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Prof. Longhua Xu
School of Environment and Resources, Southwest University of Science and Technology, Mianyang 621010, China

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0 Adsorption
0 Flotation
0 Flotation chemistry
0 Spodumene
0 Rare earth ore

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Flotation
Adsorption
Spodumene
Mixed collectors
Flotation chemistry
Aluminosilicate minerals

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Journal article
Published: 14 August 2021 in Physicochemical Problems of Mineral Processing
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ACS Style

Yaohui Yang; Longhua Xu; Jian Deng; Shujun Liu. Influence of particle size on flotation separation of ilmenite, olivine, and pyroxene. Physicochemical Problems of Mineral Processing 2021, 57, 106 -117.

AMA Style

Yaohui Yang, Longhua Xu, Jian Deng, Shujun Liu. Influence of particle size on flotation separation of ilmenite, olivine, and pyroxene. Physicochemical Problems of Mineral Processing. 2021; 57 (5):106-117.

Chicago/Turabian Style

Yaohui Yang; Longhua Xu; Jian Deng; Shujun Liu. 2021. "Influence of particle size on flotation separation of ilmenite, olivine, and pyroxene." Physicochemical Problems of Mineral Processing 57, no. 5: 106-117.

Journal article
Published: 21 July 2021 in Colloids and Surfaces A: Physicochemical and Engineering Aspects
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Grinding, an essential pretreatment procedure before flotation, has particularly significance in spodumene flotation. The effects of grinding media on the flotation behavior of spodumene were investigated through zeta potential measurement, X-ray diffraction (XRD) test, scanning electron microscopy combined with energy dispersive spectrometry (SEM-EDS) and X-ray photoelectron spectroscopy (XPS). The particle size of spodumene ground by a corundum ball is concentrated around −74 + 38 µm, and the flotation recovery of spodumene upon grinding with a corundum ball was higher than that with an agate ball when DDA/NaOL are used as mixed collectors with a dosage of 0.4 mM (molar ratio = 1:6). Spodumene ground with corundum balls had a more exposed {110} cleavage plane and more Al active sites, while a more exposed {010} surface and less Al active sites were found in particles ground by agate balls. It also proved that spodumene milled by corundum balls has a higher adsorption density under the anion and cation mixed collector system. Given these results, it can be inferred that spodumene milled by corundum balls enhanced the adsorption of collectors on the surfaces.

ACS Style

Jinping Meng; Longhua Xu; Liping Luo; Kaiqian Shu. Effects of grinding media on the flotation behavior of spodumene in mixed anionic/cationic collectors system. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2021, 627, 127213 .

AMA Style

Jinping Meng, Longhua Xu, Liping Luo, Kaiqian Shu. Effects of grinding media on the flotation behavior of spodumene in mixed anionic/cationic collectors system. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2021; 627 ():127213.

Chicago/Turabian Style

Jinping Meng; Longhua Xu; Liping Luo; Kaiqian Shu. 2021. "Effects of grinding media on the flotation behavior of spodumene in mixed anionic/cationic collectors system." Colloids and Surfaces A: Physicochemical and Engineering Aspects 627, no. : 127213.

Journal article
Published: 07 May 2021 in Minerals Engineering
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Elucidation of the co-adsorption characteristics of multiple functional groups will help to screen suitable reagents to improve the floatability and comprehensive utilization of valuable minerals. Herein, salicylhydroxamic acid (SHA), an anionic collector with two functional groups, mixed with a cationic collector dodecylamine (DDA) in ilmenite-titanaugite flotation system was in-depth studied mainly using in-situ attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) combined with the two-dimensional correlation spectroscopic analysis (2D–COS) and X-ray photoelectron spectroscopy (XPS). The highest flotation separation performance, at pH 8–9, can be achieved using the SHA/DDA complex with a molar ratio of 6:1. Moreover, atomic force microscope (AFM) analysis ulteriorly proved the selectivity of the mixed SHA/DDA collector in the ilmenite-titanaugite flotation system. In-situ ATR-FTIR combined with 2D-COS gave the characteristic sequential adsorption and interaction with the functional groups related to SHA/DDA, which was further confirmed in the results of XPS. The preferred adsorption configuration for the adsorption of the mixed collector were drew to explain the flotation separation between ilmenite and titanaugite. It is predictable that the detailed study into the hybrid collectors with multiple functional groups will provide new insights into the design, synthesis and development of more-powerful collectors.

ACS Style

Liping Luo; Longhua Xu; Jinping Meng; Jiahui Lu; Houqin Wu. New insights into the mixed anionic/cationic collector adsorption on ilmenite and titanaugite: An in situ ATR-FTIR/2D-COS study. Minerals Engineering 2021, 169, 106946 .

AMA Style

Liping Luo, Longhua Xu, Jinping Meng, Jiahui Lu, Houqin Wu. New insights into the mixed anionic/cationic collector adsorption on ilmenite and titanaugite: An in situ ATR-FTIR/2D-COS study. Minerals Engineering. 2021; 169 ():106946.

Chicago/Turabian Style

Liping Luo; Longhua Xu; Jinping Meng; Jiahui Lu; Houqin Wu. 2021. "New insights into the mixed anionic/cationic collector adsorption on ilmenite and titanaugite: An in situ ATR-FTIR/2D-COS study." Minerals Engineering 169, no. : 106946.

Journal article
Published: 10 July 2020 in Applied Surface Science
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Bastnaesite is a chief natural source of light rare earth elements (LREEs). The effective depression of Ca-containing minerals such as fluorite and calcite in bastnaesite flotation system is normally difficult, and it is imperative to exploit more environmentally-friendly depressants which can inhibit these gangue minerals simultaneously. Hence, we employ citric acid (H3Cit), a green, cheap and commonly available organic acid, to selectively depress the flotation of fluorite and calcite, and use octanohydroxamic acid (OHA) and sodium oleate (NaOL) with a molar ratio of 2:1 as mixed collectors. Micro-flotation results show that H3Cit decreases the recoveries of fluorite, calcite, and bastnaesite by 84.73%, 62.96%, and 9.23%, respectively at pH 8–9. The depression mechanism of H3Cit was investigated through zeta potential measurements, microcalorimetry measurements, solution chemistry and reaction thermodynamic analyses, and X-ray photoelectron spectroscopy (XPS) analyses. These further analyses at the minerals/water interfaces indicate that H3Cit preferentially adsorbs on the gangue mineral surfaces due to the positively charged fluorite and calcite surfaces which interact more easily with citrate ions (Cit3-), and the spontaneous interaction between Cit3- and Ca2+ on the surfaces. Accordingly, H3Cit is supposed to be a potential depressant for Ca-containing minerals in the flotation separation of bastnaesite.

ACS Style

Yanbo Xu; Longhua Xu; Houqin Wu; Jia Tian; Zhoujie Wang; Xiaochuan Gu. The effect of citric acid in the flotation separation of bastnaesite from fluorite and calcite using mixed collectors. Applied Surface Science 2020, 529, 147166 .

AMA Style

Yanbo Xu, Longhua Xu, Houqin Wu, Jia Tian, Zhoujie Wang, Xiaochuan Gu. The effect of citric acid in the flotation separation of bastnaesite from fluorite and calcite using mixed collectors. Applied Surface Science. 2020; 529 ():147166.

Chicago/Turabian Style

Yanbo Xu; Longhua Xu; Houqin Wu; Jia Tian; Zhoujie Wang; Xiaochuan Gu. 2020. "The effect of citric acid in the flotation separation of bastnaesite from fluorite and calcite using mixed collectors." Applied Surface Science 529, no. : 147166.

Journal article
Published: 02 July 2020 in Separation and Purification Technology
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Herein, benzohydroxamic acid/dodecylamine (BHA/DDA, optimal molar ratio of 6:1) demonstrated the excellent separation in the flotation of spodumene (ca. 88% recovery) from feldspar (ca. 24% recovery) at pH 8–9. To detect the underlying mechanism, in-situ attenuated-total-reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy with two-dimensional correlation spectroscopy (2D-COS), zeta potential measurements, in-situ microcalorimetry, and X-ray photoelectron spectroscopy (XPS) were performed. In-situ microcalorimetry results indicated that the mixed collector released more heat than the individual collectors for both minerals. Moreover, The order of the difference in the adsorption reaction heat between this two minerals is as follows: |ΔQ| BHA/DDA (13.948 J·g-1) ˃ |ΔQ|DDA (3.116 J·g-1) ˃ |ΔQ|BHA (1.110 J·g-1), confirming the excellent separating ability of mixed collector. In-situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and two-dimensional correlation spectroscopy (2D-COS) sequences results showed that the sorption process and configuration of BHA/DDA (0.4 mM, molar ratio = 6:1) on spodumene and feldspar surfaces were different at pH of 4 – 5 and 8 – 9, mainly due to the different BHA structure and the formation of hydrogen bond between BHA and DDA at different pH range. Zeta-potential and X-ray photoelectron spectroscopy (XPS) also suggested that their prominent separation is not simply due to the higher adsorption density for a single collector in the presence of mixed collector. Lastly, recommended adsorption models for the adsorption of the complex on the surfaces of spodumene and feldspar were proposed. This work provided powerful in-situ detection technologies to reveal the reagent-solid interaction in selective separation processes.

ACS Style

Kaiqian Shu; Longhua Xu; Houqin Wu; Lin Peng; Yanbo Xu; Liping Luo; Jie Yang; Zhen Tang. In situ adsorption of mixed collectors BHA/DDA in spodumene-feldspar flotation system. Separation and Purification Technology 2020, 251, 117325 .

AMA Style

Kaiqian Shu, Longhua Xu, Houqin Wu, Lin Peng, Yanbo Xu, Liping Luo, Jie Yang, Zhen Tang. In situ adsorption of mixed collectors BHA/DDA in spodumene-feldspar flotation system. Separation and Purification Technology. 2020; 251 ():117325.

Chicago/Turabian Style

Kaiqian Shu; Longhua Xu; Houqin Wu; Lin Peng; Yanbo Xu; Liping Luo; Jie Yang; Zhen Tang. 2020. "In situ adsorption of mixed collectors BHA/DDA in spodumene-feldspar flotation system." Separation and Purification Technology 251, no. : 117325.

Research article
Published: 19 June 2020 in Langmuir
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Herein, we investigated the effects of mixed collectors with varying alkyl chain lengths and ligand types on the hydrophobicity of the spodumene–feldspar flotation system. Various collector–mineral interactions were compared using in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy with two-dimensional correlation spectroscopy (2D-COS), in situ microcalorimetry, and X-ray photoelectron spectroscopy (XPS). The highest flotation separation performance can be achieved at a molar ratio of 6:1 and pH 8–9. The in situ microcalorimetry results revealed that the difference in the adsorption reaction heat of the mixed collector is larger than that of the single anionic collector. Moreover, the inconformity between the magnitude of adsorption reaction heat and the results observed for flotation recovery indicates that the heat of the reaction presumably involves the adsorption configurations of the collectors and the amounts adsorbed. In in situ ATR-FTIR with 2D-COS, it can be observed that octanohydroxamic acid/dodecylamine (OHA/DDA) is adsorbed much more intensely onto feldspar than onto spodumene due to the availability of more space on feldspar for the subsequent sorption of DDA after the prior bidentate chemisorption of OHA under alkaline conditions, whereas the sodium oleate (NaOL)/DDA adsorption sequence at pH 4–5 was the reverse of that at pH 8–9. Lastly, XPS was employed to provide further supplemental evidence for the bonding between these two minerals and single anionic/mixed collectors at the optimal pH of 8–9. In this study, the powerful in situ detection technologies can establish a new platform for exploring the underlying mechanism of new reagents at the solid–liquid interface. Moreover, the in-depth understanding related to the adsorption behavior of the mixed collector is beneficial for facilitating the selection and design of efficient and environmentally friendly flotation collectors with improved selectivity.

ACS Style

Kaiqian Shu; Longhua Xu; Houqin Wu; Yanbo Xu; Liping Luo; Jie Yang; Zhen Tang; Zhoujie Wang. In Situ Adsorption of Mixed Anionic/Cationic Collectors in a Spodumene–Feldspar Flotation System: Implications for Collector Design. Langmuir 2020, 36, 8086 -8099.

AMA Style

Kaiqian Shu, Longhua Xu, Houqin Wu, Yanbo Xu, Liping Luo, Jie Yang, Zhen Tang, Zhoujie Wang. In Situ Adsorption of Mixed Anionic/Cationic Collectors in a Spodumene–Feldspar Flotation System: Implications for Collector Design. Langmuir. 2020; 36 (28):8086-8099.

Chicago/Turabian Style

Kaiqian Shu; Longhua Xu; Houqin Wu; Yanbo Xu; Liping Luo; Jie Yang; Zhen Tang; Zhoujie Wang. 2020. "In Situ Adsorption of Mixed Anionic/Cationic Collectors in a Spodumene–Feldspar Flotation System: Implications for Collector Design." Langmuir 36, no. 28: 8086-8099.

Journal article
Published: 19 May 2020 in Minerals Engineering
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The selective separation of titanium-containing minerals is industrially important. Microwave irradiation pre-treatment can be used to modify the surface properties of minerals to promote selective flotation. However, the effects of MW treatment on titanium-containing minerals is not well understood. Therefore, in this study, we investigated the effects of microwave treatment on the flotation behaviour of ilmenite and titanaugite in a mixture of these minerals. The effects of this pre-treatment method were investigated by various techniques, including flotation tests, scanning electron microscopy (SEM), inductively coupled plasma-optical emission spectrometry (ICP-OES), zeta potential measurements, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared (FTIR) spectroscopy. The flotation tests results reveal that, under the optimum microwave conditions (800 W, 450 s), microwave irradiation has a remarkable effect on the flotation of ilmenite but no significant effect on the floatability of titanaugite at pH 6.0. The results of the SEM and ICP-OES analyses indicate that microwave irradiation promotes the dissolution of Ca2+ and Mg2+ ions from the titanaugite surface, whereas the dissolution of these ions from ilmenite is limited. Further, the zeta potential of the microwave-irradiated ilmenite shifted toward negative values, and the isoelectric point shifted from pH 4.9 to pH ~1.9. In addition, the XPS results reveal that microwave irradiation facilitates the conversion of Fe2+ to Fe3+ on the mineral surfaces. The FTIR spectra and zeta potential values indicate that microwave irradiation can enhance the chemical adsorption of oleate ions on the surface of the ilmenite. After microwave irradiation, the effects of both the dissolution of Ca2+ and Mg2+ ions and the oxidation of Fe2+ to Fe3+, the floatability of ilmenite was significantly improved, whereas that of titanaugite was not changed significantly.

ACS Style

Liping Luo; Houqin Wu; Jie Yang; Zhen Tang; Kaiqian Shu; Yanbo Xu; Weipin Yan; Longhua Xu. Effects of microwave pre-treatment on the flotation of ilmenite and titanaugite. Minerals Engineering 2020, 155, 106452 .

AMA Style

Liping Luo, Houqin Wu, Jie Yang, Zhen Tang, Kaiqian Shu, Yanbo Xu, Weipin Yan, Longhua Xu. Effects of microwave pre-treatment on the flotation of ilmenite and titanaugite. Minerals Engineering. 2020; 155 ():106452.

Chicago/Turabian Style

Liping Luo; Houqin Wu; Jie Yang; Zhen Tang; Kaiqian Shu; Yanbo Xu; Weipin Yan; Longhua Xu. 2020. "Effects of microwave pre-treatment on the flotation of ilmenite and titanaugite." Minerals Engineering 155, no. : 106452.

Journal article
Published: 19 May 2020 in Separation and Purification Technology
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Sodium alginate (SA) was investigated for use as a depressant in the spodumene–feldspar system. In this flotation system, the SA is added before the cation collector, dodecylamine (DDA). The effects of SA on mineral floatability were systematically investigated by flotation experiments, X-ray photoelectron spectroscopy (XPS), Fourier transform IR spectroscopy (FTIR), zeta potential measurements, and speciation analysis. Single-mineral flotation results showed that using 30 mg/L SA allowed the separation of spodumene from feldspar at pH 6, although there was a strong pH dependence. Zeta potential measurements and FTIR analysis showed that SA and DDA can adsorb onto both minerals. XPS analysis revealed the adsorption mechanism: the strong affinity of SA for the mineral surface arose from the complexation of SA and Al sites. Analysis of the surface and solution chemistry revealed that SA chelated Al3+ or its hydroxides and hindered the subsequent adsorption of DDA, resulting in a hydrophilic feldspar surface. In addition, there were more aluminium hydroxides and unsaturated O atoms on the spodumene surface than on that of feldspar, and these provided available sites for the adsorption of DDA to form a stable reticular structure with SA, thus improving the floatability of the spodumene at certain pH values. Lastly, a model for SA and DDA adsorption at the water–solid interface is proposed.

ACS Style

Kaiqian Shu; Longhua Xu; Houqin Wu; Zhen Tang; Liping Luo; Jie Yang; Yanbo Xu; Bo Feng. Selective flotation separation of spodumene from feldspar using sodium alginate as an organic depressant. Separation and Purification Technology 2020, 248, 117122 .

AMA Style

Kaiqian Shu, Longhua Xu, Houqin Wu, Zhen Tang, Liping Luo, Jie Yang, Yanbo Xu, Bo Feng. Selective flotation separation of spodumene from feldspar using sodium alginate as an organic depressant. Separation and Purification Technology. 2020; 248 ():117122.

Chicago/Turabian Style

Kaiqian Shu; Longhua Xu; Houqin Wu; Zhen Tang; Liping Luo; Jie Yang; Yanbo Xu; Bo Feng. 2020. "Selective flotation separation of spodumene from feldspar using sodium alginate as an organic depressant." Separation and Purification Technology 248, no. : 117122.

Review article
Published: 05 May 2020 in Minerals Engineering
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Focusing on salt-type and oxide minerals, this paper reviews the research on anisotropic surface chemistry properties, including broken bonds, surface energy, wettability, and surface charge. Moreover, based on the analysis of anisotropic surface properties, the anisotropic adsorption behaviour of reagents on mineral surfaces is also reviewed. The research on anisotropic surface chemistry is instructive to understand some of the properties of the minerals themselves and the reactions in which minerals participate. In addition, the investigation on the anisotropic adsorption behaviour of reagent molecules on mineral surfaces will definitely strengthen the understanding of the efficiency of the interactions. In general, with the knowledge of mineral anisotropy, the relationship between the selective pre-treatment of a mineral and the efficient adsorption of reagent molecules on mineral surfaces will be established.

ACS Style

Houqin Wu; Jia Tian; Longhua Xu; Zhoujie Wang; Yanbo Xu; Zhiyong Gao; Wei Sun; Xu Longhua. Anisotropic surface chemistry properties of salt-type and oxide mineral crystals. Minerals Engineering 2020, 154, 106411 .

AMA Style

Houqin Wu, Jia Tian, Longhua Xu, Zhoujie Wang, Yanbo Xu, Zhiyong Gao, Wei Sun, Xu Longhua. Anisotropic surface chemistry properties of salt-type and oxide mineral crystals. Minerals Engineering. 2020; 154 ():106411.

Chicago/Turabian Style

Houqin Wu; Jia Tian; Longhua Xu; Zhoujie Wang; Yanbo Xu; Zhiyong Gao; Wei Sun; Xu Longhua. 2020. "Anisotropic surface chemistry properties of salt-type and oxide mineral crystals." Minerals Engineering 154, no. : 106411.

Journal article
Published: 10 February 2020 in Applied Surface Science
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The inability of rare earth and gangue minerals to be efficiently separated by flotation due to their similar physicochemical properties is a major challenge of the rare earth industry. Bastnaesite is one of the principal sources of light rare earth elements. The use of traditional flotation reagents often poses the problem of poisonous wastewater generation. Therefore, we use xanthan gum (XG) as a non-toxic, biodegradable, and cheap depressant to selectively separate bastnaesite from calcite by flotation and probe the corresponding mechanism. Microflotation experiments/zeta potential measurements conducted with/without XG using sodium oleate as a collector demonstrate that at pH 8, XG decreases the flotation recoveries of calcite and bastnaesite by 85.09 and 22.37%, respectively. Further analysis of adsorption behaviour on the mineral surface and possible reagent-mineral interactions shows that selective mineral separation is due to the preferential interaction of XG with Ca ions on the calcite surface and the suppression of oleate ion adsorption thereon due to the steric hindrance of polymeric XG. Hence with regard to the potential of XG in calcium-bearing mineral separation, XG could be as a new depressant for RE mineral flotation.

ACS Style

Zhoujie Wang; Houqin Wu; Jie Yang; Zhen Tang; Liping Luo; Kaiqian Shu; Yanbo Xu; Longhua Xu. Selective flotation separation of bastnaesite from calcite using xanthan gum as a depressant. Applied Surface Science 2020, 512, 145714 .

AMA Style

Zhoujie Wang, Houqin Wu, Jie Yang, Zhen Tang, Liping Luo, Kaiqian Shu, Yanbo Xu, Longhua Xu. Selective flotation separation of bastnaesite from calcite using xanthan gum as a depressant. Applied Surface Science. 2020; 512 ():145714.

Chicago/Turabian Style

Zhoujie Wang; Houqin Wu; Jie Yang; Zhen Tang; Liping Luo; Kaiqian Shu; Yanbo Xu; Longhua Xu. 2020. "Selective flotation separation of bastnaesite from calcite using xanthan gum as a depressant." Applied Surface Science 512, no. : 145714.

Journal article
Published: 21 January 2020 in Minerals Engineering
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Issues related to environmental pollution and resource wastage have made the utilisation of Pb-bearing Zn residue an extremely urgent requirement. The floatability of artificial galena (AG) with a traditional xanthate collector was greatly improved by using a catanionic mixture (CM) as a collector, and the micromechanism was examined using flotation, zeta potential, adsorption, and slow positron beam measurements, together with molecular dynamics simulation. The flotation results revealed that the floatability of AG was inferior to that of natural galena (NG) when potassium amyl xanthate (KAX) was used as the collector, but it improved when using the CM. The results of zeta potential measurements, adsorption experiments, and slow positron beam detection demonstrated that the amount of KAX adsorbed on AG in the KAX/AG system was lower than that on NG in the KAX/NG system because of the greater electronegativity of surface Pb active sites resulting from the presence of S vacancy defects in AG. The molecular dynamics simulation showed that cetyl pyridine chloride and KAX promoted each other’s adsorption in the CM/AG system because of the electrostatic attraction between the sulfhydryl and pyridyl groups and the hydrophobic attraction between the amyl and cetyl groups. An adsorption model was proposed to better explain the greater floatability of AG when using the CM.

ACS Style

Zhen Wang; Yang Peng; Yongxing Zheng; Wei Ding; Jinming Wang; Longhua Xu. Improved flotation of artificial galena using a new catanionic mixture. Minerals Engineering 2020, 148, 106206 .

AMA Style

Zhen Wang, Yang Peng, Yongxing Zheng, Wei Ding, Jinming Wang, Longhua Xu. Improved flotation of artificial galena using a new catanionic mixture. Minerals Engineering. 2020; 148 ():106206.

Chicago/Turabian Style

Zhen Wang; Yang Peng; Yongxing Zheng; Wei Ding; Jinming Wang; Longhua Xu. 2020. "Improved flotation of artificial galena using a new catanionic mixture." Minerals Engineering 148, no. : 106206.

Journal article
Published: 24 December 2019 in Powder Technology
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Herein, a novel method of ultrasonic treatment for selectively recovering ilmenite from titanaugite was investigated via systematic mineral flotation tests along with dissolution texts, microcalorimetry, scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS) analyses. Flotation tests indicate that ultrasonic treatment promotes the ilmenite floatability but depresses titanaugite floatability. When ultrasonic time and power are 5 min and 500 W, selectivity of ilmenite from titanaugite can be enhanced. Dissolution tests show that ultrasound can strengthen the dissolution of Ca and Mg but has little effect on Fe species. Microcalorimetric measurements confirm that ultrasonic-treated ilmenite is more prone to release heat than titanaugite. SEM images reveal that the surface roughness of the titanaugite is greater than that of the ilmenite, indicating that the particle collision of titanaugite is greater than ilmenite. XPS indicates that NaOL adsorption on ultrasonic-treated ilmenite surfaces is greater than that for titanaugite.

ACS Style

Houqin Wu; Shuai Fang; Kaiqian Shu; Yanbo Xu; Zhoujie Wang; Liping Luo; Jie Yang; Longhua Xu. Selective flotation and adsorption of ilmenite from titanaugite by a novel method: Ultrasonic treatment. Powder Technology 2019, 363, 38 -47.

AMA Style

Houqin Wu, Shuai Fang, Kaiqian Shu, Yanbo Xu, Zhoujie Wang, Liping Luo, Jie Yang, Longhua Xu. Selective flotation and adsorption of ilmenite from titanaugite by a novel method: Ultrasonic treatment. Powder Technology. 2019; 363 ():38-47.

Chicago/Turabian Style

Houqin Wu; Shuai Fang; Kaiqian Shu; Yanbo Xu; Zhoujie Wang; Liping Luo; Jie Yang; Longhua Xu. 2019. "Selective flotation and adsorption of ilmenite from titanaugite by a novel method: Ultrasonic treatment." Powder Technology 363, no. : 38-47.

Journal article
Published: 04 December 2019 in Separation and Purification Technology
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The flotation of rare earth minerals, which is of current interest in the mineral processing field, is challenging owing to the dissolution of gangue minerals. In this study, dissolved fluorite and barite species were found to significantly affect the flotation behavior of bastnaesite. The mechanism was investigated using microflotation tests, zeta potential measurements, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and solution chemistry analysis. The microflotation results confirmed that the presence of gangue supernatants significantly reduces the recovery of bastnaesite during flotation with sodium oleate as a collector. The zeta potential and solution chemistry analyses showed that the supernatant species can adsorb onto the bastnaesite surface by forming hydroxy and carbonate compounds, thus affecting the zeta potential value and reducing the adsorption of oleate species. The FTIR analysis suggested that treatment with supernatants weakens the adsorption of oleate species, and that Ca/Ba-oleate complexes are adsorbed on the bastnaesite surface. The XPS analysis confirmed that lattice ions from the gangue minerals adsorb/precipitate on the bastnaesite surface, hindering the chemisorption of oleate species and thus decreasing the floatability of bastnaesite.

ACS Style

Zhoujie Wang; Houqin Wu; Yanbo Xu; Kaiqian Shu; Jie Yang; Liping Luo; Longhua Xu. Effect of dissolved fluorite and barite species on the flotation and adsorption behavior of bastnaesite. Separation and Purification Technology 2019, 237, 116387 .

AMA Style

Zhoujie Wang, Houqin Wu, Yanbo Xu, Kaiqian Shu, Jie Yang, Liping Luo, Longhua Xu. Effect of dissolved fluorite and barite species on the flotation and adsorption behavior of bastnaesite. Separation and Purification Technology. 2019; 237 ():116387.

Chicago/Turabian Style

Zhoujie Wang; Houqin Wu; Yanbo Xu; Kaiqian Shu; Jie Yang; Liping Luo; Longhua Xu. 2019. "Effect of dissolved fluorite and barite species on the flotation and adsorption behavior of bastnaesite." Separation and Purification Technology 237, no. : 116387.

Journal article
Published: 07 November 2019 in Journal of Alloys and Compounds
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Octanohydroxamic acid (OHA) and sodium oleate (NaOL) were employed as mixed collectors to reduce the cost, increase the recovery, and retain the selectivity for the flotation of bastnaesite. Flotation experiments, zeta potential measurements, Fourier transform infrared (FTIR) spectroscopy, pyrene fluorescence measurements and X-ray photoelectron spectroscopy (XPS) were used to investigate the flotation and possible adsorption mechanism of mixed OHA/NaOL collectors on bastnaesite. The flotation experiments show that a lower dosage of mixed OHA/NaOL collectors (total concentration 1 × 10−4 mol/L, OHA:NaOL = 2:1 at pH 7) can achieve a recovery of 94.02%, which is 33% higher than that using single OHA at the same condition. Zeta potential measurements and FTIR analyses indicate that OHA/NaOL chemisorb more strongly on bastnaesite surface than each of its components. Pyrene fluorescence measurements illustrate that the critical micelle concentration (CMC) of the mixed OHA/NaOL is lower than that of either component alone, together with a higher adsorption density on bastnaesite. XPS measurements show a new peak at 288.4 eV and an increase in the C (1s) peak intensity at 284.8 eV from 15.87% to 37.85% when using the mixed OHA/NaOL. Therefore, the mixed collectors have a stronger flotation ability and produce a thicker adsorption layer.

ACS Style

Yanbo Xu; Longhua Xu; Houqin Wu; Zhoujie Wang; Kaiqian Shu; Shuai Fang; ZhenYue Zhang. Flotation and co–adsorption of mixed collectors octanohydroxamic acid/sodium oleate on bastnaesite. Journal of Alloys and Compounds 2019, 819, 152948 .

AMA Style

Yanbo Xu, Longhua Xu, Houqin Wu, Zhoujie Wang, Kaiqian Shu, Shuai Fang, ZhenYue Zhang. Flotation and co–adsorption of mixed collectors octanohydroxamic acid/sodium oleate on bastnaesite. Journal of Alloys and Compounds. 2019; 819 ():152948.

Chicago/Turabian Style

Yanbo Xu; Longhua Xu; Houqin Wu; Zhoujie Wang; Kaiqian Shu; Shuai Fang; ZhenYue Zhang. 2019. "Flotation and co–adsorption of mixed collectors octanohydroxamic acid/sodium oleate on bastnaesite." Journal of Alloys and Compounds 819, no. : 152948.

Journal article
Published: 24 October 2019 in Minerals Engineering
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The flotation behavior of bastnaesite, a major mineral source of rare earth elements, is strongly affected by the dissolved species of gangue minerals that change the solution chemistry and mineral surface properties. In this work, the effect of dissolved calcite species on the flotation of bastnaesite was investigated by conducting micro-flotation experiments, zeta potential measurements, Fourier-transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS) analysis. Micro-flotation experiments confirmed that calcium and carbonate ions in calcite supernatant significantly reduced the flotation of bastnaesite in strongly alkaline condition. Zeta potential measurements showed that the IEP of higher bastnaesite was obtained after the addition of calcite supernatant species. Species distribution diagram demonstrated that the adsorption of sodium oleate on the surface species of bastnaesite was inhibited by the generation of calcium-containing hydroxy complexes and precipitates. FT-IR analysis suggested that the decrease the sodium oleate concentration in solution and the generation of calcium oleate precipitate on the mineral surface are possible reasons for the reduced recovery. XPS analysis further revealed that the metal carbonates and hydroxy complexes of calcium adsorbed on the bastnaesite surface in the presence of calcite supernatant, which concealed the surface active sites, caused the decrease in bastnaesite flotation recovery.

ACS Style

Zhoujie Wang; Houqin Wu; Yanbo Xu; Kaiqian Shu; Shuai Fang; Longhua Xu. The effect of dissolved calcite species on the flotation of bastnaesite using sodium oleate. Minerals Engineering 2019, 145, 106095 .

AMA Style

Zhoujie Wang, Houqin Wu, Yanbo Xu, Kaiqian Shu, Shuai Fang, Longhua Xu. The effect of dissolved calcite species on the flotation of bastnaesite using sodium oleate. Minerals Engineering. 2019; 145 ():106095.

Chicago/Turabian Style

Zhoujie Wang; Houqin Wu; Yanbo Xu; Kaiqian Shu; Shuai Fang; Longhua Xu. 2019. "The effect of dissolved calcite species on the flotation of bastnaesite using sodium oleate." Minerals Engineering 145, no. : 106095.

Journal article
Published: 01 October 2019 in Applied Surface Science
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Selective separation of ilmenite from gangue minerals after ultrasonic preconditioning was studied in terms of surface dissolution. After preconditioning, ilmenite exhibited better single-mineral flotation capacity while titanaugite and olivine had lower recoveries. Significant separation could be obtained at pH 6.0 after ultrasonic treatment (500 W, 5 min). Zeta potentials of preconditioned titanaugite and olivine shifted positively compared to those of raw titanaugite and olivine treated with sodium oleate (NaOL), respectively. Meanwhile, the zeta potential of ilmenite was similar before and after NaOL adsorption. Mineral dissolution results indicate that ultrasonic preconditioning promotes the dissolution of Mg and Fe species but not the Ca species. The dissolution of Ca and Mg is much higher than that of Fe. According to solution chemistry calculation, Fe(OH)3 precipitate is dominant at pH greater than 2.5, and Ca2+, Mg2+, Fe2+, and Fe(OH)+ are dominant under acidic conditions. Microcalorimetric measurements demonstrate that the preconditioned ilmenite releases more heat during NaOL adsorption than titanaugite and olivine do. XPS results reveal that ultrasonic treatment facilitates the conversion of Fe2+ to Fe3+. After preconditioning, Fe species interacted with NaOL to promote the latter’s chemisorption on ilmenite and olivine, while Ca2+ was more likely to interact with NaOL on titanaugite.

ACS Style

Shuai Fang; Longhua Xu; Houqin Wu; Yanbo Xu; Zhoujie Wang; Kaiqian Shu; Xu Longhua. Influence of surface dissolution on sodium oleate adsorption on ilmenite and its gangue minerals by ultrasonic treatment. Applied Surface Science 2019, 500, 144038 .

AMA Style

Shuai Fang, Longhua Xu, Houqin Wu, Yanbo Xu, Zhoujie Wang, Kaiqian Shu, Xu Longhua. Influence of surface dissolution on sodium oleate adsorption on ilmenite and its gangue minerals by ultrasonic treatment. Applied Surface Science. 2019; 500 ():144038.

Chicago/Turabian Style

Shuai Fang; Longhua Xu; Houqin Wu; Yanbo Xu; Zhoujie Wang; Kaiqian Shu; Xu Longhua. 2019. "Influence of surface dissolution on sodium oleate adsorption on ilmenite and its gangue minerals by ultrasonic treatment." Applied Surface Science 500, no. : 144038.

Journal article
Published: 12 September 2019 in Minerals Engineering
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In this work, the performance of the novel depressant aluminum–sodium silicate (Al–Na2SiO3) was compared to that of Na2SiO3, and the flotation and adsorption on the olivine surface were investigated with single-mineral flotation tests, zeta potential measurements, microcalorimetry, Fourier-transform infrared (FTIR) spectroscopy, and thermodynamic analyses. From the mineral flotation test results, Al–Na2SiO3 was found to exhibit an improved depression capacity as compared to the samples in the absence of Al3+, and the depression properties of Al–Na2SiO3 were found to depend on the Al3+ concentration. Thus, when the Al3+ concentration was higher than or equal to 0.1 mM, a significant depression capacity for olivine could be realized. From the obtained zeta potentials, it was found that by introducing assistant Al(III) species, the zeta potential of olivine exhibited a more positive integral shift than that of pure olivine and NaOL + Na2SiO3. In addition, according to the species distribution of Al2(SO4)3 and Na2SiO3, Si(OH)4 could interact with Al(OH)2+, Al(OH)2+, and Al3+ ions to form some monomeric silicate species and/or a polysilicate–aluminum material to inhibit the floatability of olivine. Moreover, the results of microcalorimetric measurements revealed that the reaction heats of the utilized reagents could be in the order of Al3+ < Na2SiO3 < NaOL and Al–Na2SiO3 + NaOL < Na2SiO3 + NaOL, suggesting that the NaOL species exhibited the highest affinities to the olivine surface and Al–Na2SiO3 impeded the adsorption of NaOL on the olivine surface. Furthermore, the thermodynamic analyses revealed that in the pH range of 2–9, the standard Gibbs free energy of Al3+ reacting with NaOL was lower than those of Mg2+ and Fe2+ but similar when the pH was above 9. This indicates that NaOL is more likely to interact with the Al3+ species in the pH range of 2–9; however, above pH 9, there is no significant difference in adsorption with Mg2+ or Fe2+. Finally, the FTIR spectra revealed that the adsorption of Al–Na2SiO3 + NaOL on the olivine surface was weaker than that of the sample without assistant Al ions.

ACS Style

Shuai Fang; Longhua Xu; Houqin Wu; Kaiqian Shu; Zhoujie Wang; Yanbo Xu. Influence of aluminum–sodium silicate on olivine flotation with sodium oleate. Minerals Engineering 2019, 143, 106008 .

AMA Style

Shuai Fang, Longhua Xu, Houqin Wu, Kaiqian Shu, Zhoujie Wang, Yanbo Xu. Influence of aluminum–sodium silicate on olivine flotation with sodium oleate. Minerals Engineering. 2019; 143 ():106008.

Chicago/Turabian Style

Shuai Fang; Longhua Xu; Houqin Wu; Kaiqian Shu; Zhoujie Wang; Yanbo Xu. 2019. "Influence of aluminum–sodium silicate on olivine flotation with sodium oleate." Minerals Engineering 143, no. : 106008.

Journal article
Published: 31 July 2019 in Minerals
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Fine particles in the presence of flotation reagents exhibit different dispersion and aggregation behaviors in a mineral suspension, and affect the flotation separation processes. In this study, the effects of three quaternary ammonium salts (i.e., dodecyltrimethylammonium chloride (DTAC), tetradecyltrimethylammonium chloride (TTAC), and hexadecyltrimethylammonium chloride (CTAC)) on the dispersion and aggregation behaviors of kaolinite and quartz were studied. The mechanism was systematically investigated using sedimentation tests, reagent adsorption analysis, zeta potential measurements, and SEM analysis. In the absence of reagents, the kaolinite and quartz particles exhibited good aggregation behaviors at acid and neutral pHs compared with alkaline conditions. Except for CTAC, the presence of DTAC and TTAC improved the aggregation behavior of both minerals in neutral and alkaline conditions. More, the sedimentation yields of both minerals were increased significantly with increasing the concentration of DTAC and TTAC. However, the increasing concentration of CTAC resulted in an increase in the dispersion of kaolinite and quartz particles under the same conditions. At neutral and alkaline conditions, the zeta potentials and adsorbed amounts of all three salts on the mineral surfaces were increased significantly with increasing the concentrations of salts, and the adsorbed amount adopted the following sequence: CTAC > TTAC > DTAC. The zeta potential results showed that the stronger adsorption of quaternary ammonium salts on mineral surfaces at neutral and alkaline conditions was mainly because of electrostatic interactions.

ACS Style

Hao Jiang; Guoyuan Xiang; Sultan Ahmed Khoso; Jiahui Xie; Kai Huang; Longhua Xu. Comparative Studies of Quaternary Ammonium Salts on the Aggregation and Dispersion Behavior of Kaolinite and Quartz. Minerals 2019, 9, 473 .

AMA Style

Hao Jiang, Guoyuan Xiang, Sultan Ahmed Khoso, Jiahui Xie, Kai Huang, Longhua Xu. Comparative Studies of Quaternary Ammonium Salts on the Aggregation and Dispersion Behavior of Kaolinite and Quartz. Minerals. 2019; 9 (8):473.

Chicago/Turabian Style

Hao Jiang; Guoyuan Xiang; Sultan Ahmed Khoso; Jiahui Xie; Kai Huang; Longhua Xu. 2019. "Comparative Studies of Quaternary Ammonium Salts on the Aggregation and Dispersion Behavior of Kaolinite and Quartz." Minerals 9, no. 8: 473.

Journal article
Published: 16 May 2019 in Ultrasonics Sonochemistry
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In this study, we used flotation tests, Fourier transform infrared spectroscopy (FTIR), zeta potential, X-ray photoelectron spectroscopy (XPS), and microcalorimetry measurements to investigate the flotation and possible adsorption mechanisms of the ilmenite surface before and after ultrasonic pre-treatment. Flotation results show that under optimum conditions, the promotion effect of sonication on ilmenite is remarkable. The maximum recovery is 89.54% for ultrasonicated ilmenite at a pH of 4–5. For pH of 8–9, recovery increased again to 66.34%. Microcalorimetry indicates that the adsorption-driven heat release (-Qads) is higher for ultrasonicated ilmenite than for raw one. After pre-treatment, the iso-electric point (IEP) changed from pH 6.2 to pH 4.2. FTIR spectra and zeta potential measurements indicated that metal ions as active sites on the ilmenite surface are probably changed by the ultrasonic treatment. XPS analysis shows that ultrasonic treatment can promotes the oxidation of Fe2+ to Fe3+ and improves the solubilization of Ca2+ and Mg2+ in the pH range of 4–5. Under weakly alkaline condition, ultrasound also can make Ca2+ and Mg2+ re-absorb onto the ilmenite surface as main active sites.

ACS Style

Kaiqian Shu; Longhua Xu; Houqin Wu; Zhoujie Wang; Yanbo Xu; Shuai Fang. Influence of ultrasound pre-treatment on ilmenite surface chemical properties and collectors’ adsorption behaviour. Ultrasonics Sonochemistry 2019, 57, 98 -107.

AMA Style

Kaiqian Shu, Longhua Xu, Houqin Wu, Zhoujie Wang, Yanbo Xu, Shuai Fang. Influence of ultrasound pre-treatment on ilmenite surface chemical properties and collectors’ adsorption behaviour. Ultrasonics Sonochemistry. 2019; 57 ():98-107.

Chicago/Turabian Style

Kaiqian Shu; Longhua Xu; Houqin Wu; Zhoujie Wang; Yanbo Xu; Shuai Fang. 2019. "Influence of ultrasound pre-treatment on ilmenite surface chemical properties and collectors’ adsorption behaviour." Ultrasonics Sonochemistry 57, no. : 98-107.

Journal article
Published: 23 April 2019 in Powder Technology
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The dissolved components of calcium-bearing gangue minerals will adsorb onto the celestite surface, which increases the difficulty of the flotation separation of celestite from fluorite and calcite. Single mineral and artificial mineral flotation experiments show that EDTA exhibits an excellent selective inhibition effect towards celestite and calcium-bearing minerals. Surface dissolution experiments reveal that EDTA can strongly inhibit the dissolution of calcium ions on the fluorite surface, thus reducing the influence of dissolved calcium ions on celestite flotation. Zeta potential experiments and adsorption experiments demonstrate that the amount of depressant EDTA adsorbed on the fluorite surface is greater than that on the celestite surface, which is contrary to the adsorption amount of collector sodium dodecyl sulfate (SDS) on the fluorite and celestite surfaces. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses further reveal that, through chelating with calcium ions, EDTA can change the chemical surroundings of elements on the fluorite surface, while the chelation is not evident on the celestite surface. Based on the experimental and analytical results above, a possible model for the flotation separation process is created.

ACS Style

Jia Tian; Longhua Xu; Wei Sun; Haisheng Han; Xiaobo Zeng; Shuai Fang; Kai Hong; Xu Longhua. The selective flotation separation of celestite from fluorite and calcite using a novel depressant EDTA. Powder Technology 2019, 352, 62 -71.

AMA Style

Jia Tian, Longhua Xu, Wei Sun, Haisheng Han, Xiaobo Zeng, Shuai Fang, Kai Hong, Xu Longhua. The selective flotation separation of celestite from fluorite and calcite using a novel depressant EDTA. Powder Technology. 2019; 352 ():62-71.

Chicago/Turabian Style

Jia Tian; Longhua Xu; Wei Sun; Haisheng Han; Xiaobo Zeng; Shuai Fang; Kai Hong; Xu Longhua. 2019. "The selective flotation separation of celestite from fluorite and calcite using a novel depressant EDTA." Powder Technology 352, no. : 62-71.