Selective Separation Research Articles

Application of calcium hypochlorite and carboxymethyl chitosan as combined depressants for selective flotation separation of chalcopyrite from pyrite at low alkalinity

Flotation separation of copper-sulfur at low alkalinity has attracted soaring interest in the beneficiation of copper sulfide ore. In this work, application of calcium hypochlorite (Ca(ClO)2) and carboxymethyl chitosan (OCMC) as combined depressants for selective flotation separation of chalcopyrite from pyrite was investigated. A maximum recovery difference of 71.35 % between both minerals is observed under the recommended conditions ([Ca(ClO)2] = 60 mg/L, [OCMC] = 400 mg/L and 40 mg/L SBX at pH=8). Besides, the copper-sulfur flotation separation indexes were assessed by the artificial mixed-mineral tests. Results of contact angle measurement, zeta potential and adsorption amount analysis reveal that the combined depressants severely impede the collector adsorption onto pyrite surfaces, and has a light effect on the chalcopyrite. OCMC exhibits a stronger complexing ability on Ca2+ and Fe2+ ions than Cu2+ ions. XPS results confirm that the combined depressant interact with pyrite surfaces intensively, and prompt a deep conversion of S22- and Sn2-/S0 into S2- and SO42- species, as well as a deep transformation of Fe(II)-S into Fe(III)-O/OH on the pyrite surface. ToF-SIMS and thermodynamic calculation results afford the favorable evidence for the selective suppression of the pyrite with added the combined depressant. Thereby the selective oxidation and intense complexation on the pyrite stemming from the combined depressant synergy are responsible for the selective separation of chalcopyrite from pyrite.

Density functional theory study on vanadium selective leaching separation from iron in stone coal via Fe2O3 (001) surface passivation

When vanadium is extracted from stone coal, iron impurities readily precipitate and reduce the purity of the vanadium product. Thus, separating vanadium from iron impurities at source is essential. The mechanism of surface passivation of Fe2O3 (001) for the selective leaching separation of vanadium from iron in stone coal was established in the present work. Analysis of mineral phase transformation and microscopic morphology indicates that Fe2O3 in stone coal can undergo a reaction with HF and F-. Subsequently, the hematite surface was covered with FeF3 passivation layer, resulting in the inhibition of hematite dissolving reaction. The results of density functional theory (DFT) computations demonstrate that the HF and F- can reform the Fe2O3 (001) surface via sedimentary behavior at mineral interface, and the adsorption energy can be down to -99.93kJ/mol for the F- adsorption configuration. During sulfuric acid leaching with CaF2 as an aiding agent, the transfer of electrons from Fe atoms to F atoms can weaken the stable Fe-F bonds and decrease the reactive activation of Fe atoms in Fe2O3. This study demonstrates the separation of vanadium from iron by means of hematite passivation in the attendance of fluoride at the atomic level of analysis.

Efficient selective flotation separation of talc and molybdenite with a novel molybdenite depressant: Remarkable performance and mechanism

The separation of talc and molybdenite is a challenging and research hotspot in mineral processing. In the work, a nitrous acid ester depressant (M−DEP) was first synthesized and used as a molybdenite depressant for the separation of talc and molybdenite via reverse flotation. Flotation tests of single-mineral and multi-mineral samples were carried out to evaluate the effect of M−DEP on the flotation behavior of molybdenite and talc. Zeta potential, X-ray photoelectron spectroscopy, and Fourier Transform Infrared Spectroscopy were used to analyze the selective depression mechanism of M−DEP on molybdenite and talc. Furthermore, the adsorption behavior of M−DEP on specific crystallographic planes of minerals has been studied by contact angle, atomic force microscope, and DFT calculation. Flotation experiment results indicated that M−DEP had excellent selective depression on molybdenite in the pH range of 5 to 10. The results of mechanism analysis showed that M−DEP could be adsorbed on molybdenite “basal” surface by hydrophobic interaction, and on molybdenite “edge” surface by chemical interaction, while could not be adsorbed on the surface of talc due to electrostatic repulsion. M−DEP enlarged the surface floatability difference between talc and molybdenite and promoted the efficient separation of talc and molybdenite via reverse flotation.

A metal–organic frameworks-imprinted emulsion interface with dynamic size- and site-selective recognition for significantly enhanced flavoniods extraction

The boronic acid suspended Cr based MIL-100 (MIL-100-B) sorbents have been widely used to separation of cis-diol containing molecules. However, it’s still challenging in fabrication of high performance metal organic frameworks (MOFs) due to its irregular size and low content of functional groups. For improving identification efficiency, the emulsion microreactor were firstly designed to purify MIL-100-B prior to their use. Herein, a highly ordered MOFs-imprinted polymer microsphere was synthesized by O/W Pickering emulsion template, which can highly selective separation of MIL-100-B via the synergistic effect of boronic acid sites and imprinted cavities. The obtained purified H-MIL-100-B exhibited the uniform size and abundant boronic acid groups (B elements ratio up to 27.37 %). The emulsion imprinted microsphere (EIMs) showed the good selectivity towards MIL-100-B. Additionally, the obtained MOF-imprinted microsphere exhibited green, convenient, sustainable separation process towards the purification and recycle of MIL-100-B. The purified MOFs (H-MIL-100-B) were used to specific bind with cis-diol flavoniods naringin (NRG). Satisfactorily, H-MIL-100-B show high adsorption amount (43.69μmol/g at 308 K), fast capture kinetics (160 min), high selectivity and excellent regenerability (up to seven cycles). Remarkably, the purified NRG solutions displayed lasting antibacterial activity against Staphylococcus aureus (S. aureus) with inhibition zone of 13.47 mm. More importantly, the H-MIL-100-B could effectively promote the specific recognition ability of NRG by reducing matrix interference and improving purification efficiency (93.93 %) from complex natural extracts. A high score (0.75) was predicted via analytical GREEnness (AGREE) approaches, demonstrating environmentally friendly and greenness of separation process. The MOFs-imprinted emulsion microspheres possessed dynamic recognition properties towards target MOFs, thus opening new direction for the development of convenient and efficient microreactor for the purification of other functional MOFs.

Deep eutectic supramolecular polymers based HPLC stationary phase: Green synthesis strategy and promising application prospects

BackgroundDeep eutectic solvents (DESs) have been widely and significantly applied in various fields due to their outstanding features such as low cost, easy preparation and good biodegradability. As novel derivatives of DESs, deep eutectic supramolecular polymers (DESPs) combine the macroscopic state of DESs with the covalent interactions of supramolecular polymers, which also possess the properties of DESs as multifunctional materials. Therefore, DESPs are believed to be promising candidates for separation science. However, there are no studies on the application of DESPs as stationary phases for HPLC analysis. ResultsIn this work, a novel DESP based HPLC stationary phase (Poly(DES)@SiO2) was developed for the first time through a green synthesis method by using DES as the polymerization monomer as well as the reaction medium. The results manifest that this novel Poly(DES)@SiO2 column can well interact with analytes through various mechanisms, and realize selective separation of a wide range of structurally similar hydrophilic/hydrophobic substances. More importantly, the separation of hydrophobic analytes on the Poly(DES)@SiO2 column is less time-consuming with fewer organic eluent, although the column efficiency is slightly lower than that of commercial C18 column. Furthermore, the Poly(DES)@SiO2 column exhibits excellent mechanical stability and satisfactory separation repeatability for steroid hormones. Therefore, a reliable method was established for detecting steroid hormones in actual samples with the recoveries ranging from 94.56 % to 103.84 %, which can meet the detection needs of commonly seen steroid hormones in food and the environment. SignificanceIn summary, this work provides some valuable theoretical references for the synthesis of new DESP based stationary phases through a green and facile strategy, and meanwhile, verifies the feasibility of DESP for effective HPLC separations. In addition, the promising application prospect of DESP based stationary phases in the analysis of complex samples has also been demonstrated, expanding the potential application of DES in separation science.

A Study on the Potential for the Application of Peanut Shells as a Reducer in the Process of Metal Recovery from Metallurgical Slags

Copper production technology is a complex process consisting of many stages. The combination of pyrometallurgical and hydrometallurgical stages, on the one hand, complicates production while, on the other hand, allowing for a relatively selective separation of intermediate or waste materials that can be subjected to the process of recovery of useful components. Materials of this type are characterised by a much higher copper content relative to the ore material. On the other hand, due to the oxide form, reduction processes are used in which coke is mainly applied. Reduction of the unfavourable phenomenon of CO2 emissions, in this case, can be performed through the use of bioreducers, which are characterised by an inert carbon footprint since the generation of carbon dioxides is the same as its absorption at the stage of vegetation and growth. In this paper, the topic of determining the feasibility of using selected bioreducers, such as peanut shells, to verify their suitability in the process of reducing copper oxides as well as the impact on the working components of the laboratory reactor in which the process is carried out are discussed. In this case, raw materials with a composition similar to the that of slags produced at the copper production stage in a flash furnace were tested for reduction. The results referring to reducing lead and copper contents above 88% Pb and 98% Cu indicate the great potential of this type of bioreducer. An additional advantage is the relatively wide availability of peanut resources. The effects of the copper reduction time on the degree of decopperisation performed with a constant reducer addition at 1300 °C were studied in this paper. Following 1 h of the process, the copper content in the slag was 0.78 wt%, while the longer process duration resulted in a copper fraction of 0.19 wt%. Considering lead, its content was 0.33 wt% after the reduction process.

Viscoelastic and antimicrobial dental care bioplastic with recyclable life cycle

Medical plastic-appliance-based healthcare services, especially in dentistry, generate tremendous amounts of plastic waste. Given the physiological features of our mouth, it is desirable to substitute dental care plastics with viscoelastic and antimicrobial bioplastics. Herein, we develop a medical-grade and sustainable bioplastic that is viscoelastic enough to align the tooth positions, resists microbial contamination, and exhibits recyclable life cycles. In particular, we devise a molecular template involving entanglement-inducing and antimicrobial groups and prepare a silk fibroin-based dental care bioplastic. The generated compactly entangled structure endows great flexibility, toughness, and viscoelasticity. Therefore, a satisfactory orthodontic outcome is accomplished, as demonstrated by the progressive alignment of male rabbit incisors within the 2.5 mm range. Moreover, the prepared bioplastic exhibits resistance to pathogenic colonization of intraoral microbes such as Streptococcaceae and Veillonellaceae. Because the disentanglement of entangled domains enables selective separation and extraction of the components, the bioplastic can be recycled into a mechanically identical one. The proposed medical-grade and sustainable bioplastic could potentially contribute to a green healthcare future.

Zwitterionic Nanochannels in Covalent Organic Framework Membranes for Improved Flux and Antifouling Property.

Zwitterionic membranes demonstrate excellent antifouling property in water purification. The covalent organic frameworks (COFs), due to the ordered channels and abundant organic functional groups, have distinct superiority in constructing zwitterionic surfaces.Here, the zwitterionic COF membrane is prepared with precise framework structures and uniform charge distribution. The negatively charged 4,4'-diaminobiphenyl-2,2'-sisulphonic acid sodium (SA) and positively charged ethidium bromide (EB) fragments are used to react with 1,3,5-triformylphloroglucinol (TP) at the gas-liquid interface to prepare zwitterionic COF membrane. The complementary charged fragments in the inter-layer and inner-layer facilitate the formation of continuous and tight hydration layer on the membrane surface and pore walls to resist the adsorption of pollutants. The zwitterionic COF membrane effectively resists both negatively charged bovine serum albumin and positively charged lysozyme pollutants with flux recovery ratio (FRR) of 97% and 85%, respectively. Furthermore, the regular nano-channels and balanced interactions between water and surface/pore walls of the zwitterionic membrane result in outstanding permeability of up to 146 L m-2 h-1 bar-1 and excellent dye/salt separation selectivity. The water permeation and antifouling mechanism of membranes are elucidated by experimental and molecular dynamics calculation. Zwitterionic COF membranes can find promising applications in preparing high-performance antifouling membranes.

Boronate affinity metal–organic frameworks molecularly imprinted membranes with hierarchical porous channels for the selective separation of naringin

Naringin (NRG), known as an important natural flavoniod compounds, exhibits excellent phamaceutical value and clinical application prospect. However, the main obstacle to the isolation and purification of NRG is the low concentration and complexity of the extraction system. Herein, a new kind of hierarchical porous metal–organic frameworks (MOFs) based molecularly imprinted membranes (PBMMA-MIMs) for the specific separation of NRG. The prepared PBMMA-MIMs showed the fast adsorption kinetics (within 120 min). Moreover, the abundant boronic acid imprinted recognition sits and hydrophilic hierarchical porous MOFs improved the adsorption capacity (the maximum adsorption amounts 57.39 μmol/g) and exhibited selective NRG adsorption (imprinting factor 2.31) with efficiency over 91.69 % after seven adsorption–desorption cycles. In addition, the coarse NRG could be effectively extracted to a promising purity of 93.13 % via PBMMA-MIMs. This study provides new insights into the design molecularly imprinted membranes via environmentally friendly synthesis route for the preparation for enriching high-value flavoniods, achieving efficient purification rate of agricultural wastes for pollution control, and promoting the sustainable reuse in complex agricultural wastewater.

Construction of a Fluorinated-Anion Pillared Metal-Organic Framework Exhibiting Dual-Pore Architecture for Simultaneous Enhancement of C2H2 Adsorption Capacity and Selectivity.

Physisorption-based separation processes represents a promising alternative to the conventional thermally driven methods, such as cryogenic separation. However, a significant challenge lies in balancing the trade-off between adsorption capacity and selectivity of adsorbents. In this study, we introduce a novel fluorinated-anion pillared metal-organic frameworks (APMOFs) featuring a dual-pore architecture, constructed using a pyridine-oxazole bifunctional ligand. The inherent low symmetry of the ligand leads to significant distortion of the fluorinated-anion pillars, resulting in a distinctive type of APMOFs characterized by dual-pore architecture. On pore structure with constrict pore width is enriched with a high density of anion fluorinated pillars, offering numerous active sites advantageous for enhancing separation selectivity. Concurrently, the other pore structure exhibits larger dimensions, facilitating increased gas molecule accommodation and thereby augmenting adsorption capacity. Gas sorption studies reveal a substantial C2H2 adsorption capacity and a high C2H2/CO2 separation selectivity. Breakthrough experiments confirm its exceptional separation performance, while theoretical investigations elucidate a sequential adsorption process within these APMOFs, underscoring the efficacy of this strategy in overcoming trade-off limits in adsorbents.

Low Fouling Molecular Selective Channels through Self-assembly of Cross-linked Block Copolymer Micelles for Selective Separation of Dye and Salt.

We report the solvent-evaporation and ionic cross-linking mediated self-assembly of the shell cross-linked micelles of the amphiphilic triblock copolymer containing middle poly(methyl methacrylate) block (hydrophobic) and poly(2-dimethylamino)ethyl methacrylate end blocks (hydrophilic) on the membrane substrate to create molecular selective channels. The formation of selective channels on the substrate is attributed to the local increase of micelle concentration upon solvent evaporation, which leads to the core-core hydrophobic interaction. The post-ionic cross-linking of the shell part further reduces the intermicelle distance, thereby creating interstices for selective separation. The TUF-1:1 membrane prepared by the self-assembly of the cross-linked micelles (triblock copolymer:halide-terminated PEG-based = 1:1 w w-1) and by the post-ionic cross-linking shows molecular weight cutoff of 3000 g mol-1 and pure water permeance of 52 L m-2 h-1 bar-1. The membrane shows 99.5-99.9% rejection of Congo red and Direct red-80 in the presence or absence of salts and Na2SO4 to dye separation factor of about 900. The added functionality (PEG) in the micelle structure provides good fouling-resistant properties toward dye and bovine serum albumin. This work provides the membrane formation mechanism and the advantages of the membrane for fractionation and resource recovery applications.

Thin film nanocomposite membranes based on renewable polymer Pebax® and zeolitic imidazolate frameworks for CO2/CH4 separation

This study investigates the impact of integrating Pebax® Rnew® 30R51, a sustainable elastomer-type copolymer material, with zeolitic imidazolate frameworks (ZIFs) to develop advanced membranes for CO2/CH4 gas separation. The fabrication process of ZIF/Pebax® Rnew® 30R51 thin films was optimized to achieve uniform and defect-free thin film composite (TFC) membranes. Crucial membrane properties, including permeability, selectivity and separation efficiency, were analyzed with variations in ZIF type, loading levels, film thickness and operating conditions. Additionally, the resulting TFC and ZIF/Pebax® Rnew® 30R51 thin film nanocomposite (TFN) membranes were subjected to characterization via FTIR, XRD, TGA and SEM to evaluate their physicochemical properties. Nanoparticles of ZIF-8, NH2-ZIF-8 and ZIF-94 were individually added (at 5–15 wt% loadings) to the Pebax® Rnew® 30R51 matrix to develop the CO2 separation efficiency. The pristine TFC membrane showed a 66 GPU CO2 permeance and a 37.5 CO2/CH4 separation selectivity, primarily due to improved CO2 mass transport. Upon inclusion of ZIFs, the CO2 permeance with 5 wt% loadings of ZIF-8, NH2-ZIF-8 and ZIF-94 increased to 148, 99 and 125 GPU, respectively, despite this, the CO2/CH4 separation selectivity maintained at 29.4, 37.0 and 27.0, respectively.

Ligand content and driving force effects on ion-ion permselectivity in ligand-functionalized membranes

Ion-selective membranes could enable sustainable critical material separations processes because of their scalability, low energy consumption, and low chemical input. The effects of membrane water content and incorporation of ion-coordinating ligands have been studied via computation and experiment to develop structure-performance relationships. However, few studies systematically investigate the effects of membrane composition beyond monomer chemical identity or the balance of driving forces such as diffusion and electromigration. Here we synthesized a library of poly(ethylene glycol) acrylate membranes with varying percentages of ion-coordinating monomers (acrylic acid, 4-vinylpyridine) to investigate the influence of ligand content on cation permeabilities and permselectivities. Trends in membrane performance under electrodialysis and diffusion were compared to elucidate the relative effects of separation driving forces and to inform electrochemical operation. We observed order-of-magnitude permeability reductions with ligand content for ions capable of multidentate ligand complexation, especially for nickel in the pyridine-containing membranes. As a result, lithium/nickel permselectivity gradually increased by a factor of 1.65 × from 10 to 50 mol% pyridine membranes. We further demonstrated simultaneous improvements in lithium/nickel separation productivity (1.75 ×) and selectivity (2.99 ×) with increasing electric potential driving force. Ultimately, results from this study provide design insights for ligand-functionalized membranes in electrified ion-ion separations processes.

Introducing Phosphate Ester into DAPhen by Propyl Enhanced the Selectivity for UO22+ over Th4.

A new type of phenanthroline carboxamide(DAPhen)-phosphate ester ligand (L1/L2) was synthesized for the selective separation of U(VI) over Th(IV). Liquid-liquid extraction experiments showed that the introduction of phosphate ester could increase the extraction ability of ligands for U(VI), especially L2, which showed high selectivity for the separation of U(VI) over Th(IV). The slope analysis indicated that L1 could form 1:1 and 1:2 complexes with U(VI) and 1:1 complexes with Th(IV). NMR titration revealed that the DAPhen unit of ligands combined with one U(VI) to form 1:1 complexes, and then the phosphate ester unit of the 1:1 complexes further combined with another U(VI) to form 1:2 complexes. Ligands provide only the DAPhen unit to Th(IV) to form 1:1 complexes. The crystal structures found 1:2 complexes of L1 and U(VI), 1:1 complexes of L2 and U(VI), and 1:1 complexes of L1 and Th(IV). The larger stability constant (log β) of the 1:1 complexes of L2 with U(VI) than that of the 1:1 complexes of L1 with U(VI) showed that the binding ability of U(VI) with the DAPhen unit of L2 is stronger than that of U(VI) with the DAPhen unit of L1. This study provides new ideas for designing extractants with excellent properties.

Selective Separation of Thiophene Derivatives Using Metal-Organic Frameworks-Based Membranes.

The removal of sulfur compounds, particularly thiophene derivatives, from oil is crucial due to concerns about environmental issues. Therefore, the deep desulfurization of transportation fuels is currently an urgent problem, and numerous attempts have been made in this direction. Membrane-based desulfurization can be a good alternative to the traditional hydrodesulfurization method, which has several limitations. In this work, the use of membranes containing a metal-organic framework, MOF-5, doped with transition metals (Ag, Cu, Ni), in the adsorptive desulfurization process was studied. The efficiency of membranes was evaluated based on selective removal of thiophene and dibenzothiophene from model oil. Characterization techniques, including scanning electron microscopic (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), confirmed the successful synthesis and incorporation of metal-organic frameworks (MOFs) into mixed matrix membranes (MMMs). Desulfurization experiments showed that MOF-5/Ag exhibited the highest thiophene adsorption efficiency (86.8%), outperforming MOF-5/Cu and MOF-5/Ni. The enhanced performance is attributed to the strong interaction between silver and sulfur. These findings demonstrate the potential of MOF-based MMMs for efficient and selective desulfurization, offering a viable alternative to traditional hydrodesulfurization (HDS) methods.

Engineering of Covalent Organic Framework Nanosheet Membranes for Fast and Efficient Ion Sieving: Charge-Induced Cation Confined Transport.

Artificial membranes with ion-selective nanochannels for high-efficiency mono/divalent ion separation are of great significance in water desalination and lithium-ion extraction, but they remain a great challenge due to the slight physicochemical property differences of various ions. Here, the successful synthesis of two-dimensional TpEBr-based covalent organic framework (COF) nanosheets, and the stacking of them as consecutive membranes for efficient mono/divalent ion separation is reported. The obtained COF nanosheet membranes with intrinsic one-dimensional pores and abundant cationic sites display high permeation rates for monovalent cations (K+, Na+, Li+) of ≈0.1-0.3mol m-2 h-1, while the value of divalent cations (Ca2+, Mg2+) is two orders of magnitude lower, resulting in an ultrahigh mono/divalent cation separation selectivity up to 130.4, superior to the state-of-the-art ion sieving membranes. Molecular dynamics simulations further confirm that electrostatic interaction controls the confined transport of cations through the cationic COF nanopores, where multivalent cations face i) strong electrostatic repulsion and ii) steric transport hindrance since the large hydrated divalent cations are retarded due to a layer of strongly adsorbed chloride ions at the pore wall, while smaller monovalent cations can swiftly permeate through the nanopores.

Healable, Recyclable, and Upcyclable Gel Membranes for Efficient Carbon Dioxide Separation

AbstractIonic liquids (ILs) are prized for their selective dissolution of carbon dioxide (CO2), leading to their widespread use in ionogel membranes for gas separation. Despite their advantages, creating sustainable ionogel membranes with high IL contents poses challenges due to limited mechanical strength, leakage risks, and poor recyclability. Herein, we leverage copolymerized and supramolecularly bound ILs to develop ionogel membranes with high mechanical strength, zero leakage, and excellent self‐healing and recycling capabilities. These membranes exhibit superior ideal selectivity for gas separation compared to other reported ionogel membranes, achieving a CO2/nitrogen selectivity of 61.7 and a CO2/methane selectivity of 24.6, coupled with an acceptable CO2 permeability of 186.4 Barrer. Additionally, these gas separation ionogel membranes can be upcycled into ionic skins for sensing applications, further enhancing their utility. This research outlines a strategic approach to molecularly engineer ionogel membranes, offering a promising pathway for developing sustainable, high‐performance materials for advanced gas separation technologies.

Flotation of Copper Sulfide Ore Using Ultra-Low Dosage of Combined Collectors

Copper sulfide ores frequently co-occur with pyrite, presenting a significant challenge for their selective separation during beneficiation processes. Despite advancements in flotation technology, there remains a critical need for efficient methods to enhance copper recovery while suppressing pyrite interference, particularly without compromising the associated precious metals such as gold and silver. Current practices often struggle with achieving high selectivity and recovery while maintaining environmental sustainability. Here, we investigate the efficacy of a ternary collector mixture consisting of ammonium dibutyl dithiophosphate (ADD), butyl xanthate (BX), and ethyl xanthate (EX) for the selective flotation of copper sulfide from a complex ore containing 0.79% Cu and associated precious metals (0.233 g/t Au and 5.83 g/t Ag). A combination of lime and hydrogen peroxide as inhibitors was employed to suppress pyrite effectively under alkaline conditions (pH = 11.33). The results demonstrate that the optimized ternary collector system (ADD:BX:EX at a ratio of 1:0.5:0.5) significantly improves the copper grade and recovery at an ultra-low dosage of 10 g/t. The optimized flotation method using the combined collectors and inhibitors effectively separated chalcopyrite from pyrite, achieving a copper concentrate with 20.08% Cu content and a recovery of 87.73%. Additionally, the process yielded notable recoveries of gold (9.22%) and silver (26.66%). These findings advance the field by providing a viable and environmentally conscious approach to the beneficiation of sulfide ores, potentially serving as a blueprint for processing similar mineral deposits while minimizing reagent usage and costs.

Charge‐Sign‐Independent Separation of Mono‐ and Divalent Ions With Nanofiltration Membranes

AbstractAchieving precise selective separation of monovalent and divalent cations, as well as anions, is vital yet challenging in practical applications involving complex component treatments. Current membranes are typically effective for separating either cation pairs or anion pairs. To address this issue, a straightforward strategy for fabricating a nanofiltration (NF) membrane is developed that selectively permeates monovalent ions. This study focused on neutralizing the surface charge and tuning the pore size distribution of the polyamide membranes through a secondary interfacial polymerization using a zwitterionic copolymer consisting of 2‐methacryloyloxyethyl phosphorylcholine and 2‐aminoethyl methacrylate hydrochloride. The optimized NF membrane prepared in this study, with a near‐neutrally charged membrane surface and appropriate pore size distribution, demonstrates favorable performance in precisely separating monovalent and divalent ions, irrespective of the ion charge sign. The optimum NF membrane features high selectivity for both Cl−/SO42− (93) and Li+/Mg2+ (67) ion pairs, along with high water permeance of 8.5 L m−2 h−1 bar−1, making it competitive with many reported membranes. This study offers new insights into the ion‐selective mechanisms of polyamide membranes for monovalent/divalent ions and may guide the development of advanced membranes with single‐solute selectivity.

Oriental covalent immobilization of N-glycan binding protein via N-terminal selective modification

Lectin affinity chromatography is one of powerful tools for the study of protein glycosylation. Different lectin proteins can recognize different structures of monosaccharides or oligosaccharide units, allowing for the selective separation of glycopeptides or glycoproteins containing different polysaccharide structures. However, the N-glycans were only partially captured by most of common lectins, reducing the coverage rate of identifying N-glycoconjugates. Recently, it has been reported that the engineering variant of glycan binding protein Fbs1 has a high affinity for innermost Man3GlcNAc2 structure and is able to bind diverse types of N-glycans, which can be suitable for the analysis of protein N-glycosylation. However, efficient immobilization of protein to separation matrix is particularly challenging as it requires the functionality and integrity of the protein to be preserved. Herein, we describe a simple and robust strategy for oriental covalent immobilization of proteins on magnetic nanoparticles by N-terminal selective labeling techniques. We inserted the enterokinase cleavage site to produce the specific N- terminal glycine of protein. Under physiological conditions, the protein was immobilized on the surface of the MNPs by this glycine tag, and the enrichment process could be completed within 30 min. A whole enrichment and purification of glycan and glycopeptides were completed and analyzed by MALDI TOF-MS. The functional materials achieved stable enrichment of glycan structure in different enzyme digestion systems or complex samples, showing excellent anti-interference and applicability.