Extraction of copper from chalcopyrite with potassium dichromate in 1-ethyl-3-methylimidazolium hydrogen sulfate ionic liquid aqueous solution
Introduction
Chalcopyrite (CuFeS2), as one of the most abundant and important copper-bearing minerals worldwide, accounting for nearly 70% of known copper reserves (Toro et al., 2020, Wang et al., 2020, Wu et al., 2020). Currently, approximately 80% of world copper production was generated by pyrometallurgical routes, which include flotation, smelting, refining, and electrorefining (Agacayak et al., 2014, Phuong Thao et al., 2020, Sokić et al., 2009). However, although pyrometallurgy has achieved great success, its development is hampered by the tailings generated by flotation processes (approximately 151 tonnes for every ton of copper), the decline of copper grade and emissions of sulfur dioxide, which increasing the processing costs and causing environmental problems (Córdoba et al., 2008, Rodríguez et al., 2021, Wang et al., 2020, Zhong and Li, 2019). In this context, the hydrometallurgical process has received widespread attention as an effective and environmentally benign method of extracting copper from chalcopyrite, which consists of leaching, solvent extraction, and electro-winning (Velásquez-Yévenes et al., 2018, Wu et al., 2020, Zhao et al., 2019a, Zhao et al., 2019b).
In recent decades, many efforts have been devoted to hydrometallurgical leaching of chalcopyrite. The most often used leaching medias were acidic sulfate, acidic chloride, and basic ammonia solutions (Li et al., 2020). Nevertheless, despite the enhanced copper extraction to some extent, some disadvantages still exist. In acidic sulfate media, the kinetics of copper dissolution is generally slow (several months) and the copper recovery is always unsatisfactory, which were ascribed to the generation of the passivation layer over chalcopyrite particles’ surface under oxidative conditions, such as iron precipitate (e.g. jarosite) and elemental sulfur (Li et al., 2013). Moreover, leaching of chalcopyrite in sulfate media is often performed on autoclaves with high temperatures and high pressures at an industrial scale, which leads to huge energy consumption and high capital investment (Li et al., 2020). While for acidic chloride media, the copper dissolution rate is faster than that of sulfate solutions, due to the higher solubility of copper and iron in chlorite media and the oxidation behavior of Fe(III) ions and Cu(II) ions stabilized in concentrated chloride solutions. Moreover, the oxidation product of elemental sulfur instead of sulfate in chloride systems is beneficial to store and consume less neutralizing agent in the downstream process (Watling, 2014). However, the corrosivity of chloride media still poses a serious threat to equipment. And it is very difficult to manuscript high-grade copper from chloride systems by electro-winning (Li et al., 2020). Despite basic ammonia solutions can complex with cupric ions at alkaline pH and has the merit of selectively extracting copper, it has adverse health effects and is toxic to aquatic organisms even at low concentrations (Tanda et al., 2019). Besides, the evaporative loss and cost of ammonia also hindered its commercial implementation (Kartal et al., 2020). In this case, all leaching medias mentioned above have their limitations, it is a big challenge to develop new and sustainable lixiviants for copper extraction from chalcopyrite. Recently, ionic liquids (ILs) are emerged as “green agents” to replace traditional solvents and have been extensively applied in hydrometallurgy technologies for the leaching, recovery, and purification of metal ions (Quijada-Maldonado et al., 2020, Rodríguez et al., 2020, Tian et al., 2010). However, ionic liquid also has some disadvantages with respect to sulfuric acid or other leaching system, such as expensive price and high viscosity (Quijada-Maldonado et al., 2020). Choosing appropriate solvents and synthesis methods, especially large-scale synthesis methods to prepare ionic liquids, and recycling ionic liquid systems can greatly reduce the production cost of ionic liquids. (Quijada-Maldonado et al., 2020, Zhang et al., 2009).
Ionic liquids, which are salts composed of particular organic/inorganic anions and organic cations, are liquids at or near ambient temperature and have some excellent properties, such as good thermal stability, recyclability, wide electrochemical window, low vapor pressure and low flammability (Rodríguez et al., 2020, Seddon et al., 2000, Tian et al., 2021). In recent years, ILs has been widely reported to be an effective leaching agent for recovery of copper from copper sulfide minerals (Anggara et al., 2019, Hu et al., 2017), brass wastes (Kilicarslan et al., 2014), and waste printed circuit boards (Huang et al., 2014) as their acidic nature and water solubility. For example, McCluskey et al. (2002) studied the dissolution of chalcopyrite with Fe(BF4)3 in 1:1 water:1-Butyl-3-methyl-imidazolium tetrafluoroborate ([BMIm]BF4) solution and found an available copper extraction of 90% was achieved after 8 h at 100 °C. Whitehead et al. (2007) reported that 1-Butyl-3-methyl-imidazolium hydrogen sulfate ([BMIm]HSO4) media exhibited markedly better copper extraction performance than that of classical sulfate-ferric system with the dissolution rates increasing from 55.7 to 86.6% as the [BMIm]HSO4 composition increased from 10 to 100% w/w. Kuzmina et al. (2017) compared the leaching efficiency of chalcopyrite with various ILs media based on ethylammonium and imidazolium cations and hydrogensulfate, acetate, nitrate, or dicyanamide anions, and concluded that [BMIm]HSO4 exhibited the best leaching performance. Aguirre et al. (2016) analyzed the effect of chloride and sulfuric acid concentration, temperature, and IL concentration on the recovery of copper from chalcopyrite with [BMIm]HSO4 as a leaching agent. The authors obtained the highest recovery under the optimal copper extraction conditions of 90 °C, 100 g/L chlorides, and 20 vol% of [BMIm]HSO4 in water. All aforementioned studies imply that ionic liquid is a promising green medium for chalcopyrite leaching.
Chalcopyrite is one of the most refractory minerals in acid media due to its exceptional stable electronic structure and superficial chemical transformations, which could generate stable, compact, and electrically resistive passive layers (Ruiz-Sánchez and Lapidus, 2017). For this reason, numerous leaching tests were performed by using various oxidizing agents in acidic media, such as hydrogen peroxide (Mahajan et al., 2007, Turan and Altundoğan, 2013), potassium dichromate (Aydogan et al., 2006), ammonium persulfate (Turan et al., 2015), ferric ion (Kocaman et al., 2016, Mohammadabad et al., 2016), potassium nitrate, sodium chlorate, and hypochlorous acid (Shiers et al., 2016). Among them, potassium dichromate is known to be a strong oxidant and has been widely used to deal with chalcopyrite (Aydogan et al., 2006), pyrite (Chojnacka et al., 2007), copper converter slag (Altundogan et al., 2004, Boyrazli et al., 2006), millerite (NiS) (Mulak, 1983) and Ni3S2 (Mulak, 1992) in acidic solutions. However, to the best of our knowledge, leaching of sulfide mineral with potassium dichromate in ionic liquid media are rarely reported. In this work, we proposed a hydrometallurgical process for copper extraction from chalcopyrite in ionic liquid media with potassium dichromate as an oxidant. In this regard, the effects of temperature, concentration of K2Cr2O7 and ILs, stirring speed, and particle size on chalcopyrite dissolution were exhaustively investigated. Besides, the leaching kinetics to explain the reaction mechanism has also been investigated.
Section snippets
Materials
The Chalcopyrite mineral used in this study was obtained from Dongchuan Copper Mine (Yunnan, China). The mineral was ball milled and dry sieved into various size fractions (–45, +45–75, +75–150, and +150–300 μm). The [OMIm]HSO4, [HMIm]HSO4, [BMIm]HSO4, [EMIm]HSO4, [BMIm]BF4, [BMIm]PF6, [BMIm]CF3SO3 and [BMIm]NTf2 ILs were purchased from Lanzhou Institute of Chemical Physics. Potassium dichromate (Guangzhou pharmaceuticals) used in this study was analytical reagent and without any further
Influence of the anion and cation on chalcopyrite leaching in ionic liquids
Ionic liquids possess different physical and chemical properties with different types of anions and cations, which could affect the leaching behavior of chalcopyrite. To study the influence of ionic liquids on non-oxidative chalcopyrite leaching, five kinds of ionic liquid with same [BMIm]+ cation and different anions (HSO4-, BF4-, PF6-, NTf2-, and CF3SO3-) was chosen to study the influence of anion on leaching in ionic liquids, and four kinds of ionic liquid with same HSO4- anion and different
Conclusions
In this study, a hydrometallurgical process for copper extraction from chalcopyrite in [EMIm]HSO4 aqueous solution with potassium dichromate was developed. The most effective ionic liquids medium for chalcopyrite dissolution was varied with the specific oxidant. The main findings are the following:
Copper extraction from chalcopyrite in [EMIm]HSO4-K2Cr2O7 leaching system is closely related to the temperature, the particle size of chalcopyrite, as well as concentrations of ionic liquids and K2Cr2O
CRediT authorship contribution statement
Junxian Hu: Data curation, Investigation, Methodology, Validation, Writing–original draft. Futing Zi: Investigation, Supervision. Guocai Tian: Conceptualization, Supervision, Funding acquisition, Project administration, Resources, Formal analysis, Writing–review & editing.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
This work was supported by the National Natural Science Foundation of China (51774158, 51264021) and the Department of Science and Technology of Yunnan Province (2011HR013).
References (60)
- et al.
Leaching of chalcopyrite (CuFeS2) with an imidazolium-based ionic liquid in the presence of chloride
Miner. Eng.
(2016) - et al.
A study on the sulphuric acid leaching of copper converter slag in the presence of dichromate
Miner. Eng.
(2004) - et al.
Dissolution kinetics of chalcopyrite in acidic potassium dichromate solution
Hydrometallurgy
(2006) - et al.
Ionic liquids as additives for acid leaching of copper from sulfidic ores
Hydrometallurgy
(2016) - et al.
Treatment of copper concentrates containing chalcopyrite and non-ferrous sulphides by the BRISA process
Hydrometallurgy
(2004) - et al.
Leaching of chalcopyrite with ferric ion. Part II: Effect of redox potential
Hydrometallurgy
(2008) - et al.
Peroxodisulfate assisted leaching of chalcopyrite
Hydrometallurgy
(2012) - et al.
Leaching of chalcopyrite with Brønsted acidic ionic liquid
Hydrometallurgy
(2009) - et al.
Leaching behaviour of sulphides in ammoniacal thiosulphate systems
Hydrometallurgy
(2002) - et al.
Kinetics and mineralogical analysis of copper dissolution from a bornite/chalcopyrite composite sample in ferric-chloride and methanesulfonic-acid solutions
Hydrometallurgy
(2019)
Leaching of chalcopyrite with hydrogen peroxide in 1-hexyl-3-methyl-imidazolium hydrogen sulfate ionic liquid aqueous solution
Hydrometallurgy
Leaching behavior of copper from waste printed circuit boards with Bronsted acidic ionic liquid
Waste Manage.
Enhancing chalcopyrite leaching by tetrachloroethylene-assisted removal of sulphur passivation and the mechanism of jarosite formation
Hydrometallurgy
A review of the structure, and fundamental mechanisms and kinetics of the leaching of chalcopyrite
Adv. Colloid. Interfac.
Enhanced leaching of copper from chalcopyrite in hydrogen peroxide–glycol system
Miner. Eng.
Kinetics of dissolution of synthetic millerite (β-NiS) in acidic potassium dichromate solutions
Hydrometallurgy
Kinetics of dissolution of Ni3S2 in acidic potassium dichromate solutions
Hydrometallurgy
Leaching of chalcopyrite with hydrogen peroxide in hydrochloric acid solution
Trans. Nonferrous Met. Soc. China
Redox potential-dependent chalcopyrite leaching in acidic ferric chloride solutions: Leaching experiments
Hydrometallurgy
Possibilities and challenges for ionic liquids in hydrometallurgy
Sep. Purif. Technol.
Study of chalcopyrite leaching from a copper concentrate with hydrogen peroxide in aqueous ethylene glycol media
Hydrometallurgy
Copper extraction from chalcopyrite: Comparison of three non-sulfate oxidants, hypochlorous acid, sodium chlorate and potassium nitrate, with ferric sulfate
Miner. Eng.
Kinetics of chalcopyrite leaching by sodium nitrate in sulphuric acid
Hydrometallurgy
The kinetics of chalcopyrite leaching in alkaline glycine/glycinate solutions
Miner. Eng.
Application of ionic liquids in hydrometallurgy of nonferrous metals
Trans. Nonferrous Met. Soc. China
Dissolution of pure chalcopyrite with manganese nodules and waste water
J. Mater. Res. Technol.
Optimization of the leaching conditions of chalcopyrite concentrate using ammonium persulfate in an autoclave system
J. Taiwan Inst. Chem. E.
Pressure leaching of chalcopyrite with oxalic acid and hydrogen peroxide
J. Taiwan Inst. Chem. E.
Leaching of chalcopyrite ore agglomerated with high chloride concentration and high curing periods
Hydrometallurgy
Chalcopyrite hydrometallurgy at atmospheric pressure: 2. Review of acidic chloride process options
Hydrometallurgy
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