Conventional mining of metalliferous rock typically involves physical excavation followed by mineral processing. These are energy intensive and environmentally invasive processes which produce large amounts of wastes. In situ leaching of mine wastes with acidic lixiviants may provide an opportunity to recover additional metals and decontaminate residual material. However, the use of high concentration

The extraction of rare earth elements (REEs) such as YIII, LaIII, PrIII, NdIII, EuIII, TbIII, DyIII, ErIII and YbIII in aqueous two-phase system (ATPS) formed by PEG/MgSO4 and polyoxometalates (POMs) as extractants was investigated under various conditions. Increased vacant sites in the POM and higher POM concentrations enhanced the competitive effect among REEs extraction. Lower acidity also enhanced

Electric arc furnace (EAF) dust is a by-product of the stainless-steel industry that contains significant amounts of zinc and iron as well as lead and is classified as hazardous waste. Recovering metals from the EAF dust would increase the zinc supply from waste and decrease the amount of hazardous waste. Cleaning of industrial gases using EAF dust is a potential low-cost alternative to non-regenerable

This study reports an acid-free, efficient, and selective method for Li leaching at room temperature from end-of-life (EoL) LiFePO₄ (LFP) batteries using sodium persulfate (Na₂S₂O₈) as a promising lixiviant. The objective of this study is to leach target metal, i.e., Li, as efficiently as possible while minimizing chemical consumption. First, valuable metal-containing materials called black powders

This paper presents a novel investigation into the species distribution and stability phase diagrams for the Fe-S-O-H and Fe-As-S-O-H systems under conditions below 300 °C, using available thermodynamic data. This range of temperatures is important for this system, as it informs the behavior of iron and arsenic species in the pressure oxidation of complex refractory ores and in the fixation of arsenic

The mineralogical attributes of uranium ore within sandstone-hosted uranium deposits hold paramount significance in the selection and refinement of in-situ leaching (ISL) of uranium. Nevertheless, the relationship between these mineralogical characteristics and uranium leaching efficiency under varying operational conditions remains an understudied area. Therefore, this study collected uranium ore

Acid leaching has been widely employed for the extraction of rubidium (Rb) and lithium (Li) from mica owing to operational simplicity, reduced energy consumption, and enhanced efficiency. However, previous investigations have primarily focused on Li leaching behavior and mechanisms, with limited attention paid to understanding the lattice occupancy of Rb in mica and its influence on the leaching mechanisms

The Uranium Corporation of India Limited (UCIL) Tummalapalle facility processes a low-grade uranium ore (0.042 % U3O8), necessitating the enhancement of low uranium concentration (0.74 g/L U3O8) in the clarified leach liquor as a critical goal for process optimization in the precipitation stage. Enhanced concentration of U3O8 in the process liquor is pivotal for maximizing the recovery of the final

The rapid growth in global demand for lithium-ion batteries (LIBs) has led to a corresponding increase in the number of spent LIBs. This situation highlights the importance of recycling these batteries to conserve the environment and preserve the raw materials used in their production. Among the various commercial recycling methods, leaching is widely used in hydrometallurgical flowsheets. Through

Titanium gypsum is a solid waste produced when titanium dioxide manufacturers use sulfuric acid and neutralize the waste acid with lime. The global production of titanium gypsum waste has reached 10 million tons annually. To address the environmental hazards, this study proposes a cost-effective ($2.39/ton), emission-free method to sustainably produce high-value α-hemihydrate gypsum by consuming large

The development of industrial technology has significantly promoted the production and accumulation of spent precious metal-based catalysts. This work describes the synthesis of an ionic liquid – [BIim][Cl3] and its application as an alternative to toxic and corrosive reagents for precious metal leaching from waste catalysts. The leaching process using [BIim][Cl3] is proved to be safe and green. It

Bifunctional ionic liquids (Bif-ILs) are a class of liquids in which both cations and anions actively participate in the extraction process through chemical bonds. These liquids exhibit high selectivity and stability. This study investigated the solvent extraction of molybdenum (Mo) and rhenium (Re) using the Bif-IL [A336][Cy272], diluted in xylene. Various parameters, such as stirring speed, temperature

The extraction of gold (Au) from refractory ores poses major challenges due to the inclusion of gold particles in sulfide minerals. In this study, an alternative and highly efficient oxidative pretreatment for refractory gold ores and concentrates was developed using persulfate-based advanced oxidation process. This approach generates strong oxidizing radicals to oxidize sulfide minerals, thereby releasing

Ferric and titanium oxides are the main impurities in low-grade bauxite that significantly affect alumina extraction in the Bayer process. This study aims to investigate the reaction and transformation behavior of ferric and titanium oxides in diasporic bauxite during a mild alkaline hydrothermal process to minimize the inhibitory effects of Fe and Ti impurities on bauxite digestion. Analytical techniques

In this work, indium was extracted from zinc oxide dust leachate using a microwave-assisted P507 extractant, and microwave-assisted indium stripping with hydrochloric acid. The effects of extractant concentration, pH, volume ratio of organic phase to aqueous phase, contact time, temperature and microwave power on indium extraction were investigated. The optimum conditions for indium extraction were

The increasing adoption of lithium-ion batteries in new energy sectors has substantially increased lithium consumption. Chilean salt lakes consist of high concentrations of Li+, (1.14 g/L) and Ca2+ (>10 g/L) and low concentration of Cl− (<200 g/L). The TBP-FeCl3 system can efficiently extract lithium from high Mg brine, but the system has not yet been studied in low chloride and high calcium brine

The rapid growth of electronic waste (e-waste) presents both environmental challenges and economic opportunities. This study investigates efficient methods for recovering valuable metals from printed circuit boards (PCBs) using hydrometallurgical processes. The PCB samples from various end-of-life electronic devices were subjected to a series of five leaching stages targeting the leaching of Ag, Au

Jarosite is a mineral that holds significant importance in the metallurgical industry. For decades, the jarosite process, operating at high temperatures, has been employed to precipitate jarosite and recover Zn. Consequently, many studies have been undertaken to understand the precipitation behavior of jarosite-type compounds. More recently, the development of different hydrometallurgical processes

Electric arc furnace slag (EAFS) is produced in large amounts during steel manufacturing and can pose ecological hazards when disposed of in nature. Its heterogeneity, intricate mineralogy, and low solubility restrict its applicability in numerous fields, such as cementitious binders, resource recovery, and mineralization. This study investigated three different microwave irradiation techniques—direct

The carbonation reaction of sodium aluminate solution is the most important, green and economical process for preparing aluminum hydroxide and alumina. Controlling carbonation reaction rate and hydroxyl ion concentration (pH) at the reaction endpoint of NaAlO2 solution is the most critical technical requirement. However, carbonation reaction mechanism is still controversial, and there is no relevant

Traditional alkaline decomposition process for tungsten ore is facing significant challenges, including release of large amounts of hazardous waste and lengthy procedures. A previously proposed novel process for scheelite using NaHSO4·H2O roasting yielded ammonium para-tungstate (APT) of high-purity. However, the applicability of this method to wolframite ((Fe, Mn)WO4) concentrate remains uncertain

In a flowsheet of sulfide roasting, leaching, purification and electrowinning, fluoride ions in zinc sulfate (ZnSO4) solution significantly impair the subsequent electrowinning process for zinc production. The effective removal of fluoride ions is essential for the smooth and effective operation of the entire production workflow. In this study, mesoporous alumina was synthesized using a template method

Due to the exceptional performance and irreplaceable nature of materials containing rare earth metals, their application across various fields of modern society is increasingly widespread. China possesses substantial reserves and abundant resources of rare earth elements, which confer a unique edge in their research and application. However, challenges such as an oversupply of low-end products and

High-purity tellurium is in high demand for applications in high-tech fields such as semiconductors and solar cells. To produce high-purity tellurium, one of the challenges is to effectively reduce selenium content of telluride (IV) solution. This study reports the thermodynamic and kinetic analysis for selenium removal by tellurium powder substitution in a TeCl4 solution. The thermodynamic analysis

Hydrometallurgical practices represent a vital area of focus within the metallurgical sector, and it is critical that these practices are carried out in an environmentally friendly manner in order to promote sustainability and responsible processing. One promising approach is the use of hydrogen gas (H2), known for its ‘green’ properties, along with the pollutant carbon dioxide (CO2), at various stages

This study evaluated the potential of 15 biological amino acids as eco-friendly lixiviants for copper (Cu) extraction from printed circuit boards (PCBs) under alkaline conditions. The Cu leaching behaviors, complexation mechanisms, and the effect of temperature were examined. The amino acids were classified by their Cu leaching efficiencies: Type-I (Gly, Val, Ala, Arg, His, Lys), Type-II (Pro, Glu

This research explores the intricate chemistry of deep eutectic solvents (DESs), particularly those formed with carboxylic acids and choline chloride, highlighting their effectiveness in metal leaching and the potential for sustainable recovery of valuable materials from electronic waste. The utilization of DESs in this context demonstrates a promising avenue for advancing eco-friendly methods in the

The effective separation and recovery of heavy rare earth elements from wastewater presents a significant challenge. This work successfully achieved the separation and recovery of Dy(III), Yb(III), and Y(III) from wastewater using shear-induced dissociation-ultrafiltration technology with acidic phosphoric chitosan (aPCS) as the complexing agent. Unlike traditional methods that depend on organic solvents

Addition of chemical agents to inhibit the CaCO3 precipitation process is a potential way to solve the blocking problem in the industrial in situ leaching process for uranium recovery. This research investigated the role of P(V) added as sodium hexametaphosphate ((NaPO3)6), anhydrous sodium pyrophosphate (Na4P2O7), and sodium tripolyphosphate (Na5P3O10) as inhibitors for the precipitation of CaCO3

The paper summarizes results from long-term observations of the (234U/238U) activity ratios in in-situ uranium leach liquors produced in a uranium mining plant. Measurements of the activity ratios of 234U/238U were performed from March 2018 to November 2022 in liquors from new and old leaching wells. The results have shown a significant dominance of 234U (234U/238U activity ratios up to 2.27) in the

Tungsten finds numerous industrial applications owing to its excellent physicochemical properties and applications in high-tech material production, which make tungsten containing ores, minerals and scrap material strategic raw materials/resources. Tungsten extractive metallurgy (TEM) is a vital process in the tungsten industry for producing diverse high-purity products from raw tungsten-containing

Alum is an important intermediate for the extraction and purification of Cs or Rb chemicals, due to its excellent separation ability for Cs, Rb and K. Although the solubility sequence K-alum > Rb-alum > Cs-alum has been well known, the separation factors among Cs, Rb and K during the formation of alum have not been determined. The formation of solid solution of alum controls the Cs or Rb content and

Copper recovery from electronic waste in the form of copper oxide was investigated using hydrometallurgy-based process. The recovery process involved dismantling of electronic components, their size reduction, ashing at 600 °C for 4 h to disintegrate the polymer matrix to facilitate metal recovery and remove volatiles as pretreatment, followed by nitric acid leaching, solvent extraction of leachate

The pyrometallurgical extraction of valuable metals including nickel, cobalt, and copper from spent lithium-ion batteries (LIBs) has been applied in the industrial recycling of spent LIBs for many years. In conventional pyrometallurgical methods, lithium (Li) is concentrated in smelting slag, which is often discarded as waste without recycling. Given the global scarcity of Li resources, the extraction

Despite being a common hazardous solid waste, pyrite cinder (PyC) contains valuable metals such as iron and gold, which has attracted considerable research attention. The recovery of gold and Iron from gold-bearing PyC was systematically investigated using an environmentally friendly approach involving non-cyanide extraction and magnetic separation. The results showed that with PyC not subjected to

The environmental footprints of batteries and battery chemicals play an important role in the transition towards decarbonized transportation. Lithium carbonate is a conventional lithium salt that is used in manufacturing lithium-ion batteries for electric vehicles and other applications. It is mainly produced either from lithium rich brines or from spodumene ores, the latter being generally more energy

The residue produced after extracting rare earth elements from sedimentary rare earth ore (SREO) contains valuable metals. The effective separation and extraction of valuable metals from this residue is crucial for enhancing the utilization value of SREO and addressing the challenges associated with solid-waste disposal. In this study, Al and Fe were leached from SREO residue using a mixture of sulfuric

A sample of beneficiated rock phosphate from Minjingu Mine and Fertilizer Plant, Tanzania was analysed by energy-dispersive X-ray fluorescence (ED-XRF) spectroscopy and found to contain 15.8 % and 5.30 × 10−2 % w/w P2O5 and U, respectively. The U content of the same sample was estimated to be 3.70 × 10−2 % w/w when the digested mass was analysed by inductively coupled plasma mass spectrometry (ICP-MS)

Limonitic laterites consist of a high amount of iron oxides/hydroxides, such as goethite and hematite, being recalcitrant in hydrometallurgical processing for nickel and cobalt recovery. High pressure acid leaching (HPAL) is the currently most applied processing technology for limonitic laterites. Still, research is ongoing to develop technologies with less energy consumption and a lower carbon footprint

Mixed nickel‑cobalt hydroxide precipitate (MHP) obtained via pretreatment and leaching of nickel laterite ore, is a vital source of nickel and cobalt. This work proposes an efficient and economical hydrometallurgical process for recovering Ni and Co from MHP. Initially, an acid leaching process was employed, achieving leaching efficiencies of 99.9 % for Ni and 98.3 % for Co. Notably, the leaching efficiency

Controlling the dispersed phase droplet size within a reasonable range in the extraction column is crucial for enhancing mass transfer efficiency. Traditional high energy-inputs may result in excessive droplet fragmentation in low interfacial tension systems, posing significant challenges in intensifying the extraction process. This work proposes a novel gas-agitated technology to prevent excessive

This paper presents a thermodynamic, kinetic, and mechanistic examination of indium and tin extraction from indium tin oxide (ITO) in acidic sulfate solutions containing hydrogen peroxide (H2O2). The experimental approach included a comprehensive characterization of commercial ITO powder and leach residues by different techniques, as well as a systematic investigation of the effects of temperature

The heap leaching of ion-adsorption type rare earth (RE) ores confronts the problems of the poor extent of leaching and high reagent consumption. This work explored the optimization of the mass transfer process by mixed-ammonium salt leaching of RE ore samples based on the column-packing order of particle size, chromatographic plate theory, and hierarchical column leaching experiments. Furthermore

In this work, the effect of proton-donor additives (monocarboxylic acids, aliphatic alcohols, and phenol derivatives) on scandium extraction from sulfate solutions with di-(2-ethylhexyl)phosphoric acid (D2EHPA, HR) in decane or toluene as the diluent was investigated. It was shown that addition of these additives into the organic phase leads to an antagonistic effect, i.e., to a decrease in the extraction

Traditionally zirconium is leached from washed dried frit (WDF) powder using commercial-grade nitric acid at 80 °C, which results in a leachate containing significant colloidal silica, leading to emulsion and solvent loss. This work used red fuming nitric acid (RFNA) which consists of 84 % nitric acid, 13 % dinitrogen tetroxide and 1–2 % water, as a novel leaching agent. The reduced water content in

Vanadium is an extremely useful element that is primarily sourced from steelmaking slags via hydrometallurgical processes that use an oxidative roasting step. This roasting step oxidises vanadium to soluble high valent states and influences vanadium extraction in the subsequent leach step. This study examines the structural and speciation behaviour of vanadium in vanadium-rich slag during roasting

In this study, novel guanidinium ionic liquids (GILs) were designed to achieve efficient extraction of Au(I) from thiosulfate solution. A series of process parameters affecting extraction efficiency, including reaction time, phase ratio, different types of guanidinium ionic liquids and their concentrations, as well as different stripping agents, were tested. The results showed that 2,2-dioctyl-1,1

Acidiplasma cupricumulans is recorded as an acidophilic chemomixotrophic iron-oxidising archaeal species that is prevalent within the mineral biooxidation community. The archaeal strain was persistently exposed to 1 mg/L of SCN−, a toxic anion present in low concentrations in remediated cyanidation tailings wastewater from gold recovery plants, to potentially facilitate adaptation. Adaptation to a

Manganese leaching was carried out on a small pilot scale with 110 kg of ore using manganese-reducing organisms and fermentative organisms with biomass (Typha latifolia) as the source of nutrition. This study was carried out without externally supplied chemical reagents and with minimal capital investment. The process involves fermentative organisms to ferment biomass from T. latifolia and generate

The depletion of primary resources and the ever-increasing demand for advanced products containing rare earth elements (REEs) have recently attracted significant attention in the processing of low-grade REEs resources. This study proposes a pre-leach stage to extract non-REEs and enrich the REEs in the residue from apatite concentrate (AP) containing 1.28 % REEs. Over 98.9 % calcium and 98.1 % phosphorous

Coal fly ash (CFA), an anthropogenic waste generated from the combustion of coal, is in research focus for the potential it holds in extracting critical metals. Within the classification of critical metals, includes a group of 16 commercially significant metals known as rare earth elements (REEs). The supply of REEs is touted as one of the building blocks of the 21st century to realize a sustainable

Indium and germanium are rare elements and contribute to supporting materials for contemporary high technology new materials. Research and development of efficient separation and extraction of indium and germanium have important practical significance. A new process of “one step extraction and stepwise stripping” is proposed in this work to coextract indium and germanium with D2EHPA-YW100 synergistic

Spent fluorescent lamps are alternatives to primary sources of rare earth elements. For recycling, the most common hydrometallurgical processes involve leaching with mineral acids, combined or not with alkaline fusion, which must be followed by another acidic leaching step for terbium, cerium, and lanthanum recovery. This study proposes a novel method employing acid fusion with potassium pyrosulfate

The mechanical processing of cemented carbide often generates a considerable amount of grinding waste from cemented carbide (GWCC), which serves as an important secondary resource for recovering Co and W. However, efficient separation of tungsten carbide (WC) and Co from GWCC remains challenging. This study tested an efficient process for separating Co from GWCC using a mixed solution of H2SO4-Na2S2O8

The acid-soluble residue from end-of-life NdFeB magnet waste is often introduced into the ferrous metallurgical process to recover iron oxide as a value added product, but this approach has a low economic value. In this work, a ferrous chloride solution from NdFeB magnet waste containing rare earth elements, which was obtained after the leaching and impurity removal process from the acid-soluble residue

Cerium removal from solution via oxidative precipitation with hydrogen peroxide was investigated in a batch reactor to identify optimum conditions for maximum Ce removal. Tests were performed under ambient temperature at pH 2, 3, 4 and 5, using the exact stoichiometric requirement and 30 % and 50 % excess, respectively. It was found that, unlike the usual direct Ce(OH)4 formation presented in the literature

Germanium plays an essential role in many high-tech fields because of its excellent electrical and optical properties. As a zinc refining by-product, zinc oxide dust (ZOD) is one of the most important sources of germanium recovery. However, the low leaching efficiency of germanium seriously hinders germanium recovery. This study focuses on the phase evolution and elemental distribution of zinc and

The growing demand for rare earth elements, pivotal for modern technologies, has necessitated the development of efficient and sustainable extraction methods from ionic clays. This review provides a comprehensive analysis of the advancements in rare earth recovery from ionic clays, focusing on the geological, geochemical, and technological aspects of the extraction processes. Historically, traditional

A separation method for the recovery of neodymium(III) from two different media, chloride and nitrate, by implementing solvent extraction technique with a novel lipophilic diamide derivative of ethylenediamine tetraacetic acid (EDTA), namely 2,2’-N,N′-didecyl-dioxo-N,N′,N″,N″’-tetraazatetratriacontane-N″,N″’-diyl diacetic acid (H2E-4C10), has been investigated. Initial screening results demonstrated

Hydrothermal pretreatment of copper concentrates in acidified copper sulfate solution has been known since the beginning of the last century as an approach to the chemical enrichment of copper concentrates. While the pilot-scale demonstration of this approach exists, detailed investigations into the underlying chemical interactions that form the basis of this technology are rarely available in open