International Journal of Minerals Metallurgy and Materials
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2023
·Vol. 30
·期 9
·1705-1715
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IF 4.8
Zhou Guotao,Wang Yilin,Qi Tiangui,Zhou Qiusheng,Liu Guihua,Peng Zhihong,Li Xiaobin
Goethitic bauxite is a widely used raw material in the alumina industry. It is an essential prerequisite to clarify the effect of Ti- and Si-containing minerals on goethite transformation in the Bayer digestion process, which could efficiently utilize the Fe- and Al-containing minerals present in goethitic bauxite. In this work, the interactions between anatase or kaolinite with goethite during various Bayer digestion processes were investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results showed that anatase and kaolinite hindered the transformation of goethite. Anatase exerted more significant effects than kaolinite due to the dense sodium titanate layer on the goethite surface after reacting with the sodium aluminate solution. Adding the reductant hydrazine hydrate could eliminate the retarding effect by inducing the transformation of goethite into magnetite. In this process, titanium was embedded into the magnetite lattice to form Ti-containing magnetite. Furthermore, the weakening of the interaction between magnetite and sodium aluminosilicate hydrate reduced the influence of kaolinite. As a validation of the above results, the reductive Bayer method resulted in the transformation of goethite into goethitic bauxite with 98.87% relative alumina digestion rate. The obtained red mud with 72.99wt% Fe 2 O 3 could be further utilized in the steel industry. This work provides a clear understanding of the transformative effects of Ti- and Si-containing minerals on iron mineral transformation and aids the comprehensive use of iron and aluminum in goethitic bauxite subjected to the reductive Bayer method.
研究领域:
矿物学
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冶金工程
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产品关联
DOI
高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2022
·
IF 3.752
Guo-tao ZHOU,Yi-lin WANG,Tian-gui QI,Qiu-sheng ZHOU,Gui-hua LIU,Zhi-hong PENG,Xiao-bin LI
The conversion mechanism of Al-goethite under the action of different additives (lime or reductant for typical or reductive Bayer digestion) was investigated by thermodynamic calculation, XRD, and SEM−EDS. The results show that the formation of Fe-substituted hydrocalumite is crucial to converting Al-goethite to hematite during Bayer digestion by adding lime. However, the conversion proceeds more easily under the action of reductant due to the rapid formation of magnetite. Additionally, Bayer liquor composition significantly affects the product composition and also the conversion rate of Al-goethite. Compared to typical Bayer digestion with Al-goethite containing gibbsitic bauxite as raw material, the red mud yield of reductive Bayer digestion decreases from 39.02% to 31.19%, and the grade of TFe in red mud increases from 41.66% to 53.80%.
研究领域:
矿物加工工程
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材料科学与工程
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产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Zhenjiang Fu,Guihua Liu,Tiangui Qi,Leiting Shen,Zhihong Peng,Xiaobin Li,Qiusheng Zhou,Yilin Wang
The imperative for eco-friendly and cost-efficient removal of anionic organics (surfactants) from Bayer liquor has persisted for decades. This paper proposes a novel and simple self-purification of anionic organics in Bayer liquor through trace amounts of cationic surfactants , synergistically integrated with the security filtration process in the Bayer process. Adding trace amounts of cationic surfactants (≤ 10 μmol· L −1 ) effectively compressed the cross-sectional of organics, generated the formation of ion pairs (complexes), reduced the critical micelle concentration of organics, and transformed the adsorption layer of organics from loose to dense. In addition, cationic surfactants changed the zeta potential from negative to positive in the electrical double layer of tricalcium aluminate hexahydrate (TCA) through strong physisorption . The physisorption also enhanced the surface dispersion force of TCA. Long- and double-tailed cationic surfactants were more effective in the regulation of molecular interactions than short- and single-tailed cationic surfactants. Ultimately, owing to the reduction of the repulsion among polar groups, the enhanced interaction among hydrophobic groups, as well as the reduced adsorption of OH − and Al(OH) 4 − , a dense-ordered interfacial structure of organics was subtly generated by trace amounts of cationic surfactants, contributing to the great adsorption capacity of 69.44 mg organic carbon/g. The simple and green self-purification of anionic organics in Bayer liquor is conducive to the sustainable development of the global alumina industry.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
LANGMUIR
·
2025
·
IF 3.9
Hanli Wang,Bianli Quan,Jun Xu,Dongyu Li
In this study, the corrosion environment in the evaporation stage of alumina production by the Bayer process was simulated, and TiO2-MMT/EP composite coating was prepared on the surface of Q235 steel. Montmorillonite (MMT) was functionalized via cation exchange and surface grafting using 3-aminopropyl triethoxysilane (KH550), enabling the introduction of organic groups onto the MMT surface and intercalation into its interlayer spacing. After compounding with titanium dioxide, the interlayer spacing of MMT was enlarged (from 1.27 to 2.13 nm) and its hydrophobicity was enhanced (contact angle from 48.14° to 105.6°). TiO2-MMT was added to epoxy resin (EP) to prepare a composite coating with multidimensional synergistic effect. The results show that the composite material can effectively fill the EP microhole defects, and the surface roughness of the coating is only 1.7 nm (pure EP is 65.5 nm). Electrochemical tests reveal that the corrosion current density (Icorr) was 1.126 × 10–5 A·cm–2, the protection efficiency was 98.40%, and the charge transfer resistance (Rct) reached 696.1 Ω·cm2, indicating that the coating effectively prolonged the diffusion pathways of corrosive ions through.
研究领域:
材料科学
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化学工程
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表面工程
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腐蚀科学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）