ACS Sustainable Chemistry & Engineering
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2020
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IF 7.632
Zhihua Li,Jin Lu,Shengxi Wu,Guiqing Zhang,Wenjuan Guan,Li Zeng,Qinggang Li,Zuoying Cao
Complete separation of tungsten from molybdenum has long been a technical bottleneck in the metallurgy of molybdenum because no theoretical basis exists for the complexation and extraction mechanism of tungsten and molybdenum from aqueous solution. To completely separate tungsten from ammonium molybdate, the speciation and equilibria of compounds in H+–WO42–, H+–MoO42–, and H+–MoO42––WO42– aqueous systems were systematically investigated. With decreasing pH, the stability of polymerized tungsten species in H+–MoO42––WO42– decreased in the following order: MoW6O246– > Mo2W5O246– > Mo3W4O246– > Mo4W3O246– > Mo5W2O246– > Mo6WO246–, and as the W(VI) concentration decreased, low-molecular-weight species increasingly dominated the W(VI) and Mo(VI) polymerization products. The extraction characteristics of tungsten and molybdenum with primary N1923 were consistent with their polymerization behaviors. Methods based on the thermodynamic theory and the aforementioned extraction mechanism were used to completely separate W(VI) from ammonium molybdate solution containing different grades of W(VI) (trace to macro). Ammonium molybdate solution with a 2.25 × 10–7 W/Mo mass ratio met the purity requirement for ultra-high-purity ammonium molybdate (99.999%, 5N) and further molybdenum products. During extraction, the equilibrium pH was controlled by extractant acidification using inexpensive mineral acids. The proposed process is cheap and sustainable and has a broad spectrum and high efficiency; these advantages are expected to provide economic and environmental benefits.
研究领域:
冶金学
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环境科学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2015
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IF 3.091
Dandan Jiang,Naizhong Song,Sufen Liao,Yu Lian,Jiutong Ma,Qiong Jia
In the present study, the solvent extraction of vanadium from chloride medium with acidic organophosphorus extractants, primary amine N1923, and their mixtures were investigated. The organophosphorus acids included di(2-ethylhexyl) phosphoric acid (D2EHPA), 2-ethylhexylphosphonic acid mono-(2-ethylhexyl) ester (HEHEHP), and bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex272). The extraction effects from chloride medium were studied in detail, illustrating that all the three mixtures of organophosphorus acids and N1923 have synergistic effects on vanadium. As a representative, extraction stoichiometries of vanadium with D2EHPA + N1923 were studied with the methods of slope and constant mole. The extraction capacity of temperature dependency was also investigated. Moreover, the separation of vanadium, nickel, and chromium with mixtures of D2EHPA + N1923 was studied.
研究领域:
化学工程
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冶金学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2011
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IF 2.775
Huihui Ma,Yin Lei,Qiong Jia,Wuping Liao,Li Lin
A synergistic extraction system consisting of sec -octylphenoxy acetic acid (CA12, H 2 A 2 ) and primary amine N1923 (B) for gallium(III), indium(III), and zinc(II) has been developed from chloride medium. Synergistic and antagonistic effects are observed for the title metals at low and high CA12 concentration ratios, respectively. On the basis of the distribution ratios, the values of the separation factors are calculated and used for the discussion of the selectivities between gallium(III)/indium(III) and zinc(II). The synergistic extraction of zinc(II) with the mixtures has been investigated with the methods of slope analysis and constant mole. The synergistic adduct has been determined together with the equilibrium constant and thermodynamic constants.
研究领域:
湿法冶金
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溶剂萃取
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无机化学
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分离科学
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稀有金属回收
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Hongtao Liu,Zekai Qin,Xueli Wang,Maolin Tian,Wenjie Zhang,Lin Li,Jiawei Wen,Guoyong Huang,Shengming Xu
Spent hydrodesulfurization catalysts contain more than 10 ∼ 25 wt% V, Mo and Co, which are not only hazardous materials, but also can be considered as valuable secondary resources. The complete separation of these complex critical metals by solvent extraction still needs to be improved. Here, a selective extraction route for the separation of V/Mo/Co is proposed based on the weak interaction differences between extractants and metal, which is realized by theoretical calculation and experimental verification. This process does not require pretreatment of N1923 and Cyanex272 (C272), thus reduced the consume of acid and base as well as generation of waste water. With the preliminary results of V/Mo, Co/Mo, and V/Co separation, the weak interaction between extractants and metal molecules was revealed by quantum chemical calculations quantitatively. The molecular charge distribution, surface electrostatic potential distribution (ESP) and the average local ionization energy (ALIE) shows the priority reactivity of the metal molecules as: H 6 V 10 O 28 > H 2 Mo 4 O 13 > H 4 V 4 O 12 > H 3 VO 4 > H 2 MoO 4 . The independent gradient model based on Hirshfeld partition (IGMH) show differences in the weak interaction forces as: N1923-V>C272-Mo > C272-V>N1923-Mo > C272-Co. The selective separation process of V/Mo/Co was designed with the guide of above results. The combined recovery of the three metals V, Mo and Co amounted to 83.88 %, 87.08 %, and 99.01 %, respectively. The whole route reduces 3.92 t sulfuric acid and 7.83 t sodium hydroxide per solid, and reduces 1.99 t carbon emissions compared to the conventional route.
研究领域:
化学工程
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环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
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