This work describes the processing of a monazite concentrate containing iron mineral phases in order to recover the rare earth elements (lanthanum was taken as representative for REEs) with minimum iron interference. Three classical routes were tested: acid leaching, alkaline conversion and acid baking. Control of iron bearing mineral phases was performed during REEs leaching. The most important variables

The extraction of rare earth elements (REEs) from rare earth fluoride molten-salt electrolytic slag has recently attracted attention because of the potential environmental hazards of this material and its rich content of valuable REEs. In this study, we used a selective nitration method to completely transform powdered samples into a nitrate mixture. We conducted a suitable selective roast-water leaching

Arsenic trisulfide (As2S3) is known as one of the possible precipitates in arsenic removal from metallurgical waste streams. The advantage of precipitation in the form of arsenic trisulfide is its high arsenic content (up to 61% theoretically). However, arsenic trisulfide is unstable, especially under alkaline and oxidizing conditions, which is a significant barrier to arsenic fixation in the form

Hydrometallurgy is considered a promising method to produce solar-grade silicon (SOG-Si) from metallurgical-grade silicon (MG-Si) due to its advantages of low cost, simple operation, and easy control. Researchers have investigated different hydrometallurgy techniques for impurity removal from MG-Si. This study systematically reviews hydrometallurgy techniques for the removal of impurities from MG-Si

In this study, a wet refining process for indium purification was developed aiming at the problem that the electrolysis refining method is difficult to remove cadmium, lead (Pb), and tin in indium, so as to reduce the energy-consuming and time-consuming process of smelting at the same time. The original electrolyte made by crude indium (99%) is co-precipitated to remove lead and pre-electrified to

Two extractants, N,N′-((octylazanediyl)bis(ethane-2,1-diyl))dioctanamide (LI) and N,N′-((octylazanediyl)bis(ethane-2,1-diyl))di-2-methylheptanamide (LII), have been synthesised in two steps starting from diethylenetriamine and involving a peptide coupling step. The efficiency and selectivity of the extractants in dodecane/octanol (95/5 v/v) toward the extraction of uranium from sulfate media have been

As hazardous materials, jarosite residues pose severe challenge to the environment due to the presence of coexistent metals. Although acid washing conducted in the industrial process could recover acid extractable metals, a significant amount of strongly surface-bound, entrapped, and lattice-incorporated metals in jarosite residues could not be extracted easily. Fe(II) has received increasing attention

The oxidative decomposition of thiosulfate is one the main problems found in the thiosulfate leaching of precious metals. This work presents a detailed analysis of the effect of different dissolved components on the silver sulfide dissolution kinetics and efficiency faced by the thiosulfate-citrate‑copper-ammonia system. The analysis comprises the quantification of thiosulfate concentration; furthermore

In this study, the synergistic solvent extraction of lanthanide(III) with mixtures of di-(2-ethylhexyl)phosphoric acid (D2EHPA, H2A2) and monoisodecyl phosphoric acid (MIDPA, H2B2) in phosphonium-based ionic liquid was investigated from amide acid medium. The method of slope analysis was used for the determination of the extraction reaction. In the case of D2EHPA or MIDPA single extractant system,

A series of ex-situ precipitation experiments were firstly performed to investigate the effects of Eh/pH and impurity molar ratio on the transition of arsenic bearing precipitates from amorphous phase to crystalline phase. Based on the analyses of the ex-situ experiments, another series of in-situ precipitation experiments were designed and conducted to explore the effects of current density, circulation

Arsenic removal from metallurgical waste streams in the form of arsenic trisulfide (As2S3) is promising due to its high arsenic content. However, the major barrier to widely implementing the sulfidization process is the stability of arsenic trisulfide. Our previous study has shown that the release rate of arsenic and sulfur increased with pH, the dissolved oxygen concentration, and temperature. The

E-waste has become a global risk to the environment and humans due to the improper disposal. Recently, a novel approach has been reported to effectively extract copper (Cu) from waste printed circuit boards (WPCBs) using environmentally friendly glycine solutions, with the co-extraction of other base metals. This process step is ideally positioned after the bulk of the aluminium, copper and iron is

This study investigated the pressure leaching of lithium and other valuable metals from lepidolite using NaOH and Ca(OH)2. The findings showed that NaOH concentration, temperature, and stirring rate are the most significant process parameters. The addition of Ca(OH)2 facilitates the leaching of lithium and minimizes the concentration of silicate and fluoride in the leach liquor by forming solid phases

The calcification‑carbonation method is a novel technology recovering Na2O and Al2O3 from bauxite residue through mineral transformation, which realizes the harmless treatment of bauxite residue simultaneously. It is mainly realized by two key transformation steps such as calcification transformation and carbonation transformation of the slag phase, and multiple wet process series steps. In this paper

Lepidolite is an important mineral resource of lithium, rubidium and cesium. Lithium, rubidium and cesium were extracted simultaneously from a lepidolite concentrate by sulfuric acid baking and water leaching. A crystallization-roasting-dissolution-solvent extraction process was developed to recover cesium from the leach solution in this study. During crystallization, leach solution was cooled from

The main sulphide minerals that serve as gold carriers in low-grade raw materials are pyrite and arsenopyrite. Traditional methods of processing such refractory raw materials rely on high-pressure or pyrometallurgical oxidisation, which destroys the crystal lattice of sulphides and releases gold particles. An alternative method of oxidation is leaching with nitric acid. The study examined the kinetics

This paper discusses the removal of arsenic scorodite from the gold ore. Kinetic studies on the possibility of removal of arsenic in a compact shape of arsenic sulfide were carried out, which occupies a small volume. The reagent reaction order and activation energy are calculated. The limiting stage of the process occurred in the intradiffusion region, i.e. the rate of the process limits the diffusion

In this study, the effect of using strong oxidants with alkaline glycine solutions on the leach rate and recovery of gold was studied in the absence of cyanide. Prior research indicated that when using only alkaline glycine and air at ambient temperature in the absence of catalysts, leaching times would be too long for conventional agitated tank leaching of ores. The ores used in this study were from

Chile is host to one of the most considerable Cu resources in the world. The primary source of Cu is from porphyry deposits. However, associated “exotic-Cu” deposits are also significant in the Atacama Desert of northern Chile. The critical processing issue for these ores is that they are refractory to dissolution under acidic and oxidative conditions, and consequently their dissolution kinetics are

Lithium carbonate is the primary product of the lithium extraction process and is an important compound for the battery making industry. A major step in the conventional sulfuric acid extraction of lithium from mineral ore is the precipitation of lithium carbonate from lithium sulfate media by sodium carbonate addition. Because of the high solubility of lithium carbonate in water and challenges with

Under the advocacy of the sustainable development concept, the extraction process and reaction mechanism for arsenic in alkaline solution were studied with the aim of optimizing the alkaline leaching process of high‑arsenic copper smelting ash and promoting the recovery and harmlessness of arsenic. At 25 °C, the extractant methyltrioctylammonium underwent 6–8 conversions of Na2CO3 solution with a concentration

In this paper, trioctylphosphine oxide (TOPO) was combined with some environmental-friendly molecules to form hydrophobic deep eutectic solvents (HDESs) for platinum (Pt) extraction from secondary resources. Due to the formation of HDESs, the loss of TOPO content in the aqueous solution obviously decreased. Then, the extraction behaviors under different vibrating time, acidity and salinity (NaCl/NaBr)

Bauxite residue (red mud) is a promising anthropogenic source of scandium because only at the aluminum plants of Ural region (Russia) nearly 150 tons of this trace metal appears in the waste dumps annually. This work describes a method of red mud carbonization by carbon dioxide that results on the one hand to scandium leaching and on the other hand decrease of toxicity of the red mud due to conversion

In this paper, as an alternative to the traditional extraction systems, multicomponent biphasic solvent systems used in liquid-liquid chromatography are suggested for application in hydrometallurgy. Three-component biphasic solvent system (1:1:1) consisting of water, hexane, and isopropyl alcohol was tested for the extraction of lanthanides(III) from chloride and nitrate media by adding different extractants

Niobium and tantalum have a wide range of application in various industries such as steel and electronic industry. The conventional tributyl phosphate based solvent extraction process for producing pure niobium and tantalum generates solid waste which is a mixture of fluoride with other anions like sulphate, chloride and acetate. This waste has no industrial application and requires effective disposal

The objective of this study is to increase the gold recovery from the gold ore heaps of Uşak Kışladağ Gold Company adding nut shell as percolation enhancer. In the first step of this study, bottle roll experiments were carried out on the ore sample crushed below 18 mm, 10 mm, 2.36 mm and 74 μm. Gold recovery values obtained for bottle roll tests were 53%, 55%, 65% and 85% respectively for the particle

Ongoing research to develop a new generation of materials to achieve a more reliable and higher energy density lithium-ion batteries has attracted working groups attention worldwide in academia and industry. Products like lithium carbonate or lithium hydroxide are fundamental as the main feedstock for future materials. Recently, metal-atom substituted cathode materials with various metals has proved

To alleviate the energy consumption and the effluent of traditional oxidizing roasting and leaching process of vanadium extraction, a novel method to extract the vanadium from iron vanadate spinel mineral (Fe3-xVxO4) by one leaching step was developed. In this method, the Fe powder was found as a synergist of oxalic acid to leach the vanadium as [V(C2O4)3]3− complex under hydrothermal condition. With

Recently, with the decrease in the quality of manganese resources, the efficient use of low-quality manganese ore resources has attracted widespread attention. At present, pyrite is often used as reducing agent to recover Mn(IV) in industrialization. However, the passivation of pyrite in the leaching reaction process will lead to a decreased reaction efficiency. Hence, in this study, microwave heating

In this paper, the potential-pH diagrams of Co-Cl-H2O/Co-C-Cl-H2O systems under the temperature of 25°C were drawn through the basic potential-pH principle with a number of thermodynamic data, and the predominant area of Co(OH)2/CoCO3 in the Co-Cl-H2O/Co-C-Cl-H2O systems which existed stably in the agueous solution were obtained. According to the potential-pH diagram of Co-Cl-H2O/Co-C-Cl-H2O systems

Iodine–iodide leaching is an effective and environmentally friendly gold extraction method that is expected to replace cyanidation. However, as the price of iodine is relatively high, for the industrial application of iodine–iodide leaching, decreasing the required amount of iodine is important to reduce production costs. In this study, persulfate was used to replace iodine as the oxidant for the extraction

Several (U1-xPux)O2±δ powders with different morphologies and different plutonium contents were synthetized using a sol-gel route. All the powders were fully characterized to quantify their structural parameters. After understanding and verification of the morphological effects on mixed oxide dissolution, this study consists of quantification of effect of plutonium content on dissolution kinetics using

There are a number of attempts to release and recover the valuable metals from spent refinery catalysts by bioleaching, and the heat pretreatment is widely used to remove the oil-like compounds for better bioleaching performance. However, the irrational selection of high calcinations temperature of 600–800 °C not only resulted in high energy consumption but also might be cause lower bioleaching efficiencies

In this study, a novel, efficient, and eco-friendly method is proposed to precipitate Cl− as BiOCl from MnSO4 electrolyte using (BiO)2SO4 as the chloride removal agent. The effects of different factors on the transformation and activation of Cl− removal agent, chloride precipitation, recovery and recycling, and purification processes were investigated. Increasing the L/S ratio could promote transformation

Titanium dioxide is an important material with a wide range of applications. Different methods and processes have been introduced and applied to produce pure TiO2 from available titanium ores and mineral sources. This paper describes the production of nano-sized titanium dioxide (TiO2) from ilmenite concentrate provided by the main Iranian Ilmenite processing complex. Ilmenite (FeTiO3) concentrate

This study investigates the influence of salinity on the bioleaching efficiency of a copper‑nickel‑cobalt bearing sulphidic tailing obtained from Golgohar iron ore desulphurization plant (Sirjan, Iran). The effects of several critical parameters including, suspension pH, nutrient medium, microorganism type, and pulp density were investigated on the extraction of copper, cobalt and nickel from the sulphidic

TSL flue dust is a waste residue, rich in Zn, generating from the pyrometallurgical process of Cu recycling and constitutes a potential raw material for ZnO production. In order to valorize this waste by introducing a novel process, its selective impurity removal by integrating different commercially viable hydrometallurgical technologies was investigated on both laboratory and pilot scale. Special

Zinc(II) was recovered from dilute ammoniacal media through an integrated process combining solvent extraction and electrolysis with ammonia stripping. Zinc ions were firstly enriched into organic phase at pH 7.56 through synergistic extraction between β-diketone and TBP or Cyanex 923. The concentration of extracted zinc(II) increased at pH < 7.56, but clearly decreased at pH 7.56–9.98. The extracted

The speciation of iron and arsenic species in DES media after electrodissolution of five different iron sulfide and arsenide minerals was determined via UV–Vis and EXAFS spectroscopy. Iron formed FeIII O-donor complexes, whilst arsenic formed cationic AsV-O-donor complexes. The ethylene glycol component of the DES was observed to play a role in the coordination of these species. The dissolution behaviour

The recovery of chromium from vanadium precipitated solution obtained by adding Ca(OH)2 into the chromium-containing vanadate solution and ball milling was investigated by precipitation with lead salt and leaching with sodium carbonate. It has been found that chromium can be effectively enriched by adding PbCO3. The precipitate is the mixture of PbCO3 and PbCrO4∙PbO. The concentration of Cr residue