Leaching Solution Research Articles

Paired electrochemical recovery of metal ions from emulated e-waste leached solutions in an RCE electrochemical reactor

This work proposes the paired electrochemical recovery of metal ions, cathodically and anodically, from emulated e-waste leached solutions. Under this methodology, the recovery of a bimetallic deposit of copper-silver at the cathode, and lead dioxide at the anode, was successfully achieved in an undivided rotating cylinder electrode (RCE) electrochemical reactor. The RCE electrochemical reactor was implemented at 300 rpm and different current densities, 50, 40, 30, 20, and 10 mA/ cm2. Different compositions of the bimetallic copper-silver deposits were obtained depending on the current density applied, while in the anodes, only the deposition of lead dioxide was performed at any current density. The concentration depletion of metal ions was determined at different intervals of time. The cell voltage, cathode, and anode potential vs. SCE, were continuously monitored, and the values were useful to evaluate the energetic performance of the RCE electrochemical reactor. Figures of merit are presented to describe the performance of the RCE electrochemical reactor in the paired recovery of metal ions from emulated e-waste leached solution.

Lutein-Rich Beverage Alleviates Visual Fatigue in the Hyperglycemia Model of Sprague-Dawley Rats.

Asthenopia is a syndrome based on the symptoms of eye discomfort that has become a chronic disease that interferes with and harms people's physical and mental health. Lutein is an internationally recognized "eye nutrient", and studies have shown that it can protect the retina and relieve visual fatigue. In this study, lutein was extracted from marigold (Tagetes erecta L.) and saponified. The purified lutein concentration measured by HPLC was 50.12 mg/100 g. Then, purified lutein was modified to be water-soluble by nanoscale modification and microencapsulation technology. Water-soluble lutein was then mixed with a leaching solution of Chinese wolfberry and chrysanthemum to make a functional beverage. The effects of this beverage on hepatic antioxidant enzymes and the alleviation of visual fatigue in a rat model of diabetes were investigated for 4 weeks. Lutein intake of 0.72 (medium-lutein beverage group) and 1.44 mg/mL (high-lutein beverage group) relieved visual fatigue, ameliorated turbidity symptoms of impaired crystalline lenses, reduced hepatic MDA concentration, increased hepatic GSH concentration, and significantly increased the activities of the hepatic antioxidant enzymes SOD, CAT, GSH-Px, and GR in rats. These data suggest that a lutein-rich beverage is an effective and harmless way to increase the total anti-oxidation capacity of lenses and alleviate visual fatigue.

Separation of cobalt/lithium in spent NCM-based lithium ion battery leaching solution via reactive extraction-reextraction with microdispersed (G1/L1+G2)/L2 emulsion

Separation of Co and Li in hydrometallurgy for the recovery of valuable metals from waste NCM-based lithium ion battery leaching solution is realized by extraction, with P507/TBP/sulfonated kerosene as extractant. Process intensification is realized via emulsion structure design and novel equipment development, aiming in overcoming operation limitations in traditional equipment caused by increased viscosity and phase ratio. Effects of emulsion structure and operating conditions on extraction are investigated. A multiphase emulsion, (G1/L1+G2)/L2, is designed and prepared by a micro-dispersion module. Efficient extraction is realized with (G1/O+G2)/W emulsion, with which Murphree efficiency of Co2+ reaches 99.1 % within a contacting volume of 7.35 mL, when reverse extraction is realized applying (G1/W+G2)/O emulsion. With (G1/L1+G2)/L2 emulsions, a single-stage extraction and reverse extraction process is realized in 9.11 s, with which Co2+/Li + solution with initial Co2+ concentration of 27.60 mol.% is separated into raffinate of 0.12 mol.% and strip liquor of 81.08 mol.%. The intensification fundamentals are studied, by calculating mass transfer coefficients in formation and flowing stages of varied heterogeneous systems and establishing mathematical models. This study presents simple and effective methods for intensifying extraction and reverse extraction processes with viscous extractants in spent lithium ion battery recycling.

Selective isolation of gallium and indium from waste photovoltaic modules facilitated by extractant-mesoporous activated carbon composites

With the expanded installation and decommission of photovoltaic modules, the recovery of critical metals involved, such as gallium (Ga) and indium (In), is becoming an important issue. Liquid–liquid extraction, as a conventional recovery method, is always accompanied by serious emulsification, poor phase-separation, and huge volatile organic solvent consumption. Here, a more efficient and environmentally benign solid adsorbent was innovatively prepared by combining P507 with coconut shell-derived mesoporous activated carbon (P507@MAC) for Ga and In recovery. Surprisingly, P507@MAC retained an excellent selectivity for In3+ from the coexisting ions (Al3+, Zn2+, Cd2+, Cu2+, and Mg2+), and the selectivity for Ga3+ was actually increased compared to P507. Unexpectedly high adsorption capacities of P507@MAC for Ga3+ (67.0 mg·g−1) and In3+ (52.6 mg·g−1) were found to be 1.85 and 1.23 times the accumulation of MAC and P507, respectively, and much superior to that of P507-impregnated resin (11.8 mg·g−1 (Ga3+) and 36.5 mg·g−1 (In3+)). Moreover, the adsorption capacity of this novel adsorbent demonstrated no significant decrease over 6 cycles. Such desirable capture capability of Ga3+ and In3+ was ascribed to the rich mesopores and high surface area of MAC, providing adequate adsorption sites for phosphoryl groups and metal ions. Going forward, by demonstrating successful Ga3+ and In3+ separation from the leaching solution of waste CIGS photovoltaic modules, the extractant-MAC composites might provide a promising and industry-compatible approach for valuable metal recovery.

Combination of separation and degradation methods after PFAS soil washing

The current study evaluated a three-stage treatment to remediate PFAS-contaminated soil. The treatment consisted of soil washing, foam fractionation (FF), and electrochemical oxidation (EO). The possibility of replacing the third stage, i.e., EO, with an adsorption process was also assessed. The contamination in the studied soils was dominated by perfluorooctane sulfonate (PFOS), with a concentration of 760 and 19 μg kg−1 in soil I and in soil II, accounting for 97 % and 70 % of all detected per-and polyfluoroalkyl substances (PFAS). Before applying a pilot treatment of soil, soil washing was performed on a laboratory scale, to evaluate the effect of soil particle size, initial pH and a liquid-to-soil ratio (L/S) on the leachability of PFAS. A pilot washing system generated soil leachate that was subsequently treated using FF and EO (or adsorption) and then reused for soil washing. The results indicated that the leaching of PFAS occurred easier in 0.063–1 mm particles than in the soil particles having a size below 0.063 mm. Both alkaline conditions and a continual replacement of the leaching solution increased the leachability of PFAS. The analysis using one-way ANOVA showed no statistical difference in means of PFOS washed out in laboratory and pilot scales. This allowed estimating twenty washing cycles using 120 L water to reach 95 % PFOS removal in 60 kg soil. The aeration process removed 95–99 % PFOS in every washing cycle. The EO and adsorption processes achieved similar results removing up to 97 % PFOS in concentrated soil leachate. The current study demonstrated a multi-stage treatment as an effective and cost-efficient method to permanently clean up PFAS-contaminated soil.

The Relationship between Acid Production and the Microbial Community of Newly Produced Coal Gangue in the Early Oxidation Stage.

Coal gangue is a solid waste formed during coal production, and the acid mine drainage it generates during open-pit storage severely pollutes the ecological environment of mining areas. Microorganisms play a crucial catalytic role in acidification, and their species and gene functions change during the oxidation process of coal gangue. In this study, the changes in microbial community structure were investigated during the initial acidification process for newly produced gangue exposed to moisture by monitoring the changes in pH, EC, sulfate ion concentration, and the iron oxidation rate of gangue leaching solutions. Moreover, the composition and functional abundance of microbial communities on the surface of the gangue were analyzed with rainfall simulation experiments and 16S rRNA sequencing. The study yielded the following findings: (1) The critical period for newly produced gangue oxidation spanned from 0~15 d after its exposure to water; the pH of leaching solutions decreased from 4.65 to 4.09 during this time, and the concentration and oxidation rate of iron in the leaching solutions remained at low levels, indicating that iron oxidation was not the main driver for acidification during this stage. (2) When the gangue was kept dry, Burkholderia spp. dominated the gangue microbial community. When the gangue was exposed to moisture, the rate of acidification accelerated, and Pseudomonas replaced Burkholderia as the dominant genus in the community. (3) In terms of gene function, the microbial community of the acidified gangue had stronger nitrogen cycling functions, and an increase in the abundance of microorganisms related to the sulfur cycle occurred after day 15 of the experiment. The microbial community in the acidified gangue had more stress resistance than the community of the newly formed gangue, but its potential to decompose environmental pollutants decreased.

Investigation of the Impact of Leaching Agent Concentration and pH on the Stability of Agglomeration of Ion-Absorbed Rare Earth Deposits

Ion-absorbed rare earth deposits react with the leaching agent during the in situ leaching process through ion exchange and hydration, which change the stability of ore agglomerates and even result in mining slopes or landslides. Indoor simulated column leaching assays were conducted on ion-absorbed rare earth deposit samples by using magnesium sulfate solution as the leaching solution. Surface zeta potential, double electric layer thickness, particle gradation, and pore structure were analyzed to measure the different concentrations and pHs of leaching solutions’ impact on the stability of ore agglomerates. Results show that the critical magnesium sulfate solution concentration and pH affecting the stability of deposit sample agglomerates are 3.5% and 4, respectively. The chemical replacement reaction between the leaching agent and rare earth ions occurs during column leaching when it reaches its zero-point potential at a pH of 3.5168. This breaks the balance between the van der Waals gravitational force and double-layer repulsion in clay particles and induces the disruption of agglomerates, which causes the difference in the pore radius ratio of the ore samples before and after column leaching. It is of great engineering guidance to solve the problems of slope instability and landslides that may occur in the ore body during the mining process of ionic rare earth ore.

A novel eco-friendly strategy for removing phenanthrene from groundwater: Synergism of nanobubbles and rhamnolipid

Nanobubbles (NBs), given their unique properties, could theoretically be paired with rhamnolipids (RL) to tackle polycyclic aromatic hydrocarbon contamination in groundwater. This approach may overcome the limitations of traditional surfactants, such as high toxicity and low efficiency. In this study, the remediation efficiency of RL, with or without NBs, was assessed through soil column experiments (soil contaminated with phenanthrene). Through the analysis of the two-site non-equilibrium diffusion model, there was a synergistic effect between NBs and RL. The introduction of NBs led to a reduction of up to 24.3 % in the total removal time of phenanthrene. The direct reason for this was that with NBs, the retardation factor of RL was reduced by 1.9 % to 15.4 %, which accelerated the solute replacement of RL. The reasons for this synergy were multifaceted. Detailed analysis reveals that NBs improve RL's colloidal stability, increase its absolute zeta potential, and reduce its soil adsorption capacity by 13.3 %–19.9 %. Furthermore, NBs and their interaction with RL substantially diminish the surface tension, contact angle, and dynamic viscosity of the leaching solution. These changes in surface thermodynamic and rheological properties significantly enhance the migration efficiency of the eluent. The research outcomes facilitate a thorough comprehension of NBs' attributes and their relevant applications, and propose an eco-friendly method to improve the efficiency of surfactant remediation.

An environmentally friendly approach for the extraction and recovery of Mn from pyrolusite by ammonium sulfate roasting‐water leaching and ammonium carbonate precipitation

AbstractWith the growth of the new energy industry, the requirements for manganese have increased significantly. In this paper, the method of manganese extraction from pyrolusite using ammonium sulfate roasting and water leaching was presented. At the optimal process parameters: mass ratio of (NH4)2SO4 to pyrolusite of 2:1, the roasting temperature of 420°,C and duration of 120 min, the leaching efficiency of Mn and Fe was 94.55% and 54.38%, respectively. The mechanism analysis shows that MnO2 and Fe2O3 in pyrolusite were converted to (NH4)2Mn2(SO4)3, (NH4)3Fe(SO4)3, and NH4Fe(SO4)2 by roasting with ammonium sulfate. Iron was removed from the leaching solution with the addition of ammonia. Afterward, manganese carbonate products were prepared from iron‐free manganese sulfate solution by adding ammonium carbonate at a stirring duration of 60 min, a reaction temperature of 40°C, a pH of 7, and a molar ratio of ammonium carbonate to the manganese of 1.1:1, the precipitation efficiency of manganese could reach 99.8%, and the obtained manganese carbonate products were compliant with the industry standards. The ammonia released during the roasting process could be absorbed to regenerate (NH4)2SO4 and the final filtrate after evaporation and crystallization could be used to recycle (NH4)2SO4, both of which were used again into roasting process to reduce the consumption of raw material. In this process, the roasting temperature was only 420°C, which was significantly lower than the pyrometallurgical process suggested in earlier studies.

The Effect of Leaching Time on ZrO<sub>2</sub> Synthesis through Alkali Fusion and Acid Leaching

Zircon (ZrSiO4) is one of Indonesia's most abundant mineral reserves that have yet to be fully utilized since zircon mine production in Indonesia is only 110.000 tons/year while Australia produces zircon up to 500.000 tons/year. Indonesia has 167 million tons of zircon sand reserves, especially in West Kalimantan. One of the most efficient methods of zircon sand processing in terms of energy use and environmental pollution is the alkali fusion of NaOH. This study used zircon sand with NaOH, a stoichiometric ratio of 1:4 (excess 1.5), to be roasted in a muffle furnace at 600°C for 120 min. The following process is washing the frit with water, and the frit is dissolved with aquades with ratio frit: H2O=1g:10 ml at 30°C and stirring 300 rpm for 60 min. The frit leaching solution is filtered to obtain Na2ZrO3. The water-wash product is leached using HNO3 as the leaching agent with the ratio of water-wash product: HNO3=1:5, the acid concentration is 6 M, at 90°C, agitation use 260 rpm with the variation of time 60, 120, 180, 240, and 300 minutes. The pregnant leach solution is deposited with NH4OH and calcinated. According to the results of this experiment, the optimum time to obtain high Zr extraction is 240 minutes. This research produced single-phase zirconia with a cubic crystal structure containing 91.23% ZrO2 and 1.18% SiO2.

Separation and Recovery of Copper from Ammonia Pregnant Leach Solution (PLS) by Cyanex®272

Separation and Recovery of Copper from Ammonia Pregnant Leach Solution (PLS) by Cyanex®272

Removal of silver from chloride solutions using new polymer materials

This work presents the synthesis of polymer resins with heterocyclic functional groups, that is, N-(3-aminopropyl)-2-pipecoline, N-(3-aminopropyl)-2-pyrrolidinone, and trans-1,4-diaminocyclohexane for the recovery of Ag(I) from chloride solutions. The modification yield was 69.2, 74.6 and 88.3%, respectively. The best Ag(I) sorption was achieved from synthetic and real chloride solutions in the case of trans-1,4-diaminocyclohexane resin (sorption was 26.8 and 21.5 mg/g, respectively). The sorption kinetic data were well fitted to the pseudo-first-order kinetic model. The maximum sorption capacity of Ag(I) is 105.4, 117.8 and 130.7 mg Ag(I)/g for N-(3-aminopropyl)-2-pipecoline resin, N-(3-aminopropyl)-2-pyrrolidinone resin and trans-1,4-diaminocyclohexane resin, respectively. The trans-1,4-diaminocyclohexane modified resin was very selective towards Ag(I) compared to Cu(II), Pb(II), and Zn(II) from the real chloride leaching solution. The N-(3-aminopropyl)-2-pipecoline and N-(3-aminopropyl)-2-pyrrolidinone resins showed high preferences for Ag(I) over Pb(II) in real solution. These results indicated that the polymers can be applied in the recovery of Ag(I).

Oxidative leaching of rhenium from grinding waste of rhenium-containing superalloys

The study investigated the feasibility of oxidative leaching rhenium in the presence of hydrochloric acid from machining waste (grinding waste) derived from products made of ZhS-32VI, a nickel-based heat-resistant alloy containing rhenium. This was achieved through agitation leaching process. The grinding waste fraction size of –0.071 mm, which accounted for the highest yield (49.2 wt.%), was utilized in the experiments. The rhenium leaching process was conducted in two variations: in the first option, grinding waste was mixed with a hydrochloric acid solution at ~100 °C, followed by the addition of hydrogen peroxide to the leaching solution after it had cooled; in the second option, leaching was performed using a hydrochloric acid solution with the gradual addition of hydrogen peroxide solution. The highest degree of rhenium leaching (91.0 %) was achieved in the first option. In this case, the initial concentration of hydrochloric acid was 8 M, and the molar ratio of the added reagents was ν(HCl): ν(H2O2) = 2.7 : 1.0. The kinetics of nickel leaching using a 6 M hydrochloric acid solution at 70 °C, with a solid-to-liquid phase ratio of 1 g : 50 ml, was also examined. The analysis of the kinetic data, processed using the “contracting sphere,” Ginstling–Brounshtein, and Kazeev–Erofeev models, indicates that the nickel leaching process occurs within the kinetic region. Additionally, the kinetics of rhenium leaching from the solid residue obtained after the hydrochloric acid leaching of nickel from grinding waste was investigated. Employing the same kinetic models to analyze the data, it was determined that the limiting stage of this process involves the diffusion of hydrogen peroxide within the rhenium-containing solid residue.

Thermodynamics of Separating Molybdenum(VI) Over Iron(III) from High Acid Leach Solutions with Mixtures of P507 and N235

Thermodynamics of Separating Molybdenum(VI) Over Iron(III) from High Acid Leach Solutions with Mixtures of P507 and N235

Efficient and Selective Recovery of Gold from Thiosulfate Leaching Solution Using Functionalized β‐Cyclodextrins Synthesized by a Steric Hindrance Strategy

AbstractDesigning suitable adsorbents is a key challenge in the recovery of Au(I) from thiosulfate gold‐leaching solutions as the ideal adsorbent not only possesses abundant active sites with high affinities and selectivities toward Au(I), but also demonstrates fast recovery of Au(I) at high purity and large capacity. Herein, guided by theoretical calculations, a water‐insoluble inclusion complex is synthesized using β‐cyclodextrin (β‐CD) and diphenylphosphine (DPP) as host and guest molecules, respectively, by a steric hindrance strategy for highly efficient and selective Au(I) recovery. The prepared β‐CD@DPP exhibits outstanding Au(I) adsorption performance, with a saturated loading capacity of 146.28 mg g−1. The excellent adsorption performance of β‐CD@DPP for Au(I) is mainly attributed to the full exposure of the adsorption site and the weakly alkaline adsorption environment. Furthermore, β‐CD@DPP demonstrates outstanding selectivity for Au(I) in a Cu─NH3─thiosulfate gold‐leaching solution, and the Au(I) recovery rate is higher than 99%. Synthesis of β‐CD@DPP primarily depends on the weak interactions between DPP and β‐CD. Mechanism of adsorption of Au(I) on β‐CD@DPP involves ligand exchange between PPh2− and [Au(S2O3)2]3−. This study provides a new idea and material preparation method for highly efficient, selective, and large‐capacity recovery of Au(I) from thiosulfate leaching solution.

Statistical modelling and kinetics of copper loss to printed circuit board (PCB) fibreglass during PCB ammine leaching

ABSTRACT PCB dust leach feed contains fibreglass particles responsible for incomplete copper recovery observed during PCB dust leaching. Interaction of fibreglass particles with ammine leach solution was studied by varying contact time, operating temperature and pulp density at different initial concentrations. Box Behnken RSM design was utilised to design the experimental tests. The 3D plots, ANOVA, Pearson correlation and multiple regression analysis show the initial copper concentration impacts the response QCu most. Of the five non-linear adsorption kinetic models employed, Elovich and Avrami's kinetic model best fitted the experimental data with R2 of 0.9632 and 0.9435, respectively. The pHpzc analysis of fibreglass particles shows the material possesses a neutral surface charge at pH = 7.1. Evaluation of the kinetic models and pHpzc analysis of copper losses to PCB fibreglass particles supports dual mechanisms of physisorption and ion exchange co-occurring in the solid–liquid systems. At 1 g fibreglass particles in 100 mL of 50 mg/L copper ammine leach solution, maximum loss of about 1.5 mg/L copper was obtained in 12 h. This clearly indicates limitation to maximum target metal recovery. Copper loss to fibreglass particles occurs during PCB leaching up to an amount which depends on the mass fraction of the glass fiber particles in the pulp, leach solution concentration and time.

Research on recovery/purification of ZnO from the Waelz oxide by NH4Cl leaching-CaO precipitation method

Zinc recovery from secondary sources has become a key issue for sustainable development of zinc metallurgy with the shortage of zinc concentrate supply. As the main intermediate product of the Waelz process, Waelz-fume has always been the focus of research. In this paper, a new hydrometallurgical process to recovery ZnO from Waelz oxides is developed. The main steps include leaching Waelz oxide with NH4Cl solution, purifying the leachate by zinc cementation, and precipitating zinc as ZnO by CaO addition. The zinc extraction can reach 87.9 % through NH4Cl leaching, and more than 99.0 % of Pb and Cd are from the leaching solution removed by the zinc cementation. Under optimal precipitation conditions, 96.6 % of the zinc in the leachate is precipitated as ZnO with high purity. The preliminary estimation shows that the process provides a cost-effective and environmentally feasible scheme for high purity ZnO preparation from Waelz oxide.

Acid-leaching mechanism of electroplating sludge: based on a comprehensive analysis of heavy-metal occurrence and the dynamic evolution of coexisting mineral phases.

Electroplating sludge is a typical heavy metal-containing hazardous waste with tens of millions of tons produced annually in China. Acid leaching is the most common method to extract valuable heavy metals for resource recycling and environmental protection. However, the coexisting elements, which are released from electroplating sludge to the leaching solution, will hinder the recycling of valuable heavy metals. In this work, dynamic acid-leaching experiments, X-ray diffraction analysis, and simulation calculations were conducted. It was found that coexisting elements (mainly Ca, Fe, and Al) account for a large proportion, and calcium salts as coexisting mineral phase (especially CaCO3) are ubiquitous in electroplating sludge. Moreover, the evolution of coexisting mineral phase plays an essential role in the acid-leaching process: (1) the dissolution of CaCO3 contributed a strong acid-neutralization capability and released Ca2+; (2) H2SO4 is the optimal extracting reagent, since it triggered the transformation of calcium salts to CaSO4·2H2O, reducing the Ca2+ concentration; (3) the coexisting elements Fe and Al would form ferrous and aluminum salt minerals with the acid-leaching process, which reduces the leaching of low-value elements. This work provides a new perspective on the acid-leaching mechanism of electroplating sludge, where the evolution of the mineral phase effect the release of valuable heavy metals and coexisting elements. This work also provides as comprehensive information as possible on electroplating sludge and inspires the improvement of the acid-leaching method.

Development of nanofibers functionalized with Cyanex 272 for selective recovery of gold from printed circuit board

AbstractAdvances in technological development mean that the recovery of rare and strategic metals from secondary sources has become essential, due to the high demand for these metals in the production of electronic equipment. Contributing to this goal, the main purpose of this work was to develop Nylon 6 nanofibers modified with the Cyanex 272 organic extractant, for use in the selective recovery of gold present in printed circuit boards from armored vehicles. The nanofibers were produced by the centrifugation technique, employing the Forcespinning® system. The best extraction conditions for the separation and concentration of gold were 10% Cyanex 272, fixed pH of 1.5, contact time of 15 min, and solid:liquid ratio (S/L) of 1/700. Gold extraction efficiencies above 77% were achieved in this step. In the stripping step, efficiencies exceeding 85% were obtained using 1 M HCl, 1 M thiourea, S/L of 1/50, and contact time of 3 min. The nanofibers were evaluated in terms of their adsorption capacity, stability, and capacity for reuse in successive cycles. The results showed that the Nylon 6/Cyanex 272 nanofibers could be used in several extraction and stripping cycles. These nanofibers provided high selectivity in the recovery of gold when applied using real leachate solutions, in the presence of other metals (lead, tin, zinc, and copper). The use of nanofibers modified with Cyanex 272 was shown to be an effective option for gold recovery, with lower environmental impacts, compared to conventional liquid–liquid extraction methods that require the use of organic solvents.

Functionalized agriculture-derived biomass-based adsorbent for the continuous recovery of gold from a simulated mobile phone leachate

Electronic waste has become a global concern, as it has been steadily increasing over the years. The lack of regulation and appropriate processing facilities has rendered these wastes an environmental hazard. However, they represent excellent alternative sources of precious metals, which are highly in demand in various industries. Adsorption has been a popular method for metal removal/recovery because of several advantages, such as ease of use and low cost. In this regard, it is crucial to develop an inexpensive and functionalized adsorbent to selectively adsorb precious metals. Thus, silica, which is derived from rice husk and is abundantly present in Indonesia, was functionalized using an ionic liquid (SiRH_Im) and used for Au(III) adsorption from a simulated mobile phone leach liquor. SiRH_Im exhibited a high adsorption capacity (232.5 mg g−1). The Au(III) adsorption kinetic suitably fitted with the pseudo-second-order kinetic model. The Au(III) adsorption followed a chemisorption route that suited the monolayer model. Thomas' and Yoon-Nelson's models were well suited for the continuous Au(III) behavior. Selective recovery of Au(III) from SiRH_Im was achieved via sequential desorption. SiRH_Im also showed excellent reusability, as indicated by a negligible decrease in adsorptive performance over three cycles. The functionalization of silica derived from rice husk using an ionic liquid led to the successful creation of a solid adsorbent with a high adsorption capacity toward precious metals present in a simulated leach solution. Our results highlight the benefit of the functionalization of biomass through the immobilization of an ionic liquid toward the enhancement of its adsorption capability.