Experimental investigation of a new thermal energy storage system using thermo‐sensitive magnetic fluid and porous medium

In this paper, a novel thermal energy storage (TES) system based on a thermo‐sensitive magnetic fluid (MF) in a porous medium is proposed to store low‐temperature thermal energy. In order to have a better understanding about the fluid flow and heat‐transfer mechanism in the TES system, four different configurations, using ferrofluid as the basic fluid and either copper foam or porous carbon with different porosity (90 and 100 PPI, respectively) as the packed bed, are investigated experimentally. Furthermore, two thermal performance parameters are evaluated during the heat charging cycle, which are thermal storage velocity and thermal storage capacity of the materials under a range of magnetic field strength. It is shown that heat conduction is the primary heat‐transfer mechanism in copper foam TES system, while magnetic thermal convection of the magnetic fluid is the dominating heat‐transfer mechanism in the porous carbon TES. In practical applications in small‐scale systems, the 90‐PPI copper foam should be selected among the four porous materials because of its cost efficiency, while porous carbon should be used in industrial scale systems because of its sensitivity to magnetic field and cost efficiency.     

Experimental study and thermodynamic modeling of the Cu–Sn–Si–O system and sub-systems

Phase equilibria between slag, Cu–Sn alloy and solid oxide phases, SnO₂ (cassiterite) or SiO₂ (tridymite, cristobalite) are important for oxidizing fire refining of black copper produced during the recycling of copper scrap and waste electrical and electronic equipment. Integrated experimental and thermodynamic modeling study is presented for the Cu–Sn–Si–O chemical system and its sub-systems. Experimental technique involved high-temperature equilibration, followed by rapid quenching and direct measurement of Cu, Sn and Si concentrations in the liquid and solid phases using the electron probe X-ray microanalysis. Experimental results and literature data have been used to develop the thermodynamic database for the system. The database works within the environment of FactSage software, as well as ChemApp, ChemSheet and SimuSage. Combined with other assessments, it can be used to optimize and develop recycling processes using the black copper route.     

催化铁内电解法降低城市生活污水生化出水色度

研究了催化铁内电解法对城市生活污水生化出水色度去除的影响。喷淋式装置的水力停留时间2h,当铁铜比例为12∶1,出水色度值最低,基本都在10以下。当铁铜质量比为4∶1时,TN去除率可以达到10%以上;出水NO_3~-减少量最大,去除率大约为24.5%;NH_4~+的增加量可以达到3mg/L左右。     

MOF-derived PPy/carbon-coated copper sulfide ceramic nanocomposite as high-performance electrode for supercapacitor

To obtain a battery-type ceramic electrode material for supercapacitors, we used a metal-organic framework (HKUST-1) as a template to prepare ceramic material Cu₉S₈@C. Firstly, we adopted the calcination–vulcanization method to synthesize Cu₉S₈@C. Then we deposited it onto a carbon fiber cloth and employed it. Moreover, polypyrrole PPy/Cu₉S₈@C-CC nanocomposite electrodes were prepared via electrochemical deposition. By means of high-temperature calcination and vulcanization, the copper atoms of HKUST-1 were successfully transformed into Cu₉S₈ nanoparticles, and the organic ligand was carbonized into amorphous carbon in Cu₉S₈@C. The results showed that the PPy/Cu₉S₈@C-CC electrode presented a specific capacitance of 270.72F/g at a scan speed of 10 mV/s in a 1 M KCL aqueous solution. This value was much higher than that of Cu₉S₈@C-CC and Cu₉S₈-CC electrodes, as confirmed by the results of electrochemical test. At a scan rate of 10 mV/s, the capacitance retention rate for PPy/Cu₉S₈@C-CC after 3000 cycles was 80.36%, indicating its superior cycle characteristics. Moreover, PPy/Cu₉S₈@C-CC exhibited good frequency response. These results indicate that PPy/Cu₉S₈@C is an ideal electrode material for energy storage and conversion applications.     

Gas‐phase removal of indoor volatile organic compounds and airborne microorganisms over mono‐ and bimetal‐modified (Pt,Cu, Ag) titanium(IV) oxide nanocomposites

The photocatalytic deactivation of volatile organic compounds and mold fungi using TiO₂ modified with mono‐ and bimetallic (Pt, Cu, Ag) particles is reported in this study. The mono‐ and bimetal‐modified (Pt, Cu, Ag) titanium(IV) oxide photocatalysts were prepared by chemical reduction method and characterized using XRD, XPS, DR/UV‐Vis, BET, and TEM analysis. The effect of incident light, type and content of mono‐ and bimetallic nanoparticles deposited on titanium(IV) oxide was studied. Photocatalytic activity of as‐prepared nanocomposites was examined in the gas phase using LEDs array. High photocatalytic activity of Ag/Pt‐TiO₂ and Cu/Pt‐TiO₂ in the reaction of toluene degradation resulted from improved efficiency of interfacial charge transfer process, which was consistent with the fluorescence quenching effect revealed by photoluminescence (PL) emission spectra. The photocatalytic deactivation of Penicillium chrysogenum, a pathogenic fungi present in the indoor environment, especially in a damp or water‐damaged building using mono‐ and bimetal‐modified (Pt, Cu, Ag) titanium(IV) oxide was evaluated for the first time. TiO₂ modified with mono‐ and bimetallic NPs of Ag/Pt, Cu, and Ag deposited on TiO₂ exhibited improved fungicidal activity under LEDs illumination than pure TiO₂.     

磁性硅铁载铜吸附Hg0动力学机制及密度泛函研究

采用粉末冶金法将纳米单质铜(Cu⁰)、硅铁(FeSi)、四氧化三铁硅涂层(Fe₃O₄@SiO₂)混合煅烧并制备出新型磁性硅铁载铜吸附剂MagFeSi-Cu⁰。实验研究不同烟气温度下MagFeSi-Cu⁰的汞吸附能力基础上,结合颗粒内扩散模型、准二阶动力学模型、Elovich模型及Bangham模型分析了MagFeSi-Cu⁰吸附Hg⁰过程的主要控制步骤。在此基础上,依据密度泛函理论(DFT)研究了不同反应温度下FeSi表面Cu⁰原子与Hg⁰原子的汞齐作用机制。研究结果表明,Bangham模型的拟合值与MagFeSi-Cu⁰汞吸附实验值拟合度最高,MagFeSi-Cu⁰表面痕量Hg⁰吸附由汞的外扩散和表面铜汞齐吸附共同控制;通过密度泛函计算,发现Cu⁰颗粒表面Cu-Hg齐吸附能为-0.534 eV,当烟气温度从80℃上升至200℃时,Hg⁰原子与单质Cu原子的吸附自由能从-22.47 kJ/mol下降至-13.96 kJ/mol,这些结果为深入了解Hg⁰在Cu(111)表面的反应机理提供了理论基础。     

Encapsulation of Synthesized Plant Growth Regulator Based on Copper(II) Complex in Chitosan/Alginate Microcapsules

A new copper complex, trans-diaqua-trans-bis [1-hydroxy-1,2-di (methoxycarbonyl) ethenato] copper (abbreviation Cu(II) complex), was synthesized and its plant growth regulation properties were investigated. The results show a sharp dependence of growth regulation activity of the Cu(II) complex on the type of culture and its concentration. New plant growth regulator accelerated the development of the corn root system (the increase in both length and weight) but showed a smaller effect on the development of the wheat and barley root systems. Stimulation of corn growth decreased with increasing Cu(II) complex concentration from 0.0001% to 0.01% (inhibition at high concentrations—0.01%). The development of corn stems was also accelerated but to a lesser extent. Chitosan-coated calcium alginate microcapsules suitable for delivery of Cu(II) complex to plants were prepared and characterized. Analysis of the FTIR spectrum showed that complex molecular interactions between functional groups of microcapsule constituents include mainly electrostatic interactions and hydrogen bonds. Microcapsules surface exhibits a soft granular surface structure with substructures consisting of abundant smaller particles with reduced surface roughness. Release profile analysis showed Fickian diffusion is the rate-controlling mechanism of Cu(II) complex releasing. The obtained results give new insights into the complexity of the interaction between the Cu(II) complex and microcapsule formulation constituents, which can be of great help in accelerating product development for the application in agriculture     

The kinetics of copper corrosion in nitric acid

The strategy for the permanent disposal of high-level nuclear waste in Canada involves sealing it in a copper-coated steel container and burying it in a deep geologic repository. During the early emplacement period, the container could be exposed to warm humid air, which could result in the condensation of nitric acid, produced by the radiolysis of the humid air, on the copper surface. Previous studies have suggested that both nitrate and oxygen reduction will drive copper corrosion, with the nitrate reduction kinetics being dependent on the concentration of soluble copper(I) produced by the anodic dissolution of copper in the reaction with oxygen. This study focused on determining the kinetics of nitrate and oxygen reduction and elucidating the synergistic relationship between the two processes. This was investigated using corrosion potential and polarization measurements in conjunction with scanning electron microscopy and X-ray photoelectron spectroscopy. Oxygen reduction was shown to be the dominant cathodic reaction with the oxidation of copper(I) to copper(II) by nitrate, promoting the catalytic cycle involving the reaction of copper(II) with copper to reproduce copper(I).     

“双闪”铜冶炼工艺技术的发展

“双闪”铜冶炼工艺技术具有环境指标优越、综合能耗低、自动化程度高等优势，在中国得到广泛应用，目前中国已建成4个“双闪”铜冶炼厂，1个正在建设。通过对肯尼科特犹他冶炼厂、阳谷祥光铜业有限公司、铜陵有色金冠铜业分公司、广西金川有色金属有限公司、中铜东南铜业有限公司以及阳新弘盛铜业有限公司“双闪”铜冶炼工艺技术进行对比，研究了铜精矿干燥、铜精矿输送、闪速熔炼、冰铜粒化、冰铜制粉和输送、闪速吹炼、阳极精炼、残极处理以及烟气处理等工艺技术的发展情况，为“双闪”铜冶炼工艺技术的应用，以及未来的发展方向提供思路。