Extraction of gold(III) in hydrochloric acid solution using monoamide compounds

Vacuum pump oil (VPO) in toluene was employed as a solvent extraction reagent for Au(III) from HCl. The effects of shaking time and concentration of HCl on the extraction of Au(III) were investigated. It was found that the selectivity of VPO for Au(III) was superior even to dibutylcarbitol (DBC) which is currently employed as a commercial extactant for gold. The extraction of Au(III) with VPO is nearly quantitative over the whole HCl concentration range, while the extraction of other metal ions is nearly negligible. In addition, in case of the VPO system, the extraction of Au(III) was independent of HCl concentration regardless of the VPO concentration, while in the case of DBC, it is independent of HCl concentration only for 100% DBC. The loading capacity for Au(III) was compared between 10 % VPO in toluene and 100 % DBC. The stripping of Au(III) from the loaded VPO was also investigated using aqueous mixtures of thiourea and hydrazine in combination with varying concentrations of HCl and NaOH. It was found that complete stripping can be achieved by these combinations and that gold is recovered as solid particles in some cases.

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Solvent Extraction and Stripping of Gold(III) from Hydrochloric Acid Solution Using Vacuum Pump Oil

Xiong

Kawakita

Inoue

et al. 2010

“…Oxygen-containing compounds such as methyl isobutyl ketone (MIBK) and amide compounds are found to act as extractants for Au (III) in hydrochloric acid solution [6][7][8][9][10]. Au(III) can also be extracted using O Figure 1.…”

Section: Introductionmentioning

confidence: 99%

Extraction of Gold(III) Using Cyclopentyl Methyl Ether in Hydrochloric Acid Media

Oshima

Ohkubo

Fujiwara

et al. 2017

Recently, cyclopentyl methyl ether (CPME) has found use as a commercially available solvent for various applications. As CPME shows better properties such as more hydrophobicity, less solublity in water, less volatility, and more stablity compared with typical ethereal solvents, it could be used as a diluent or an extractant in liquid-liquid extraction systems. In the present study, CPME was found to be useful for the extraction of Au(III) in hydrochloric acid media. Extraction of Au(III) increased with as increase in the hydrochloric acid concentration. Au(III) was selectively extracted using CPME from other precious metal ions and base metal ions. From the result of the dependency of the Au(III) concentration, CPME can load at least 0.93 g/dm 3 Au(III). Extracted Au(III) was quantitatively stripped from CPME using 0.1 M aqueous thiourea solution. As the solubility of water into CPME is much smaller than that into alcohols such as 1-hexanol, CPME is more favorable as an extractant for Au(III) in hydrochloric acid media.

“…Therefore, it is important to develop a technology to recover and separate precious and base metals from such dilute solutions. Solvent extraction is an effective process for the treatment of dilute solutions [1]. However, the conventional solvent extraction technique has some disadvantages, i.e.…”

Section: Introductionmentioning

confidence: 99%

Separation and Recovery of Precious and Base Metals using a Column Packed with Microcapsules Containing an Extractant

Kondo

Ishihara

Matsumoto

2010

A fundamental investigation of the separation and recovery of PdCl 4 2-, PtCl 6 2-, HCr 2 O 7 -, Cu 2+ , Ni 2+ and Zn 2+ from an aqueous solution by using microcapsules containing a metal extractant has been undertaken. As extractants, 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHPNA) and tri-n-octylamine loaded with hydrochloric acid (TOA-HCl) were used. The extractants were successfully encapsulated in microcapsules during the in situ microencapsulation process. The extractabilities of the metals into the microcapsules were estimated from the extraction isotherm of the metal ions. According to the Langmuir model, the saturation amount of metal extracted and the extraction equilibrium constant were determined. The microcapsules containing EHPNA and TOA-HCl were suitable for the extraction of base metal ions and precious metal ions, respectively. Using a reactor in which two columns packed with each microcapsule containing EHPNA and TOA-HCl are connected in series, the separation and recovery of precious metals from base metals was examined. In this way, the mutual separation of precious metals can be successfully achieved by feeding a suitable eluent stepwise into the column.