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Recovery of vanadium and molybdenum from spent petrochemical catalyst by microwave-assisted leaching

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International Journal of Minerals,Metallurgy and Materials 2019年第1期26卷 33-40页

作者： Zhi-yuan Ma Yong Liu Ji-kui Zhou Mu-dan Liu Zhen-zhen Liu Guangdong Institute of Resources Comprehensive Utilization Guangdong Academy of Sciences State Key Laboratory of Separation and Comprehensive Utilization of Rare Metals Guangdong Provincial Key Laboratory of Development and Comprehensive Utilization of Mineral Resources

The study of the leaching of vanadium(V) and molybdenum(Mo) from spent petrochemical catalysts in sodium hydroxide(NaO H) medium was performed using two approaches, namely, conventional leaching and microwave-assisted leaching methods. The influence of microwave power, leaching time, leaching temperature, and NaOH concentration on the leaching efficiency of spent petrochemical catalyst was investigated. Under microwave-assisted conditions(600 W, 10 min, 90°C, 2.0 mol·L^(-1) NaOH, and 0.20 g·mL^(-1) solid–liquid ratio), the leaching efficiencies of V and Mo reached 94.35% and 96.23%, respectively. It has been confirmed that microwave energy has considerable potential to enhance the efficiency of the leaching process and reduce the leaching time. It is suggested that the enhancement of the leaching efficiencies of V and Mo can be attributed to the existence of a thermal gradient between solid and liquid and the generation of cracks on the mineral surface.

关键词： microwave spent petrochemical catalyst vanadium molybdenum

Fluid dynamics analysis and pyrolysis of brewer’s spent grain in a spouted bed reactor

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Particuology 2019年第1期17卷 199-207页

作者： Marcos A.S. Barrozo Lidja D.M.S. Borel Taísa S. Lira Carlos H. Ataíde School of Chemical Engineering Federal University of UberlandiaBrazil Department of Engineering and Technologies Federal University of Espirito SantoBrazil

Brewer’s spent grain (BSG) is a large-scale agroindustrial waste that could be more efficiently utilized. This waste is composed of lignocellulosic material and so may serve as a good source of biomass for thermochemical conversion. The present study investigated the fluid dynamics behavior of mixtures of sand and BSG in a spouted bed to assess the viability of the thermochemical conversion of this biomass via fast pyrolysis. Fluid dynamics analyses were performed while varying the mass fraction of BSG (6–80%) and the static bed height (6.6–13.4 cm). Empirical equations for predicting the minimum spouting conditions and the mixing index were obtained using a regression technique, and the selected fluid dynamics parameters were employed in the spouted bed pyrolysis. The bio-oil resulting from this process was rich in phenolic compounds, various nitrogenated compounds (representing precursors for pharmaceuticals) and long-chain hydrocarbons. The products obtained from the analytical and spouted bed pyrolysis processes were also compared.

关键词： Brewer’s spent grain Agroindustrial residue Spouted bed Fast pyrolysis Particle mixing

Mild oxidative degradation of spent auricularia auricular substrate and molecular composition of carboxylic acids in the resulting soluble portion

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Chinese Journal of Chemical Engineering 2020年第2期28卷 548-555页

作者： Xiaoli Xue Zhimin Zong Guanghui Liu XianyongWei Key Laboratory of Coal Processing and Efficient Utilization Ministry of EducationChina University of Mining&TechnologyXuzhou 221116China Key Laboratory of Changbai Mountain Animal and Plant Resource Utilization and Protection of Universities in Jilin Province Jilin Agricultural Science and Technology UniversityJilin 132101China State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering Ningxia UniversityYinchuan 750021China

spent auricularia auricular substrate(SAAS)was oxidatively degraded with aqueous hydrogen peroxide(AHPO)/acetic anhydride(AAH)to produce carboxylic acids(CAs)under mild conditions.The results show that up to 53.6%of the organic matter in SAAS was converted to the soluble species(SSs).In total 122 CAs were detected in the SSs by the analysis with a gas chromatograph/mass spectrometer,which can be classified into 29 group components,mainly being aliphatic acids and along with small amount of aromatic acids.Among the aliphatic acids,normal alkanedioic acids are the most abundant.The detected aromatic acids include benzoic acids,phthalic acids,trimellitic acids,pyromellitic acids,and their derivatives.The synergistic oxidation and the released·OH,CH3COO·,and HOO·induced by AHPO/AAH play crucial roles in oxidatively degrading SAAS.

关键词： spent auricularia auricular substrate Mild oxidation Aliphatic acids Aromatic acids

Enhancement of the nickel converter slag-cleaning operation with the addition of spent potlining

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International Journal of Minerals,Metallurgy and Materials 2018年第8期25卷 881-891页

作者： Dawei Yu Kinnor Chattopadhyay School of Metallurgy and Environment Central South University Canmet MINING Natural Resources Canada Process Metallurgy & Modelling Group Department of Materials Science and EngineeringUniversity of Toronto

The slag cleaning(or matte settling) process was experimentally investigated at 1573 K using a fayalitic nickel converter slag containing spinel and matte/alloy particles.The addition of various amounts of spent potlining(SPL) was studied in terms of its influence on matte settling and the overall metal recoveries.The slags produced were characterized by scanning electron microscopy,energy-dispersive spectroscopy,and wet chemical analysis using inductively coupled plasma optical emission spectrometry.The presence of solid spinel particles in the molten slag hindered coalescence and settling of matte/alloy droplets.Matte settling was effectively promoted with the addition of as little as 2 wt% SPL because of the reduction of spinel by the carbonaceous component of the SPL.The reduced viscosity of the molten slag in the presence of SPL also contributed to the accelerated matte settling.Greater metal recoveries were achieved with larger amounts of added SPL.Fast reduction of the molten slag at 1573 K promoted the formation of highly dispersed metal particles/clusters via accelerated nucleation in the molten slag,which increased the overall slag viscosity.This increase in viscosity,when combined with rapid gas evolution from accelerated reduction reactions,led to slag foaming.

关键词： converter slag spent potlining matte nickel matte settling fayalite

Recovery and regeneration of Al_2O_3 with a high specific surface area from spent hydrodesulfurization catalyst CoMo/Al_2O_3

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Rare Metals 2019年第1期38卷 1-13页

作者： Qi Liu Wen-Qiang Wang Yue Yang Xue-Gang Liu Sheng-Ming Xu Institute of Nuclear and New Energy Technology Tsinghua University School of Minerals Processing and Bioengineering Central South University Beijing Key Laboratory of Fine Ceramics Tsinghua University

Aluminum recovery is a key issue for the overall recycling of valuable metals from spent catalysts. This paper focuses on the recovery and regeneration of alumina with high additional value from the spent hydrodesulfurization catalyst CoMo/Al_2O_3. The results indicate that 98.13% alumina is successfully leached from the treated spent catalysts by an alkaline leaching process under the conditions of 5 mol·L^(-1) sodium hydroxide,a liquid/solid ratio of 20 ml·g^(-1),a temperature of 160 0 C and a reaction time of 4 h. In the leaching residue, no difficult leaching compound is found and cobalt and nickel are enriched,both of which are conducive to the subsequent metal recovery step. The reaction order of aluminum leaching is 0.99. This reaction fits well with the interfacial chemical reaction model, and its apparent activation energy is calculated as 45.50 kJ mol^(-1). Subsequently, y-Al_2O_3 with a high specific surface area of 278.3 m^2·g^(-1), a mean size of 2.2 μm and an average pore size of 3.10 nm is then regenerated from the lixivium, indicating its suitability for use as a catalyst carrier. The recovery and regeneration of alumina from spent catalysts can not only significantly contribute to the total recycling of such hazardous spent catalysts but also provide a new approach for the preparation of y-Al_2O_3 with a high specific surface area using spent catalysts as the aluminum sources.

关键词： spent catalysts CoMo/Al2O3 Aluminum leaching Regeneration γ-Al2O3

Reaction kinetics modeling for lithium and cobalt recovery from spent lithium-ion batteries using acetic acid

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International Journal of Minerals,Metallurgy and Materials 2019年第1期26卷 98-107页

作者： Hendrik Setiawan Himawan Tri Bayu Murti Petrus Indra Perdana Sustainable Mineral Processing Research Group Department of Chemical Engineering Faculty of Engineering Universitas Gadjah Mada

Lithium and cobalt recovery from spent lithium-ion batteries(LIBs) is a major focus because of their increased production and usage. The conventional method for recycling spent LIBs using inorganic acids produces harmful byproducts. In this work, the leaching agent was substituted with a less expensive and more environmentally friendly alternative—acetic acid—and a mathematical model was developed to describe the kinetics of the recovery process. The variables used were the pH value, temperature, H_2O_2 concentration, and the solid-to-liquid(S/L) ratio. The mathematical model used was the shrinking core model, which was modified to accommodate an equilibrium reaction. The experimental results show that the rate of recovery of Li and Co over time was only affected by temperature. The leaching behaviors of Li and Co were found to oppose each other. An increase in temperature resulted in increased recovery of Li but decreased recovery of Co because of the product-favoring endothermic reaction of Li and the reactant-favoring exothermic reaction of Co. The product of Li has a lower entropy value than the reactant as a free-moving ion, whereas the product of Co leaching has a higher entropy value as a stiff crystal complex. Thus, temperature conditioning is a pivotal factor in the leaching of spent LIBs.

关键词： spent libs lithium cobalt kinetics modeling recovery equilibrium

Chlorine-free emission disposal of spent acid etchant in a three-compartment ceramic membrane reactor

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Chinese Journal of Chemical Engineering 2020年第1期28卷 271-278页

作者： Fanglu Yuan Lele Cui Peipei Ding Wenheng Jing State Key Laboratory of Materials-Oriented Chemical Engineering National Engineering Research Center for Special Separation MembraneCollege of Chemical EngineeringNanjing Tech UniversityNanjing 211800China

Electrochemical technologies for the on-site treatment of spent acid etchant have received great attention due their ease of operation and economic benefits. On the other hand, a large amount of Cl2 is generated during the electrolysis process, which leads to potential environmental risks. In the present work, a novel threecompartment ceramic membrane flow reactor, including a cathode chamber, an anode chamber, and a gas absorption chamber was developed. The three chambers were divided by an Al2O3 ceramic membrane and a breathable hydrophobic anode diffusion electrode(ADE). The Cl2 evolution onset potential of the ADE was increased to 1.19 V from 1.05 V of the graphite felt, effectively inhibiting the chlorine evolution reaction(CER).The anode-generated Cl2 diffused into the gas absorption chamber through the ADE and was eventually consumed by the H2O2 adsorbent. Cu could be recovered without emitting chlorine due to the special structure of reactor. The current efficiency of copper precipitation and cathode reduction from Cu2+to Cu+reached 97.7%at a working current of 150 m A. These results indicated that the novel membrane reactor had high potential for application in the copper recovery industry.

关键词： spent acid etchant Chlorine evolution reaction Anode diffusion electrode Three-compartment reactor Ceramic membrane

Synthesis of Fe_3O_4 Magnetic Powder from spent Pickling Liquors

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Transactions of Tianjin University 2018年第1期24卷 45-50页

作者： Xingyao Wang Feifei Lv Department of Chemistry School of SciencesTianjin University

spent pickling liquors pose a serious environmental problem in most industrialized countries, mainly owing to their corrosive properties and their ferrous iron and hydrochloric acid content. In this paper, spent pickling liquor was used as an inexpensive raw material to prepare Fe304 magnetic powder via an oxidation method. Being able to recover the dissolved iron from spent pickling liquors would not only salvage a valuable material but also render the effluent environmentally benign. The structure of the Fe_3O_4 magnetic powder was characterized by X-ray diffraction. The morphology and size were characterized by scanning electron microscopy and transmission electron microscopy. Their magnetic properties were tested at room temperature by a vibrating sample magnetometer. In addition, the saturation magnetization of Fe_3 O_4 products can be further enhanced to 96.1 emu/g after purification.

关键词： spent pickling liquor Fe3O4 magnetic powder Oxidation

Removal of nickel from spent electroless nickel-plating bath with nickel foam cathode

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Journal of Harbin Institute of Technology(New Series) 2002年第4期9卷 332-335页

作者：于秀娟郑彤魏杰周定 Dept.of Environmental Engineering and Science

The electrochemical method was used to remove nickel ion from spent electroless nickel plating bath (pH=5 3). An electrolytic cell was composed of a porous nickel foam cathode and an inert RuO 2/Ti anode. Nickel ions were reduced and deposited on the surface of the nickel foam cathode. The effect of current density (i), linear velocity of wastewater(v), gap between cathode and anode(d C/A) and reaction time(t) on nickel removal rate and current efficiency were studied. As reaction time prolonged, nickel removal rate increased while current efficiency decreased. And larger v and smaller d C/A can enhance nickel removal rate and increase current efficiency by promoting mass transfer and dropping concentration polarization. The effect of current density on nickel removal by electrochemistry was related to other parameters. After three hours’ electrolysis with i=1 0 A/dm2, v=18 5 cm/min and d C/A=0 5 cm, nickel removal rate and current efficiency reached 85 6% and 29 1%, respectively.

关键词： spent electroless nickel plating bath electrochemical treatment nickel foam cathode