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Preparation of calcium carbonate particles coated with titanium dioxide

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International Journal of Minerals,Metallurgy and Materials 2009年第5期16卷 592-597页

作者： hai lin ying-bo dong Le-yong Jiang School of Civil and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China

The preparation of a new mineral composite material, calcium carbonate particles coated with titanium dioxide, was studied. The mechanism of the preparation process was proposed. The new mineral composite material was made by the mechanoehemieal method under the optimum condition that the mass ratio of calcium carbonate particles to titanium dioxide was 6.5：3.5. The mass ratios of two different types of titanium dioxide （anatase to rutile） and grinding media to grinded materials were 8：2 and 4：1 respectively, and the modified density was 60%. Under this condition, the new material was capable of forming after 120-min modification. The hiding power and oil absorption of this new material were 29.12 g/m^2 and 23.30%, respectively. The results show that the modification is based on surface hydroxylation. After coating with titanium dioxide, the hiding power of calcium carbonate can be improved greatly. The new mineral composite materials can be used as the substitute for titanium dioxide.

关键词： calcium carbonate mechano-chemical process titanium dioxide film hydroxylation

Leaching behavior of V,Pb,Cd,Cr,and As from stone coal waste rock with different particle sizes

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International Journal of Minerals,Metallurgy and Materials 2018年第8期25卷 861-870页

作者： ying-bo dong Yue Liu hai lin School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants Beijing 100083China

This paper investigates the leaching behavior of heavy metals(V,Pb,Cd,Cr,and As) from stone coal waste rocks with various particle sizes using dynamic leaching *** results show that the dissolved concentrations of V and As initially increased and then slightly decreased as time progressed and that the dissolved concentrations of Pb,Cd,and Cr were high in the early stage before *** particle size of the stone coal waste rocks strongly influenced the heavy metal concentration in the leaching *** effects of the particle size of the stone coal waste rocks on the dissolved concentrations of V,Pb,and As decreased in the order fine fraction > medium fraction > coarse fraction,and the effects of particle size on the dissolved concentrations of Cr and Cd decreased in the order medium fraction > coarse fraction > fine fraction and coarse fraction > medium fraction > fine fraction,*** quantities of heavy metals dissolved from the stone coal waste rock with fine particle sizes were observed to decrease in the order V(17104.36 μg/kg) > As(609.41 μg/kg) > Pb(469.24 μg/kg) > Cr(56.35 μg/kg) > Cd(27.52 μg/kg),and the dissolution rates decreased in the order As(2.96%) > Pb(0.93%) > V(0.35%) > Cd(0.25%) > Cr(0.01%).The specific surface area,pore size of the stone coal waste rocks,and chemical forms of heavy metals also influenced the release of heavy metals from the stone coal waste *** analysis showed that the dissolution of heavy metals fundamentally agreed with the rate equation controlled by the shrinking core *** results of this study are expected to serve as a reference for the evaluation of heavy metals contamination from stone coal waste rocks.

关键词： stone coal waste rocks heavy metal leaching behavior dynamic leaching test particle size

Dissolution characteristics of sericite in chalcopyrite bioleaching and its effect on copper extraction

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International Journal of Minerals,Metallurgy and Materials 2017年第4期24卷 369-376页

作者： ying-bo dong Hao Li hai lin Yuan Zhang School of Energy and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China

The effects of sericite particle size, rotation speed, and leaching temperature on sericite dissolution and copper extraction in a chalcopyrite bioleaching system were examined. Finer particles, appropriate temperature and rotation speed for Acidithiobacillus ferrooxidans resulted in a higher Al3+dissolution concentration. The Al3+dissolution concentration reached its highest concentration of 38.66 mg/L after 48-d leaching when the sericite particle size, temperature, and rotation speed were −43 μm, 30°C, and 160 r/min, respectively. Meanwhile, the sericite particle size, rotation speed, and temperature can affect copper extraction. The copper extraction rate is higher when the sericite particle size is finer. An appropriately high temperature is favorable for copper leaching. The dissolution of sericite fitted the shrinking core model, 1–(2/3)α–(1–α)2/3= k1t, which indicates that internal diffusion is the decision step controlling the overall reaction rate in the leaching process. Scanning electron microscopy analysis showed small precipitates covered on the surface of sericite after leaching, which increased the diffusion resistance of the leaching solution and dissolved ions. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.

关键词： Aluminum Bioleaching Copper Dissolution Extraction Leaching Rotation Scanning electron microscopy Shrinkage

Bioleaching of vanadium from barren stone coal and its effect on the transition of vanadium speciation and mineral phase

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International Journal of Minerals,Metallurgy and Materials 2018年第3期25卷 253-261页

作者： Xin Wang hai lin ying-bo dong Gan-yu Li School of Civil and Resource Engineering University of Science and Technology Beijing Beijing 100083 China School of Energy and Environmental Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants Beijing 100083 China

This study determined the optimal conditions required to obtain maximum vanadium extraction and examined the transition of mineral phases and vanadium speciation during the bioleaching process. Parameters including the initial p H value, initial Fe^(2+) concentration, solid load, and inoculum quantity were examined. The results revealed that 48.92 wt% of the vanadium was extracted through bioleaching under optimal conditions. Comparatively, the chemical leaching yield(H_2SO_4, pH 2.0) showed a slower and milder increase in vanadium yield. The vanadium bioleaching yield was 35.11 wt% greater than the chemical leaching yield. The Community Bureau of Reference(BCR) sequential extraction results revealed that 88.62 wt% of vanadium existed in the residual fraction. The bacteria substantially changed the distribution of the vanadium speciation during the leaching process, and the residual fraction decreased to 48.44 wt%. The X-ray diffraction(XRD) and Fourier transform infrared(FTIR) results provided evidence that the crystal lattice structure of muscovite was destroyed by the bacteria.

关键词： bioleaching stone coal BCR-sequential extraction vanadium speciation mineral phase

Bioleaching of two different types of chalcopyrite by Acidithiobacillus ferrooxidans

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International Journal of Minerals,Metallurgy and Materials 2013年第2期20卷 119-124页

作者： ying-bo dong hai lin Kai-bin Fu Xiao-fang Xu Shan-shan Zhou Key Laboratory of High-Efficient Mining and Safety of Metal Mines (Ministry of Education) University of Science and Technology Beijing School of Civil and Environmental Engineering University of Science and Technology Beijing

Two different types of chalcopyrite （pyritic chalcopyrite and porphyry chalcopyrite） were bioleached with AcidithiobaciUus ferrooxidans ATF6. The bioleaching of the pyritic chalcopyrite and porphyry chalcopyrite is quite different. The copper extraction reaches 46.96% for the pyritic chalcopyrite after 48-d leaching, but it is only 14.50% for the porphyry chalcopyrite. Proper amounts of initial ferrous ions can improve the efficiency of copper extraction for the two different types of chalcopyrite. The optimum dosage of ferrous ions for the pyritic chalcopyrite and porphyry chalcopyrite is different. The adsorption of ATF6 on the pyritic chalcopyrite and porphyry chalcopyrite was also studied in this paper. It is found that ATF6 is selectively adsorbed by the two different types of chalcopyrite; the higher adsorption onto the pyritic chalcopyrite than the porphyry chalcopyrite leads to the higher copper dissolution rate of the pyritic chalcopyrite. In addition, the zeta-potential of chalcopyrite before and after bioleaching further confirms that ATF6 is more easily adsorbed onto the pyritic chalcopyrite.

关键词： chalcopyrite bioleaching adsorption functional groups

Coupling relationship between multicomponent recovery of rare earth tailings

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Rare Metals 2017年第3期36卷 220-228页

作者： Yue Zhang hai lin ying-bo dong Xiao-Fang Xu Xin Wang Yue-Jiao Gao School of Civil and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory of High-Efficient Mining and Safety of Metal Mines Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083China

About 90 % rare earth minerals and many other valuable minerals are heaped as iron tailings without comprehensive utilization. In order to comprehensively recover these valuable minerals, in a view of the valuable ore type of Baotou Steel tailing and embedded features, valuable components flow and their respective recovery coupling relationship in beneficiation flowsheet were ana- lyzed; process flows and parameters which could give consideration to four kinds of components were deter- mined. TFe, rare earth oxide （REO）, niobium and fluorite recoveries could reach 72.70 %, 81.84 %, 78.58 % and 60.18 % in low-intensity/high-intensity magnetic separa- tion, respectively. High-intensity magnetic concentration was treated by REO direct flotation; the recovery is 75.43 %, on the base of which Fe could be separated completely from Nb. The underflow was treated by reduction roasting-low-intensity magnetic separation. And the relationship between the recoveries of these valuable components was also discussed.

关键词： Rare earth tailings Recovery Couplingrelationship

Ammonia nitrogen removal from aqueous solution using zeolite modified by microwave-sodium acetate

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Journal of Central South University 2016年第6期23卷 1345-1352页

作者：董颖博林海 Department of Environmental Engineering University of Science and Technology Beijing Beijing 100083 China Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants Beijing 100083 China

The characteristics of the zeolite modified by microwave and sodium acetate and its sorption of ammonia-nitrogen from simulated water sample were *** results show that the modified zeolite by microwave-sodium acetate(SMMZ)has a high sorption efficiency and removal *** ammonia-nitrogen removal rate of SMMZ reaches 92.90%.The surface of SMMZ becomes loose and some pores appear,the specific surface area,total pore volume and average pore diameter increase after *** to the natural zeolite,SMMZ has a more concentrated pore size distribution in the range of 0-10 *** cation exchange capacity(CEC)of SMMZ is higher than that of the natural *** the ammonia nitrogen removal rate is consistent with the change of *** SMMZ possesses rapid sorption and slow balance characteristics and ammonia-nitrogen sorption is consistent with both Langmuir adsorption isotherm model and Freundlich adsorption isotherm *** adsorption kinetics of ammonia-nitrogen follows the pseudo-second order kinetic model.

关键词： modified zeolite microwave sodium acetate ammonia-nitrogen sorption characterization

Electrochemistry of Hydroquinone Derivatives at Metal and Iodine-modified Metal Electrodes

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Chemical Research in Chinese Universities 2006年第4期22卷 493-499页

作者： HOU Peng HAN dong-xue NIU Li lin hai-bo State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 P. R. China Graduate School of the Chinese Academy of Sciences Beijing 100039 P. R. China College of Chemistry Jilin University Changchun 130021 P. R. China

The difference in the electrochemical behavior of hydroquinone and pyrocatechol at platinum and gold surfaces was analyzed using voltammetry and attenuated total reflection Fourier transform infrared spectroscopy. The results show that the hydroquinone derivatives are adsorbed on a gold surface with vertical orientation, which makes the electron transfer between the bulk species and the electrode surface easier than that in the case of flat adsorption of hydroquinone derivatives that occurs at a platinum electrode. The formation of the vertical conformation and the rapid process of electron transfer were also confirmed by quantum chemistry calculations. In addition, the pre-adsorbed iodine on the electrodes played a key role on the adsorbed configuration and electron transfer of redox species.

关键词： Hydroquinone derivatives Iodine-modified Electrochemistry

Machining distortion prediction of aerospace monolithic components

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第5期10卷 661-668页

作者： Yun-bo BI Qun-lin CHENG Hui-yue dong ying-lin KE State Key Lab of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China Shanghai Spaceflight Precision Machinery Research Institute Shanghai 201600 China

To predict the distortion of aerospace monolithic components, a model is established to simulate the numerical control (NC) milling process using 3D finite element method (FEM). In this model, the cutting layer is simplified firstly. Then, the models of cutting force and cutting temperature are established to gain the cutting loads, which are applied to the mesh model of the part. Finally, a prototype of machining simulation environment is developed to simulate the milling process of a spar. Key factors influencing the distortion, such as initial residual stress, cutting loads, fixture layout, cutting sequence, and tool path are considered all together. The total distortion of the spar is predicted and an experiment is conducted to validate the numerical results. It is found that the maximum discrepancy between the simulation results and experiment values is 19.0%

关键词： Monolithic component Machining distortion Finite element simulation