Z. Wang, C. Shi, L. Guo, C. Guo and Z. Guo: ISIJ Int., 60
11) L. S. Li, X. R. Wu, L. Yu and Y. C. Dong: Ironmaking Steelmaking, (2020), 205.
35 (2008), 367. 45) N. Sun, Z. Wang, L. Guo, L. Wang and Z. Guo: J. Alloy. Compd.,
12) W. J. Huang, S. Yu, X. Shen, L. Xu, N. Wang and M. Chen: Steel 843 (2020), 155814.
Res. Int., 87 (2016), 1228. 46) X. G. Huang: Principles of Steel Metallurgy, Metallurgical Industry
13) W. Zhao, M. S. Chu, H. T. Wang, Z. G. Liu, J. Tang and Z. W. Ying: Press, Beijing, (2017), 234 (in Chinese).
ISIJ Int., 58 (2018), 823. 47) W. J. Huang, Y. H. Zhao, S. Yu, L. X. Zhang, Z. C. Ye, N. Wang
14) B. Liu, H. Du, S. N. Wang, Y. Zhang, S. L. Zheng, L. J. Li and D. and M. Chen: ISIJ Int., 56 (2016), 594.
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