COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Yanfei Chen,Xueyi Guo,Yuanlin Chen
In the present study, sesbania gum (SG) was introduced as a depressant to achieve the selective flotation separation of smithsonite from calcite , and the deep adsorption mechanism was systematically examined using a variety of methods, including density functional theory (DFT) calculation and a series of advanced analytical manners. Micro-flotation experiments indicated that SG strongly depressed the flotation of calcite at pH 9.5, while having little impact on the flotation of smithsonite, leading to the successful separation of the two minerals. DFT calculation predicted that SG could be adsorbed onto the calcite surface, but not onto the hydroxylated smithsonite surface in an aqueous solution system. This was supported by zeta potential tests, Fourier-transform infrared spectroscopy (FTIR) tests, and time-of-flight secondary ion mass spectrometry (TOF-SIMS) detection. As a result, the adsorption of sodium oleate (NaOL) onto the calcite surface was hindered by the pre-adsorption of SG, while the adsorption of NaOL onto the smithsonite surface was not affected. X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM) tests confirmed that SG was mainly adsorbed onto the calcite surface via physical adsorption . This finding provided a new perspective for the interaction between mineral and hydroxyl containing depressant.
研究领域:
矿物加工工程
·
表面化学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Zhoujie Wang,Houqin Wu,Jie Yang,Zhen Tang,Liping Luo,Kaiqian Shu,Yanbo Xu,Longhua Xu
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.
研究领域:
矿物学
·
环境科学
✓ 已验证
DOI
高影响因子
CHEMICAL GEOLOGY
·
2023
·
IF 3.9
Huan Peng,Peng Liu,Hongtao Zheng,Nicholas S. Belshaw,Shenghong Hu,Zhenli Zhu
Adsorption on mineral surfaces is a crucial process controlling (bio)geochemical cycling of Cd, and Cd isotopic behaviour during adsorption is an important but little investigated aspect of Cd isotope systematics. This work looked at the fractionation of Cd isotopes during Cd adsorption onto calcite , which is an important sink of Cd but isotopic behaviour has only previously been investigated in co-precipitation experiments. The Cd isotope composition of calcite adsorbed components was determined to be lighter and consistent with equilibrium fractionation in all experiments. And degree of fractionation observed in our experiments is not influenced by the Cd/CaCO 3 ratio, pH value or Cd/PO 4 3− ratio in the studied range. In MQ water, the observed fractionation value α sorbed-aqueous is 0.99934 but this α value is affected by the presence of other compounds. Notably, α sorbed-aqueous = 0.99984, a reduced but resolvably lower value fractionation, was observed in the presence of PO 4 3− which may be an important factor to be considered when interpreting Cd isotope signatures in nature. The enrichment of lighter Cd isotopes may result from highly distorted octahedral Cd O 6 sites of inner-sphere Cd complexes on calcite, indicated by extended X-ray absorption fine structure (EXAFS). However, near identical coordination environments of the aqueous and sorbed Cd species in the presence of PO 4 3− likely led to the reduced Cd isotope fractionation. This work suggests adsorption of Cd onto carbonates minerals may produce significant Cd isotope fractionation between fluids and solid phase. Our observations offer an alternative process apart from co-precipitation when interpreting Cd isotope ratios in the presence of calcite in paleo-geological studies and could be helpful to better understand Cd (bio)geochemical cycling.
研究领域:
地球化学
·
环境科学
·
同位素地球化学
·
矿物学
·
古地质学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Xun Wang,Jie Liu,Yimin Zhu,Yanjun Li
Adenosine 5′-triphosphate disodium salt (Na 2 ATP) was used as the efficient depressant for the separation of cassiterite from calcite . The effect of Na 2 ATP on the flotation of cassiterite and calcite was evaluated by the micro-flotation experiments, and the results showed that an excellent separation performance was achieved at the reagents regime of 1.0 mM Na 2 ATP and 0.14 mM NaOL when pulp pH was 9.11. Moreover, the adsorption and depression mechanism of Na 2 ATP on calcite was investigated via a series of surface analyses. The contact angle analysis and zeta potential measurements showed that Na 2 ATP was strongly adsorbed onto the calcite surface rather than cassiterite surface, and that could still significantly enhance the hydrophilicity of the calcite after conditioned with NaOL. The FTIR analysis and XPS analysis results indicated that the interaction between Na 2 ATP and calcite was the chemical binding, and the calcium atom on the calcite surface and the phosphate group of Na 2 ATP was the major reaction unit in this processing. Furthermore, the pre-adsorption of Na 2 ATP on calcite surface would impede the interaction between NaOL and calcite, but the adsorption of NaOL on cassiterite surface could not be affected by the weak physical adsorption of Na 2 ATP. Therefore, Na 2 ATP could be utilized as a potential depressant for removing calcite from cassiterite.
研究领域:
矿物加工工程
·
环境科学
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
GIANT
·
2020
·
IF 0
Xinyi Jin,Jinqiao Xue,Dong Hee Kang,Yujing Liu,Jie Ren,Quan Wen,Dapeng Hu,Yan Yu,Wei Yang,Binyang Du,Myung-Han Yoon,Hanying Li
Single crystals have been shown to incorporate guest materials (e.g., gel networks and functional particles) and the incorporated materials endow the crystal hosts with non-intrinsic properties. The acquisition of the non-intrinsic crystal properties impels us to diversify the incorporated guest materials and thus to spread the potential applications of single-crystalline materials. Here, fluorescent NIPAM-based microgels have been selected as the guest materials to be incorporated into the crystal hosts. In the presence of microgels, calcite crystallize from either solution or gel media have been examined. Solution-grown crystals exclude the microgels, while two gel-grown methods have proved effective for incorporating these microgels inside calcite single crystals. On one hand, an additional macroscopic agarose gel-network is introduced to trap the microgels. Crystallization in the agarose gel leads to incorporation of agarose gel-network together with the trapped microgels. The microgel concentration in the crystal reaches 33 mg/mL. On the other hand, dispersions of microgels are concentrated to about 352 mg/mL and the microgels aggregate into non-flowing macroscopic gels (termed as macrogels). Crystallization in a macrogel results in its incorporation. By showing the incorporation of microgels through physical entrapment, this work provides a new platform to functionalize single crystals by the microgels.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
MINERALS ENGINEERING
·
2026
·
IF 6
Hongqin Chen,Yanhai Shao,Xiao Meng,Jinhui Li,Xinru Jia,Hong Lin,Chengxiang Li
An efficient flotation separation strategy for smithsonite and calcite was established using a ternary collector (ABN) and sodium phytate (SP) at weakly alkaline pH. • Optimized SP-ABN system yields a mixed-ore Zn grade of 36.39% with 62.75% recovery. • XPS, AFM and Zeta potential analyses confirm that SP selectively shields calcite via strong Ca-chelation. • SP forms a dense layer on calcite, effectively blocking the adsorption of the ABN collector via steric hindrance and electrostatic repulsion. This study systematically investigated the selective depression behavior of sodium phytate (SP) in the flotation separation of smithsonite from calcite using an Al-BHA-NaOL collector system (ABN). Although ABN (2.5 × 10 -5 mol/L) exhibited moderate selectivity toward smithsonite under weakly alkaline conditions, calcite remained relatively floatable, resulting in limited separation efficiency. The addition of SP effectively depressed calcite flotation while only slightly influencing smithsonite, thereby significantly improving the separation performance. Under the optimal conditions of pH 8.0 and SP dosage of 21.65 × 10 -6 mol/L, artificial mixed mineral flotation tests produced a concentrate with a Zn grade of 36.39% and Zn recovery of 62.75%. To elucidate the selective depression mechanism, zeta potential measurements, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle analysis were performed. The results demonstrated preferentially interacted with calcite rather than with smithsonite, resulting in greater changes in surface charge, surface morphology, and hydrophobicity. XPS analysis revealed a significant shift in the Ca 2p 3/2 peak on calcite after SP treatment, whereas the Zn 2p 3/2 peak of smithsonite exhibited only a negligible change, indicating a much stronger interaction between SP and calcite. SP significantly hindered ABN adsorption on calcite, while its influence on collector adsorption on smithsonite remained limited. These findings indicate that SP as an environmentally friendly selective depressant for calcite provides new insights into the selective regulation of carbonate mineral surfaces, offering a promising strategy for the flotation beneficiation of carbonate-associated zinc oxide ores. Download: Download high-res image (236KB) Download: Download full-size image
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
·
2026
·
IF 6.6
Jian Ding,Zhenxuan Li,Lidong Huang,Zhu Zhu,Jingxin Shi,Naren Tuya,He Li
P loading increases calcite surface area by 56–95% and forms Ca P phases. • Ca P domains enhance removal efficiency of F by 33–60% at low concentration. • XPS confirms fluorine bound to surfaces via complexation at low F and precipitation at high F. • P-loaded calcite offers a feasible route for F removal. Phosphate (P) and fluoride commonly coexist in aquatic systems. Although P loading restructures calcite through Ca P phase formation, its influence on subsequent fluoride removal remains unclear. Calcite conditioned with high P concentrations at pH 8.3, 7.7, and 7.3 developed P-rich surface layers, with 56–95% higher specific surface areas and Ca P signatures in FTIR and XPS. SEM–EDS further revealed the development of Ca P coatings with uniform elemental distributions. Fluoride-removal experiments revealed a concentration-dependent response. At low fluoride concentrations (3–20 mg·L −1 ), P-loaded calcite consistently outperformed pristine calcite, achieving 33–60% higher removal efficiencies without measurable changes in solution pH or Ca 2+ concentration, indicating adsorption-dominated immobilization. XPS F 1 s spectra (∼684.4 eV) support fluoride association with Ca P surface domains under these conditions. At 20 mg·L −1 fluoride, HRTEM/SAED identified calcite lattice and diffraction features but no self-consistent evidence of crystalline CaF 2 in the examined regions. DFT yielded stronger F − adsorption on a representative Ca₃(PO 4 ) 2 (010) surface than on calcite (104) (−5.926 versus −3.655 eV) and showed adsorption-induced interfacial charge redistribution. In contrast, at high fluoride concentration (100 mg·L −1 ), fluoride removal was accompanied by pronounced Ca 2+ depletion and pH increases, and F 1 s binding energies (∼684.7–685.0 eV) characteristic of CaF 2 , demonstrating precipitation-dominated control irrespective of P conditioning. These results show that P loading creates chemically distinct Ca P surface environments that enhance fluoride adsorption only within a concentration window where precipitation is not thermodynamically dominant. This study clarifies the mechanistic basis for repurposing P-loaded calcite in fluoride control applications. Download: Download high-res image (281KB) Download: Download full-size image
✓ 已验证
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2024
·
IF 3.2
Jianhui Li,Qihang Wang,Zhengyi Fu,Zhaoyong Zou
Biomimetic mineralization can facilitate the fabrication of materials with intricate hierarchical structures and distinctive functional properties under ambient conditions. However, precise replication of the complex biomineralization process in vitro remains a big challenge. In this study, aimed at mimicking the biomineralization process of calcite prismatic layers of mollusk shells, a peristaltic pump was employed to slowly transport a sodium carbonate solution into a calcium-containing solution in the presence of poly(acrylic acid) (PAA). Through delicate control of the ion transport rate and reaction conditions, a calcite seed layer was first deposited on the chitosan-coated substrate, followed by the fabrication of a continuous, dense, and highly oriented shell-like calcite prismatic structure. The influences of PAA concentration and ion transportation rate on the growth kinetics and morphology of calcite were studied, showing that optimal conditions are required to form the prismatic structure. It was demonstrated that the prismatic structure started from random formation of an individual spherical disk on the seed layer, which grew larger in diameter and fused with adjacent disks. Furthermore, using confocal Raman mapping analysis, the orientation of calcite crystals at different growth stages was revealed. This study provides a novel bioprocessing-inspired strategy to fabricate a uniform calcite prismatic structure and significantly improves our understanding of the growth mechanisms.
研究领域:
材料科学
·
生物矿化
·
仿生学
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2024
·
IF 4.9
Zhengquan Zhang,Lin Zhang,Fen Jiao,Congren Yang,Qian Wei,Wenqing Qin,Chen Wang,Xiang Lin
Considering that smithsonite has a similar crystal structure to calcite, more selective collectors are required to achieve its flotation separation. In this study, a new collector, cupferron, was used for the selective flotation of smithsonite from calcite. The selective mechanism of the effect of cupferron was investigated by FTIR analysis, zeta potential experiments, adsorption measurements, and DFT studies. Results of the microflotation test showed that the flotation recovery of smithsonite was 90.45 % at pH 8.0 with 10 × 10 −4 mol/L of cupferron, whereas the flotation recovery of calcite was lower than 15.00 %. The FTIR results demonstrated that the cupferron was chemisorbed on the surface of smithsonite through a five-membered chelate ring formed with zinc atoms, whereas the adsorption on the surface of calcite was weak. The results of the zeta potential test further indicated that the cupferron was adsorbed selectively on the surface of smithsonite, whereas almost no adsorption was observed on the surface of calcite. In addition, the adsorption amount test results illustrated that the adsorption amount of cupferron on the surface of smithsonite was higher than that on the surface of calcite, which led to the difference in the flotation recovery of smithsonite and calcite under the same conditions. The results of the DFT study proved that the adsorption energy of cupferron acting on the surface of smithsonite is lower than that on the calcite surface. Moreover, the stronger covalent nature of Zn-O 2 bonds than Ca-O 2 bonds is responsible for the selective collection of smithsonite from calcite by cupferron. Therefore, cupferron can be applied as a potential collector for the flotation separation of smithsonite from calcite. Meanwhile, this study also provides a reference for the development of collectors for the flotation separation of smithsonite and calcite.
研究领域:
矿物加工工程
·
材料科学与工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Ziyang Chu,Tianhu Chen,Haibo Liu,Dong Chen,Xuehua Zou,Hanlin Wang,Fuwei Sun,Peixun Zhai,Min Xia,Meng Liu
In this study, calcite was investigated as an activator for the norfloxacin (NOR) degradation by peroxymonosulfate (PMS). Under optimum conditions, the NOR removal percentage was 99.7% within 60 min, and the pseudo-first-order kinetics effectively described the two-stage oxidation process. The NOR removal percentage improved from 10.4% to 91.5% and the reaction rate constant elevated from 0.0010 to 0.1217 min −1 when 0.5 g/L calcite was added compared to that without calcite addition. Furthermore, the results of radical scavenger and electron spin resonance trapping indicated that the favorable alkaline environment and a proper level of carbonate in the Calcite/PMS system facilitated the activation of PMS to generate 1 O 2 for rapid NOR degradation. Compared with NaOH, calcite was able to maintain the pH (8–9) of the reaction system stable. Besides, the content of anions with buffering capacity and organic matter in the water matrix influenced the removal percentage of NOR. Seven intermediates were identified and the NOR degradation pathways were suggested. The findings of this research provided an environmentally friendly activator for remediation of organic wastewater and deepened the understanding of the interaction between calcium carbonate and PMS.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2015
·
IF 4.321
Linyu Deng,Yawei Liu,Tinglin Huang,Tian Sun
The removal of fluoride from water by induced crystallization using fluorapatite (FAP)/calcite seed crystals was investigated. Batch experiments were conducted to determine optimal operating parameters. The effect of FAP/calcite mass ratio of the seed crystals, initial seed crystal concentration, molar ratios of Ca 2+ :PO 4 3− :F − and contact time were examined. FAP/calcite with any mass ratio reduced fluoride concentrations from 9.5 mg/L (0.5 mM) to less than 1 mg/L. The use of FAP alone and calcite alone was not effective. Use of initial seed crystal concentrations greater than 4.0 g/L were correlated to residual fluoride concentrations less than 1.0 mg/L. The optimal parameters for fluoride removal were an initial seed crystal concentration of 6 g/L (FAP 4.8 g/L, calcite 1.2 g/L), Ca/P/F molar ratio of 8:4:1, and contact time of 1 h. The final pH was always close to neutral. The presence of natural organic matter (NOM) in the raw water was found to not affect fluoride removal. SEM–EDS and XRD analysis showed that fluoride removal was due to crystallization of Ca 5 (PO 4 ) 3 F on the surface of FAP. Phosphate, but not fluoride, accumulated on calcite by adsorption. The seed crystal could be regenerated easily, and used repeatedly, and used seed crystals could also be used as resources in phosphorus fertilizer production. Induced crystallization using FAP/calcite as a seed crystal is an economically and environmentally friendly process, and has the potential to remove fluoride from groundwater.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Bo Feng,Wei Guo,Jinxiu Peng,Wenpu Zhang
The flotation separation of scheelite and calcite by froth flotation is difficulty as these two minerals have similar physicochemical characteristics. To solve this problem, the role of calcium lignosulphonate (CLS) in the flotation separation of scheelite from calcite has been studied and the separation mechanism has been discussed. The micro-flotation tests show that calcium lignosulphonate has strong depression effect to calcite and the depression effect decreased with the increase in pH. However, its depressive effect to scheelite is weak at pH 6–9. A concentrate with WO 3 grade of 65.02%, and WO 3 recovery of 79.64% was achieved in the flotation separation of mixed mineral, while calcium lignosulphonate was used. The reason is that the adsorption amount of calcium lignosulphonate on scheelite surface is far less than that of calcite according to adsorption tests. The interaction mechanism of calcite and CLS was studied by XPS and the results shows that the interaction between calcite and CLS were chemisorptions, and this interaction that SO 3 group were involved hindered the absorption between Ol − and the Ca 2+ on the surface of calcite, it also shows that a small amount of Ca(OH) 2 was generated on the surface of calcite in the presence of CLS, the coefficient of these two mechanisms brings about the depression effect for calcite.
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）