Silver Leaching Research Articles

A novel acid-free combined technology to achieve the full recovery of crystalline silicon photovoltaic waste

To achieve the global carbon neutrality commitment, photovoltaics, a clean and renewable source of energy, is increasingly deployed. Photovoltaic panels are core components of photovoltaic systems. As these panels reach the end of their life, recovering the photovoltaic waste becomes crucial. Currently, strong acid reagents are commonly used in the recovery of silver from crystalline silicon photovoltaic waste, posing environmental risks and restricting the industrialization of their recycling. In this study, a novel acid-free technology to achieve the full recovery of crystalline silicon photovoltaic waste was proposed. A pyrolysis process was first conducted for decapsulation, with carbon dioxide being the main gas component at 60.64 %. Next, bioleaching technology was employed to leach silver from waste crystalline silicon photovoltaic cells. The silver leaching rate in a single leaching cycle reached 44.7 %. Meanwhile, the mechanism of silver leaching was further analyzed. Finally, high-velocity fluid frictional separation, a technique that uses high-speed fluid flow to separate material, was chosen to obtain silicon wafers. The reclaimed silicon samples had a total thickness variation of 6.64 µm to11.62 µm, with average carrier lifetimes exceeding 4.9 µs, higher than that obtained by wet etching. This study is expected to advance the industrialization of the recovery of photovoltaic waste, which is also beneficial for the sustainable development of the photovoltaic supply chain.

Stepwise oxidation of refractory pyrite using persulfate for efficient leaching of gold and silver by an eco-friendly copper(II)-glycine-thiosulfate system

Chemical oxidation is a promising pretreatment method for refractory pyrite enclosure to enhance Au/Ag extraction. Here, persulfate was employed for stepwise oxidation of a refractory pyrite concentrate with encapsulated Au/Ag: (i) pyrite oxidation began with heating-activation persulfate, where hydroxyl radical (•OH) acted as the primary oxidative species for fast-dissolving pyrite into Fe ions; (ii) pyrite self-dissolved Fe ions were in-suit used as a moderate activator of persulfate to generate •OH for sustainable oxidizing pyrite at room temperature. Mineralogical studies have confirmed that oxidation of the sulfide enclosure (FeS2) significantly reduced the particle size of pyrite, accompanied by pores creation and an increase in specific surface area. The variation of microstructure liberated Au and Ag particles to lixiviants for extraction, significantly improving leaching efficiency in an eco-friendly copper(II)-glycine-thiosulfate system to 92.2 % for Au and 88.6 % for Ag, respectively. This work provides a promising process for separating precious metals from refractory pyrite.

Influence of silver coated zeolite fillers on the chemical and mechanical properties of 3D-printed polyphenylene sulfone restorations

ObjectivesTo investigate the chemical and mechanical properties of polyphenylene sulfone (PPSU) depending on its composition and manufacturing. MethodsUnfilled–PPSU1 and with antimicrobial silver coated zeolites filled–PPSU2 specimens were made of granulate–GR, filament–FI, or printed–3D. Scanning microscopy and X-ray spectroscopy were performed. Martens hardness–HM, elastic indentation modulus–EIT and flexural strength–FS were determined initially and after aging. Shear bond strength–SBS to veneering and luting composite after conditioning with 7 adhesive systems were examined after aging. Silver leaching was tested after 1-, 3-, 7-, 14-, 21-, 28- and 42 days. Analyses of variance, Kolmogorov–Smirnov, Kruskal–Wallis, Mann–Whitney U, unpaired t-tests and Weibull modulus were computed (p < 0.05). ResultsZeolites were homogeneously distributed. PPSU1-GR and PPSU1-FI showed the highest HM/EIT, followed by PPSU2-GR, PPSU1-3D and PPSU2-3D. PPSU2-FI presented the lowest HM/EIT, displaying micro pits. Aging showed reduced HM/EIT in PPSU1 and no impact on PPSU2, while FS increased (PPSU1) or decreased (PPSU2). PPSU2-3D presented lower FS than PPSU1-3D. High SBS to the luting (7.0–16.2 MPa) and veneering composite (11.8–22.2 MPa), except for adhesive system PR, were observed. PPSU2-3D showed the highest silver release (9.6%), with all compositions dispensing silver over 42 days. ConclusionsFor the examined period of 6 weeks, antimicrobial silver ions were released from filled PPSU. The high SBS between PPSU and veneering/luting composite confirmed the feasibility of esthetically veneering and luting filled PPSU. To achieve mechanical properties like unfilled PPSU, the processing parameters of filled PPSU require refinement. Clinical significanceThis investigation provides proof of principle that PPSU can be successfully doped with silver-coated zeolites. The combination of 3D-printing with an antimicrobial thermoplastic constitutes a great opportunity in the field of prosthetic dentistry. Potential applications include clasps for removable dental prostheses, provisional or permanent fixed dental prostheses and implant abutments.

Short-process leaching and kinetic behaviour of aluminium and silver from waste photovoltaic modules

Efficient recycling and reuse of resources are essential for global resource transformation. Researchers worldwide have focused on the proper disposal of waste photovoltaic (PV) modules produced by the rapidly developing PV industry. The utilisation of waste PV modules has high economic value and helps prevent the pollution of harmful elements in the environment to achieve sustainable development in the PV industry. This work proposes short 'rapid H2O2-H2SO4 leaching' for the efficient recovery of aluminium and silver from waste PV modules. The extraction for aluminium and silver were 99.20 % and 99.01 %, respectively. Fractal geometry method was used to modify and optimise the leaching kinetics. The fitting calculation indicated that the leaching of aluminium and silver conformed to internal diffusion-controlled process.

Silver Recovery from Crystalline Silicon Photovoltaic Solar Cells Using Continuous Stirred-Tank Reactors.

Silver can be recycled from the end-of-life crystalline silicon photovoltaic (PV), yet the recycling and its technology scale-up are still at an early stage especially in continuously operations e.g., continoursely stirred tank reactors (CSTR). Here, the silver recovery from the solar cells is technically understood and optimized in the CSTR system from the point of view of silver recovery efficiency, through integrating experimental and numerical investigations. Specifically, based on the experiments, a kinetics model is developed and scanning electron microscopy surface morphology is characterized; and a computational fluid dynamics-discrete element method (CFD-DEM) particle-scale model is integrated with the kinetics model and validated against the fluid-flow pattern and silver leaching performance results from lab measurements. The validated CFD-DEM model is then applied to understand the particle-scale behavior of silver leaching in the CSTR system in terms of hydrodynamics and AgNO3 distribution under different impeller speeds. The simulation results show that the silver leaching performance is improved in an improved CSTR design with a lower impeller position and doubled impeller layers. This work reveals the effectiveness and underlying hydrodynamics of silver leaching in CSTR systems and lays a foundation for improving silver recovery in PV recycling.

Effects of pyrite, quartz and sodium sulfite on roasting of a refractory sulfide concentrate and gold, silver, copper leaching during cyanidation

The oxidation roasting pretreatment process, which is a mature and dominant industrial practice for treating complex polymetallic gold deposits, has a low recovery of associated silver and exhibits an unclear reaction sequence. This study takes a silver-containing gold ore as the research object and investigates the effect of (i) sodium sulfite as an additive, (ii) main gold-bearing mineral pyrite, and (iii) gangue mineral quartz, on silver during the roasting process in roasting and leaching tests. Characterization techniques included scanning electron microscopy–energy dispersive spectroscopy analysis, and thermogravimetry–differential scanning calorimetry analysis. The results based on thermodynamic calculations and characterization show that the main reason for the low extraction of silver is that the calcined product (i.e., iron silicate) formed by the reaction between pyrite and quartz during the roasting process is mutually absorbed and wrapped with silver oxide. In addition, silver minerals decompose some iron sulfides and iron oxides under high-temperature conditions, promoting the reaction of iron and quartz to form iron silicate while strengthening the secondary encapsulation of silver by products of roasting, thus deteriorating the extraction of silver. The addition of sodium sulfite reduces the formation of iron silicate and increases the extraction of silver by directly promoting the conversion of pyrite to iron oxide. This study provides a theoretical basis for further improving the roasting and leaching of silver.

Effect of silver chloride deposition technique on modified bentonite operating properties for radioactive iodide-ions localization in geological disposal facility for radioactive waste

This work discusses the influence of the technique of silver chloride deposition (via one-stage or two-stage method) onto performance attributes of modified bentonite for iodine ions localization in radioactive waste repositories. It has been established that bentonite modified via both techniques in wide range of AgCl content has high sorption properties (more than 95%) towards iodide anions, the AgCl deposition method has little-to-no effect on sorption properties. Investigation by scanning electron microscopy and energy dispersive X-ray spectroscopy methods and studying of silver leaching in various media showed that two-stage technique yield more uniform AgCl distribution and significantly higher resistance of AgCl to leaching than one-stage technique. Therefore, as a component of bentonite engineered safety barrier in geological disposal facility for radioactive waste use of bentonite modified with two-stage technique is preferable.

Investigation of the use of foams for silver leaching using the thiosulfate‑copper(II)-ammonia system in the context of e-waste recycling

Due to its physical properties, metallic silver is present in numerous electronic wastes. Its recycling requires selective extraction, which involves leaching of silver as the first step. This work focusses on leaching silver with Cu(II)/NH3/S2O32− which has been widely used for gold leaching. As recently shown for the leaching of copper, using foams whose aqueous phase consists of leaching chemicals is a promising way to reduce the environmental footprint, by improving the metal oxidation caused by the fast transfer of O2 from bubble to bubble. In this work, metallic silver samples are dissolved by foams made of Cu(II)/NH3/S2O32− solution with bubbles composed of O2-N2 mixtures. The main problem of the thiosulfate route is its degradation during metal oxidation hence it requires using large quantities of this reactant. The results obtained for our leaching foams show that the quantity of silver leached per quantity of thiosulfate used is about three times greater in comparison with a solution, which would bring a new approach to this problem. Moreover, we investigate the role of the bubble size and the gas composition (dioxygen partial pressure). Besides we find that the dissolved silver is inhomogeneously distributed between the foam column and the bottom solution, with an accumulation of 90 % of silver inside the foam, hence opening an interesting perspective for an easy separation of silver upon leaching. Comparing several surfactants, we show that only non-ionic surfactant polyoxyethylene oleyl ether, Brij O10, shows satisfying results, while dodecyl trimethyl ammonium chloride most likely binds with silver complexes and triggers a quick collapse of the foams.

Recovery of critical and strategic metals from scrap marble-cutting tools by oxidative leaching and precipitation

Scrap marble-cutting tool segments (SMCTSs) generated within marble-cutting applications can be regarded as an important secondary resource owing to their high content of base/precious/critical metals (i.e. Co, Cu and Ag) as well as synthetic diamonds. In this study, sulphuric acid-hydrogen peroxide leaching of copper cobalt and silver from SMCTSs was studied using the central composite design for experiments. Extractions of cobalt (≥73.8 %) and iron (≥86.6 %) were more extensive than copper (≤78.3 %) and silver (≤35.1 %), linked with their relative nobilities. Data analysis has confirmed that increasing the acid concentration or temperature enhances the leaching of metals. Copper and silver leaching improves with H2O2 concentration, while high cobalt and iron leaching can be readily achieved without H2O2. Silver was selectively precipitated (98.9 %) as AgCl with 8.8 % Cu and 0.7 % Co losses from the leach solution. Copper and cobalt were also recovered selectively by increasing the pH to 5.5 and 8.5 respectively after the removal of iron at pH 3.5. These findings have revealed that cobalt, copper, and silver could be selectively recovered by the proposed leaching and precipitation approaches from SMCTSs.

Investigation of the Impact of Electrochemical Hydrochlorination Process Parameters on the Efficiency of Noble (Au, Ag) and Base Metals Leaching from Computer Printed Circuit Boards

The development of environmentally friendly and energy-saving processes for recycling electronic waste (e-waste) is still relevant today. The research presented in this work relates to hydrometallurgy, namely, the electrochemical leaching of metals from e-waste under the action of alternating current (AC) into hydrochloric acid solutions of electrolytes, and can be used for leaching both noble and non-ferrous metals from secondary raw materials. The main object of the study was disintegrator-crushed mixed computer PCBs metal-rich powders with a particle size (d) of &lt;90 µm. The impact of such leaching process parameters as temperature (Tel) and composition of the electrolyte solution, AC density (i) on the electrodes, experiment duration (tex) while maintaining a constant electrolyte temperature (60 °C, 70 °C, and 80 °C) on the metal (Au, Ag, Cu, Al, Ni, Pb, Sn, Ti, Zn, and Fe) leaching efficiency has been studied. In addition, under similar experimental conditions, but without external control of Tel, the kinetics of metal leaching from raw material powders obtained via PCBs single and double crushing in a disintegrator has been also presented. Comparison of raw material powders obtained from different batches of the source material showed both the variability of its chemical composition and the different kinetics of Au and Ag leaching under the same experimental conditions. The optimal conditions for pretreatment of the raw material obtained by single crushing in a disintegrator (CHCl = 6 mol·L−1, i = 0.88 A·cm−2, tex = 1 h, solid-to-liquid ratio—8.6 g·L−1 and without external control of Tel) were determined. It has been shown that this electrochemical pretreatment is accompanied by transition of only base metals into the electrolyte solution, making it possible to significantly reduce their concentration in the final solution. Under pretreatment conditions, the following degree of metal leaching (RMe) has been established: RCu = 98.2%, RAl = 62.8%, RNi = 53.4%, RPb = 93.2%, RSn = 98.0%, RTi = 88.5%, RZn = 61.6%, and RFe = 78.8%. As a result of a subsequent two-hour electrochemical treatment of a solid residue, the degree of leaching of gold and silver was 73.6% and 86.7%, respectively. The presented results provide a broader understanding of the possibility of using the proposed electrochemical hydrochlorination method for noble and base metals leaching from waste PCBs. The novelty and practical value of this research is a validation of the developed technology in laboratory conditions using the real batch of the PCBs. This approach may also be useful to researchers involved in the recycling of other types of secondary raw materials.

Effect of process variables on leaching behavior and kinetics of silver element from waste photovoltaic modules

In order to achieve efficient leaching of silver, in waste photovoltaic panels, the leaching process using nitric acid was investigated. The effects of nitric acid concentration, leaching time, solid–liquid ratio, and leaching temperature on the silver leaching rate were examined. The response surface method was used to establish an experimental model for analyzing and optimizing the leaching experiment. The results showed that the nitric acid concentration had the most significant effect on the leaching rate. The leaching rate of 98.02% was achieved under the following optimal leaching conditions: a nitric acid concentration of 18%, a leaching time of 32 min, a solid–liquid ratio of 1:30, and a leaching temperature of 60 °C. According to the shrinkage nuclear model, the leaching kinetics of silver using nitric acid followed a chemical reaction-controlled process with an apparent activation energy of 42.26 kJ/mol. Scanning electron microscopy–energy-dispersive x-ray spectrometry results of minerals before and after leaching confirmed the efficient recovery of silver in waste photovoltaic cells.

In-situ complexation of silver nanoparticle on thin film composite reverse osmosis membrane for improving desalination and anti-biofouling performance

The study on the state-of-art desalination membranes related to their fundamental structure, property and performance has been sparked by the demand for commercially attractive high-performance membranes. In this study, the surface of polyamide (PA) reverse osmosis (RO) membrane was modified by integrating tannic acid (TA) and silver nanoparticles (Ag NPs) to increase the water flux, anti-biofouling and antifouling properties of the membrane. The anti-biofouling properties was optimized by varying the duration required for the in-situ formation of Ag NPs on the surface grafted TA. The findings revealed that the PES/PA-TA-Ag(20 min) membrane prepared from the in-situ reduction of Ag precursor for 20 min exhibited the maximum flux of 20.56 L/m2·h. The PES/PA-TA-Ag(40 min) membrane also demonstrated increased antibacterial ability as proven by an increase in the number of dead bacteria (48 ± 1.71 μm3/μm2) and a reduction in biofilm thickness (1.6 ± 0.12 μm) for E. coli. The antifouling performance of the SA-fouled PES/PA-TA-Ag(40 min) membrane is appealing, with higher FRR of 98.05 % observed. The PES/PA-TA-Ag(40 min) membrane showed minimal silver leaching of ≤2.5 % and reduced flux loss of 25 % upon filtration. The facile surface modification through complexation of TA and Ag NPs offers an opportunity to heighten the desalination productivity and antifouling characteristics of PA TFC membranes.

One-Pot Synthesis of Silver Nanoparticles from Garcinia gummi-gutta: Characterisation, Antimicrobial, Antioxidant, Anti-Cancerous and Photocatalytic Applications.

Methods like the bio-synthesis of silver nanoparticles (Ag NPs) using plant extracts have become promising due to their eco-friendly approach. The study aimed to examine the utilization of Garcinia gummi-gutta fruit phytochemicals as agents in the biosynthesis of Ag NPs, evaluation of the antimicrobial, antioxidant, and anti-cancerous properties, as well as the photocatalytic ability of bio-synthesized Ag NPs against Crystal Violet (CV), a triphenylmethane dye. The characterization of the physical properties of the Ag NPs synthesized via the green route was done using UV-Vis spectrophotometry (UV-Vis), X-ray Diffraction (XRD), Fourier Transform Infrared Spectrophotometry (FTIR), Scanning Electron Microscopy (SEM), Zeta potential analysis, and Transmission Electron Microscopy (TEM). The dye degradation efficiency of CV was determined using synthesized Ag NPs under UV light by analyzing the absorption maximum at 579 nm. The antimicrobial efficacy of Ag NPs against E. coli, S. aureus, Candida tropicalis, and Candida albicans was examined using the broth dilution method. The antioxidant and anti-cancer properties of the synthesized Ag NPs were assessed using the DPPH and MTT assays. The UV analysis revealed that the peak of synthesized Ag NPs was 442 nm. Data from FTIR, XRD, Zeta potential, SEM, and TEM analysis confirmed the formation of nanoparticles. The SEM and TEM analysis identified the presence of spherical nanoparticles with an average size of 29.12 nm and 24.18 nm, respectively. Maximum dye degradation efficiency of CV was observed at 90.08% after 320 min without any silver leaching, confirming the photocatalytic activity of Ag NPs. The bio-efficiency of the treatment was assessed using the Allium cepa root growth inhibition test, toxicity analysis on Vigna radiata, and Brine shrimp lethality assay. The findings revealed the environmentally friendly nature of green Ag NPs over physical/chemically synthesized Ag NPs. The synthesized Ag NPs can effectively be used in biomedical and photocatalytic applications.

The accelerated recovery of silver using the nitrite-copper novel system: Development of the kinetic model

This research presents a systematic-kinetic analysis of silver leaching from pure metallic silver using the NO2-Cu2+ novel system, with the aim to maximize the silver recovery and decrease the massive consumption of reagents. The effect of pH, nitrite ions concentration, cupric ions concentration, temperature and stirring rate on silver leaching kinetics and recovery was evaluated. The thermodynamic and leaching results showed that a decrease of pH from 5.4 to 4.5 increases remarkably the silver leaching kinetics, while the parasite precipitation of copper hydroxysulfate species is inhibited. The silver leaching kinetics is also favored when nitrite and copper concentrations are increased up to 1.5 and 0.2 M, respectively. The fundamental kinetic analysis revealed that silver leaching mechanism from its metallic form with this system was incomplete and follows the next kinetic model: t = [ 10-0.52pH [NO2–]1.2 [Cu2+]0.522.63 × 109e-56,900/RT][ 1–3(1-x)2/3 + 2(1-x)], where the diffusion of fluid species through a non-conventional ash layer is the rate determining step of the leaching process. Finally, the dissolved silver can be easily recovered in its metallic form (high purity > 99%) using a simple cementation step, which permits the recycling of the leaching solution.

Research into percolation leaching of copper and silver from aged tailings

This paper investigates the extraction of silver by percolation leaching of a pelletized sample of aged tailings with organic binder Alcotac® CB6. Laboratory studies of percolation leaching were conducted using a column with a height of 0.5 m and an internal diameter of 56 mm. Pelletization was performed in a drum-type pelletizer with the consumption of Alcotac® CB6 (BASF, Germany) of 800 g/t and the pellet moisture content of 8–10% and size of 8–10 mm. The sample composition was analyzed taking into account the data obtained by optical tests, electron microscopy, X-ray diffraction, local X-ray spectrometry, X-ray fluorescence analysis, and inductively coupled plasma mass spectrometry. The research object was aged tailings of the Zhezkazgan processing plant (Ulytau region, the Republic of Kazakhstan), where copper is mostly represented by oxidized minerals (78.47%) and sulfide minerals (21.53%). The results of physical and chemical analyses conducted to determine the material composition of samples are presented, along with observations over percolation leaching of copper and silver from Zhezkazgan aged tailings. The copper leaching studies included two stages using a sulfuric acid solution as a solvent. The subsequent stage was silver dissolution by cyanide leaching. Copper extraction into the solution comprised 88.55% with a sulfuric acid consumption of 80.0 kg/t; silver extraction comprised 75.31% with a sodium cyanide consumption of 0.55 kg/t. The conducted studies showed the efficiency of using Alcotac® CB6 for percolation leaching of pre-pelletized aged tailings. During leaching, the pelletized material exhibits sufficient porosity and permeability, thus providing access of cyanic solutions to the surface of precious metals.

Hydrothermal Leaching of Silver and Aluminum from Waste Monocrystalline and Polycrystalline Photovoltaic Panels

The aim of this study was to investigate the hydrothermal leaching of silver and aluminum from waste monocrystalline silicon (m-Si) and polycrystalline silicon (p-Si) photovoltaic panels (PV) from both cells and metal ribbons using mild HNO3 solutions. Prior to leaching, pretreatment was applied to remove the fluoropolymer backsheet and thermally degrade the ethyl vinyl acetate (EVA) polymer. Several hydrothermal parameters were investigated, such as the liquid-to-solid (L/S) ratio, HNO3 concentration (N), time (t) and temperature (T). Based on preliminary tests, the HNO3 concentration was set in the range of 1–2 N to reduce hazardous waste effluents. The response surface methodology (RSM) was applied to optimize the hydrothermal leaching parameters. It was found that processing time was the most important factor for Ag leaching, followed by HNO3 concentration and L/S ratio, while the processing temperature (100–140 °C) was not a statistically significant factor. Aluminum leaching was efficient under most hydrothermal conditions. For comparison, leaching was also applied at lower temperatures of 25–45 °C for prolonged times; however, lower efficiencies were observed. Under the optimal hydrothermal conditions, Ag can be completely leached, while Al dissolution was favored at hydrothermal conditions compared with lower temperature leaching. Silver leaching efficiency was 100% under hydrothermal conditions; however, under conventional lower temperature conditions, it was 80.7–85.3% for m-Si and p-Si waste panels. Under conventional lower temperature conditions, Al leaching efficiency was 56.6–61.3% for p-Si and m-Si waste panels.

A resource-efficient and portable nanotechnology-enabled disinfection system: Performance studies and a novel strategy to recycle spent material

The paper describes developing a point-of-use disinfection system consisting of a film-forming nanocomposite packed in a nylon sachet. The composite film consists of silver nanoparticles embedded in a matrix containing chitosan, reduced graphene oxide, and tannic acid. The long-term ability of the portable sachet bag to release silver ions and disinfect surface and groundwater is demonstrated. The sachet bag's disinfection potential is demonstrated by taking Escherichia coli MTCC 443 as the model microorganism. The system produced a complete and consistent 3 log10 reduction of E. coli over multiple cycles of use. The paper also describes a green recycling approach to utilise spent composite film and prevent AgNPs from entering the waste stream. The spent nanocomposite film is transformed into a concrete micro-crack sealant through a soft chemical route. The sealant's ability to plug micro-cracks in concrete is demonstrated, and the mechanism of sealant interaction with concrete is proposed. The sealant can fill cracks and solidify in an alkaline environment. The concrete cube specimens repaired with sealant showed enhanced compressive strength compared to the residual concrete cube specimens. The possible leaching of residual silver from the sealant in concrete is investigated via toxicity characteristic leaching procedure analysis. The study demonstrates that silver leaching is negligible (< 0.05 mg/L) and well below the permissible limit of 5 mg/L.

Mineralogy and geochemistry of tellurium in the some mining sites of Transbaikalia

The first results of the study of the occurrence and mineral forms of tellurium in hypogenic and hypergenic conditions on the example of some deposits in Transbaikalia are presented in the article. Their paragenesis and the variations of tellurium content in ores and the hypergenesis zone are considered. Experiments on water leaching of tellurium, bismuth, lead, uranium and silver were carried out. The physicochemical model of mineral associations with the participation of these elements in conditions of the hypergenesis zone was calculated.

Titanium dioxide and table sugar enhance the leaching of silver out of nanosilver packaging

TiO2 and sugar cooperatively enhance the quantity and alter the form of silver that migrates out of nanosilver-enabled plastic food packaging under intended use conditions.

Selective Hydrochloric Acid Leaching of Zinc, Lead and Silver from Mechanically Activated Zinc Plant Residue

Selective Hydrochloric Acid Leaching of Zinc, Lead and Silver from Mechanically Activated Zinc Plant Residue