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

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

The separation of yttrium (Y) from heavy rare-earth elements (HREEs) is a major issue for ion-adsorbed rare-earth deposits. This study describes a new extraction system to develop efficient separation of Y from HREEs in a chloride medium using diglycolamic acid as the extractant. The extraction performance of N,N-di(2-ethylhexyl)-diglycolamic acid (HDEHDGA) for mixed REEs of an ion-adsorbed rare-earth

Because of the common presence of different silicate minerals, like kaolinite, montmorillonite and muscovite as gangue minerals in the beneficiation of copper oxide ores, the interaction between copper(II) ions in solution and each of these minerals is a field of strong interest, considering their implications on the aggregation of these minerals in the extreme pH conditions typical of hydrometallurgical

The ion exchange process using an anion exchange resin (Bio-Rex 5) was employed with batch and column techniques to isolate nuclear-grade zirconium/hafnium from a leach solution of zircon ore. Batch studies were conducted to optimize the conditions for sorption and desorption of Zr(IV) and Hf(IV). The highest separation factor of 10.3 was achieved under equilibrium conditions of 11.0 mol/L HCl, contact

The occurrence of most gold in an encapsulated state often results in poor extraction efficiency, and efficient pretreatment is the key to effective gold recovery from Carlin-type gold ores. This study investigated the enhancement of citric acid (CA) assisted microwave (MW) roasting on gold extraction from Carlin-type gold ores by sulfide/thiosulfate leaching, primarily analyzing in-situ phase transformation

The formation of stable multi-phase emulsions (crud) is a serious problem in almost all commercial solvent extraction (SX) plants. Crud is a mixture of organic and aqueous phases, air, and organic or inorganic solid particles, often found to distribute itself randomly throughout the separating phases of SX plants. Crud formation is encountered in almost all SX units in metal extraction plants. It causes

This study of the simultaneous leaching of copper, gold and uranium from a flotation concentrate is aimed at establishing the conditions that could be applied in a possible heap leach process that would recover all three metals (plus silver, if present) in a single step. The results obtained in this study confirm the results obtained in Part I (Nicol et al., 2024) that enhanced rates for leaching of

In a study (Part II) aimed at the simultaneous heap leaching of copper (predominantly chalcopyrite), gold and uranium from an ore, it was found that this could be achieved using chlorate as the oxidant in chloride solutions. As a result, a more detailed study has been made using electrochemical and batch leach tests on pure chalcopyrite electrodes under typical heap leach conditions.

The influence of a commercially available modified polysaccharide (HydroStar®, Chemstar Chemical Products) on the roughness of short-term and small-scale copper electrodeposits was investigated using Atomic Force Microscopy (AFM), linear scan profilometry and scaling analysis. Copper was deposited on a 316L stainless steel cathode at 40 °C and 300 A m−2 from an electrolyte containing 40 g L−1 Cu2+

Bayer vanadium sludge (BVS), discharged during the Bayer alumina production, is a promising secondary resource for the supply of vanadium. Previous vanadium extraction process involving Pb5(VO4)3OH precipitation by PbSO4, H2SO4 and (NH4)2SO3 leaching, (NH4)2S2O8 oxidation followed by ammonium vanadate precipitation, suffered from large amounts of reagent consumption and discharge of ammonia-containing

Titanium extraction from acidic solutions was investigated using Aliquat-336, considering factors like acid type and concentration for leaching, diluent type for solvent extraction, equilibration time, extractant concentration, phase ratio, and temperature. Kerosene exhibited superior performance as an aliphatic diluent for Aliquat-336 compared to other utilized diluents. The extraction efficiency

In this work, an industrial hazardous jarosite residue produced in the zinc hydrometallurgical process containing silver was used to evaluate the feasibility of using thiourea (Tu) for silver leaching under acidic conditions in the presence of oxalate (C2O42− ion denoted as Ox2−). The shrinking core kinetic model (SCKM) was applied to evaluate the effect of variables on the reaction rate. The chemical

Ultrasonic radiation is widely used in the enhancement of leaching process with outstanding advantages in leaching efficiency. In this study, a germanium concentrate was leached with NaClO and the influence of factors such as ultrasound power and oxidant addition on the leaching efficiency of germanium from the concentrate were investigated. The leaching efficiency of germanium reached 96.8% at the

This study investigated the effects of mean particle size fraction, bottom particle size, particle porosity and wettability on solution scale preferential flow behaviour via step input tracer tests in drip irrigated, narrowly and mixed-sized beds under steady state fluid flux. Nine solute transport models were used to quantify this behaviour reflected in the residence time distribution (RTD) profiles

In the present study, the sorption of perrhenate ions from sulfuric acid liquors was studied using three types of polymer ion exchange resins. An anion exchange resin type 1 (a copolymer of 2-methyl-5-vinylpyridine with divinylbenzene (VP-DVB)) as well as two polyfunctional resins containing anion and cation exchange functional groups, namely, type 2 (a carboxylated VP-DVB with pyridine-2-carboxylic

In this study, the mineralogy of a novel resource of deep-sea sediments containing rare earth elements (REEs) was investigated, along with the leaching of REEs using hydrochloric acid. The results revealed that, apart from 62.0% of the Ce found in the Mn oxides, the other REEs in the deep-sea sediments mostly existed in hydroxyapatite mineral which can be easily decomposed via a hydrochloric acid leaching

The key to achieving sustainable metal extraction development is to avoid the generation of high-salt wastewater from the source. Here, a new system for the extraction and separation of lanthanide elements Eu(III), Gd(III) and Tb(III) from the acetic acid solution using HEHEHP (2-ethylhexyl hydrogen-2-ethylhexylphosphonate) was studied. The corresponding parameters including contact time, HEHEHP concentration

Trichloroisocyanuric acid (TCCA), which is used for gold leaching, is an alternative to cyanidation due to its lower toxicity and higher efficiency. This study investigated the gold recovery procedures from highly effective chloride leaching solution using the D301 resin. This approach prevented the inhibition of gold adsorption when using activated carbon. Herein, the optimal conditions for gold adsorption

Spent hydrodesulfurization (HDS) catalysts containing large amounts of valuable metals, such as Mo and V, are hazardous solid wastes but also valuable secondary resources. However, the current recovery process suffers from the difficulty of balancing the leaching efficiency of Mo and V and their selectivity over Al. This work focused on the effect of phase transformation during roasting operation on

The regeneration of failed hydroxyoxime extractants in the copper hydrometallurgy industry is crucial. However, the existing regeneration system has limitations in terms of operability, yield, and environmental friendliness, which restricts its industrial application. This paper presents a clean one-pot ammoximation regeneration system for the in-situ preparation of hydroxylamine for the oximation

The low bio-production of Fe as a leaching agent is one of the main limitations to implementing industrial bio-processes at feasibility conditions. The main limitation of the bio-oxidation process of Fe is the low oxygen transfer to the aqueous phase because of the low oxygen solubility. This study assesses the effectiveness of the venturi jet as an innovative and intensive aeration device for overcoming

The phosphoric acid produced by the nitric acid method cannot be used as an industrial-grade product as a result of the high calcium nitrate content. It can only be used for fertilizer production due to difficulty of complete removal of calcium nitrate. Herein, an efficient approach for the removal of calcium nitrate from the phosphoric acid produced by the nitric acid process was studied. The proposed

Hydration of In is the main factor limiting its extraction efficiency from an aqueous solution during a liquid-liquid extraction process. In this study, KCl was introduced into the aqueous solution to facilitate the formation of InCl of low charge density, which is expected to possess much weaker hydration compared with In, promoting the solvent extraction of indium. The crown ethers (CEs) with varied

With a decline in high-grade molybdenum reserves, the development of other types of molybdenum resources have received increasing attention. Vanadium shale is a multi-metal shale and fine-grained sedimentary rock comprising small grains and various minerals. After leaching and extracting vanadium, the solution often contains a low concentration of molybdenum. However, because of the low molybdenum

Glycine has been intensively investigated as a “green” lixiviant for precious and base metals. Alkaline glycine solutions to extract Ni from sulfide resources has shown promising results. However, a considerable amount of Ni will be lost in the wash solutions when leaching residues are washed during solid-liquid separation of the leachates from their respective leach residues. In this context, this

The harmful effects of sulfur and organic substances pose constraints on the green and sustainable development of the Bayer process for alumina production. This research aims to develop a method that utilizes HO to remove sulfur and organic substances during the digestion stage of bauxite, based on the mineralogical investigation of sulfur and organic substance. The extent of removal of S and total

A green chemistry process has been developed to recycle cathode material from end-of-life lithium ion batteries. NCM111 (LiNi1/3Co1/3Mn1/3O2) was completely leached with 13 M formic acid to produce two groups of salts with different solubilities: sparingly soluble cobalt, manganese, and nickel (CMN) formates and highly soluble lithium formate. During leaching, CMN formate salts exceeded their solubility

In the intensive cyanidation of gravity gold concentrates, sodium m-nitrobenzene sulfonate (NBS) is often used to supplement dissolved oxygen as the oxidant in the process. A previous paper presented the results of a largely electrochemical study of the behaviour of NBS during cyanidation of gold. The results confirmed that NBS acts as an oxidant in the cyanidation of gold and that the mixed potential

In the intensive cyanidation of gravity gold concentrates, sodium m-nitrobenzene sulfonate (NBS) is often used to supplement dissolved oxygen as the oxidant in the process. This paper presents the results of a largely electrochemical study of the behaviour of NBS during cyanidation. The results have confirmed that NBS acts as an oxidant in the cyanidation of gold and that the mixed potential model

Three platinum group metals (PGMs), platinum (Pt), palladium (Pd), and rhodium (Rh), are key components in automotive catalytic convertors, playing a pivotal role in controlling harmful emissions. The recycling and recovery of Pt, Pd, and Rh from spent automotive catalysts (SACs) have gained increasing attention as essential measures to mitigate resource depletion, supply risks, and environmental impacts

In hydrometallurgical recovery of LIB metals, ion exchange (IX) has hitherto played only a minor role. Separation experiments were conducted in single laboratory-scale IX columns with the aim of laying the foundation for a continuously operated multicolumn IX process similar to a simulated moving bed (SMB) configuration. In this study, the initial process developed earlier was improved by reducing

Copper isotopic fractionation (in δCu) and leachate characterization were studied in the context of heap leaching at the Tschudi copper mine in northern Namibia. The leached solution is of Mg-SO type with high Al and Fe concentrations. The source of Mg and Al in the leachate can be from the alteration of micas such as Mg-bearing muscovite confirmed by X-ray diffraction and scanning electron microscopy;

Cyanidation has long served as the industrial standard in the gold industry, necessitating heightened attention to cyanide management owing to its inherent toxicity. This study developed a novel MnO-assisted thiocyanate leaching system as an alternative to cyanide. The sample was generated from a refractory gold concentrate processed by roasting, containing 54.4 g/t gold with iron oxide and quartz

In-situ leaching is essential for mining rare earth elements (REEs) from ion-adsorption rare earth (RE) ores. The efficiency of RE mining is dependent on the permeabilities of ion-adsorption RE ores, and the permeabilities are controlled by their pore structures. However, the current understanding of the pore structures and permeabilities of the RE ores during leaching is limited, particularly their

Given the limitations of current processing methods and the potential of high recovery of silver as a flotation concentrate, this study proposes a pre-oxidation followed by oxygen pressure sulphuric acid leaching route for zinc, copper and indium and thoroughly examines the alteration in micro-morphology of the silver concentrate of 1.22% Pb, 3010 g/t Ag and 649 g/t In. Under the optimal conditions

Alpha titanium bis(hydrogenphosphate) monohydrate, α-Ti(HPO)·HO, (α-TiP) is a precursor material utilized to obtain a broad range of important compounds having a great deal of applications ranging from ion-exchange chromatography, chemical catalysis to energy storage materials. The novel synthetic procedure developed in this study shows a higher conversion of titanium in ilmenite to α-TiP with a good

Cesium is an important strategic resource, and solvent extraction is the most frequently used technology for its extraction from various minerals and brines. However, this common method faces operational and cost problems owing to large alkali consumption. A synergistic extraction system consisting of 4--butyl-2-(α-methylbenzyl) phenol (t-BAMBP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) was designed

Efficient separation of lithium from alkaline solution with high Na/Li ratio is of great importance for the development of batteries for new energy industry. This work proposes the use of a novel extraction system composed of ethylhexyl salicylate (ES) and trialkylphosphine oxide (TRPO). The equilibrium experiment revealed that the order of metal ions extracted by ES/TRPO extraction system is Mg > Ca > Li > Na > K

Bayan Obo mixed rare earth (RE) concentrate is one of the most significant rare earth mineral resources worldwide. However, the concentrated sulfuric acid roasting method, which is commonly used to treat ores, generates pollutants such as waste gas, wastewater, and leach residue, resulting in the squandering of the associated resources. This paper introduces a green process involving selective mineral

There are two well-defined processes for the types of copper ores. One for the processing of copper sulfides and another for the processing of the copper oxides. There are similarities between the two, particularly in the preparation stage of the run of mine (ROM) such as the crushing. However, significant differences exist in how to concentrate the elements of interest. Flotation is the most used

Base metal hydrometallurgy in a chloride medium has considerable advantages, as metals can be recovered by solvent extraction through a neutral complex mechanism without extra reagent addition, leading to ready lixiviant recycling and significantly reduced wastewater discharge. However, the recovery of Ni(II) using this hydrometallurgical method is challenging because of the unavailability of appropriate