Herein, the first-ever use of Fe2(SO4)3 solution as a leaching reagent to leach Zn from smithsonite under mechanical activation is reported. Thermodynamic calculations demonstrate that the leaching reaction's Gibbs free energy change is negative at ambient temperature and pressure (298.15 K, 100 kPa), implying the thermodynamic spontaneity and feasibility of the reaction. The feasibility assessment

A mixture of TBP and P507 was proposed for the separation of molybdenum (Mo) and tungsten (W) from iron (Fe) in a hydrochloric-phosphoric acid (HCl-H3PO4) solution that was obtained from the hydrochloric acid preleaching of low-grade scheelite. Various extractants with TBP were investigated, and P507 showed synergistic effects on Mo and W extraction and a strong antagonistic effect on Fe extraction

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

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

In this paper, the separation of tungsten and molybdenum by selective precipitation is evaluated, and the addition of cetyltrimethyl ammonium bromide (CTAB), as complex agent, is developed to reduce Mo loss. Thermodynamic equilibrium calculations show that manganese salt has selectivity to precipitate tungsten from molybdenum. Through single factor experiments, the influence of precipitation factors

Due to the high heavy and rare element contents, bauxite residue rejects (red mud) are simultaneously an ecological hazard and economic virtue. The abilities of two strains of Aspergillus niger isolated from pistachio husk and grape skin were investigated in the bioleaching of metals from the red mud produced in the Iran Alumina Company. Citric acid secretion (~15 g/l) by both strains was ten times

Jarosite is a harmful by-product of hydrometallurgical process and is categorized as hazardous waste due to the presence of heavy metals (Cu, Ni, Pd, etc.) in it. It is difficult to recycle these metals due to their complex phase structures. In this study, a facile and novel process for recovering metal values from jarosite in nickel hydrometallurgical process was developed. The jarosite was firstly

Molybdenum, a precious metal with important roles in industries, is projected to experience future shortage. Despite this, there is still no practical recycling process of this metal and around 25 thousand tons of molybdenum are discharged into wastewater annually. Biorecovery is a promising approach to resolve the above problem because of its high selectivity, high sensitivity, low running cost and

When gold was leached using copper ammonia thiosulfate solution, the dissolution rate of gold decreased as the leaching time increased. The dissolution of gold powder with 44 and 77 μm particles was studied，and the results indicated that the dissolution rate was not decreased by surface passivation or the decrease in copper concentration but by the changes of the electronic structure of the gold surface

The performance of bioleaching stirred tank reactors (STR) is related to the homogeneity of biomass, substrates and dissolved gases. This work was focused on the characterization of the impeller design on bioreactor hydrodynamics and, more specifically on power, mixing efficiency and particle stress. Few studies addressed the issue of the impact of the impeller design on these, especially for multi-stage

The consumption of lithium has been increasing rapidly due to its increasing application in lithium-ion batteries. The recovery of lithium from salt lake brines, which accounts for more than 70% of global lithium resources, has become increasingly studied; however, some challenges remain. In a previous study, a mixed ternary solvent extraction system consisting of TBP (tributyl phosphate), FeCl3 and

This paper presents an eco-friendly method for recovery of cadmium by solvent extraction and stabilization of arsenic through one-pool treatment on arsenic-rich flue dust. The morphology-controlled scorodite can be realized by adjusting reaction temperature. It is worth emphasizing that the arsenic-immobilized scorodite precipitates have superior crystallinity which exhibit excellent safety for long-term

Chalcopyrite leaching at moderate temperature exhibits slow kinetics due to surface passivation. The presence of iodine has been reported to significantly enhance copper dissolution from chalcopyrite in ferric sulfate media at ambient temperature. However, the key factors controlling the reaction rate and the mechanisms have not been well understood. This study quantified the effect of different parameters

Instead of conventional two or three-stage zinc dust cementation purification, one-stage purification was proposed to remove copper, cadmium and nickel as well as cobalt by CuSb activation simultaneously from solution for an electrolytic zinc production process under development by MMG Limited. Copper was rapidly removed, forming a porous copper shell around a zinc particle. The shell acted as a cathode

The mining of non-ferrous metals produces the largest volume of metal-containing, extractive waste in Europe, and about 29% of all the waste produced in the EU-28. In the framework of the European project NEMO (Near-zero-waste recycling of low-grade sulfidic mining waste for critical-metal, mineral and construction raw-material production in a circular economy), new ways to valorize sulfidic tailings

Boron removal from lithium-rich brine was systematically investigated by solvent extraction using 2,2,4-trimethyl-1,3-pentanediol (TMPD) dissolved in 2-ethylhexanol and sulfonated kerosene. The extraction parameters were determined, including the concentration of mixed alcohols, lithium and solvents loss. During the extraction, a single TMPD molecule reacted with a single boric acid molecule to form

A closed-loop, Ni extraction and mineral carbonation process is being developed for producing Ni from laterite ores, where the only inputs are heat that can come from regenerable resources, and the ore. This closed-loop relies on efficient regeneration of acid and base, which are required for leaching and neutralisation respectively. This contribution investigates the leaching efficacy of regenerated

Mining activities generate Acid Mine Drainage (AMD) and wastewater streams rich in dissolved inorganic species that negatively affect water quality. Conventional lime treatment of AMD leads to the precipitation of a voluminous sludge, comprising mainly of Ferri-Oxyhydroxide (Fe-O-OH) and gypsum, whose matrix renders it difficult to dewater. Such precipitates also show poor post-precipitation stability

In recent years, an increasing attention has been paid to the bioleaching of copper from waste computer motherboards. Here, we investigate the effect of humic acid on the bioleaching of waste computer motherboards using the mixed culture HQ0211. For this, the response surface methodology (RSM) is employed to investigate the effect of pulp density, initial pH and humic acid content on copper recovery

Present paper reports an application oriented approach to recover precious metals such as silver (Ag) and palladium (Pd) from multilayer ceramic capacitors (MLCCs) of waste printed circuit boards (PCBs). These capacitors are being widely used in modern electronic gadgets to provide advance features as well as to enhance their performance. Due to the generation of large amount of e-waste as well as

In this work is evaluated the bioleaching capacity of a bacterium isolated from a mine in Guanajuato, México, namely LR-1. The bacterium oxidized Fe2+ and S2O32− at acidic pH for its energy metabolism. This oxidant activity provided Fe3+ and/or protons that provoke sulfide ore dissolution. Five sulfide ore samples were obtained from different Mexican mines: Remedios, Guerrero, Bolañitos, Aldama, and

A novel leaching process has been reported in this paper to extract silver from silver-bearing residue, which was obtained by low-temperature roasting and sulfuric acid leaching of sphalerite direct leaching residue after sulfur separation. The silver in the silver-bearing residue primarily existed in the form of silver chloride by energy dispersive spectrometer (EDS) analysis. The extraction of silver

The mineralogical studies on Black mica raw material revealed the presence of notable high radioactive minerals such as uranium minerals (Soddyite, Uranophane, Uranothorite, and Ishikawaite), niobium - tantalum minerals (Columbite and Plumbopyrochlore), and rare earth elements minerals (Allanite, Xenotime, and monazite). From mineralogical and chemical studies make it possible to determine optimal

A large amount of waste rock, coal discards and coal fines result from the extraction and beneficiation of coal. These wastes may present a major environmental hazard. Exposure of their sulphidic mineral content, mainly pyrite, to moisture and oxygen causes acidic runoff or leachate from waste rock dumps, coal discard dumps and tailings facilities, referred to as acid rock drainage (ARD). Whereas sulphide

Biological sulphate reduction (BSR) represents a sustainable process option for the remediation of low-flow acid rock drainage (ARD) effluents. The linear flow channel reactor (LFCR) was developed as a semi-passive bioreactor facilitating sulphate reduction and sulphide removal, through the action of sulphate-reducing bacterial (SRB) and sulphur oxidising bacterial consortia, within a single reactor

The paper presents the conceptual separation process of lithium and cobalt(II) ions from aqueous solution using lanthanum enriched TiO2-ZrO2 hybrid material. The material was synthesized via modified sol-gel method and thoroughly characterized with respect to porous structure, morphology, chemical composition, nature of characteristic functional groups, crystallinity and electrokinetic behaviour. Furthermore

The formation and evolution of desilication products (DSPs) in synthetic sodium aluminate solution with different reaction temperatures, holding time, CaO additions and carbonate concentrations were investigated based on the Bayer process. The DSPs precipitated at 145 °C and 195 °C are mainly composed of hydrogarnet, tricalcium aluminate hexahydrate and zeolite, and the precipitation sequence is: tricalcium

Scattered and precious metals (SPMs: Se, Te, Au, Ag, Pt, and Pd) play an irreplaceable role in advanced methods and materials, and their global consumption has been growing in recent decades. However, SPM consumption and recycling are very unbalanced, resulting in a shortage of supply and some uncertain risk regarding their sustainability. Copper anode slime (CAS) is an important component of secondary

High-efficiency and good-selectivity extraction systems are very attractive in the solvent extraction process. A synergistic extraction of scandium (III) from a spent sulfuric acid solution of titanium dioxide production by using a mixture of bis-2-ethylhexyl phosphoric acid (D2EHPA, P204) and primary amine (N1923) has been proposed in this study. The effect of the molar fraction of N1923 in the mixed

Semi-passive sulphate reducing bioreactors show potential to play an important role in remediation of persistent, low volume acid or neutral rock drainage, characterised by high sulphate concentration. The hybrid linear flow channel reactor (LFCR) integrates biological sulphate reduction and partial sulphide oxidation within a single operating unit, allowing elemental sulphur recovery. Here, the impact

A pretreatment to remove and recover base metals present in complex sulfide refractory ores is proposed as a method to improve the extraction of precious metals with thiourea. Sodium citrate solutions at pH 8 and 5 were employed to extract lead and iron, respectively, from two concentrates: one having silver in a primarily galena matrix and the other, with gold associated with pyrite. The pretreatment

A two-stage chemical-biological oxidation approach, which applied a high temperature chemical oxidation stage prior to the bio-oxidation stage, was employed to accelerate the bio-oxidation rate of Axi gold concentrate with pyrite as the main sulfide phase. The extraction levels of Fe and S were 67.0% and 72.9% in the traditional one-stage bio-oxidation approach, while the values were elevated respectively

In this study, the enhanced extraction of zinc from a blast furnace dust (BFD) ammonia leaching solution via carbon dioxide (CO2) was investigated. 1-Benzoyl-2-nonyl ketone (commercially known as Mextral54–100) and tri-alkyl phosphine oxide (TRPO) were used as the extractant and synergistic extractant, respectively. The effects of different operational factors, such as the CO2 pressure, extractant

The interaction of gold cyanide complex with elemental sulphur and all metastable sulphur species has been studied using Density Functional Theory (DFT). The elemental sulphur and sulphide species formed during pre-treatment of refractory gold ores or dissolution of sulphide minerals form a series of metastable species including hydrosulphide, polysulphide, thionates, sulphite and finally sulphates

Most coal mines produce waste which has the potential to generate acid mine drainage (AMD). If not properly managed, this can cause environmental damage through contamination of ground and surface waters and soils for hundreds of years. At the same time, the pace of technological development means that most electrical and electronic equipment becomes obsolete within a matter of years, resulting in

In this study for the first time, a magnetic Fe3O4/MgAl-layered double hydroxide (LDH) nanocomposite was used as an adsorbent for recovery of gold and iridium from soils around the mining area. The morphological and structural properties of the obtained Fe3O4/MgAl-LDH was characterized by transmission electron microscopy, Brunauer-Emmett-Teller, scanning electron microscopy coupled with energy dispersive

Tungsten, considered a specialty metal, plays a remarkable role in the development of new tools for aerospace, defense, and other trending technological applications. However, due to its high supply risk index, extensive research on alternative sources for recycling has been conducted. In this contribution, the recovery of tungsten from spent electroless nickel solutions as a secondary metal source

This study systematically evaluated the separation performance of thorium, uranium, and rare earths when coal and coal byproduct were utilized as a non-traditional feedstock for rare earth production. A synthetic solution was prepared following the elemental composition of a strip solution generated from coarse coal refuse and used throughout the study. Various separation techniques including selective

Though many studies pertaining to heap leaching have been carried out to study the reaction kinetics in cylindrical columns, in the scaled up variants the extraction efficiency has not always complemented the laboratory expectations. Since heap leaching is a hydrometallurgical process, the reactions are contingent on the effective interactions between the two main phases (i.e. solid and the fluid)