Rapid development of electronic technique has led to decreasing lifespan of electronic products. Meanwhile, the amount of waste electrical and electronic equipment (WEEE) is rapidly growing in recent ...years especially in China. The generation amount of WEEE is one of the basic information for waste management. In our study, the generation of obsolete cellular phones and metals containing of cellular phones were estimated from 1997 to 2025. The future average possession in per 100 inhabitants of cellular phones was predicted using logistic model. Moreover, the lifespan distribution of cellular phones was analyzed using Weibull distribution. Meanwhile, the generation amount of obsolete cellular phones and its metals containing were estimated by using population balance model (PBM) and substance flow analysis (SFA), respectively. The estimated results indicate that the average possession in per 100 inhabitants will reach to 111.2 and 118.3 units in 2020 and 2025, respectively, which is about two times higher than the average possession in 2010. In addition, the total possession amount of cellular phones are expected to exceed 1.64 billion units in 2025. Moreover, the estimated results show that 781 million units obsolete cellular phones were generated in 2015, and the number will grow up to 877 and 937 million units in 2020 and 2025, respectively. In 2025, the total weight of annual generation amount of obsolete cellular phones will exceed 140Gg. The precious metals such as silver, gold contains in obsolete cellular phones will reach 56,250 and 28,130kg, respectively, in 2025. The obsolete cellular phones are the typical secondary metal resources especially for precious metals. In order to improve the recycling efficiency, it is necessary to establish a comprehensive system of waste management.
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•Future average possession and possession amount of cellular phones are predicted in China.•Generation amount of obsolete cellular phones in China from 1997 to 2025 are estimated.•The metals contain in obsolete cellular phones in China from 1997 to 2025 are analyzed.
High-capacity Ni-rich layered oxides are promising cathode materials for secondary lithium-based battery systems. However, their structural instability detrimentally affects the battery performance ...during cell cycling. Here, we report an Al/Zr co-doped single-crystalline LiNi
Co
Mn
O
(SNCM) cathode material to circumvent the instability issue. We found that soluble Al ions are adequately incorporated in the SNCM lattice while the less soluble Zr ions are prone to aggregate in the outer SNCM surface layer. The synergistic effect of Al/Zr co-doping in SNCM lattice improve the Li-ion mobility, relief the internal strain, and suppress the Li/Ni cation mixing upon cycling at high cut-off voltage. These features improve the cathode rate capability and structural stabilization during prolonged cell cycling. In particular, the Zr-rich surface enables the formation of stable cathode-electrolyte interphase, which prevent SNCM from unwanted reactions with the non-aqueous fluorinated liquid electrolyte solution and avoid Ni dissolution. To prove the practical application of the Al/Zr co-doped SNCM, we assembled a 10.8 Ah pouch cell (using a 100 μm thick Li metal anode) capable of delivering initial specific energy of 504.5 Wh kg
at 0.1 C and 25 °C.
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•Current status on pretreatment of spent Li-ion batteries is presented.•The spent Li-ion battery handling processes are reviewed.•The laboratory and industrial Li-ion battery ...pretreatment applications are reviewed.•This review provides a rundown of limitations that will help to do further research.
The production of lithium-ion batteries (LIBs) is increasing rapidly because of their outstanding physicochemical properties, which ultimately leads to an increasing amount of spent lithium-ion batteries reaching their end-of-life (EOL). Pretreatment of the discarded batteries is an indispensable part of recycling spent lithium-ion batteries. The batteries contain toxic chemicals and high-value metals that must be recycled to promote environmental protection and sustainability. This paper provides an overview of the current pretreatment methods employed in the recycling of spent LIBs. In particular, the article reviews various options (mechanical, chemical, and thermal pretreatment options) that can be adopted for the pretreatment of spent lithium-ion batteries and puts forward the recommendations for future research and development that will enable more efficient and cleaner technologies for recycling spent LIBs. The review emphasizes the safe pretreatment of the spent LIBs and provides an overview of the consequences of the individual pretreatment steps on the recyclability of the materials to be recovered, and LiCoO2 was chosen as the reference as most studies in the literature focus on LiCoO2 cathode materials. However, discussions on other battery chemistries have also been incorporated into the scope of the review.
This paper presents a dry grinding and carbonated ultrasound-assisted water leaching (CUAWL) process for recycling the black mass of spent lithium-ion batteries constituting anode material (graphite) ...and different cathode material combinations (LiCoO2, LiMn2O4, and LiNiO2). The inspiration of the method is to enhance selective Li2CO3 recovery and reduce energy requirements for evaporative crystallization while achieving maximum recovery of all the high-value metals. The influence of several factors, including roasting temperature, roasting time, grinding time, water leaching time, water leaching temperature, sonication, and CO2 flow rate, on the leaching efficiency of metals are investigated. The SEM-EDS and XRD results depict that the mixture of anode and cathode material after reduction roasting under optimum conditions of 600 °C for 30 min was primarily transformed into Li2CO3, Ni, CoO, Co, and MnO. However, the selective recovery of Li with water leaching was low, and dry grinding followed by CUAWL was adopted to enhance the recovery rate. The optimized experimental results achieved improved results for selective recovery of Li of up to 92.25% for the mixture of multiple cathode materials (LiCoO2, LiMn2O4, and LiNiO2). The recovered leach solution (LiHCO3) is subjected to evaporative crystallization to attain high-purity Li2CO3 (≥99.2%). Subsequently, over 99% of the high-value metals Ni, Mn, and Co could be leached out using 4 M H2SO4 without the addition of a reductant.
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Equilibrium, thermodynamic and kinetic studies were carried out for the biosorption of Pb
2+, Cd
2+ and Ni
2+ ions from aqueous solution using the grafted copolymerization-modified orange peel ...(OPAA). Langmuir and Freundlich isotherm models were applied to describe the biosorption of the metal ions onto OPAA. The influences of pH and contact time of solution on the biosorption were studied. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. According to the Langmuir equation, the maximum uptake capacities for Pb
2+, Cd
2+ and Ni
2+ ions were 476.1, 293.3 and 162.6
mg
g
−1, respectively. Compared with the unmodified orange peel, the biosorption capacity of the modified biomass increased 4.2-, 4.6- and 16.5-fold for Pb
2+, Cd
2+ and Ni
2+, respectively. The kinetics for Pb
2+, Cd
2+ and Ni
2+ ions biosorption followed the pseudo-second-order kinetics. The free energy changes (Δ
G°) for Pb
2+, Cd
2+ and Ni
2+ ions biosorption process were found to be −3.77, −4.99 and −4.22
kJ
mol
−1, respectively, which indicates the spontaneous nature of biosorption process. FTIR demonstrated that carboxyl and hydroxyl groups were involved in the biosorption of the metal ions. Desorption of Pb
2+, Cd
2+ and Ni
2+ ions from the biosorbent was effectively achieved in a 0.05
mol
L
−1 HCl solution.
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•A complete process of gold recovery from sulfide refractory gold ore was proposed.•The recovery efficiency of Au was increased by adding pyrite during the chlorination roasting.•The ...maximum recovery efficiency of gold reached 98.06% under optimal condition.
Recovering gold from sulfide refractory gold ore has been an important guarantee for the sustainable development of gold industry, while there are many challenges in the treatment of sulfide refractory gold ore, such as environmental pollution and low gold recovery. In this study, A novel method for gold recovery from refractory gold ore was proposed with the purpose of improving recovery efficiency of gold and reducing environmental pollution. The method consisted of two stages roasting for arsenic and sulfur removal, gold recovery by thiourea leaching, followed by an enhanced chlorination roasting for gold recovery in the presence of pyrite. In the two-stage roasting process, the phase transition of FeAsS and FeS2 during the roasting process was analyzed. In the first stage roasting process, the removal efficiency of arsenic reached 96.98% with only 43.07% sulfur was removed. We achieved removal efficiency of 97.19% for sulfur and 84.11% of gold was exposed during the second stage roasting process. The thiourea leaching combined with pyrite enhanced chlorination roasting was first proposed to effectively extract gold from the second stage roasting slag, and the pyrite shown a great role in promoting gold extraction during chlorination roasting. In this process, gold could be effectively recovered from the sulfide refractory gold ore with a recovery efficiency of 98.06%.
Orange peel (OP) was used as raw material to prepare two novel adsorbents: MgOP (Mg(2+) type orange peel adsorbent) and KOP (K(+) type orange peel adsorbent). FTIR and SEM were used to characterize ...the adsorbents. Effects of pH, solid/liquid ratio, time and metal ion concentration on the Cu(2+) adsorption by these two adsorbents were investigated. The isotherms data were analyzed using the Langmuir, Freudlich, Temkin and Dubinin-Radushkevich models. Langmuir model provides the best correlation for the adsorption of Cu(2+) by both MgOP and KOP, and the mono-layer adsorption capacity for Cu(2+) removal by MgOP and KOP are 40.37 and 59.77 mg/g, respectively. The adsorbed amounts of Cu(2+) increased with the increase in contact time and reached equilibrium within 20 min. The kinetics data were analyzed using four adsorption kinetic models: the pseudo-first and second-order equations, the Elovich equation and intraparticle diffusion equation. Results show that the pseudo-second-order equation fits the experimental data very well. Thermodynamic studies showed the spontaneous and exothermic nature of the adsorption of Cu(2+) by MgOP and KOP.
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•Liquid metal dealloying results in both chemical and structural changes of the alloy.•The applications of liquid metal dealloying for recycling alloy scraps are discussed.•A variety ...of nanoporous materials can be fabricated by liquid metal dealloying.•The morphology parameters of porous metal can be adjusted by dealloying conditions.
Liquid metal dealloying, a method of etching based on different solubilities of each component of the alloy into the liquid metal, has been extensively developed for metallurgical and structural materials applications. This review discusses the development on liquid metal dealloying for recycling alloy scraps and the fabrication of nano-porous materials. Extracting and recycling the valuable metal from alloy scraps by liquid metal dealloying can be more efficient and environmentally friendlier comparing to traditional alloy treatment processes for metal recovery. Manufacturing of nano-porous materials by liquid metal dealloying, not only can meet the need for efficient production of less noble metal nano-porous materials, but also can precisely control the morphology of the nano-pores by adjusting the dealloying conditions. This review demonstrates that liquid metal dealloying opens new avenues for the recycling of alloy scraps and for the fabrication of nano-porous metals, in addition to a wide variety of other promising applications.
An adsorbent, the chemically modified orange peel, was prepared from hydrolysis of the grafted copolymer, which was synthesized by interaction of methyl acrylate with cross-linking orange peel. The ...presence of poly (acrylic acid) on the biomass surface was verified by infrared spectroscopy (IR), scanning electron microscopy (SEM) and thermogravimetry (TG). Total negative charge in the biomass surface and the zeta potentials were determined. The modified biomass was found to present high adsorption capacity and fast adsorption rate for Cu (II). From Langmuir isotherm, the adsorption capacity for Cu (II) was 289.0
mg
g
−1, which is about 6.5 times higher than that of the unmodified biomass. The kinetics for Cu (II) adsorption followed the pseudo-second-order kinetics. The adsorbent was used to remove Cu (II) from electroplating wastewater and was suitable for repeated use for more than four cycles.
The high reactivity and poor machinability of titanium contribute to its high-cost fabrication, low material utilization rate, and large amount of titanium scrap production. Titanium scrap is mainly ...contaminated by oxygen and forms an oxygen-enriched layer on the surface of titanium. Oxygen has a deleterious effect on the ductility, toughness, and notch sensitivity of titanium but strengthens it. Traditionally, the contamination was removed by mechanical grinding and chemical acid cleaning. However, these processes generate substantial waste products and cause environmental problems. Deoxygenation is an alternative method for recycling of titanium and is critical when producing high-value powder products from the scrap. The typical deoxygenation technologies include thermochemical and electrolysis methods. This article mainly reviews the effect of oxygen on titanium and several deoxygenation technologies for recycling of titanium. The fundamental theory behind deoxygenation is included as well.
