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A novel nanocomposite based silica gel/graphene oxide for the selective separation and recovery of palladium from a spent industrial catalyst. Author links open overlay panel Min Li a, Si Tang a, Zhiwei Zhao b, Xiaojing Meng a, Feng Gao c, Songshan Jiang a, Yongfu Chen d, Jian Feng a, Changgen Feng e.
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Two synthetic materials composed of silica gel joint to a strong chelating agent were used as reducing agents to induce gold colloid nanoparticle formation: ethylene diamine tetraacetic acid and diethylene triamine pentaacetic acid, together with brown …
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Abstract. Gold recovery from aqueous solution was studied in the present work. Two synthetic materials composed of immobilized chelating agent on silica gel, …
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Synthesis and application of tuneable carbon–silica composites from the microwave pyrolysis of waste paper for selective recovery of gold from acidic solutions June 2020 RSC Advances 10(42 ...
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It can be seen that a material with good comprehensive properties (high adsorption capacity, high selectivity, and high recovery rate) toward gold was seldom reported, and these silica-gel-based dendrimer-like highly branched polymer adsorbents can potentially be used as an efficient gold recovery material with a good …
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Silica gel is a kind of silica-based materials fabricated using a sol–gel synthesis of soluble silica precursors with surfactant micelles acting as structure directing agents, and it is characterized of high surface area, framework structure and uniform pore channels. ... The tests for gold recovery from the pregnant solution of the Co-NH 3-S ...
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In another project, Harish et al. [148] attempted to recover silica from SBA and silica fumes as low-cost precursors for the synthesis of silica gel using a sodium hydroxide-based alkali treatment ...
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Graphical abstract. A new silica-based adsorbent functionalized with macrocyclic ligand was synthesized. The adsorbent showed high selectivity and efficient adsorption to Pd(II) in HNO 3 media. Enrichment of Pd(II) in simulated radioactive waste stream was realized with a recovery rate of high than 90%.
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Abstract A new adsorbent was synthesized via functionalizing nano-silica with 4-(aminomethyl) pyridine for selective recovery of gold. The adsorbent was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and transmission electron microscopy, and BET (surface …
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Silica gel/water, heat and mass recovery-like, two sorption chambers, two condenser/evaporator: COP = 0.403; SCOP = 0.128: Many investigations have made to improve the solar adsorption cooling system performance and there are mainly-three aspects. One is system structure optimization via combining solar collector and adsorber.
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This paper presents an up-to-date overview of the various advanced materials as adsorbent used in the recovery of precious metals from wastewater. The precious metals concentrated here include gold, silver, palladium and platinum, whose recovery is interesting mainly due to their vast industrial applications and high market prices. Among …
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This paper describes a process for improving the gold (I) adsorption capacity of mercapto-functionalized silica gel (MP-SG) by using ethylenediamine (en) as an …
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Recovery of gold(I) from thiosulfate leaching solution by using silica gel. Mercapto-modified silica gel has good adsorption capacity for gold at a weakly basic …
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The problem of metal ions being wrapped in silica gel has been solved, greatly improving the utilization efficiency of metals in copper slag, with an overall recovery of 98%. In this work, silica was obtained by controlling pH value at 9 with sulfuric acid (30%) and heating in a water bath at 80 °C for 1 h.
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A novel and sustainable technology to recover gold from thiosulfate medium using ionic liquids, i.e., Cyphos IL 101 (Cy IL 101) and Cyphos IL 102 (Cy IL 102) diluted in toluene, has been developed. Gold was extracted into the ionic liquid phase as [{P66614+}3{Au(S2O3)23–}] and stripped using NaCl solution. The recyclability of ionic …
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The SEM images of silica gel and GH-D-P were shown in Fig. 3, it could be seen that the sphere appearance and size of the samples were similar, demonstrating that the microspheres of silica gel have good mechanical stability and they have not been destroyed during the whole reactionpared with the morphology of silica gel, there …
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Silica gel (SG) was modified using 3-mercaptopropyl trimethoxysilane (MPTMS) and used as an adsorbent for the recovery of gold(I) from a thiosulfate solution, based on the hard and soft acids and ...
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Two procedures are presented which allow the homogeneous incorporation of silica-coated gold nanoparticles within transparent silica gels. Both UV−visible absorption spectra and transmission electron microscopy show that there is no aggregation of the metal particles during sol−gel transition. The optical properties of the gels are compared …
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A new method has been developed for the determination of gold based on separation and preconcentration using silica gel modified with benzoylthiourea. The optimum experimental parameters for preconcentration of gold, such as acid concentration, sample flow rate, eluent and matrix ions, have been investigated. Gold could be …
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A novel, one-pot sol–gel preparation scheme leading to reproducible incorporation of 20–40 nm sized gold nanoparticles (AuNPs) in SiO2 gels is developed based on in situ reduction during gelation using chloroauric acid and ascorbic acid. Variation in the preparation conditions affects the chemical composition, optical properties and …
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Nanomaterial composite gel has been successfully applied for enhanced oil recovery (EOR). However, the fatal flaw of using bare SiO 2 nanoparticles in polymer gel systems is their agglomeration and poor dispersion stability. In this paper, hexadecyl trimethyl ammonium bromide (CTAB) modified SiO 2 nanoparticles for the reinforcement …
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This temperature-dependence resulted in composites ranging from highly oxygenated polymerised bio-oil composites at 300 °C to aromatic carbonaceous materials covering …
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A new method has been developed for the determination of gold based on separation and preconcentration with a microcolumn packed with nanometer TiO 2 immobilized on silica gel (immobilized nanometer TiO 2) prior to its determination by flame atomic absorption spectrometry.The optimum experimental parameters for …
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Silica gel formation is one of the most common problems in hydrometallurgical processing of silica containing resources such as BR with 7 wt. % Si content which deteriorates sample handling and ...
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Mesoporous silica materials mainly of type MSU-X functionalized with simple amine and thiol (mercapto-) ligands, have been used to adsorb gold thiosulfate complex from ammoniacal copper-bearing solutions.Variation in major reagent concentrations was investigated for the determination of the appropriate dosages of …
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Silica gel forms via dissolution of silicates in acidic conditions and also has strong adsorption/reduction potential for gold. A mechanism for the adsorption and …
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Aminopropyltriethoxysilane (1 ml) was dissolved in 100 ml of distilled water and acidified with acetic acid (pH 4).Then, 2 g of activated silica was added to the solution and stirred for 2 h at room temperature [26].The product was filtered off and kept in oven at 150 °C for 4 h.The obtained aminopropyl silica gel (APSG) was washed repeatedly with …
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Gold recovery from aqueous solution was studied in the present work. Two synthetic materials composed of immobilized chelating agent on silica gel, and the brown seaweed Sargassum muticum were used as reducing agents inducing gold colloid nanoparticles formation. The results showed that there is no pH effect and no …
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Amorphous silica gel (K60) with average particle size of 0.040–0.063 mm was purchased from Sigma-Aldrich. Gold(iii) chloride 64.4% min was purchased from Alfa Aesar. Analytical grade solvents including acetone and ethanol, as well as 0.1 M HCl used for adsorption studies and ICP-OES sample preparation, were purchased from Fisher …
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The modified silica gel could adsorb Pd(II) ions quantitatively from the solutions up to 400 mL at pH 1.0 by the flow rate of 5 mL/min. The retained Pd(II) ions could be easily eluted by using 5 mL of 1% (m/v) thiourea in 1.0 M HCl solution. The recovery of Pd(II) ions was 95 ± 2% at 95% confidence level.
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