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In the process of recycling cyanide leaching solutions, the presence of iron-cyanide complex ions in gold leaching solutions leads to increased cyanide consumption and competition with gold for adsorption onto activated carbon. Consequently, the removal of iron- cyanide complex ions from cyanide leaching solutions is crucial. This study presents a novel strategy for the treatment of metal ions in leaching solutions, achieving effective waste treatment using hydrogel-like beads. To remove iron-cyanide complex ions from cyanide leaching solutions, we synthesized carboxymethyl cellulose‑iron (CMC Fe) hydrogel through a crosslinking method. The adsorbent, carboxymethyl cellulose-Prussian blue (CMC-PB) hydrogel, obtained after iron-cyanide complex ion adsorption, can directly remove Cs+ ions from solution without the need for desorption and regeneration. Notably, the CMC-Fe hydrogel exhibits exceptional adsorption performance and high selectivity toward iron-cyanide complex ions. The adsorption process of the CMC-Fe hydrogel follows a pseudo-second-order kinetic model, while the Freundlich isotherm model is more suitable for describing the adsorption equilibrium. Additionally, the CMC-PB hydrogel efficiently adsorbs 83.1% of Cs+ ions at a dosage of 86.5 μg, and desorption and regeneration studies reveal that its adsorption efficiency remains high even after three cycles. Furthermore, the proposed adsorption mechanism of CMC-PB for Cs+ ions involves a combination of chemisorption (K+/Na+ exchange) and physisorption (hole channels of hydrogels). [Display omitted] • The CMC-Fe hydrogel was applied to adsorption for iron cyanide complex ions. • The CMC-PB hydrogel adsorption cesium was developed. • The CMC-Fe exhibited excellent adsorption efficiency for iron cyanide complex ions. [ABSTRACT FROM AUTHOR]

The tetrabutylammonium bis (2-ethylhexyl) phosphate [N4444][P204] ionic liquid (IL) was synthesized, which was applied to extract copper cyanide complex ions in cyanide tailing liquid stream pressure filtration. In the extraction process, macroscopic layered solids rich in copper cyanide complex ions were formed at the phase interface, which was based on self-assembly of ionic liquids actuation. The solid samples can be obtained by simple filtration. Meanwhile, the extraction behaviors were investigated in detail. The [N4444][P204] ionic liquid exhibited excellent extraction efficiency for copper cyanide complex ions. More than 90% of copper cyanide complex ions were extracted at pH 13.4 and enriched as self-assembly solids in the process of one-step extraction and solidification. Notably, the extraction efficiency of copper cyanide complex ions can still reach more than 75% after three cycles of organic phase with fresh aqueous phase. Furthermore, the analyses of the SEM, EDS, XPS, FTIR, and ESI-MS for self-assembly sample implied that the potential mechanism of extraction for copper cyanide complex ions is coordination reaction. It is worthy of note that the extraction system of [N4444][P204] IL has no extraction effect on iron cyanide complex ions. In the end, the proposed strategy may be further expanded to the separation of other metal cyanide complex ions by designing the ionic liquids. [Display omitted] • The one-step extraction and solidification of copper cyanide complex ion was achieved. • Extraction of copper cyanide complex ion exhibited excellent extraction efficiency. • The extraction system showed the excellent selectivity to iron cyanide complex ion. • The concept of self-assembly extraction was proposed based on the [N4444][P204] IL. [ABSTRACT FROM AUTHOR]

The metal cyanide complex ions of gold extraction wastewater consume extra cyanide and compete with gold for adsorption on activated carbon during wastewater recycling. Therefore, the removal of metal cyanide complex ions from gold extraction wastewater is of great significance. In this study, polypropylene (PP) fibers were used to prepare strong acylated alkaline ion-exchange fibers (SAA-IEFs) using a polymer graft monomer method that achieved excellent adsorption of metal cyanide complex ions from gold extraction wastewater. The properties of the SAA-IEFs were characterized via scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA). Adsorption experiments were conducted to study the adsorption performance and to verify the adsorption mechanism. The results show that the highest adsorption efficiencies of the SAA-IEFs for zinc and copper cyanide complex ions were 85.5% and 91.2%, respectively, and these performances were obtained when the SAA-IEF concentration was 50 g/L and pH was 10. The adsorption efficiency of the cyanide complexes in practical wastewater reached 92% at a concentration of 30 g/L. The desorption and regeneration results indicate that the adsorption capacity of the SAA-IEFs remained high after nine cycles. Moreover, an adsorption mechanism is proposed, and the adsorption process is best modeled using the Freundlich isotherm and pseudo-second-order kinetic model. These results indicate that chemisorption plays a dominant role in the adsorption process. Overall, SAA-IEFs are a promising, efficient, and cost-effective adsorbent for metal cyanide complex ion adsorption from gold extraction wastewater. • Strong acylated alkaline ion exchange fiber was used to remove zinc/copper cyanide complex ion from cyanide gold extraction wastewater. • Freundlich isotherm and pseudo-second-order kinetic model can better describe the adsorption process. • The adsorption efficiency of total cyanide complexes in practical wastewater (pH = 10.5) can reach to 92%. • The ion exchange fiber can be effectively regenerated and reused with insignificant fiber damage. [ABSTRACT FROM AUTHOR]