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Zhou X.,Huazhong Agricultural University | Zhou X.,Chengde Iron and Steel Group Co. | Shao X.,Huazhong Agricultural University | Shu J.-J.,Huazhong Agricultural University | And 4 more authors.
Talanta | Year: 2012

A novel sol-gel-coated ionic liquid-based ([AMIM][N(SO 2CF 3) 2]-OH-TSO) fiber was successfully applied for the determination of phthalate esters (PAEs) in agricultural plastic films by ultrasonic extraction (UE) combined with solid phase microextraction-gas chromatography (SPME-GC) due to its high thermal stability, specific selectivity and extraction efficiency. The extractant for UE and the adsorption time for SPME were optimized to achieve higher extraction efficiency. The desorption temperature and time were also optimized to avoid the carryover effect of previous extraction, and ultimately improve the precision and accuracy of the method. The [AMIM][N(SO 2CF 3) 2]-OH-TSO fiber showed comparable, or even higher response to most of the investigated PAEs than the commercial PDMS, PDMS-DVB and PA fibers. The carryover problem, often encountered when using commercial fibers, had been eliminated when desorption was performed at 360 °C for 8 min. The proposed SPME-GC method showed good linearity over three to four orders of magnitude, and low limits of detection ranged from 0.003 to 0.063 μg L -1. The relative standard deviation values obtained were below 10%, and the recoveries were in the ranges of 90.2-111.4%. Some of the PAEs studied were detected at very high concentration in these agricultural plastic film samples, resulting in a potential risk of crop damage, environmental contamination and human health exposure. © 2011 Elsevier B.V. All rights reserved. Source


Liu J.-X.,Kunming University of Science and Technology | Liu J.-X.,CAS Institute of Process Engineering | Li L.-J.,CAS Institute of Process Engineering | Li L.-J.,Chengde Iron and Steel Group Co. | And 4 more authors.
Guocheng Gongcheng Xuebao/The Chinese Journal of Process Engineering | Year: 2014

The effects of vanadium slag roasting and NaOH solution of hydrothermal leaching on the leaching rate of vanadium were studied, the optimum parameters of the process were obtained, and the mechanism was analyzed. The results showed that when the roasting temperature reached over 700℃, the oxidative decomposition of vanadium iron spinel could be achieved, the optimum conditions for roasting process were roasting at 850℃ for 2 h. The optimum leaching conditions were obtained as leaching temperature of 180℃, vanadium slag particle size lass than 74 μm, leaching time 2 h, ratio of liquid to solid 5 L/g, concentration of NaOH 30%(ω) and stirring speed 500 r/min. Under these conditions, the leaching rate of vanadium could reached 95%. No harmful gases were produced in the roasting and hydrothermal leaching of NaOH. ©, 2014, Science Press. All right reserved. Source


Li L.-J.,Chengde Iron and Steel Group Co. | Li L.-J.,Chinese Academy of Sciences | Li L.-J.,Northeastern University China | Chen D.-H.,Chengde Iron and Steel Group Co. | And 5 more authors.
Guocheng Gongcheng Xuebao/The Chinese Journal of Process Engineering | Year: 2011

The major reaction factors of vanadium leaching process from vanadium-containing residue using NaOH sub-molten salt were studied, and the optimum process parameters obtained. By analyzing the decomposition process of vanadium-containing residue, the reaction mechanism was obtained at the same time. The significance of reaction temperature, particle size, reaction time, and NaOH-to-residue mass ratio on vanadium extraction was studied. The orthogonal experimental results showed that the impact order of reaction factors was reaction temperature > reaction time > NaOH-to-residue mass ratio with respect to vanadium recovery. Under the conditions of reaction temperature 170°C, NaOH-to-residue 4:1, stirring speed 700 r/min, particle size -74 μm and reaction time 3 h, leaching rate of vanadium was higher than 90%. The leaching process of vanadium, with activation energy 27.69 kJ/mol, was controlled by the chemical reaction in the initial reaction process. Acmite was decomposed, and dissoluble vanadium dissolved into NaOH solution, when the residue was decomposed by NaOH sub-molten salt. Source


Han Y.-H.,University of Science and Technology Beijing | Han Y.-H.,Chengde Iron and Steel Group Co. | Bai R.-G.,Chengde Iron and Steel Group Co. | Cang D.-Q.,University of Science and Technology Beijing | And 2 more authors.
Advanced Materials Research | Year: 2014

Combined with converter semi-steel component of Chengde steel plant, the main components of 100t ladle dephosphorization slag were calculated to propose the initial ratio of dephosphorization slag composition. The dephosphorization slag composition was then further improved by induction furnace dephosphorization. Analysis of dephosphorization rules has been done. The results show that: the dephosphorization effect reaches the best when the percent content of CaO is 35%, the amount of slag is 20kg/t, oxygen flow rate is 4L/min, oxygen blowing time is 4min, and dephosphorization efficiency can reach 56.9%; the order of the elements influencing dephosphorization rate is as follows: oxygen flow rate > slag > CaO > oxygen blowing time. From the experiment, dephosphorization in the ladle can reach the expected effect, which is the new method of hot metal pre-dephosphorization for iron and steel plant using vanadium titanium magnetite. © (2014) Trans Tech Publications, Switzerland. Source


Yang Z.-F.,Chengde Iron and Steel Group Co. | Song Z.-B.,Chengde Iron and Steel Group Co. | Xing J.-F.,Chengde Iron and Steel Group Co.
Journal of Iron and Steel Research | Year: 2014

In order to meet customer demand for the width of the index, the width control model was analyzed in the Chenggang 1780 plant. According to the research results, through using pyrometer of roughing mill under the line, the temperature prediction model of slab was built to reduce the influence of slab temperature to the width control. The effect of instable slab width on the controlled width was decreased through installing the slab width gauge and optimizing the width control strategy. Through investigating the edger curve of short stroke control, the optimizing scheme was put forward to effectively solve the problem of the head and tail width of strip steel. The strip spread control scheme is present according to different specifications. The fluctuation range of width can be decreased significantly through mentioned above measures. For example, the hit rate of finished width from 0 to 9 mm can reach above 96% , and within the scope of process control ability can be improved obviously. The higher degree of user satisfaction is also achieved. Source

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