This temperature-dependence resulted in composites ranging from highly oxygenated polymerised bio-oil composites at 300 °C to aromatic carbonaceous materials covering …

Abstract The effect of various parameters (S:L ratio, duration, temperature and intensity of ultrasonic treatment) on recovery efficiency of zirconium and rare earth elements (REE) in dissolution of silica gel is investigated. The leaching process optimization is performed using the method of Taguchi L9 orthogonal array and the …

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 …

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 …

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 ...

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%.

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.

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 …

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 …

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 ...

Tannin is well known to be an inexpensive and ubiquitous natural biomass, which has high chelating affinity towards many metal ions. In this study, bayberry tannin (BT) was immobilized on mesoporous silica matrix to prepare a novel adsorbent, which was subsequently used for the adsorptive recovery of Au 3+ from aqueous solutions. It was …

Gold was mainly recovered from ores through the cyanide process 14, 15, 16, 17, a pollutants generating method with a significant negative impact on the …

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 …

Gold reduction in batch and column experiments using silica gel derivates and seaweed biomass. July 2013. Chemical Engineering Journal 230:372. DOI: …

The silica gel in the instrument was heated using a sensor coil, and the thermal conductivity was evaluated by measuring a change in sensor voltage due to a change in interfacial temperature. The thermal conductivities were examined at least three times to identify the reproducibility, and the maximum deviation of the results was less than ±2 %.

Abstract. Gold recovery from aqueous solution was studied in the present work. Two synthetic materials composed of immobilized chelating agent on silica gel, …

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 ...

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 …

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 ...

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 …

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.

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 …

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 ...

Bis(3-aminopropyl)amine bonded silica gel (BAPA-SG) was synthesized and characterized by elemental analysis and FT-IR spectroscopy, and tested for adsorption, preconcentration, and recovery of Pd(II) ions. The effective parameters on the preconcentration of Pd(II) ions such as pH, volume, and flow rate of the Pd(II) solution, …

The oil recovery of the modified silica gel (containing n-dodecane oil film) with CTAB dilute aqueous solutionsThe data available were listed in Table 3. As the aqueous solution penetrated up in the bed, the oil film adhered on the silica gel surface was displaced and moved up. Finally, it can transcend powder bed, and formed an oil …

Precious metals (PMs) (i.e. gold, silver, and platinum group metals (PGMs)) are rare, naturally existing metallic elements with high economic value. ... functionalized with thiol and amino ligands were effective in the recovery of gold and platinum groups metals (PGMs) from ... Silica gel is a kind of silica-based materials fabricated using a ...

The separation and recovery of valuable uranium from such uranium scraps is very important [6] ... This is attributed to the incorporation of phosphate group on to the silica gel surface. Additional peak of gold (Au) is due to the application of gold coating over the sample for SEM examination. Download : Download high-res image (808KB)

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 …

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 …