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EXTRACTION OF GALLIUM, VANADIUM AND ALUMINUM FROM THE ORGANIC
PHASE BY REEXTRACTION Tagiyeva L.T. Email: [email protected]
Tagiyeva Leyla Teymur - Graduate Student, INSTITUTE OF CATALYSIS AND INORGANIC CHEMISTRY NAMED AFTER ACAD. M. NAGIYEV, NATIONAL ACADEMY OF SCIENCES OF AZERBAIJAN, BAKU, REPUBLIC OF AZERBAIJAN
Abstract: in this article, we study the re-recovery and purification of typical laboratory solutions obtained in the production of aluminum from an extractant solution of the organic phase with an acid solution H2S04. If the volume of the organic phase increases with the aqueous phase, the re-extraction rate decreases and the number of stages must be increased to increase the yield. Purification of the organic phase after the aqueous phase can be carried out using activated carbon. The extraction of gallium and vanadium from solution occurs in two stages. In the first stage, the extraction is carried out at pH-2, and in the second stage with stripping. Keywords: D2EHFA, gallium (III), vanadium (IV), aluminum (III), stripping.
ИЗВЛЕЧЕНИЕ ГАЛЛИЯ, ВАНАДИЯ И АЛЮМИНИЯ ИЗ ОРГАНИЧЕСКОЙ ФАЗЫ
ПУТЁМ РЕЭКСТРАКЦИИ Тагиева Л.Т.
Тагиева Лейла Теймур - аспирант, Институт катализа и неорганической химии им. акад. М. Нагиева Национальная Академия наук Азербайджана, г. Баку, Азербайджанская Республика
Аннотация: в этой статье мы изучаем повторное извлечение и очистку типичных лабораторных растворов, полученных при производстве алюминия из раствора экстрагента органической фазы с раствором кислоты H2S04.
Если объем органической фазы увеличивается вместе с водной фазой, скорость повторной экстракции уменьшается и количество стадий должно быть увеличено для увеличения выхода. Очистку органической фазы после водной фазы можно проводить с помощью активированного угля. Извлечение галлия и ванадия из раствора происходит в две стадии. На первой стадии экстракция проводится при pH-2, a на второй стадии с реэкстракции.
Ключевые слова: D2EHFA, галлий (III), ванадий (IV), алюминий (III), реэкстракция.
UDC 669(871, 292, 712)
INTRODUCTION
In addition to the separation of valuable components from the aqueous phase, the practical use of the extractant is to some extent associated with the rapid and selective re-extraction of one or another component of the extractant with inexpensive available reagents. Let's find out how D2EHFA, which is widely used in the extraction of rare metals, will meet these requirements for Ga and V. The literature [1, 2] investigated the use of HNO3, HCl va H2SO4 in the extraction of gallium from the organic phase from D2EHFA, as well as in the work [3, 4]. The re-extraction of Al with the indicated reagent has been studied in the literature [5, 6]. Since all three elements are studied for selective separation from synthetic products, the conditions for their re-recovery differ significantly from each other.
In this section, we study the re-recovery and purification of typical laboratory solutions obtained in the production of aluminum from an extractant solution of the organic phase with an acid solution H2SO4. EXPERIMENTAL PART
Despite the high degree of extraction of hydrochloric and nitric acids, in our studies, preference was given to a solution of sulfuric acid. The high selling prices of HCl and HNO3, rapid corrosion of equipment, and the difficulty of disposing of spent acids make research with these acids profitable.
It was determined that the extraction of gallium from sulfate solutions has an equilibrium pH of 1.8, and the extraction of vanadium - 2.5. Since these ions are in the cationic form (Ga(3 +), VO(2 +), Al(3+)), their extraction occurs in a weakly acidic medium at pH <4 and at high pH (pH>6) ions in anionic form (GaO- 1, AlO-1, H2VO-,HVO|",H2V2O7"). It should be noted that if the extraction of Ga (III), Al (III), V (IV) ions occurs in a
weakly acidic medium, then the separation (repeated extraction) from the organic phase can be carried out in strongly acidic solutions. These items can be categorized according to the speed of re-extraction.
Studies have shown that the transition of complex compounds from the organic phase to the aqueous phase depends on the initial concentration of sulfuric acid, the duration of repeated extraction, and the volume ratio of the organic and aqueous phases. In fig. 1 shows the results of the influence of the concentration of sulfuric acid on the degree of separation of Ga (III), V (IV) and Al (III) from the organic phase to the aqueous phase. The experiments were carried out for 30 minutes at a ratio of organic phase: aqueous phase = 4: 1. As you can see, the re-extraction of V (IV) occurs gradually from 0.25 to 1.0 mol/l of the concentration of H2SO4 with a slight increase in the concentration range of 1.0-3.0 mol /l. On the contrary, the displacement of Al (III) from the organic phase occurs weakly, below 1.0 mol /l and rapidly increases above 1.0 mol /l. The transition of gallium to the aqueous phase is 51.1% at 0.25 mol /l, 72% at 1 mol /l and 97.2% at 3 mol /l.
RESULTS AND DISCUSSION
The results show that the degree of separation of vanadium from the organic phase varies from 84.0% to 98.6% (3 mol /l H2SO4), aluminum from 11% to 65% at an acid concentration of 0.5 mol /l. At an acid concentration of 1 mol / l, the transition of vanadium to the aqueous phase is 95.4%, and aluminum - 20.1%. Vanadium emission rate is 81.9%. The concentration of 3.0 mol/l increases the release of elements into the aqueous phase.
100 so 90
V 80
70
a
S3 60 I 50 40 30 20 10 0
0
mol/l
Fig. 1. Influence of sulfuric acid concentration on re-extraction of Ga (III), V (IV) and Al (III) ions. (V(org.): V(water) = 4: 1, time 30 min., T = 21°C, , CAl(ln) - 2,4 g/l, CV(IV) - 0,222 g/l, CGa(IH) - 0,054 g /l)
In fig. 1 shows the percentage of Ga (III), Al (III) and V (IV) in the organic phase during the extraction. The transition of Ga (III) and V (IV) to the aqueous phase occurs quickly, in 30 minutes. 13.8% separation of Al into the aqueous phase occurs in 10 minutes, and 29% in 50 minutes.
« «
a
<u
100 90 80 70 60 50 40 30 20 10 0
Al
Ga
V
10 20 30 40 50 60
time, minutes
Fig. 2. Influence of the re-extraction time on the release of Ga (III), V (IV) and Al (III) ions into the aqueous phase (V(org.):
V(wat.) = 4: 1, t = 21°C, CH2SOi = 1 mol/1)
Fig. 2 shows that the ratio of organic to aqueous phases also has a strong effect on re-extraction. As the organic phase: the ratio of the aqueous phase increases, the extraction of vanadium and gallium into the aqueous phase decreases rapidly. 95.4% vanadium, 79% gallium and 20.2% aluminum are recovered in a 4: 1 ratio.
120
a
a a e
100 80 60 40 20
- Al
Ga
V
10
12
0
0
0
2
4
6
8
phase ratio, V (0rg.): S (wat.)
Fig. 3. Influence of the ratio of organic and aqueous phases on the separation of the aqueous phase of Ga (III), V (IV) and Al
(III) ions (time 30 min, t = 21°C, CHiS0i =1mol/1)
As can be seen from Fig. 3 If the volume of the organic phase increases with the aqueous phase, the re-extraction rate decreases and the number of steps must be increased to increase the yield. Purification of the organic phase after the aqueous phase can be carried out using activated carbon.
CONCLUSIONS
From the above, we can conclude that the transition of Ga (III) and V (IV) to the aqueous phase occurs quickly, in 30 minutes. 13.8% separation of Al into the aqueous phase occurs in 10 minutes, and 29% in 50 minutes.
It was also studied that the extraction of gallium and vanadium from solution occurs in two stages:
1-during extraction in the first stage at pH-2
2-in the second stage with stripping.
References / Список литературы
1. Jayachandran J., Dhadke P. Solvent extraction separation of gallium (III) with 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester (PC-88A) // Hydrometallurgy, 1998. V. 50. P. 117-124.
2. Lee M.S., Ahn J.G., Lee E.C. Solvent separation of indium and gallium from sulphate solutions using D2EHPA//Hydrometallurgy, 2002. V. 63. P. 269-276.
3. Xingbing Li, Chang Wei. Zhigan Denq, Cunxiong Li, Grang Fan, Minting Li, Hui Huang. Recovery of vanadium from H2SO4-HF Acidic Leaching solution of Black Shale by Solvent Extraction and Precipitation // Metals, 2016. № 6. Р. 63-76.
4. Izumi Tsuboi, Shigetami Kasai, Eiichi Kunugita, Isao Komasawa. Recovery of Gallium and Vanadium from Coal Fly Ash. // Journal of Chemical Engineering of Japan, 1991. Volume 24. Issue 1. P. 15-20. [Electronic Resource]. URL: https://doi.org/10.1252/jcej.24.15/ (date of access: 02.09.2021).
5. Debasish Mohapatra, KimHong-In, Chul-Woo Nam, Kyung-Ho Park. Liquid-liquid extraction of aluminium (III) from mixed sulphate solutions using sodium salts of Cyanex 272 and D2EHPA.//Separation and Purification Technology, 2007. 56. Р. 311-318. D0I:10.1016/j.seppur.2007.02.017.
6. Xu H., Wei C., Li C., Fan G., Deng L, Qiu S. Leaching of a Complex Sulfidic, Silicate-Containing Zinc Ore in Sulfuric Acid Solution under Oxygen Pressure, Separation and Purification Technology, 2012. Vol. 85. Pp. 206212. [Electronic Resource]. URL: https://doi.org/10.1016/j.seppur.2011.10.012/ (date of access: 02.09.2021).
