Conventional xanthates exhibit poor selectivity and struggle to achieve efficient arsenic rejection during the flotation of copper sulfide ores. This limitation increases the risk of releasing hazardous arsenic-containing species during downstream copper concentrate smelting. Therefore, we developed a molecular modification strategy for xanthates by introducing a nitrogen atom into the hydrophobic chain while simultaneously tuning the outer hydrophobic tail and linker structure to optimize their electronic properties and interfacial assembly behavior. Using this strategy, we designed and synthesized five novel amino xanthates and identified O-(3-(diethylamino)propyl) xanthate (EAPX) as the best-performing collector in this series through density functional theory calculations, wettability measurements, and single-mineral flotation tests. Compared with isobutyl xanthate, the amino xanthate series exhibited significantly improved chalcopyrite–arsenopyrite flotation separation performance, with EAPX achieving a chalcopyrite/arsenopyrite recovery difference of 77.61% at 4 × 10–5 mol/L and pH 9.0. Mechanistic investigations revealed that EAPX exhibits a stronger affinity for Cu species and forms a stable EAPX(S)–Cu interfacial complex through synergistic σ coordination and enhanced π back-donation between the sulfur atom of the xanthate group and Cu(I) sites on the chalcopyrite surface. Consistent with these findings, the adsorption energy of EAPX on chalcopyrite (112) (–1.67 eV) was substantially lower than that on arsenopyrite (001) (–1.22 eV). Furthermore, EAPX exhibited water-bridged self-assembly, suppressed molecular volatilization, reduced malodor release, and promoted the formation of a denser and more ordered hydrophobic layer on the chalcopyrite surface. This study provides a transferable molecular design strategy for developing green flotation reagents and related interfacial functional molecules.

The efficient separation of complex multi-metal ion solutions, such as copper, nickel, cobalt and manganese found in battery leaching solutions, remains challenging. While phosphoric acid extractants are commonly used for nickel and cobalt extraction, their effectiveness is limited for separating copper from battery leaching solutions containing a high concentration of copper ions under low pH conditions. To address this, we developed a novel oxime extractant, di-neodecyl ethanedione dioxime (DED), enabling the sequential separation of copper, nickel, cobalt and manganese through pH control. In a two-stage countercurrent extraction process using 15 wt% DED at the phase ratio (O/A) of 3:2 and equilibrium pH of 2.5, 98.92 % of copper was selectively recovered. Subsequently, 98.89 % of nickel and 98.55 % of cobalt were co-extracted in a two-stage countercurrent extraction using 25 wt% DED at the phase ratio (O/A) of 2:1 and equilibrium pH of 4.0. Slope analysis and mass spectrometry confirmed a 2:1 (ligand-to-metal) binding stoichiometry for DED with Cu(II), Ni(II) and Co(II). FTIR spectroscopy and DFT calculations revealed the formation of dual-ligand complexes featuring two five-membered N,N-chelate rings. The DFT-derived binding energies calculation further indicated a stronger preference of DED for copper ions over nickel and cobalt ions. These results demonstrate DED as a highly effective extractant for the separation and recovery of copper, nickel cobalt and manganese from battery leaching solutions.

Effective collectors are crucial for efficient galena (PbS) flotation beneficiation. This study introduces a novel synergistic mixed collector system, comprising sodium diethyl dithiocarbamate (DTC) and O,O'-bis(2-butoxyethyl) ammonium dithiophosphate (BEAT), for enhancing galena recovery and selectivity against sphalerite. Microflotation tests demonstrated that a premixed DTC/BEAT system (1:1 M ratio, at the total dosage of 2 x 10(-5) mol/L) at pH similar to 7.0 achieved a remarkable galena recovery of 94.23 %, significantly outperforming single collectors. This synergistic effect was further validated through bench-scale flotation of lead-zinc sulfide ores. Wettability results indicated that the mixed DTC/BEAT scheme induced superior hydrophobicity on galena surfaces compared to either single collector. Zeta potential, FTIR and XPS spectra verified the co-adsorption of both DTC and BEAT collectors onto the galena surface. The findings provide an effective strategy for improving galena flotation efficiency in mineral processing.

To address the critical incompatibility between direct recovery technology and industrial battery-crushing technology, this work proposes a short-process, eco-friendly strategy for the direct regeneration of cathode materials from spent lithium-ion battery black mass (BM). In this strategy, the cathode material (designated S-NCM) with a 99.08% recovery and a 95.92% grade is first extracted greenly and nondestructively via flotation separation after roasting pretreatment. Crucially, the residual metal impurities in BM are ingeniously utilized to capture fluorinated pollutants (e.g., HF) during the roasting process, effectively eliminating hazardous gas emissions. Following targeted prelithiation and high temperature sintering, S-NCM is transformed into a regenerated cathode material (R-NCM). Electrochemical tests demonstrate that R-NCM delivers a reversible specific capacity of 139.27 mAh g-1 at 0.1C and maintains 91.85% capacity retention after 100 cycles. Techno-economic analysis confirms the strategy's significant environmental benefits and commercial viability. The total energy consumption of direct regeneration (2.88 MJ kg-1) is substantially lower than that of pyro-methods (39.12 MJ kg-1) and hydro-methods (42.97 MJ kg-1). Owing to its simplicity, low energy demand, and elimination of secondary synthesis, the regenerated cathode material can be directly used for battery remanufacturing. Consequently, the direct regeneration strategy offers 6.8- and 2.4-fold higher profitability than pyro- and hydro-methods, respectively. This study provides a sustainable solution for the large-scale direct regeneration of spent battery-derived BM.

Because of the similar surface properties of fluorite and calcite, their separation remains quite challenging. In this study, a novel hydroxamic collector, phthaloyl hydroxamic acid (PHA), was synthesized and applied for the flotation separation of fluorite from calcite for the first time. Microflotation results demonstrated that, at pH 7 with 20 mg/L PHA, fluorite recovery reached 92.5%, while calcite recovery was only 15.5%. In contrast, sodium oleate (NaOL) exhibited poor selectivity under identical conditions, recovering both minerals at similar levels (82% for fluorite and 86% for calcite). Compared with benzohydroxamic acid (BHA), which required an elevated pH of 9 to achieve selective separation (91% fluorite vs 20% calcite), PHA delivered comparable or superior selectivity at a milder pH 7. Contact angle, FTIR, ζ-potential, and XPS analyses collectively confirmed the selective chemisorption of PHA onto fluorite surfaces via chelation between -CONHOH groups and surface Ca atoms. Adsorption experiments showed that the adsorption density of PHA on fluorite (0.045 mg/g) was approximately six times higher than that on calcite (0.007 mg/g). Density functional theory (DFT) calculations further revealed a substantially stronger adsorption energy on fluorite (-239.87 kJ/mol) than on calcite (-62.12 kJ/mol), with the optimized geometry confirming five-membered chelate ring formation. Collectively, PHA is a highly promising collector for the efficient and depressant-free flotation separation of fluorite from calcite.

The flotation separation of chalcopyrite (CuFeS2) and molybdenite (MoS2) is hindered by similar surface properties, typically requiring environmentally detrimental high-alkalinity conditions (pH > 10.0). Herein, we introduce 3,4,5-Trihydroxy-N,N-bis(2-hydroxyethyl)benzamide (TBHB), a gallic acid-derived surfactant, as an efficient selective depressant for chalcopyrite under near-neutral conditions (pH 6.0-8.0). Notably, chalcopyrite recovery is reactivatable via pH adjustment (pH > 9.0). Micro-flotation tests demonstrated TBHB's high selectivity, achieving 91.81% molybdenite recovery while suppressing chalcopyrite recovery to 12.61% at pH 8.0, outperforming conventional depressants (e.g., sodium thioglycolate). Artificial mixed minerals flotation further confirmed TBHB's efficacy, with a dosage of 75 mg/L achieving Mo recovery exceeding 80%, Cu recovery below 20%. Mechanistic investigations revealed TBHB chemisorbs on the chalcopyrite surface via phenolic hydroxyl-Fe coordination, supported by high adsorption capacity (> 1.6 mg/m2), reduced hydrophobicity, and FTIR/XPS analyses, which showed Fe-O bond formation and red-shifted C=O/benzene ring vibrations. Zeta potential measurements affirmed pH-dependent adsorption/desorption. DFT calculations confirmed spontaneous adsorption (Delta E =-1.8206 eV) and short O-Fe bond (1.99 & Aring;), verifying Fe-site affinity. Conversely, TBHB showed negligible adsorption on the molybdenite surface, with values below 0.4 mg/m(2) and a contact angle of approximately 70 degrees, preserving its floatability. This work establishes TBHB as a sustainable alternative for Cu-Mo separation, eliminating high-alkalinity requirements while advancing green reagent design through integrated experimental and computational insights.

The inherent malodor and low selectivity of xanthates limit their applicability in processing complex mineral systems under modern green chemistry principles. Therefore, the current study presents a novel surfactant, O-(2-[bis(phenylmethyl)amino]ethyl) xanthate (PAEX), characterized by a unique "umbrella-like" structure that incorporates a highly electronegative N atom and two pi-electron-rich benzyl groups into an ethyl xanthate skeleton. The intermolecular pi-pi stacking in PAEX promoted molecular association and significantly suppressed volatility, thereby eliminating the malodor associated with traditional xanthates at the molecular level. Sulfide-specific electronic nose sensors indicated a 74.78% decrease in PAEX responses compared with conventional isobutyl xanthate responses. Furthermore, the synergistic combination of tailored electronic properties and the distinctive umbrella-like architecture endowed PAEX with exceptional selective collection capabilities. Its slightly reduced electron-donating ability and enhanced electron-accepting capacity facilitate selective adsorption at Cu(I) sites on chalcopyrite surfaces. The unique umbrella-like structure promoted a homogenized vertical adsorption orientation, while, hydrophobic interactions and pi-pi stacking drove the association of "canopy" structures, thereby stabilizing adsorption and enhancing hydrophobicity. A recovery difference of 77.25% was achieved between chalcopyrite and pyrite at a dosage of 1 & times; 10-5 mol/L. The pronounced malodor and inferior flotation performance of a nonaromatic structural analog underscored the efficacy of this molecular modification strategy. Overall, this study provides a comprehensive approach to the rational molecular design of surfactants by synergistically manipulating electronic and spatial structures, establishing a foundation for the development of high-performance, environmentally benign reagents for industrial applications.

The conventional H2SO4 leaching method for recycling spent ternary lithium-ion battery (NCM) cells often led to non-selective metal extraction and was costly for partial recovery. To address these limitations, a cost-effective, eco-friendly method was introduced for selectively extracting Li and recovering transition metals (TMs) using carbon thermal reduction roasting, Na2S2O3 leaching, and H2SO4 leaching, ultimately yielding Li2CO3 and mixed sulfate products. Following reduction roasting, TMs were converted to their metallic or lower-valence oxide states, and Li was converted to Li2CO3. Na2S2O3 leaching selectively extracted 97.44

Aiming at the problems of traditional collectors in the flotation of tungsten ore, such as weak collecting ability for wolframite and difficulty in effective separation from calcium-bearing gangue (e.g., calcite), a dual-ligand hydroxamic acid surfactant, sebacoyl hydroxamic acid (SHA), was synthesized and used as the high-efficiency collector for wolframite enrichment in this study. Compared with the traditional collector benzhydroxamic acid (BHA), SHA exhibited stronger collecting ability for wolframite and better selectivity towards calcite. Micro-flotation tests indicated that at pH = 8, using 100 mg/L SHA achieved the recoveries of 90 % for wolframite and merely 48 % for calcite. Artificial mixed mineral flotation tests demonstrated that SHA yielded a wolframite concentrate with WO3 grade of 61.01 % and WO3 recovery of 94.98 %, markedly outperforming the flotation concentrate obtained from BHA. Contact angle measurements confirmed that SHA could significantly enhance the surface hydrophobicity of wolframite. Fourier transform infrared spectroscopy (FT-IR) and zeta-potential measurements exhibited that SHA had a stronger chemisorption affinity to wolframite than calcite. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations indicated that the double-CONHOH groups in SHA molecule could chelate with the Fe sites on wolframite surface to form five-membered rings. Compared with BHA, SHA had stronger chemical reactivity and van der Waals forces onto wolframite. Thus, SHA was a potential choice for the efficient separation and enrichment of wolframite from calcite, which could further promote the production of tungsten metal.

The rapid development of the new energy industry has led to an increase in the demand for lithium metal. Lepidolite is the main source of lithium metal, but the common collector dodecylamine (DDA) can only separate lepidolite from its gangue (i.e., orthoclase) in a strong acid environment (pH ∼ 2) in the presence of depressants due to its weak selectivity. The heavy consumption of inorganic acid will corrode flotation equipment and bring challenges for wastewater treatment. In this study, the amidoxime collector 3-dodecylamine propyl amidoxime (DPA) was synthesized in our lab and introduced as the collector to efficiently recover lepidolite from orthoclase. In single mineral flotation, 80 mg/L DPA could float out 91.00% lepidolite and 85.50% orthoclase at pH 6.0, and DDA recovered 77.71% lepidolite and 90.02% orthoclase under the same conditions. For mixed mineral, 80 mg/L DPA combined with 100 mg/L sodium hexametaphosphate (SHMP) at pH 6.0 could obtain a Li2O concentrate with a grade of 3.87% and a recovery of 76.86%. The surface contact angle of lepidolite could be selectively enhanced to 78°, but that of orthoclase only exhibited to 40°. Zeta potential and FTIR spectra exhibited that DPA would physically adsorb onto lepidolite. Quantum chemical calculations proved that compared with DDA+ (0.178 and 0.1942 a.u.), DPA+ had a larger electrostatic group (0.274) and a smaller ΔELUMO-HOMO (0.1431 a.u.) to adsorb on the lepidolite surface. Thus, the DPA-SHMP agent system had the ability to separate lepidolite from orthoclase in a weak acid environment.

The flotation separation of chalcopyrite and galena remains challenging due to their similar surface properties. Here, we demonstrate that H2O2 pretreatment passivates Cu sites (forming Cu-O) while activating Pb sites (forming Pb-O) on mineral surfaces, which transforms sodium 2-(dithiocarboxylato)ethyl acetate (DTCA) from non-selective into a galena-selective depressant. Micro-flotation experiments indicate that with H2O2 oxidation duration of 30 min, pH of 10, and DTCA dosage of 100 mg/g, galena recovery can be reduced to below 5% while maintaining chalcopyrite recovery above 90%. Following oxidation, the adsorption amount of chalcopyrite decreased from 96.54 to 7 mg/g, while that of galena increased from 101.32 to 102.45 mg/g. Multiscale characterizations (FTIR, XPS, ToF-SIMS) indicate that DTCA adsorbs onto the surfaces of chalcopyrite and galena, respectively, via chelation between S-Cu-S and S-Pb-S bonds. Density functional theory (DFT) calculations confirm that oxidation enhanced the adsorption strength of DTCA on the surface of galena, with the adsorption energy shifting from -2.571 to -2.645 eV. Conversely, adsorption strength decreased significantly after oxidation of chalcopyrite, with the adsorption energy shifting from -2.470 to -1.588 eV. Closed-circuit tests on industrial concentrates yielded copper recovery and grade reached 93.13% and 27.43%, respectively, while lead achieved 96.33% recovery and 43.21% grade, with a separation index (SI) of 2.55, surpassing that achieved by the toxic potassium dichromate(K2Cr2O7) method. This study proposes a Cr (VI)-free flotation strategy for efficient Cu-Pb separation, offering a promising alternative to conventional environmentally hazardous methods.

Current research on the coextraction of lithium (Li), rubidium (Rb), and cesium (Cs) from lepidolite remains limited, with low extraction ratios for Rb and Cs. Herein, we report a chlorination-sulfation roasting (CSR) process for the synergistic extraction of Li, Rb, and Cs from lepidolite, using calcium chloride (CaCl2) and sodium lignosulfonate (SLS) as eco-friendly additives. The optimal conditions were established with a lepidolite:CaCl2:SLS mass ratio of 1:0.8:0.5, roasting temperature of 850 degrees C, and duration of 60 min. Subsequently, water leaching was conducted, with the leaching ratios for Li, Rb, and Cs reaching 97.80%, 94.06%, and 93.47%, respectively. Thermogravimetric-infrared-mass spectrometry (TG-IR-MS) confirmed that the process exclusively released carbon dioxide and water within the 30 degrees C-1000 degrees C range, with no emission of corrosive fluorine- or chlorine-containing gases. Comprehensive characterization via scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) revealed a phase transformation into dicalcium silicate (Ca2SiO4), calcium fluoride (CaF2), and potassium-sodium feldspar ((K,Na)(Si3Al)O-8). Notably, fluorine was successfully immobilized as stable CaF2 effectively, preventing hazardous hydrogen fluoride emissions. Density functional theory calculations further elucidated the energetics of selective ion substitution. The substitution sequence for Na+ was Cs+ < Rb+ < Li+, while that for Ca2+ was Li+ < Rb+ < Cs+. Additionally, an integrated precipitation-extraction process enabled the efficient separation and recovery of Li, Rb, and Cs from the leachate, yielding high-purity products-lithium phosphate (Li3PO4), rubidium chloride (RbCl), and cesium chloride (CsCl). Overall, the CaCl2-SLS CSR process provides critical theoretical insights and practical guidance for a clean, high-efficiency industrial extraction of Li, Rb, and Cs from lepidolite.

Herein, a transition-metal-free diphosphination of polyfluoroarenes with diphenylphosphine is disclosed. In the presence of tBuOK, various sterically hindered diphosphine ligands and fluorinated diphosphine ligands could be prepared in good to high yields through the C-F cleavage of polyfluoroarenes. This base-promoted direct diphosphination of polyfluoroarenes exhibits high efficiency and broad substrate scope, providing a convenient way for the synthesis of diphosphine ligands.

Xanthates are the most widely employed collectors in industrial sulfide mineral flotation; however, they often cause severe malodor pollution and exhibit limited selectivity when separating sulfide minerals with similar surface properties. In this study, we applied a molecular self-assembly strategy by incorporating a nitrogen-containing linker and a dibenzyl motif into an ethyl xanthate framework to synthesize a novel xanthate collector, O-(2-(bis(phenylmethyl)amino)ethyl) xanthate (PAEX). DFT calculations indicate that the negative electrostatic potential of PAEX remains localized on the sulfur-containing xanthate moiety (which preserves the reactive center). Meanwhile, the benzyl groups provide a polarizable surface that improves π-π stacking-dominated intermolecular interactions, thereby intrinsically suppressing volatilization into the gas phase. Electronic nose measurements further confirm the low-odor advantage of PAEX, indicating that the characteristic sulfide response decreases by more than 74.78% compared with conventional isobutyl xanthate. Flotation experiments with galena and sphalerite demonstrate that PAEX achieves highly selective galena collection across a wide pH range. Interfacial characterizations demonstrate that PAEX coordinates with Pb(II) sites on the galena surface through the sulfur atoms of the xanthate group, forming PAEX(S)-Pb surface complexes. Moreover, PAEX adopts an ordered, upright adsorption configuration that forms a stable and compact hydrophobic film, significantly enhancing the wettability contrast between galena and sphalerite. Overall, the π-π stacking-assisted self-assembly strategy effectively overcomes odor and selectivity limitations of conventional xanthate collectors, providing strong industrial potential for green mineral processing and the efficient separation of complex sulfide ores.

The similar flotability of galena and sphalerite makes their selective separation challenging. In this study, metformin (MF) was used as a flotation collector for the separation of galena from sphalerite. Micro-flotation tests demonstrated that at pH 7 with 3.5 × 10−4 mol/L MF, galena recovery reached 80.5%, while sphalerite recovery was only 9.5%. Contact angle, zeta potential, and Fourier transform infrared spectroscopy confirmed that MF selectively adsorbed onto galena and enhanced its surface hydrophobicity. X-ray photoelectron spectroscopy revealed that MF chemisorbed onto galena through Pb–N coordination bonds formed between its CN and –NH2 groups and surface Pb sites. Density functional theory calculations further demonstrated that MF exhibited a much stronger adsorption affinity for galena (-161.17 kJ/mol) than for sphalerite (-67.05 kJ/mol). Molecular electrostatic potential analysis indicated that the electron-rich nitrogen atoms of the CN and –NH2 groups serve as the active sites for Pb2+ coordination. The use of MF as a flotation collector offers a promising approach for developing high-performance collectors for lead minerals.

High-purity MnSO4 center dot H2O is an essential precursor for lithium-ion batteries, but its sustainable production from low-grade manganese carbonate ores remains challenging. In this work, we proposed a saponification-free solvent extraction process using a novel extractant, alpha-hydroxy-2-ethylhexyl phosphinic acid (alpha-H-2-EHA), to achieve efficient and selective separation of Mn2+. The extraction process achieved 99.68 % Mn recovery with a high separation factor between Mn2+ and Mg2+. The process minimized alkali consumption and allowed extractant regeneration, maintaining approximately 80 % of the initial extraction efficiency after five cycles. After impurity removal and crystallization, the obtained MnSO4 center dot H2O reached a purity of 99.86 % and a Mn content of 32.46 %, meeting the HG/T 4823-2023 first-grade requirement. Finally, Li1.27Mn1.73O4 prepared from the MnSO4 center dot H2O in this work exhibited electrochemical performance comparable to that derived from commercial battery-grade MnSO4 center dot H2O, demonstrating the feasibility of this method for producing battery-grade MnSO4 from low-grade resources. Life cycle assessment revealed that H2SO4 consumption and power consumption are the main factors contributing to the environmental impact of this process. In summary, this process offers a sustainable and economically viable solution to produce manganese compounds for battery applications from low-grade manganese carbonate ores.

Environmentally friendly and sustainable alternatives to chromium-based inhibitors for metals are still limited in the industrial sector. In this study, galvanized steel was immersed in ethanol solutions containing stearic acid (SA), with and without aluminum nitrate (Al(NO3)3), to investigate the synergistic effects of aluminum salts in forming an organic-inorganic composite coating. The underlying mechanism was examined using SEM, XPS, and FTIR analyses. The SA-Al composite coating demonstrated significantly enhanced hydrophobicity, showing approximately four times greater impedance than the SA layer and ten times greater impedance than bare zinc. This enhancement was attributed to the formation of aluminum stearate (AlSt3) and aluminum oxide (Al2O3) due to the hydrolysis of Al(NO3)3. The inclusion of aluminum salts shows significant industrial potential.

In copper-molybdenum (Cu-Mo) beneficiation circuits, the incomplete liberation and extensive surface oxidation of chalcopyrite (CuFeS2) and molybdenite (MoS2) critically constrain their selective separation efficiency. To address this issue, we designed 3,4,5-trihydroxy-N,N-bis(2-hydroxyethyl)benzamide (TBHB), a derivative of the traditional grinding aid diethanolamine. TBHB demonstrates a dual-functional mechanism: on the one hand, it enhances grinding efficiency by promoting crack propagation in coarse chalcopyrite particles, reducing the D90 size (i.e., 90% passing size) by 67.26%; on the other hand, it suppresses overgrinding by inhibiting the agglomeration of fine molybdenite particles, thereby limiting the D 10 size (i.e., 10% passing size) reduction to 28.42% compared to controls. This selective grinding action optimizes mineral liberation. Concurrently, FT-IR and XPS analyses confirmed that TBHB inhibits surface oxidation, preserving the inherent hydrophobicity of both chalcopyrite and molybdenite, essential for flotation. Adsorption studies revealed distinct adsorption mechanisms: TBHB chemisorbs onto chalcopyrite surfaces (fitting the Langmuir model, Delta G = -43.12 kJ/mol) via binding at the Fe sites while exhibiting physisorption onto molybdenite surfaces (fitting the Freundlich model, Delta G = -2.51 kJ/mol). The small-scale closed-loop experimental validation showed a 21.48% reduction in grinding energy consumption. Copper recovery and grade reached 99.93 and 26.20%, respectively, while molybdenum achieved 88.19% recovery and 49.26% grade, indicating superior metallurgical performance in the selective separation of Cu-Mo. This work underscores a molecular-design strategy for developing multifunctional additives that synergistically integrate the grinding and flotation processes for complex sulfide ores.

The weak collection ability of conventional benzohydroxamic acid (BHA) impedes its widespread application in the direct flotation of copper oxide minerals. Conversely, octyl hydroxamic acid (OHA) with enhanced hydrophobicity demonstrated superior collecting ability while exhibiting weak selectivity in malachite flotation. In order to achieve a balance between collecting ability and selectivity, we synthesized a novel N-cyclohexyl-Nhydroxyacetamide collector (ECHA) that featured similar structure of hydroxamate compounds and improved selectivity for the direct flotation of malachite. The bench-scale flotation results demonstrated that ECHA exhibited stronger collecting ability and excellent selectivity, 14.66% and 15.17% of copper recoveries increased than sodium butyl xanthate (SBX) and BHA, respectively. Contact angle tests, Zeta potential tests and solution chemistry analysis revealed that the interaction intensity of ECHA with malachite was significantly stronger than that of calcite and quartz. FTIR and XPS analysis showed that the reaction sites of ECHA were primarily located on the [-N(OH)CO-] group, suggesting possible chemisorption on the malachite surface. Additionally, DFT calculations indicated that the ECHA anion could potentially form a five-membered structure chelate complex with a Cu atom on the malachite surface through its [-N(OH)CO-] functional group. ECHA proved to be promising as an attractive collector in the direct flotation of malachite.

Herein, a base-promoted C-P(O) bond formation method has been developed for the phosphorylation of polyfluoroarenes through selective C-F bond cleavage. The high selectivity and mild, transition-metal-free conditions of this method underscore its potential for sustainable synthesis applications. This method expands the scope of polyfluoroarene functionalization, providing a valuable tool for incorporating phosphorus motifs in complex aromatic frameworks.