Manganese-containing anode sludge is a common side-product in the electrowinning of zinc. The anode sludge consists mainly of oxidized manganese, but also lesser amounts of lead, calcium, and other minor metals. The impurities present in the anode sl...
This study investigates the desulfurization and smelting reduction processes of zinc leaching residue and analyzes the kinetics of the desulfurization and smelting reduction processes of zinc leaching residue. The results showed that, when the desulf...
The low-cost Fe(II) reductants used in the leaching of pyrolusite usually cause high concentrations of iron ions in the leaching solution, which are difficult to treat and recover. Herein, a green cyclic leaching process for pyrolusite with recycling...
The reductive leaching of manganese from a low-grade manganese oxide ore was investigated by using pretreated sawdust as the reductant in a sulfuric acid medium. The effects of stirring speed, liquid/solid ratio, sawdust/ore mass ratio, sulfuric acid...
The processing of Cu, Co, and Zn at the Boleo project in Mexico involves two-stage (oxidation–reduction) leaching to extract a total of 85–88% Cu in 4 h. The first stage is an oxidation leaching using sulphuric acid (120 kg/tonne ore) at an Eh of 900...
Cyanide tailings are the hazardous waste discharged after gold cyanidation leaching. The recovery of gold and iron from cyanide tailings was investigated with a combined direct reduction roasting and leaching process. The effects of reduction tempera...
The calciothermic reduction slag (CRS) generated in heavy rare earth metal production, is rich in rare earth elements (REE) and highly amenable to recovery. In the present study, the CRS was treated with a H2SO4 roasting–water leaching method f...
The sodium leaching ratio (ηN) of ferric bauxite direct reduction process is much lower than that of ordinary bauxite; thus, the former consumes more sodium than the latter. ηN can be promoted by increasing the dosage of sodium or restricted by incre...
Red mud is a by-product of alumina production, which is largely stored in landfills that can endanger the environment. Red mud, or bauxite residue, is a mixture of inorganic compounds of iron, aluminum, sodium, titanium, calcium and silicon mostly, a...
Enhancing cobalt recovery from complex low-grade copper–cobalt oxide ores represents a pressing industrial challenge in the Democratic Republic of the Congo (DRC). This study comparatively examined the sulfuric acid leaching behaviors of two co...
Methane produced from paddy fields has a negative impact on global climate change. However, the role of soil bacterial community composition in mediating methane (CH4) emission from waterlogged paddy soil using the column experiment is poorly known....
The growing demand for lithium, driven by its crucial role in energy storage technologies such as lithium-ion batteries for electric vehicles, renewable energy storage, and portable electronics, is intensifying the need for sustainable extraction met...
The reduction roasting ammonia leaching process (RRAL) originally defined by Caron (1950) has been extensively applied to treat low grade nickel laterite and a large amount of slag-containing some valuable metals, has been generated and accumulated o...
Sustainable utilization of Bauxite Residue (BR) is currently one of the greatest challenges being tackled by the alumina industry, due to its high production rates and limited reuse options. The present work is concerned with the use of BR as a candi...
The Bayer process is the main method of alumina production worldwide. The use of low-quality bauxites for alumina production results in the formation of a significant amount of technogenic waste—bauxite residue (BR). The Bayer reductive method...
Near-complete (>99%) dissolution of lithium and cobalt was achieved by the leaching of black mass from spent (end-of-life) lithium-ion batteries (LiBs) using 4 M H2SO4 or HCl at 60 °C. Raising the temperature to 90 °C did not increase the...
Bioleaching has been regarded as a green alternative to chemical leaching in metal extraction processes. In this study, the bioleaching properties of indigenous acidophilic bacteria for various sulfide minerals were compared and evaluated in terms of...
The use of reduction leaching in the production of alumina from bauxite by the Bayer process in order to decrease the amount of waste (bauxite residue) by adding elemental iron or aluminum, as well as Fe2+ salts and organic compounds in the stage of...
The Bayer process is used to extract alumina from bauxite, resulting in the formation of a highly alkaline solid residue known as bauxite residue (BR). However, such residue contains insufficient iron (<35% Fe) and complex impurity composition for...
The paper describes hydrometallurgical methods to recycle wastes of vanadium pentoxide chemical fabrication. Sludges containing a significant amount of V2O5 can be considered as an additional source of raw materials for vanadium production. We studie...
In Switzerland, waste wood fly ash (WWFA) must be treated before deposition on landfills due to its high pollutant load (Cr(VI) and heavy metals). Acid fly ash leaching, the process used for heavy metal recovery from municipal solid waste incineratio...
Manganese dioxide is typically reduced to a bivalent state before being extracted; here, sulfur is considered an efficient reductant and sulfur–based reduction has been industrialized in China. In this study, the reaction mechanism between MnO2...
Reductive leaching in the Bayer cycle using iron (2+) allows for Al extraction to be significantly increased through the magnetization of Al-goethite and Al-hematite. However, the use of expensive iron (2+) salts or iron powder as a source of iron (2...
Red mud is a hazardous waste of the alumina industry that contains high amounts of iron, aluminum, titanium and rare-earth elements (REEs). One of the promising methods for the extraction of iron from red mud is carbothermic reduction with the additi...
The thermal treatment of lithium-ion batteries is an already industrially implemented process step in some recycling chains. It provides the advantages of controlled organic removal and conditioning of the black mass for further process steps, such a...
The features of uranium mining on Kazakhstan’s enterprises have been examined, and uranium deposits located in the Syrdarya and Shu-Sarysu depressions have been described. Actual and projected data on the development of technological blocks in...
The hydrogen reduction of bauxite residue lime pellets at elevated temperatures was carried out to recover iron and alumina from the bauxite residue in a new process route. Prior to the H2 reduction, oxide pellets were initially prepared via the mixi...
The high content of iron in ilmenite ore poses a great challenge, particularly in the synthesis of titanium-containing products due to high susceptibility of iron (Fe) to corrosion. Direct leaching of ilmenite ore in hydrochloric acid (HCl) encouragi...
The high contents of disadvantageous elements contained in non-woody biomass are known to cause problems during small and large scale combustion, typically resulting in a higher risk of slagging, corrosion, and increased emissions. Mechanically leach...
Remediation of Cr(VI)-contaminated soil usually includes reducing Cr(VI) to Cr(III) with sub-sequent solidification. In this paper, a treatment technique that combines reduction, adsorption, and solidification was proposed. By introducing an adsorben...
The growing demand for lithium-ion batteries (LIBs) has led to an urgent need for sustainable recycling strategies for spent cathode materials. In this study, a mechanochemical approach was developed for the recovery of lithium and cobalt from end-of...
In the process of rice cultivation, fertilizer reduction can effectively reduce the concentration of phosphorus (P) in overlying water and leaching water. In this study, the variation characteristics of P in overlying and leaching water under the con...
Ammonium thiosulfate leaching is a promising alternative to the conventional cyanide method for extracting gold from ores. However, strategies for recovering gold from the leachate are less commercially used due to its low affinity to gold. The prese...
Recovery of valuable metals from end-of-life cylindrical lithium-ion batteries (LiBs) by leaching using acetic acid in the presence of an organic reductant is a promising combination to overcome environmental concerns that arise from employing inorga...
Carbothermic reduction-roasting tests of NCM (nickel, cobalt, and manganese) cathode active materials with carbon sources such as activated carbon and graphite followed by sulfuric acid leaching were performed to investigate the effects of roasting t...
Coal is an abundant resource which can be used to produce low-cost energy; however, its usage causes great environmental damage. Before mineral coal can be used, it must be processed to remove coal tailings. These tailings contain pyrite and accumula...
Carbothermic reduction–magnetic separation and acid leaching processes were used to produce TiN and direct reduced iron (DRI) from titanomagnetite concentrates. The effects of sodium borate on the reduction behavior of TMCs, the magnetic separa...
The rare earth calcium thermal reduction slag (RCS) generated during the production of heavy rare earth metal contains large amounts of rare earth and fluoride compounds. In this study, rare earth elements (REEs) and fluorine in the RCS were recovere...
Waste Zn-Mn batteries represent a significant contributor to e-waste, which is typically a hazardous material. Furthermore, Zn-Mn batteries possess more valuable metals than primary ore minerals, making them a crucial secondary resource for Zn and Mn...
This research is focused on analyzing the environmental pollution potential of biomass bottom ashes as individual materials, as mixtures manufactured with biomass bottom ashes and granular construction aggregates, and these mixtures treated with ceme...
This article focuses on studying the phase transformation of bauxite iron minerals during electrolytic reduction processes in alkaline solutions (400 g/L Na2O), with the aim of improving aluminum extraction in the subsequent Bayer process. The resear...
The contents of Fe and SiO2 in ferric bauxite are much higher than that in regular bauxite, and the leaching yield of Al2O3 from ferric bauxite cannot reach the general level of ordinary ores, even under optimal conditions. This paper introduces a pr...
Lead refining dross containing plenty of tin and other heavy metals, such as lead and antimony, is considered a hazardous waste generated in large quantities in lead smelter plants. In this study, calcium stannate was synthesized from lead refining d...
A significant amount of livestock manure is generated in Bangladesh, creating challenges for sustainable manure management. Bioenergy and organic fertilizer production from manure are expected to provide opportunities for renewable resources, includi...
The use of lithium-ion batteries (LIBs) has increased in recent years. Thus, efficient recycling is important. In this study, the Taguchi method was used to find the optimal selective lithium leaching parameters for spent LIB recycling. Orthogonal ar...
Direct reduction is an emerging utilization technology of ferric bauxite. However, it requires much more sodium carbonate than ordinary bauxite does. The volatilization is one of the most significant parts of sodium carbonate consumption, as reported...
Phosphorene is a promising candidate as a membrane material additive because of its inherent photocatalytic properties and electrical conductance which can help reduce fouling and improve membrane properties. The main objective of this study was to c...
Iron oxides (hematite, Fe2O3, and magnetite, Fe3O4), previously used as electron mediators in the galvanic system with zero-valent aluminum (ZVAl), have been shown to recover Au upon cementation in Au–Cu ammoniacal thiosulfate media selectively...
The influence of ultrasound and microwaves on extraction of copper, nickel, and cobalt from manganese deep-sea nodules by reductive ammoniacal leaching in the presence of ammonium thiosulfate as a reducing agent was studied. The ultrasonic ammoniacal...
This study explores both pyrometallurgical and hydrometallurgical methods for decarbonizing and recovering valuable metals from bauxite residue, with hydrogen plasma reduction and direct acid leaching as the primary approaches. The goal is to offer i...
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