POWDER TECHNOLOGY
·
2023
·
IF 5.2
Kuixin Cui,Shengming Jin,Nan Duan
The adsorption mechanism of benzohydroxamic acid (BHA) on rhodochrosite surfaces under Pb 2+ activation was systematically studied through a series of experiments. Comparing to the results of only BHA treatment, Pb 2+ ions raised the adsorption amount of BHA and the floatability of rhodochrosite, especially at pH 8.0–9.0. It was proven that Pb(OH) + was deemed as the critical species to adsorb onto rhodochrosite surfaces in the form of lead-containing complexes. Afterwards, rhodochrosite surfaces became much more activated for BHA adsorption. BHA collector reacted with adsorbed-Pb and Mn species of rhodochrosite surfaces, and the charged hydroxamic acid also adsorbed onto rhodochrosite surfaces through electrostatic attraction and co-adsorption. Besides, lead hydroxamate complexes generated in suspension had excellent adhesions on rhodochroganite surfaces. It was apparent that the BHA adsorption was strengthened under the activation of Pb 2+ ions. BHA collector matching with Pb 2+ ions had great potentials to improve the flotation recovery of rhodochrosite.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Kuixin Cui,Nan Duan,Shengming Jin
A novel collector 2-(4-Butoxyphenyl)acetohydroxamic acid (BAHA) was actively considered in the flotation of rhodochrosite. Flotation behaviors and BAHA adsorption concerning rhodochrosite, calcite and dolomite were systematacially investigated through microflotation tests, adsorption experiments, zeta potential measurements, FTIR and XPS analyses. Microflotation results showed that rhodochrosite performed a better floatability than calcite and dolomite at pH 8.0–10.0. Also, the adsorption amounts of BAHA collector on the rhodochrosite surface were obviously greater than those of calcite and dolomite. The results of zeta potential, FTIR and XPS analyses indicated that BAHA adsorbed onto rhodochrosite surfaces through chemisorption, electrostatic attraction and intermolecular hydrogen bonding, chemisorption and electrostatic attraction for calcite, and only chemisorption for dolomite. The interaction mechanisms between BAHA collector and mineral surfaces were responsible for the differences in the BAHA adsorption and floatability between rhodochrosite and two gangues. The flotation separation tests of three minerals confirmed that the rhodochrosite concentrate with Mn grade of 24.64% and recovery of 87.94% could be obtained. BAHA is a high selective collector and can realize the flotation separation of rhodochrosite against dolomite and calcite.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Zhihui Shen,Qin Zhang
Efficient separation of fine-disseminated rhodochrosite is a challenge in the purification of manganese carbonate ore and a key to reduce the discharge of electrolytic manganese slag. The agglomeration behavior of the fine particles is of importance for flotation separation. In this study, we investigated the agglomeration behavior and aggregate properties of rhodochrosite fines co-induced by oleic acid (OA) and shearing using particle size and structure analysis, surface properties measurement, extended DLVO (EDLVO) theoretical calculation and shear fracture model analysis. The results showed that rhodochrosite fines agglomerates obviously with the increasing OA concentration and pH value, and the average particle size reaches the maximum at the initial OA concentration of 1 × 10 -3 mol/L and pH of 6. The monolayer physical and chemical saturation adsorption of OA cause stronger hydrophobicity of rhodochrosite. Meanwhile, the hydrophobic attractive force between particles is stronger than electrostatic repulsive force, resulting in hydrophobic agglomeration. The moderate stirring rate is conducive to forming larger-sized and denser agglomerates with the critical rate of 500 rpm. However, intensive shearing will cause significant damage to the formed agglomerates. Besides, the volume concentrations of 10–30 μm and 30–45 μm particles increased with the increase of stirring rate after breakage and with a lower value of γ’ than 0.5, suggesting that the agglomerates breakage is mainly controlled by large-scale fragmentation mechanism. Interestingly, as recovering shearing from the higher rate to the initial rate, a secondary agglomeration is achieved by the regrowth of core (30–45 μm particles) and attach of branches and coatings (some < 10 μm and 10–30 μm particles) under the synergy of hydrophobic attraction and shearing. However, it did not fully recover back to the original balanced state before fragmentation, which was due to irreversible damage caused by excessive shearing. This research will be beneficial for in-depth understanding of agglomeration mechanisms of rhodochrosite fines and provide a basis for subsequent efficient flotation separation.
研究领域:
矿物加工
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胶体与界面化学
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资源利用技术
·
环境工程
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Kuixin Cui,Aili Zhou,Caihong Yu,Shengming Jin
The unavoidable Mn 2+ ions in pulp were considered in the flotation of rhodochrosite, and its effect and relative interaction mechanism on the floatability of calcite served as a typical gangue mineral were investigated through microflotation tests, zeta potential measurements, SEM-EDS detection, solution chemistry calculation, adsorption experiments, FTIR and XPS analyses. There exhibited a good separation performance of rhodochrosite against calcite with OHA collector, but in the presence of Mn 2+ ions, the floatability of calcite was closed to rhodochrosite within a pH of 8.0–10.0, which resulted in the separation difficulty between them. As evidenced, the surface of calcite could be modified by Mn 2+ ions, its isoelectric point shifted positively from 8.91 to 10.06, and Mn 2+ species detected on calcite surfaces were in close proximity to rhodochrosite. It indicated that MnCO 3 precipitates were generated on the surface of calcite. After modified by Mn 2+ , the calcite surface became more active and obviously increased the adsorption amount of OHA. It was verified from zeta potential and XPS analyses that Mn species on the surface of calcite were active sites for OHA adsorption, likely the hydroxamate group of OHA collector chelated with Mn species to form hydrophobic compounds. As a result, Mn 2+ ions in pulp would reduce the flotation selectivity of rhodochrosite from calcite, thus it is necessary to eliminate the disadvantage of Mn 2+ for strengthening flotation.
研究领域:
矿物加工工程
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
MINERALS ENGINEERING
·
2023
·
IF 4.8
Lingyun Fei,Xin Ma,Hongyu Sun,Shuai Wang,Zhanfang Cao,Hong Zhong,Lanqing Deng
High consumption and low selectivity of traditional collectors limit the efficient flotation recovery of rhodochrosite particles from finely disseminated complex ores. Herein, a novel “Y” structure multi-functional surfactant, 2-decanoylamino-4-hydroxycarbamoyl-butyric acid (DHBA) was developed for flotation recovery of rhodochrosite. The micro-flotation results showed that DHBA exhibited an excellent collecting ability for rhodochrosite than common collector octanohydroxamic acid (OHA) (the recovery reached 85.7% for 7 × 10 – 5 mol·L – 1 DHBA, while only 27.9% for OHA). Meanwhile, DHBA can selectively separated rhodochrosite from quartz at neutral pH and low collector dosages. The experimental analysis combined with the density functional theory calculations revealed that DHBA was lattice matched to the rhodochrosite via the oxygen atoms of carboxyl and hydroxamate groups chelating with two Mn atoms, conferring strong adsorption affinity of DHBA. In addition, intermolecular hydrogen bonds coexist through the amide groups, promoting the collectors' self-assembly on the rhodochrosite surface, improving surface hydrophobicity. This research provides a feasible collector design protocol for the separation and enrichment of manganese carbonate ore.
研究领域:
矿物加工工程
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Zhihui Shen,Qin Zhang
Efficient enrichment of fine rhodochrosite is key to purifying manganese carbonate ore and reducing the discharge of electrolytic manganese slag at the source. Enhancing the agglomeration of rhodochrosite fines is important for efficient flotation separation. In this study, we investigated the agglomeration mechanism of rhodochrosite fines co-enhanced by oleic-kerosene emulsion and static magnetic field using agglomerate and surface properties analysis, electrical conductivity and atomic force microscopy measurements, and extended Derjaguin, Landau, Verwey, and Overbeek theoretical calculations. The results showed that the agglomerate size and regularity degree increased with increasing shearing time, achieving the maximum values of the average size at 20 min with magnetic field and at 40 min without magnetic field. Larger-sized and tighter agglomerates can be formed in a shorter time by the Lorentz force in magnetic field. As magnetic field was applied, the surface electronegativity of rhodochrosite in emulsion solution was stronger and positively correlated with magnetic field intensity. In addition, due to the higher solubility of oleic acid, the adsorption capacity and net heat of emulsion increased, resulting in a stronger hydrophobicity of rhodochrosite with a shorter hydrophobization time. Interestingly, almost no attraction existed between particles with magnetic field in aqueous solution, while a larger attraction existed without magnetic field in emulsion solution, and the attraction and action distance both increased markedly with increasing magnetic field intensity. However, the magnetic attraction was much smaller than hydrophobic attraction. As a result, agglomeration of rhodochrosite fines could be enhanced by stronger hydrophobic attraction under the synergy effect of magnetic field and oleic-kerosene emulsion. This research will be conducive to in-depth insight into the enhancement mechanisms of rhodochrosite agglomeration and will provide a basis for flotation regulation.
研究领域:
矿物加工
·
胶体与界面化学
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资源利用
·
应用物理化学
✓ 已验证
DOI
高影响因子
MINERALS ENGINEERING
·
2022
·
IF 5.479
Hongyu Sun,Shuai Wang,Lingyun Fei,Zhanfang Cao,Hong Zhong,Xin Ma
Rhodochrosite is often associated with calcium- and silicon-bearing minerals, resulting in a low grade, and it is difficult to achieve efficient flotation separation with conventional collectors. A novel collector, 2-decanoylamino-pentanedioic acid (DPA), was synthesized by constructing an amide group and double-branched carboxylic acid molecular structure to selectively separate rhodochrosite against quartz and calcite . The flotation results demonstrated that, compared with sodium oleate, DPA exhibited superior collecting performance and enabled the separation of rhodochrosite from quartz and calcite under neutral pH, with no addition of a foaming agent or activator; thus, DPA is regarded as an appropriate flotation collector for rhodochrosite. Analysis of the contact angles, Fourier transform infrared spectroscopy (FTIR), zeta potential and X-ray photoelectron spectroscopy (XPS) results showed that DPA chemically adsorbed on the surface of rhodochrosite, forming 8-membered ring or two 4-membered ring structures. However, no significant interaction was detected on the surface of quartz and calcite, providing evidence for the flotation separation of rhodochrosite from calcite and quartz. This research provides a potential collector for efficient utilization of rhodochrosite.
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
DOI
高影响因子
JOM
·
2025
·
IF 2.3
Yan Yaoyu,Sun Shuchen,Wei Jing,Shubo A.,Xiao Faxin,Tu Ganfeng
Manganese is an important strategic resource for the new energy industry, and the preparation of high-purity manganese sulfate is crucial for lithium battery positive electrode materials. This study aims to thoroughly remove Ca 2+ and Mg 2+ impurities in rhodochrosite acid leaching solution, and proposes a directional purification method based on MnF 2 precipitant. Through single factor experiments and response surface optimization, the effects of MnF 2 addition, temperature, pH, and reaction time on impurity removal have been systematically studied. Under the optimized conditions (MnF 2 addition 2.35 times the theoretical value, temperature 86.94 °C, pH 4.0, reaction time 45.92 min), the removal rates of Ca 2+ and Mg 2+ reached 99.93% and 98.98%, respectively. Combining thermodynamic analysis with an E-pH diagram to explore the precipitation mechanism of impurities, the results show that the preferential precipitation of CaF 2 and MgF 2 originates from the strong coordination ability of Ca 2+ /Mg 2+ with F - (hard and soft acids and bases, HSAB, theory) and the ionic radius matching effect (r + /r − = 0.75). In addition, MnF 2 was efficiently recovered by water-washing precipitation–evaporation crystallization method, and battery-grade manganese sulfate was successfully prepared. This study provides theoretical support and technical reference for the efficient purification of rhodochrosite leaching solution and the green preparation of battery-grade manganese sulfate.
研究领域:
冶金工程
·
材料科学
·
化学工程
·
无机化学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Liuyi Pan,Jiayi Wu,Baoliang Chen,Xiaoying Zhu
Manganese (Mn) redox cycling and phase variation reactions play a crucial role in natural water settings. Rhodochrosite (MnCO 3 ), a mineral commonly found in oxygen-deprived environments, develops a surface oxide film upon exposure to oxygen. This Mn oxide film significantly influences the fate of nanoparticles within its proximity. Employing atomic force microscopy (AFM), this study examined the growth of the Mn oxide film on MnCO 3 and the encapsulation of cadmium sulfide nanoparticles (CdS-NPs). Results revealed the gradual development of a nanometer-thick oxide film on MnCO 3 over time in aerobic conditions , with the rate of film formation correlated to the solution's ionic strength. The oxide film on MnCO 3 encapsulated pre-adsorbed CdS-NPs, either through embedding or covering. Intriguingly, CdS-NPs were found to enhance the growth of the Mn oxide film, contributing to the fixation of CdS-NPs. Furthermore, an ultrasonic desorption protocol verified the stability of CdS-NPs encapsulated by the Mn oxide film on MnCO 3 . This study elucidates a novel mechanism for immobilizing CdS-NPs in aqueous oxidizing conditions, providing valuable insights into the behavior and distribution of toxic nanoparticles in environmental contexts. Environmental Implication This study classifies cadmium sulfide nanoparticles (CdS-NPs) as "hazardous material" due to the inherent toxicity of cadmium, posing risks to both ecological and human health. The research addresses environmental concerns by exploring the interaction between CdS-NPs and manganese (Mn) redox cycling. The formation of a Mn oxide film, encapsulating CdS-NPs, suggests a mechanism for limiting the dispersion of these hazardous nanoparticles in oxidizing water. This provides valuable insights for managing the environmental impact of CdS-NPs, offering a proactive strategy to mitigate their adverse effects in natural systems.
研究领域:
环境科学
·
纳米技术
·
材料科学
·
地球化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Hongyu Sun,Xin Ma,Lingyun Fei,Zhanfang Cao,Hong Zhong,Shuai Wang
Efficient recovery of fine mineral particles is challenging for minerals flotation due to a small particle mass and high specific surface area. This work innovatively applied a multifunctional surfactant 2-dodecanoylamino-pentanedioic acid (DPA) for achieving flocculation and recovery of fine rhodochrosite. Interestingly, the formation of larger aggregation induced by DPA, instead of sodium oleate (NaOL), was observed and the medium particle size ( d 50 ) was 2.29 times than that of NaOL, resulting in more strong collecting ability for fine rhodochrosite particles (with a recovery of 82.5% for 0.1 mmol/L DPA and 35.3% for 0.1 mmol/L NaOL). Analysis with EDLVO theory illustrated that the hydrophobicity force is one of the factors that induces hydrophobic flocculation, along with electrostatic repulsion, the Van der Waals force, and weak interaction. Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations revealed the “weak-to-medium” hydrogen bond formation among the amide groups or amide and carboxyl functional groups in the DPA complex, further enhancing aggregation between rhodochrosite fine particles. These discoveries are beneficial for providing new insights into aggregation generation among fine particles in the presence of surfactants containing multiple functional groups.
研究领域:
材料科学
·
化学工程
·
矿物加工
·
表面化学
✓ 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）