Extraction Of Zinc Research Articles

High-quality and efficient zinc electrodeposition in a polyethylene glycol 20,000-assisted ammonia solution

Ammonia system shows great potential in the treatment of zinc secondary resource, and electrodeposition has been confirmed as a vital process to extract zinc from the ammonia leachate. However, the ammonia system-based zinc electrodeposition is either inefficient or the zinc deposit in of undesired quality. This study proposes a polyethylene glycol 20,000 (PEG20000 polymer of formula H(OCH2CH2)nOH)-assisted ammonia system to conduct high-quality and efficient zinc electrodeposition. The practical operation achieved a low electrical energy consumption of 2391 kW h t−1 Zn and a high current efficiency of 99%, with a smooth and compact zinc deposit of fine (30.2 nm) grains. Further investigation of electrodeposition behavior revealed the following: (i) deposition principle, (ii) diffusion property, and (iii) three-dimensional (3D) instantaneous nucleation mode, and provided a useful reference for guiding the process design and conditions of the practical operation. In general, PEG20000-assisted ammonia system turns out to be a technically and economically viable option to electro-deposit zinc, for its high energy competitiveness and high-quality Zn products.

Weathering alters the profile of trace metals and organic compounds in leachates and bioavailability extracts from microplastics of trail running shoes

Microplastics (MPs) from rubber outsoles of trail running shoes may contribute significantly to contamination in protected areas. In the natural environment, weathering processes can damage MP molecular structure and alter the mobility of inorganic and organic compounds used as additives in rubber. In this study, we characterised changes in the surface morphology, functional groups, and thermal stability of MPs weathered on and below the soil surface over 12 weeks, and analysed inorganic and organic additives in leachates (0.01M CaCl2) and bioaccessibility extracts (ethyl acetate). Weathering conditions included UVC irradiation at 25 °C and 80% soil moisture. Microplastics on the soil surface exhibited cracking, fragmentation, and increased extractability of zinc, sulphur, titanium and fatty acids. Microplastics below the soil surface were not significantly physically or chemically altered, however zinc leachability increased following extended weathering by up to 155%. Bioaccessibility of thiol, aromatic and cyclic organic additives decreased from both surface and sub-surface MPs over the 12 week weathering period, but there was evidence of an increase in transformation by-products. Microplastic toxicity may be significantly altered by environmental conditions and MP weathering. It is critical ecotoxicological studies use weathered MPs to assess impacts on rare and endemic species found in protected spaces.

Feasibility and reaction process for recovery of Si and Pb from high‐calcium zinc extraction residue by alkali roasting

AbstractTo explore the feasibility of Si and Pb recovery from high‐calcium zinc extraction residues via alkali roasting, NaOH molten roasting is performed and the reaction process is discussed. Under the optimal reaction conditions—residue–alkali ratio of 1:5.0, reaction time of 1.75 h, and reaction temperature of 500°C—the Si and Pb extraction ratios remained stable at 74.00% and 40.00%, respectively. The X‐ray diffraction patterns of the specimens roasted at different temperatures indicated that the main factor affecting the extraction process was the presence of Na2CaSiO4, Ca2PbO4, and quartz. Further, the phase transformations and reaction processes of Si and Pb were determined. In the final phases, the specimen roasted at 550°C included quartz, Na4SiO4, Na2CaSiO4, Ca2PbO4, and Na2SO4. The kinetics data calculated using the unreacted shrinking core model showed that the roasting process followed a mixed control mechanism with an apparent activation energy of 16.99 kJ · mol−1.

Enhanced termination of zinc and cadmium ions from wastewater employing plain and chitosan-modified mxenes: synthesis, characterization, and adsorption performance

Zinc and cadmium pollutants cause a significant environmental effect that cannot be ignored. Due to their considerable amount in an aqueous environment, industries are seeking suitable adsorbents that are environmentally friendly and inexpensive for removing metals from wastewater before disposing of them in surface waters. This research employed original MXene (MX) and chitosan-modified MXene (CSMX) to extract zinc (Zn(II)) and cadmium (Cd(II)) metal ions from water-based solutions. The composite material produced was analyzed using techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET). The effects of contact duration, pH of the solution, and initial concentration of metal ions on the adsorption process of Zn(II) and Cd(II) onto both MX and CSMX composites were investigated. MX and prepared CSMX composite presented a high adsorption capacity for both studied heavy metals, which were 91.55 and 73.82 mg/g for Zn(II) and Cd(II) onto MX, 106.84 and 93.07 mg/g for Cd(II) and Zn(II) onto CSMX composite, respectively. Furthermore, the maximum competitive adsorption capacities for Zn(II) onto MX and CSMX composites are 77.29 and 93.47 mg/g, and for are Cd(II) 60.30 and 79.66 mg/g, respectively. Hence, the removal capacities for both single and competitive metal ions were superior to CSMX composite. However, the adsorption capacities after five successive regeneration sequences were only dropped by 13.2% for Zn(II) and 17.4% for Cd(II) onto the CSMX composite compared to the first cycle. These results confirm that both metals could be efficiently terminated from wastewater, which makes the prepared CSMX composite a favorable candidate adsorbent in practical applications.

Cloud Point Microextraction Prior to Flame-Atomic Absorption Spectrometry for the Determination of Zinc Ethylene-1,2-Bisdithiocarbamate (Zineb) in Food and Environmental Samples

Cloud point microextraction (CPME) with Triton X-114, as a nonionic surfactant, was applied for the extraction of zinc ethylene-1,2-bisdithiocarbamate (zineb) prior to its determination by flame-atomic absorption spectrometry (FAAS). The optimum CPME conditions were obtained with 250 µL of Triton X-114 at a cloud point temperature of 30 °C in 20.0 mL of the sample solution whose pH had been adjusted to 7.00. Zineb was monitored at a wavelength of 213.0 nm. The limits of detection were found to range between 13.0 and 25.0 ng mL−1 and the coefficients of determination (R2) of the calibration graphs were between 0.9975 and 0.9994. The developed CPME-FAAS method was applied to extract and determine in food and environmental samples with percentage relative recoveries ranging from 90.6 to 105.4% with percentage relative standard deviations (%RSD) less than 7.5%.

Status of Sulphur, Zinc and Boron in Onion Growing Soils of Dharwad Taluk, Karnataka, India

Survey was undertaken during rabi 2021-22, to study the sulphur, zinc and boron status in onion growing fields in selected villages of Dharwad taluk, Karnataka. One hundred surface soil samples were collected from selected ten villages of Dharwad taluk using GPS. The results revealed that soils were neutral to alkaline in reaction, low in total soluble salts, low to high organic carbon content, low in available nitrogen, medium in available phosphorus, potassium and sulphur and 49.00 and 77.00 per cent of the soils were deficient in DTPA extractable zinc and hot water soluble boron, respectively.

Liquid-Liquid Extraction of Metal Ions Using Aqueous Biphasic Systems

An investigation was conducted for the study of extraction of metal ions using aqueous biphasic systems. The extraction of iron, zinc and copper from aqueous sulphate media at different kinds of extractants SCN− , Cl- and I- , different values of pH of the feed solution, phase ratio, concentration of metals, concentration of extractant, concentration of polymer, and concentration of salt was investigated. Atomic absorption spectrophotometer was used to measure the concentration of iron, zinc and copper in the aqueous phase throughout the experiments. The results of the extraction experiments showed the use of SCN− as extractant, pH=2.5, phase ratio=1.5, concentration of metals 1g/l, concentration of extractant 0.06 %, concentration of polymer =50 %, and concentration of salt=20% gave the highest value of percent removed. Also increase of extractant concentration increases the percent removed. The results clarified that increasing the metal ions concentration in the aqueous phase causes to decease the percent removed. The addition of an inorganic salt (sodium sulphate) up to (20%) increased the dehydration of polymer chains and then increases the percent removed.

Electron structure and defect co-modulation to boost zinc storage performance of urchin-like VS4-based microspheres as advanced cathodes for aqueous Zn-ion batteries

Recently, aqueous zinc ion batteries (AZIBs) have been widely favored for their intrinsic safety, low cost and environmental friendliness; however, the vast volume expansion, poor electrical conductivity and low-density zinc insertion and extraction channels of the cathodes cannot meet the requirements of practical application for AZIBs. Herein, urchin-like Co-doped VS4 microspheres (Co-VS4-δ-x) with the co-regulation of electron structure and defect have been developed and synthesized by a one-step solvothermal procedure as an advanced cathode material for AZIBs. The introduction of active multivalent Co ions achieves the interfacial charge rearrangement of Co-VS4-δ-x electrode and the widening of the layer spacing to reduce the transfer resistance and interfacial attraction of Zn2+ between the layers. Moreover, the formation of sulfur defects shortens the Zn2+ transport distance and enhances the electrical conductivity and electrochemical kinetics of Co-VS4-δ-x material. In addition, the urchin-like micromorphology of the material dramatically increases the contact area between electrolyte and electrode material and the active sites of electrochemical reaction. Based on the above advantages, the zinc storage performance of Co-VS4-δ-x has been greatly enhanced, delivering the specific capacities of 306.4 mAh g−1 and 270.7 mAh g−1 at 0.5A g−1 and 5A g−1, respectively, and exhibiting excellent cycling stability with the capacity retention of 87.0% after 3000 cycles at 5 A g−1. This investigation proposes an effective strategy to develop high-performance vanadium-based cathodes for AZIBs by charge rearrangement, defect modulation and morphology optimization.

Efficient zinc extraction with novel phenyl phosphate PTOPP in sulfuric acid system

Traditional acidic phosphate extractants (D2EHPA and HEH/EHP) exhibit poor extraction performance under high-acid conditions and require saponification pretreatment to maintain the pH stability of the aqueous phase during the solvent extraction. However, saponification pretreatment produces a large amount of saline wastewater, resulting in high treatment costs and difficulty of the industrial waste salts utilization. Thus, we synthesized an efficient p-tert-octyl phenyl phosphate (PTOPP) extractant suitable for a high-acid system based on phenyl substitution and carbon-chain design. The structure and content of the synthesized products were confirmed to be [(CH3)3CCH2C(CH3)2C6H4O]2P(O)OH (diphenyl phosphate, P10B4, 88.26%) and (CH3)3CCH2C(CH3)2C6H4OP(O)(OH)2 (monophenyl phosphate, DHP10B4, 10.68%) via HRMS, LCMS, and NMR characterization combined with potentiometric titration. After three-stage countercurrent extraction and two-stage countercurrent stripping, the zinc extraction efficiency of PTOPP reached 85%, and the zinc concentration of aqueous phase increased from 20 g/L to 66.53 g/L with a 3.3 enrichment multiple. In comparison, the enrichment multiples of D2EHPA and HEH/EHP under the same conditions were only 1.5 and 1.1, respectively. The zinc extraction mechanism with PTOPP was determined by the slope method and structural characterization of the extracted compound (PTOPP-Zn). During the zinc extraction process, the P-OH and P=O groups in PTOPP interacted with Zn2+ to form Zn–O bonds through proton exchange and coordination reactions, and the molecular formula of the extracted compound was ZnA2·HA. The novel PTOPP significantly improves the zinc extraction performance and achieves a remarkable enrichment effect without saponification pretreatment, thereby avoiding the consumption of NaOH and the discharge of Na2SO4 wastewater. It has promising applications in the fields of low-grade zinc mineral resource recovery and heavy-metal wastewater disposal.

Leaching Kinetics of Hemimorphite with 5-Sulfosalicylic Acid

The kinetics of leaching zinc from hemimorphite was investigated. The factors that influence hemimorphite leaching were also evaluated, and a kinetic model was built. In addition, scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) was used to investigate the changes of surface morphology before and after leaching. By decreasing particle size and increasing temperature, 5-sulfosalicylic acid concentration, and stirring speed, the leaching rate of hemimorphite can be enhanced. The shrinkage nucleus model describes the surface chemistry of leaching. The activation energy of hemimorphite by 5-sulfosalicylic acid in the leaching process was determined as 55.244 kJ/mol. The reaction rate based on the shrinkage nucleus model can be expressed by the semi-empirical formula:1−1−x1/3 =[k0C0.3385(r0)−0.6083(SS)0.4992exp(−55.244/RT)]t. At the condition of 50 °C of leaching temperature, 0.175 mol/L of 5-sulfosalicylic acid concentration, 82.5 μm of particle size and 650 rpm of stirring speed, the high leaching rates of zinc were obtained. After the reaction time of 15 min, the leaching rate of zinc reached more than 95%. According to the SEM-EDS results, the hemimorphite and leaching residue are distributed in blocks, but the particle size of the leaching residue is smaller, and the atomic concentrations of Zn and Si in the leaching residue are significantly lower than those in the hemimorphite, so the leaching effect is remarkable. Therefore, 5-sulfosalicylic acid solution would be an excellent leaching agent for zinc extraction from hemimorphite.

Evaluation of Combinations Between Menthe Extract, Zinc Nano Oxide and Phenol Compound on Antifungal

From August 17 to January 1, 2023, this investigation was carried out in the postgraduate lab at the University of Kerbala. The Menthe spicata plant was removed from the city of Karbala on July 11, 2022, and phenol component was extracted from ethanol alcohol menthe extract. from the Nanomaterials, Practical size, and Zno nanoparticals (33-40nm) In order to assess the effectiveness of various concentrations of combinations of zinc nanoparticles, menthe extract, and phenol obtained from menthe extract, as well as the virulence of fungal isolates Candida albicans, Trichophyton rubrum, and Microsporum canis. The results demonstrate that menthe extract, zinc nanooxide, and phenol chemical combinations are more effective than menthe extract alone in enhancing the inhibition zone against fungus, and that nano zinc has a more significant impact than phenol and menthe extract in reducing the amount of antifungal required. The goal of this study was to diminish the pathogenic fungal growth suppression using a combination of nano zinc, phenol, and menthe extract antifungals (M. canis, T. mentagrophyte, and C. albican).

Improving the technology of copper-zinc ore beneficiation of a Uralian-type pyrite deposit

Introduction and research objective. Copper-zinc ore of pyrite deposits of the Uralian type are refractory. Difficulties in beneficiation are due to their material composition: fine coarseness and emulsion impregnation of ore minerals in each other, a large amount of flotation-active pyrite, a high content of finely dispersed and submicroscopic gold in sulfides, etc. In the course of pyrite ore processing at dressing mills, 83–91% of copper and 10–45% of gold are extracted into copper concentrates, and 46–78% of zinc and 5–15% of gold are extracted into zinc concentrates. Increasing the process performance of pyrite deposit ore processing is a promising and urgent task. Methods of research included copper-zinc pyrite ore material composition study through quantitative chemical analysis, chemical phase analysis for the forms of copper, zinc, gold and silver compounds, and mineralogical analysis. Technological studies were carried out by flotation and gravity methods using a centrifugal concentrator and a concentration table. Conclusions. In the course of pyrite deposit copper-zinc ore beneficiation at the dressing mill, the effect of circulating concentration of gold in the coarse copper concentrate regrinding cycle was established. The results of studies on the centrifugal concentration of gold in a centrifugal concentrator with further secondary cleaning of its heavy fraction on a concentration table show the possibility of obtaining a gravity product with a mass fraction of gold up to 200 g/t under its operational extraction up to 29%. It was noted that the integrated flotation-gravity technology for copper-zinc ore beneficiation will increase the through extraction of gold into marketable mineral products by more than 1.5%. The use of a combination of butyl potassium xanthate and FRIM-2920 reagent-collector in the copper-zinc pyrite ore flotation technology contributes to increased extraction of copper and gold into copper concentrate by 0.87% and 3.22%, respectively, and zinc into zinc concentrate by 0,4%. Increasing the pulp temperature in the zinc flotation cycle to 40–45 °C and returning the control zinc flotation concentrate and tailings from the first cleaning flotation of zinc to the II main zinc flotation allows increasing the mass fraction of zinc in the zinc concentrate from 48.5 to 51.1% under a simultaneous increase in the extraction of zinc into zinc concentrate from 62.6 to 65.6%.

Determining soil quality indicators for alluvial plains in the semi‐arid tropics

AbstractEvaluating soil quality in the alluvial plains of the semi‐arid tropics is vital to understand the impact of existing land management practices, thus facilitating the adoption of more sustainable agricultural methods. We analysed soil profiles using 146 horizon‐specific samples from 24 pedons, representing seven soil series from the sub‐tropical to semi‐arid River Cauvery Delta basin, Tamil Nadu, India. Using principal component analysis (PCA), we identified minimum datasets (MDS) from 30 different soil properties. The plough layer's MDS were clay content, exchangeable sodium percentage (ESP), very coarse sand content, soil pH and soil organic carbon (SOC). For the subsurface layer, sand content, ESP, SOC, diethylene‐triamine‐pentaacetic acid extractable zinc (DTPA‐Zn), and very coarse sand content were identified as the MDS. Soil quality index (SQI) values were 0.47–0.72 for the plough layer and 0.46–0.56 for the subsurface soil, suggesting limited soil function support in subsurface soils. Surface soil‐site suitability criteria displayed a moderate correlation with SQI values derived via PCA, with additive (R2 = .545) and weighted additive indices (R2 = .659). Both simple additive index and weighted derived SQIs demonstrated a moderate association with rice yield (R2 = .50 and .55, respectively). This research indicates the potential to identify soil quality indicators in alluvial plains of semi‐arid tropics.

Preparation of dual-use GPTES@ZnO photocatalyst from waste warm filter cake and evaluation of its synergic photocatalytic degradation for air-water purification

Organic pollutants are the most critical threats to the health of air and water resources. On this basis, fabricating a photocatalytic acrylic film with dual-use (i.e. removing benzene from air and MB/MO dyes from water) was aimed in this research. For this purpose, waste warm filter cake (WWFC) was used to extract zinc from it. Zinc element was separated from WWFC by a basic leaching method and acidified to prepare zinc oxide nanoparticles. In the following, a simple hydrothermal method was used to increase the surface functionality of the extracted ZnO nanoparticles in order to establish active reaction sites for reaction to silane coupling agent and increase in the holes that were prepared during photo-excitation. Thereafter, the nanoparticles were modified with 3-glycidoxypropyltriethoxysilane (GPTES) at different concentrations. The band gap of the modified nanoparticles decreased from 3.25 to 3.1 eV by surface modification. The photocatalytic performance of ZnO nanoparticles was assessed by degradation of MB and MO aqueous solution (50 ppm) under simulated UV/Visible irradiations. MB and MO were degraded 91 and 60% under UV light and 65 and 50% under visible light after 150 min of irradiation. The photo degradation rate increased after adding carboxy methyl cellulose (CMC) surfactant to methylene blue and adding cocamide-dea (CDE-G) surfactant to methyl orange. The results confirmed that the green surfactants improve the dispersion and surface interaction of the modified nanoparticles in the dyes solution and cause more electron charge transfer which creates effective photocatalytic sites. The prepared nanocomposite films were placed in a photo-reactor to remove gaseous benzene from air under UV/visible irradiation. Gas chromatography (GC) results showed that the modified nanoparticles removed up to 35.25 and 20.34% of benzene from air. Colorimetric analysis (ΔE*) showed that the acrylic film contained modified nanoparticles degraded 91 and 82% of MB, and 85 and 76% of MO under UV/visible lights, respectively. In the end, it can be said that these photocatalytic films are able to remove environmental pollution in air and water.

Extraction of Zinc from Zinc Sublimber with Sulfuric, Thermal and Extraction Phosphoric Acid

The study was conducted to extract zinc and the results on the extraction of Zn from zinc sublime with the solution of sulfuric, thermal and extraction phosphoric acids are presented depending on Solid: Liquid (S:L), concentration and duration of the leaching process. Sulfuric acid was used with a content of 8% which is a waste product of non-ferrous metallurgy, thermal phosphoric extraction phosphoric acid from phosphorites of the Central Kyzylkum. It has been established that the maximum degree of zinc extraction is noted when using extraction phosphoric acid, which is 96-98%, S:L=1:(10-15), with the temperature of 90°C and washing sulfuric acid, which is 99.8% at S:L=1:10 and above at room temperature. Increasing the duration of the process over 30 minutes has virtually no effect on the extraction percentage of zinc.

Modeling and mapping the spatial variability of soil micronutrients in the Tigris basin

BackgroundCrop production is negatively impacted by excess and lack of soil micronutrients. Due to anthropogenic and natural factors, soil micronutrients vary greatly in space, necessitating time- and money-consuming large-scale sampling. Therefore, modeling their spatial distributions and forecasting in non-sampled areas are essential for high crop production. MethodsIn this study, regional variations in soil micronutrient content of the Upper Tigris Basin were modeled to produce local change maps for the development of site-specific nutrient management systems. The concentrations of extractable zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe) in soil samples taken at 388 different sites between 0 and 20 cm deep were determined. Using variogram and kriging analyses, the spatial distribution of the micro element concentrations was modeled and mapped in a GIS environment. ResultsThe micronutrients demonstrated significant variability with a high coefficient of variation (CV > 35%). It was found that the spatial dependence of the samples ranged from low for Fe and Cu to high for Zn and Mn. The spatial distribution of soil micronutrients was influenced by soil texture in addition to distance. Overall, the results demonstrated that the management of site-specific micronutrients may be aided by the integration of geostatistics and GIS, which is particularly beneficial in terms of effective management of the lands and the optimal use of inputs. ConclusionOverall, the findings showed that the integration of geostatistics and GIS may be helpful in the management of site-specific micronutrients, which is especially advantageous in terms of efficient management of the lands and the best use of inputs.

CFD Analysis of Simultaneous Removal of Copper (II) and Zinc from Aqueous Solution Using a Hollow Fiber Membrane Contactor

ABSTRACT The current study is a new method for liquid–liquid extraction of copper (II) and zinc that was carried out using an efficient solvent called trifluoroacetylacetone in a hollow fiber membrane contactor (HFMC). To analyze the extraction process and understand its underlying mechanisms, computational fluid dynamics (CFD) was employed. The extraction was performed in three domains by coupling the mass and momentum equation to express the solute transport from the tube side to the shell side through the membrane in a hollow fiber membrane contactor. The finite element approach simulates the governing equation and validates the results. This work aims to obtain the distribution of copper (II) and zinc by performing a simulation. The effect of some crucial parameters was investigated. The results illustrate that the extraction efficiency increases by increasing the partition coefficient and decreasing the flow rate on the tube side. Also, the temperature significantly affects extraction, and by enhancing the temperature from 298 to 313 K, the efficiency increases by 12% for copper (II) and 6.6% for zinc. Furthermore, the membrane porosity was found to be another influential parameter. By increasing the membrane porosity of 25% to 90%, the efficiency increases to 95% for copper (II) and 98% for zinc.

Recovery of residual metals from jarosite waste using chemical and biochemical processes to achieve sustainability: A state-of-the-art review

Jarosite is a residue that is generated as a by-product during zinc extraction, and it consists of various types of heavy metal (loid)s such as arsenic, cadmium, chromium, iron, lead, mercury and silver. Due to the huge jarosite turn-over rate, and less efficient and expensive residual metal extraction processes, the zinc-producing industries dispose this waste in landfills. However, the leachate generated from such landfills contains a high concentration of heavy metal (loid)s that could contaminate the nearby water resources and cause environmental concern and human health risk. Various thermo-chemical and biological processes have been developed for the recovery of heavy metals from such waste. In this review, we have discussed all those pyrometallurgical, hydrometallurgical, and biological. Those studies were critically reviewed and compared on the basis of their techno-economic differences. The review indicated that these processes have their own benefits and drawbacks such as overall yield, economic and technical constraints, and the need for more than one process to mobilize multiple metal ions from jarosite. Also, in this review, the residual metal extraction processes from jarosite waste have been linked with the relevant UN Sustainable Development Goals (SDGs), which can be useful for a better approach to sustainable development.

Formulation and Evaluation of Topical Nano-Hydrogel of Zinc and Annona Muricata Extract

A scientific method is essential for phytochemists to deliver active ingredients in a consistent manner. This can be accomplished through the development of novel drug delivery systems for active plant compounds. The current study aims to prepare Annona muricata leaves extract (ALE) containing nano zinc formulation into a nano-particulate hydrogel. The active components were extracted by cold maceration of Anona muricata leaves in ethanol and then converted into polymeric nanoparticles by gelation method based on electrostatic interaction between the Hydroxyl Amine on Chitosan and a cluster of negative charge from the polyanion NaTPP. Zinc oxide nano particles (ZNPs) was formulated by precipitating zinc acetate with sodium hydroxide. These were then incorporated with Carbopol-940 to generate the gel matrix. The result demonstrated that polymeric nanoparticles are closely spherical in shape with a z-average 358.45 ± 11.3 nm and PDI in the range of 0.440-0.812. The gels exhibited a high viscosity, a neutral pH, and acceptable spreadability. Furthermore, a stability assay demonstrates that it has chemical stability and does not cause skin irritation, making it appropriate for transdermal delivery.

A new strategy for extraction of copper cyanide complex ions from cyanide leach solutions by ionic liquids

Copper cyanide complexes in cyanide leach solutions deteriorate the recoveries of gold. Herein, five phosphonate-based [P204]− ionic liquids were synthesized, which were pioneered to apply to extraction of copper cyanide complex ions in cyanide leach solutions. In the extraction process, macroscopic layered solids rich in copper cyanide complex ions were formed at the aqueous-organic phase interface, which was driven by self-assembly of ionic liquids. Notably, the layered solids can be obtained by simple filtration. The extraction behaviors were systematically studied in the present work. The results show that the extraction efficiency in excess of 90 % can be achieved at higher pH (13.16) and enriched as self-assembly solids in the process of one-step extraction and solidification, based on the self-assembly extraction systems of [P4444][P204] IL. It is worthy of note that no self-assembly sample was observed when the extraction systems is applied to extraction zinc and iron cyanide complex ions. It indicates that the present self-assembly extraction systems could be applied in separation copper and zinc/iron cyanide complex ions. Meanwhile, the coordination mechanism was investigated detaily, and the covalent nature played a leading role in the binding interaction. Remarkably, [P4444][P204] can be repeatedly used without obvious loss in extraction capacity of copper cyanide complex ions after two cycles, indicating that the IL has a good recycling ability. In conclusion, it is possible to employ the self-assembly extraction systems to separate and recover various valuable metals from aqueous solutions by designing and developing ILs extractants in the future.