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Recovery of waste rare earth fluorescent powders by two steps acid leaching

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Rare Metals 2013年第6期32卷 609-615页

作者： Shen-Gen Zhang Min Yang Hu Liu de-an pan Jian-Jun Tian Institute of Advanced Materials and Technology School of Materials Science and Engineering University of Science and Technology Beijing

The effects of the acid leaching and alkali fusion on the leaching efficiency of Y,Eu,Ce,and Tb from the waste rare earth fluorescent powders were investigated in this *** results show that hydrochloric acid is better than sulfuric acid in the first acid leaching,and NaOH is better than Na2CO3in the alkali *** the first acid leaching,the Wloss is 20.94%when the waste rare earth fluorescent powders are acid leached in H?concentration 3 mol L-1and S/L ratio 1:3 for 4 h due to red powders *** better results of the alkali fusion can be got at 800℃ for 2 h when the NaOH is *** blue powders and the green powders can be dissolved into NaAlO2and oxides such as rare earth oxide(REO).The REO can be dissolved in H?concentration 5 mol L-1,S/L1:10 for 3 h in the second acid *** leaching rates of the Y,Eu,Ce,and Tb are 99.06%,97.38%,98.22%,and 98.15%,*** leaching rate of the total rare earth is 98.60%.

关键词： Waste rare earth fluorescent powders Two steps acid leaching Alkali fusion

Inhibitory Effect of Progesterone on Inflammatory Factors After Experimental Traumatic Brain Injury

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Biomedical and Environmental Sciences 2007年第5期20卷 432-438页

作者： de-SHENG pan WEI-GUO LIU XIAO-FENG YANG AND FEI CAO department of Neurosurgery The First Affiliated Hospital Medical College of Zhejiang University Hangzhou 310003 Zhejiang China department of Neurosurgery The Second Affiliated Hospital Medical College of Zhejiang University Hangzhou 310009 Zhejiang China

Objective Traumatic brain injury （TBI） is one of the leading causes of morbidity and mortality in young people. Inflammatory cytokines play an important part in the pathophysiology of TBI. Recent studies demonstrate that progesterone significantly reduces cerebral edema and enhances functional recovery from TBI and stroke in several animal models. This study was designed to investigate the inhibitory effect of progesterone on inflammatory response after traumatic brain injury. Methods Progesterone was injected intraperitoneally using rats as a model of traumatic brain injury, and Western blot technique was applied to detect the expression of three inflammation-related factors： nuclear factor kappa B p65 （NFκB p65）, glial fibrillary acidic protein （GFAP）, and tumor necrosis factor-α （TNF-α）. The water content of injured brain was also examined. A neurological severity score was recorded to evaluate the effect of progesterone on neurodeficit recovery. Results NFκB p65, GFAP, and TNF-α were increased in all injured animals. In rats treated with progesterone, the expression level of NFκB p65 and TNF-α were reduced significantly in comparison with vehicle-treated rats. However, progesterone did not alter the expression of GFAP in the injured rats. Progesterone also reduced the water content of injured brain and the lesion volume. In addition, progesterone-treated injured rats showed significant improvements in the Neurological Severity Score test, compared with vehicle-treated ones. Conclusions Progesterone inhibits the inflammatory response after experimental traumatic brain injury and mitigates the severity of brain damage.

关键词： Traumatic brain injury Progesterone Inflammation

Strontium ferrite powders prepared from oily cold rolling mill sludge by solid-state reaction method

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Rare Metals 2013年第5期32卷 518-523页

作者： Bo Liu Shen-Gen Zang Jian-jun Tian de-an pan Hang-Xin Zhu Advanced Material and Technology Institute University ofScience and Technology Beijing

Oily cold rolling mill （CRM） sludge is one of the pollutants emitted by iron and steel plants. Recycling oily CRM sludge can not only reduce pollution but also bring social and environmental benefits. In this study, using oily CRM sludge as sources of iron oxide, the strontium ferrite powders were synthesized in multiple steps including vacuum distillation, magnetic separation, oxidizing roasting, and solidstate reaction. The optimal technological conditions of vacuum distillation and oxidizing roasting were studied carefully. To consider the effects of Fe203/ SrCO3 tool ratio, calcination temperature, milling time and calcination time on magnetic properties of prepared strontium ferrite powders, the orthogonal experimental method was adopted. The maximum saturation magneti- zation （62.6 mA-m2.g-1） of the synthesized strontium ferrite powders was achieved at the Fe203/SrCO3 mol ratio of 6, 5 h milling time, 1250 ~C calcination temperature, and 1 h calcination time. Strontium ferrite powders syn- thesis method not only provides a cheap, high quality raw material for the production of strontium ferrite powders, but also effectively prevents the environmental pollution.

关键词： Strontium ferrite powders Oily cold rolling mill sludge Solid-state reaction method Recycling

New technology for recycling materials from oily cold rolling mill sludge

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International Journal of Minerals,Metallurgy and Materials 2013年第12期20卷 1141-1147页

作者： Bo Liu Shen-gen Zhang Jian-jun Tian de-an pan Ling Meng Yang Liu Institute for Advanced Materials and Technology University of Science and Technology Beijing

Oily cold rolling mill （CRM） sludge is one of metallurgical industry solid wastes. The recycle of these wastes can not only protect the environment but also permit their reutilization. In this research, a new process of ＂hydrometallurgical treatment ＋ hydrothermal synthesis＂ was investigated for the combined recovery of iron and organic materials from oily CRM sludge. Hydrometallurgical treatment, mainly including acid leaching, centrifugal separation, neutralization reaction, oxidizing, and preparation of hydrothermal reaction precursor, was first utilized for processing the sludge. Then, micaceous iron oxide （MIO） pigment powders were prepared through hydrothermal reaction of the obtained precursor in alkaline media. The separated organic materials can be used for fuel or chemical feedstock. The quality of the prepared MIO pigments is in accordance with the standards of MIO pigments for paints （ISO 10601-2007）. This clean, effective, and economical technology offers a new way to recycle oily CRM sludge.

关键词： cold rolling mills sludge disposal hydrometallurgy hydrothermal synthesis recycling, waste utilization

Recycle of valuable products from oily cold rolling mill sludge

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International Journal of Minerals,Metallurgy and Materials 2013年第10期20卷 941-946页

作者： Bo Liu Shen-gen Zhang Jian-jun Tian de-an pan Yang Liu Alex A.Volinsky Institute for Advanced Materials and Technology University of Science and Technology Beijing department of Mechanical Engineering University of South Florida

Oily cold rolling mill （CRM） sludge contains lots of iron and alloying elements along with plenty of hazardous organic components, which makes it as an attractive secondary source and an environmental contaminant at the same time. The compound methods of ＂vacuum distillation ＋ oxidizing roasting＂ and ＂vacuum distillation ＋ hydrogen reduction＂ were employed for the recycle of oily cold rolling mill sludge. First, the sludge was dynamically vacuum distilled in a rotating furnace at 50 r/rain and 600℃ for 3 h, which removed almost hazardous organic components, obtaining 89.2wt% ferrous resultant. Then, high purity ferric oxide powders （99.2wt%） and reduced iron powders （98.9wt%） were obtained when the distillation residues were oxidized and reduced, respectively. The distillation oil can be used for fuel or chemical feedstock, and the distillation gases can be collected and reused as a fuel.

关键词： cold rolling mills sludge recycling distillation oxidation hydrogen reduction

Treatment method of hazardous pickling sludge by reusing as glass–ceramics nucleation agent

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Rare Metals 2016年第3期35卷 269-274页

作者： Jian Yang Shen-Gen Zhang de-an pan Bo Liu Chun-Li Wu Alex A.Volinsky Institute for Advanced Materials and Technology University of Science and Technology Beijing department of Mechanical Engineering University of South Florida

Heavy metal containing pickling sludge（PS） is one of the by-products of the stainless-steel-making industry,which has been considered hazardous due to contained chromium and *** methods of PS disposing are landfill and cement *** research is aimed at disposing PS by solidification/stabilization and reusing it as a nucleation agent of glass–*** crystallization behavior and the properties of a glass in the CaO–MgO–SiO2–Al2O3 system were studied by considering PS as the nucleation *** results confirm that introducing 14 wt% PS as the nucleation agent of glass–ceramics can decrease crystallization temperature by 110.8 °C,refine the grain size by forming isometric crystals with size of 2 lm,enhance Vickers hardness by 2690 MPa and decrease water absorption from（1.21 ± 0.10） wt% to（0.04 ± 0.01） wt%.Therefore,it is reasonable to conclude that PS can be utilized as a nucleation agent to improve the crystallization and mechanical properties of the glass–*** testing results of US EPA toxicity characteristic leaching procedure（TCLP）confirm the safety of this reusing method.

关键词： Glass–ceramics Pickling sludge Nucleation agent Heavy metal stabilization

Research on process modeling and simulation of spent lead paste desulfurization enhanced reactor

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Chinese Journal of Chemical Engineering 2023年第8期60卷 293-303页

作者： Lijuan Zhao Zhe Tan Xiaoguang Zhang Qijun Zhang Wei Wang Qiang deng Jie Ma de'an pan Institute of Circular Economy Beijing University of TechnologyBeijing 100124China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China China Ecological Civilization Research and Promotion Association Beijing 100035China

In the reaction process of carbonate desulfurization lead paste,the produced PbCO_(3) is easily wrapped in the outer periphery of PbSO_(4) to form a product layer,hindering the mass transfer ***,it is necessary to break the PbCO_(3) product *** this work,the rotor stator-reinforced reactor was selected as the enhanced desulfurization reactor for the purpose of breaking the PbCO_(3) product layer and promoting mass *** breakage process of the PbCO_(3) product layer generated during the PbSO_(4) desulfurization was *** fluid dynamics simulation to the rotation conditions was carried out to theoretically analyze the fluid flow characteristics of PbSO_(4) slurry and the wall shear stress affecting the breakage of PbCO_(3) product *** optimizing the rotation conditions,the distribution ratio of effective rotor wall shear stress range achieved 96.1%,and the stator wall shear stress range reached 99.15%under a rotation of 2000 r·min^(-1).The research work provides a reference for analysis of the mechanism of product layer breakage in the PbSO_(4) desulfurization process,and gives a clear and intuitive systematic study on the fluid flow characteristics and wall shear stress of the desulfurization reactor.

关键词： Chemical reactors Computational fluid dynamics CFD Simulation desulfurization Core-shell structure

Electromagnetic and microwave absorbing properties of FeCoB powder composites

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Rare Metals 2013年第4期32卷 402-407页

作者： Shen-Gen Zhang Hang-Xin Zhu Jian-Jun Tian de-an pan Bo Liu Yan-Tao Kang Advanced Material and Technology Institute University of Science and Technology Beijing

The electromagnetic and microwave absorbing properties of FeCoB powder composites prepared by sin- gle-roller melt-spinning and mechanical milling processes were investigated in this paper. The result indicates that the flake-like powders are obtained. As milling time increases, the flake-like powder particles tend to agglomerate, causing the flake-like powders decrease gradually. The milling time plays an important role in the electromagnetic parameters which relates to the shape and size of the powder particles. The calculation shows that the sample milled for 6 h could achieve an optimal reflection loss of -11.5 dB at 5.8 GHz, with mass fraction of 83 % and a matching thickness of 1.8 mm. The result also indicates that the microwave absorbing properties of the FeCoB powder composites are adjustable by changing their thickness, and can be applied as a thinner microwave absorbing material in the range of 2-8 GHz.

关键词： Fe48Co48B4 powder composites Mechanical milling Electromagnetic parameters Microwave absorbing properties

One-step Crystallization Kinetic Parameters of the Glass-ceramics Prepared from Stainless Steel Slag and Pickling Sludge

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Journal of Iron and Steel Research International 2016年第3期23卷 220-224页

作者： Shen-gen ZHANG Jian YANG Bo LIU de-an pan Chun-li WU Alex A.VOLINSKY Institute for Advanced Materials and Technology School of Materials Science and EngineeringUniversity of Science and Technology Beijing department of Mechanical Engineering University of South Florida

One-step crystallization is one of the most energy conserving methods for glass-ceramics ***,only a few kinetics studies focused on the glass-ceramics prepared by the one-step *** onestep crystallization kinetic parameters were studied using differential scanning *** activation energy（Ea）and the Avrami parameter（n）were calculated as 152.79kJ·mol-1 and 4.39,*** parameters indicate that continuous nucleation and three-dimensional crystal growth are the dominating mechanisms in the one-step crystallization process of the parent *** properties of the obtained glass-ceramics can be compared to the glass-ceramics prepared by the two-stage heat treatment and sintering *** crystallization kinetics research can be used to evaluate the one-step crystallization potential of a parent glass.

关键词： glass-ceramics one-step crystallization crystallization kinetics continuous nucleation