Table of Content

20 October 2017, Volume 17 Issue 5

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Frontier Forum

Quasi-liquid: from Natural Cognition to Precise Regulation

Suojiang ZHANG Yumiao LV Hongyan HE Feng HUO Yanlei WANG Xiaochun ZHANG Kun DONG

Chin. J. Process Eng.. 2017, 17(5):  883-884.  DOI: 10.12034/j.issn.1009-606X.217327

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准液体不仅在自然界广泛存在，而且在能源、材料和生命科学等诸多领域的实际过程中发挥着重要的作用，然而迄今为止，人们尚未认识到准液体的重要性及对其探究的重大意义。对这种新物态的研究将带来新认识、新理论和新突破，并可能产生重大的技术革新。本文首先总结了准液体的类型，指出了准液体的结构特征，提出了准液体精准调控的理念，最后展望了准液体的巨大潜在应用，对促进准液体的理论发展和应用意义重大。

Reviews

Effect of Change in Aqueous-to-oil Phase Ratio on the Performance of Mixer?Settler in Extraction Processes

Chuanxu XIAO Kun HUANG Huizhou LIU

Chin. J. Process Eng.. 2017, 17(5):  885-892.  DOI: 10.12034/j.issn.1009-606X.216369

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Effect of the change in aqueous-to-organic phase ratio on the performance of mixer?settler was summarized. The effect of aqueous-to-organic phase ratio on drop dispersion, mass transfer of target metal ion between phases in mixer chamber and phase separation in settler chamber were paid particular attention. In addition, the effect of impeller type and installation position on the performance of mixer?setter were discussed. How to meet the requirement from a wide aqueous-to-organic phase ratio in mixer?settler was suggested for complex separation. Future development of mixer?settler was indicated, including how to achieve high mixing efficiency in mixer chamber and high clarification efficiency in settler chamber under a wide aqueous-to-organic phase ratio range.

Progress of Single-dose Vaccine Using Nanoparticle-based Delivery System

Meiyang YANG Lianyan WANG Tingyuan YANG Xueying YAN?

Chin. J. Process Eng.. 2017, 17(5):  893-902.  DOI: 10.12034/j.issn.1009-606X.217101

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Vaccination is one of the most effective methods for the prevention and treatment of infectious diseases. The scientists have focused on the research and development of vaccines for many years. Traditional vaccines usually require immunization for many times to achieve good immune response. Many people have not received timely immunization in remote area, which result in that there are over 100 million children each year around the world to be infected with disease or even death. Scientists have tried to develop novel single-dose vaccine basing on study of sustained and controlled release delivery systems in recent years. The successful development of single-dose vaccine will help to improve the vaccination rate and realize effective prevention and control of infectious diseases. This review elaborates the development process of single-dose vaccination, properties and regulation of single-dose vaccination based on biodegradable nanoparticles, potential strategies for the single-dose vaccination.

A Review of Forming Process and Flotation Mechanism of Hemimorphite

Qihong WANG Xiaolin ZHANG Man JING Fei RAO Luqing WU Kangkang LI Shiming CAO

Chin. J. Process Eng.. 2017, 17(5):  903-910.  DOI: 10.12034/j.issn.1009-606X.216387

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Properties of hemimorphite were summarized from three aspects, the forming process, crystal structure and flotation mechanism of ore. The relationship between crystal structure and floatability was discussed, impact factors and characteristics of hemimorphite in forming process were also analyzed. The mechanisms between hemimorphite and commonly used reagents such as xanthate, amines, fatty acids, chelating agents etc. were also introduced, which reflects the inner connection of the characteristics of the three aspects mentioned above. The results showed that zinc is easily loss in fine slime because the hemimorphite is often mixed with clay minerals in the formation process. Pre-sulfidization or extended sulfuration time is needed for the activity of Zn atoms in crystal lattice and the migration ability of Zn2+ cations is low. Chelating agent method is expected to open up new directions for the flotation of hemimorphite. Moreover, theory system of selection, design and synthesis of chelating agents and research in reducing reagent cost should be enhanced.

Research Progress of Preparation Methods of Spherical Titanium Powders for 3D Printing

Baoqiang LI Huacheng JIN Yanchang ZHANG Peng HU Fangli YUAN Yunfa CHEN

Chin. J. Process Eng.. 2017, 17(5):  911-917.  DOI: 10.12034/j.issn.1009-606X.217129

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Spherical titanium powder is one of the most important raw materials used in metal additive manufacturing (3D printing). The development and optimization of the preparation method of spherical titanium powders are hot issues around the world. In this work, the research advance on the preparation of spherical titanium powders was analyzed. Specifically, the main preparation methods of spherical titanium powders were analyzed and their features were summarized in this work, which included gas atomization (GA), plasma atomization (PA), centrifugal atomization (CA) and plasma spheroidization. Finally, the future development trend of spherical titanium powders was forecasted and preparation high purity spherical titanium powders with low price and fine particle size will be an important research content in the future.

Flow & Transfer

Structure Optimization and Performance Prediction of Compact Flotation Unit Using BP Neural Network and Computational Fluid Dynamics

Xiaolei CAI Jiaqing CHEN Xianggong KONG Meili LIU Jiecheng YU Yipeng JI

Chin. J. Process Eng.. 2017, 17(5):  918-925.  DOI: 10.12034/j.issn.1009-606X.217135

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The method of BP neural network coupled with computational fluid dynamics (CFD) was used to optimize the structural parameters of inlet diameter, annular gap width, ratio of height to diameter and concentric inner cylinder diameter of compact flotation unit. The effects of these structural parameters on the separation efficiency were also predicted. The results showed that the separation efficiency of the CFU after optimization has been improved from 81.07% to 92.82% and the deviation between estimation and actual value is only 1.15%. Increasing distribution flow tube diameter, the ratio of height to diameter and the inlet diameter and decreasing the width of annular gap are beneficial to strengthen oil?water transmission and improve the separation efficiency.

Numerical Simulation and Single Factor Influence Analysis of Multi-phase Flow in Copper Top-blown Furnace

Jun PENG Zhuo CHEN Sixuan LIU Lizhen CHENG

Chin. J. Process Eng.. 2017, 17(5):  926-935.  DOI: 10.12034/j.issn.1009-606X.217145

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Based on the volume of fluid model, simulation of the multi-phase flow in a copper top-blown furnace was carried out. Taking the gas volume fraction and the average velocity of the melt as the indexes to assess the smelting effort/efficiency of the copper top-blown furnace, influences of three main parameters on the smelting process which were the lance outer diameter, the lance air flux and the lance submerged depth were investigated by single factor analysis method. Appropriate ranges of three main operational parameters were determined by taking the practical production parameter values into consideration. The results showed the appropriate increase of lance submerged depth or air flux can obviously improve gas volume fraction and average velocity of the melt attaining a higher smelting efficiency. Properly decreasing the lance outer diameter can enlarge the assessment indexes and get a better smelting effect. The appropriate ranges of three main parameters were the lance outer diameter of 403~428 mm, the lance air flux of 12000~14000 Nm3/h and the lance submerged depth of 225~275 mm.

Discrete Simulation of Vertical Screw Conveyor Based on Particle Scaling Theory

Jianli REN Longhai ZHOU Long HAN Jiani ZHOU Mi YAN

Chin. J. Process Eng.. 2017, 17(5):  936-943.  DOI: 10.12034/j.issn.1009-606X.217109

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With the principles of similarity and dimensional analysis, the cast iron pulverized coal was enlarged from 0.5 mm to 2 mm. The virtual experiment was carried out to calibrate the basic contact parameters of scaled particles. The simulation of particle movement in vertical screw conveyor with discrete element model was carried out to verify the exactness of the scaling method. The results showed that when the screw rotation speed is 500, 550, 600, 650 r/min, particle axial velocity and peripheral speed is increased. The maximum axial velocity is in the upper part and on the verge of blade, respectively 0.486, 0.535, 0.596, 0.657 m/s. The axial velocity decreases obviously in area more than spiral radius. Compared with simulation and experiment, the mass flow rate in the device outlet and particle axial velocity is true on the whole and meets the principles of similarity under the reasonable approximations.

Numerical Simulation of Gas-Liquid-Solid Three-phase Flow in Airlift Loop Reactor

Bin XU Jian YU Dehua SHU Decai YIN

Chin. J. Process Eng.. 2017, 17(5):  944-951.  DOI: 10.12034/j.issn.1009-606X.217127

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Based on the Euler three-phase model in Fluent, the improved drag model was applied to the two-dimensional unsteady numerical simulation of continuous three-phase airlift inner-loop bioreactor. The improved model was applied to simulating the time-averaged liquid velocity in the downcomer, the maximum liquid velocity, the gas holdups under different aeration rates and different volumes of sand and the diffusion process of phenol when the aeration rate was 10.2 L/min and the volume of sand was 2 L. The result showed the simulated values of liquid velocity, gas holdups and the diffusion process were consistent with the experiment results. Then the time-averaged liquid velocity in the downcomer was simulated with the improved model when the solid density was 1200, 1500, 1800, 2220 kg/m3, respectively, and particle sizes was 0.3, 0.6, 0.9 mm, respectively. The time-averaged liquid velocity increased with the solid density and the particle sizes decreasing.

Coalescence Mechanism of Thermal Bubbles Movement on Warship Wake

Zhiyou ZHANG Liang'an JIN Zhijiang YUAN Shengyang HE

Chin. J. Process Eng.. 2017, 17(5):  952-958.  DOI: 10.12034/j.issn.1009-606X.216380

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According to the characteristics of gas thermal bubbling in the sea, along with the gas?liquid mass and heat transfer process, the coalescence model of thermal bubbles and wake microbubbles was set up on the basis of bubble population balance equation model. Corresponding coalescence efficiency was solved and validated by relevant experiment. The results showed that 1 mm was the bubbles coalescence critical radius. The coalescence efficiency increases obviously with the increasing of radius below critical radius. When the radius is bigger than the critical radius, it had a reverse rule. The coalescence efficiency increased stepwise as the increasing of big bubbles numerical density. When the big bubbles numerical density was equal with microbubbles, the effect of defoaming efficiency was well.

Mixing Effect in Two Horizontal Opposed Impinging Stream Mixer

Jianwei ZHANG Panlong SHANG Junjie YAN Ying FENG

Chin. J. Process Eng.. 2017, 17(5):  959-964.  DOI: 10.12034/j.issn.1009-606X.216385

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The mixing effect in two horizontal opposed impinging stream mixer under turbulent flow condition was studied by using plane laser induced fluorescence (PLIF) technique, the influence of Reynolds number, the nozzle separation, the nozzle diameter and the inlet velocity ratio. The results showed that when the distance between two nozzles L increased from d’ to 3d’ (d’ was the average inner diameter between two nozzles), the mixing time decreased, but when L increased from 3d’ to 5d’, the mixing time increased, when L was 3d’, the mixing time was the smallest. When the Reynolds numbers was equal to 17544 at both ends of the inlet, the mixing time gradually decreases as the diameter of the nozzle increased from 6 mm to 14 mm, but the trend gradually slowed down. When the ratio of the inlet velocity of the two nozzles increased from 0.71 to 1.67, the mixing time decreased and then increased, when the velocity ratio was 1, the mixing time was the smallest. With the Reynolds number increasing from 7519 to 40936, the mixing time decreased. The mixing effect was best when L was 3d’ under symmetrical impact, the increase of nozzle diameter and Reynolds number can enhance the mixing effect significantly.

Characteristic of Online Measurement for Particles in Gas Pipelines

Lifeng LU Xiaolin WU Xuan SONG Zhongli JI

Chin. J. Process Eng.. 2017, 17(5):  965-970.  DOI: 10.12034/j.issn.1009-606X.216370

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Impact of physical properties of particles irradiated by white light on online measurement was explored. The shifting phenomenon of measured particle channels was analyzed based on the Mie scattering theory and thermodynamic principles. The results showed that the particle absorptivity affects the shifting of particle channels, the number of which relies greatly on the particle diameter as well as both the real and imaginary parts of refractive index. The online measurement of the diameters of two absorbing particles (A and B) reveals that the measured values (0.751 and 1.657 μm, respectively) are far smaller than their real counterparts, thus requiring further correction to the preliminary data based on the foregoing theories. Besides, particles of both types strode over multiple particle channels. The newly-corrected diameters of particle A and B transformed to be 1.668 and 2.759 μm, respectively, with an acceptable deviation of 5% as compared to the SEM result of 1.604 and 2.685 μm, which validates the rationality of the theoretical methods adopted here and further corroborates our results.

Measurement Conditions of Particle Size of Combustion Synthesis Silicon Nitride Using Laser Particle Size Analyzer

Pengfei LIU Luwei CHENG Baosong XU Mengxing LI Zhao HAN

Chin. J. Process Eng.. 2017, 17(5):  971-975.  DOI: 10.12034/j.issn.1009-606X.217111

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Silicon nitride powder was prepared by combustion synthesis with silica fume. The effects of solid content, ultrasonic time, dispersant concentration and settling time on the particle size measurements were investigated by using median particle diameter d50 and particle diameter distribution width d90?d10 as evaluation indications. The results indicated that the laser particle size analyzer was applicable to measurement particle size of silicon nitride powder by combustion synthesis showing high reproducibility. The above four factors influenced significantly on the measurement results. When solid content was 1.25 g/kg, the needed ultrasonic time was 60 min, and dispersant content was 3 g/g, optimum dispersion results of Si3N4 by combustion synthesis can be achieved using water as the dispersing medium. In addition, the particle size measurement was the most reliable within 0.5 h after ultrasonic treatment.

Reaction & Separation

Forward Osmosis Performance of Chitosan Oligosaccharide as Draw Solution

Luyi ZOU Xiteng XU Yue TENG Wenxiu GU

Chin. J. Process Eng.. 2017, 17(5):  976-981.  DOI: 10.12034/j.issn.1009-606X.216352

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Three different molecular weights of chitosan oligosaccharide (COS) were explored as draw agents in the forward osmosis (FO) process. The physical properties such as pH, conductivity, viscosity and osmotic pressure were investigated. The change regularity of water flux, reverse solute flux, rejection rate in the FO processes under different molecular weights, different concentrations and different membrane orientations were explored. Water recovery rates were also evaluated. The results showed that their characteristics of high conductivity and high osmotic pressure can provide favorable FO performance. The water flux of AL?DS mode is higher than that of AL?FS mode and reverse solute flux of AL?DS mode is also slightly higher than that of AL?FS mode. The rejection rates are both over 99.9% in the two membrane orientations. Moreover, rejection rate of AL?FS mode is slightly higher than that of AL?DS mode. Water recovery rates of draw solutions also exhibit good performance under different concentrations of COS as draw agents.Key words: forward osmosis; draw solution; chitosan oligosaccharide

Direct Solvent Extraction of Indium from the Leaching Solution of Zinc Oxide

Xiaodong GUO Chang WEI Xingbin LI Zhigan DENG Cunxiong LI Gang FAN

Chin. J. Process Eng.. 2017, 17(5):  982-988.  DOI: 10.12034/j.issn.1009-606X.217119

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In order to improve the comprehensive recovery rate of indium from the zinc hydrometallurgy process, a direct solvent extraction process was employed to selectively extract indium from the leaching solution of zinc oxide. The extraction rates of indium and other ions with P204 were studied under different parameters such as concentration of extractant, contact time, acid concentration, and temperature. Besides, the effects of concentration of HCl and phase ratio on the stripping rate of indium were carried out. Extraction and stripping isotherm were prepared to determine the number of stages required for quantitative extraction and stripping of indium at the chosen aqueous to organic phase ratio (A/O ratio). A pilot test and continuous countercurrent extraction test were developed to study the behavior of various metal ions. Quantitative indium was extracted by 10% P204 with three stages countercurrent extraction at A/O ratio of 2/1. The extraction rate of indium reached 99.9%, while the extraction rates of iron, zinc and cadmium were 1.5%, 0.5% and 1.1%，respectively. Indium in the P204 loaded organic was effectively stripped by 6 mol/L HCl with four stages at A/O ratio of 1/5 and the stripped organic phase can be reused in the extraction process.

Process & Technology

Percolation Evolution and Structure Characterization for Coal-based Porous Carbon

Qili WANG Min HE Xiaochuan LI Qi LIU

Chin. J. Process Eng.. 2017, 17(5):  989-994.  DOI: 10.12034/j.issn.1009-606X.217120

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The porous carbon was prepared using coal char particles and coal tar as raw materials, and the roasting process of green body of carbon was analysed from the perspective of fluid mechanics of porous media. The evolution process of pores of porous carbon during the forming process in roasting was developed, and the heterogeneous characteristics of pore structure were demonstrated by fractal theory and mercury intrusion test. The results showed that the hydrodynamic nature of the roasting process for carbon blank is the flow of the volatile in porous media. With the various stages of the roasting process, the percolation evolution process of the pore structure is developed from the emergence of the pores, local area and finite clusters to global material and infinite clusters. The volume porosity range from 29.67% to 36.59%, the specific surface area range from 2.32?3.91 m2/g, the area fractal dimensions of skeleton range from 1.788 to 1.854, the area fractal dimensions of pores range from 1.638 to 1.732, the volume fractal dimensions range from 2.844 to 2.949, the fractal dimensions of tortuosity range from 1.319 to 1.386, the percolation threshold in mercury intrusion test range (8.94?13.08)?104 Pa, respectively. Consequently, the fractal and percolation characteristics of porous carbon are clearly demonstrated.

Influence of Shenmu Coal Ash on the Reaction Characteristics and Structure of Fe-based Oxygen Carrier in Coal Char Chemical Looping Gasification

Qishun WAN Yongzhuo LIU Qingjie GUO Anhong TIAN

Chin. J. Process Eng.. 2017, 17(5):  995-1001.  DOI: 10.12034/j.issn.1009-606X.217105

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The influence of coal ash accumulation content on the reaction between Shenmu coal char and Fe4Al6 oxygen carrier (Fe2O3: Al2O3 mass ratio 4:6) and the oxygen carrier microstructure by adding Shenmu coal ash was investigated in a laboratory-scale fluidized bed. The results showed that addition 5%?15%(?) ash can reduce the reduction reaction temperature of Fe4Al6 oxygen carrier and increase the reaction rate between oxygen carrier and coal char at the temperature of 800?900℃. Carbon conversion rate curve was fit by Gaussian peak fitting method, indicating that 15% ash can promote the char gasification stage and increase the carbon conversion rate. It found that low-melting-point compounds, such as Fe2SiO4, FeAl2O4, CaAl8Fe4O19 and CaFe4Al2O10 formed in the oxygen carrier with 20% ash at 950?1000℃ of reduction reaction temperature of Fe4Al6 oxygen carrier and with 15% ash high than 1000℃. The compounds with low melt point and low thermal conductivity may attribute to the sintering and agglomeration of the Fe4Al6 oxygen carrier.

Structures of Several Lignins Isolated from Sugarcane Bagasse and Their Effects on Enzymatic Hydrolysis of Cellulose

Xingkai CUI Ke CHEN Xuebing ZHAO Dehua LIU

Chin. J. Process Eng.. 2017, 17(5):  1002-1010.  DOI: 10.12034/j.issn.1009-606X.216376

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Five types of lignin by-products were isolated from sugarcane bagasse by organic acid, alkaline and oxidative pretreatments, respectively, namely acetic acid lignin (AAL), acetosolve lignin (AsL), milox lignin (ML), peracetic acid lignin (PAAL) and alkaline lignin (AL). Structure characterizations were performed by analysis of elements, functional groups, chemical components, molecular weights and spectra. The results confirmed that sugarcane bagasse lignin was a typical H?G?S lignin. Except PAAL lignin, other four isolated lignins showed similar structures. PAAL lignin had lower molecular weight, higher carbonyl and acid-soluble lignin contents. Inhibition of cellulose conversion were observed when addition of these five lignins individually into the system of enzymatic hydrolysis of cellulose, and PAAL showed the highest inhibitive action. Further experiments by addition of lignin model compounds in to the system indicated that phenolic hydroxyl group (Ph-OH) was a key functional group mediating the inhibition of cellulose conversion by lignin, and the inhibitive effect of Ph-OH in p-hydroxyphenyl (H) was stronger than those in guaiacyl and syringyl structures. The finding of this work demonstrated that the inhibitive action of lignin to enzymatic hydrolysis of cellulose was not only attributed to non-productive adsorption of enzymes, but also to the inhibition of small-molecule phenol compounds yielded by deplymerization of lignin during the pretreatment.

Anti-scaling Method and Process Optimization in the Advanced Treatment of Mine Water

Jianjun LIU Yanchun ZHANG Rongji LI Sen WANG Binqi WANG

Chin. J. Process Eng.. 2017, 17(5):  1011-1015.  DOI: 10.12034/j.issn.1009-606X.217103

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According to the process and site conditions of the Yongcheng Kaikong reuse mine water project, it was suggested to control the hardness, regulate pH, select the reasonable rate of recovery and optimize the choice of antiscalant after theoretical analysis, calculation and experimental study. The optimal conditions for a safe and economical reverse osmosis system were calcium concentration lower than 160 mg/L, pH equal to 7.4, antiscalant dosage 2.8?10?6(?). The results of three-year running showed that the scaling problem has been effective controled, and the pressure difference and the desalination rate have undergone little change.

Alkylation of Isobutane with Butene over Ether-functionalized Composited Chloroaluminate Ionic Liquids

Zhenhua ZHANG Guoying ZHAO Dan LU Jingheng WANG Baozeng REN

Chin. J. Process Eng.. 2017, 17(5):  1016-1022.  DOI: 10.12034/j.issn.1009-606X.217126

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Four ether-functionalized ionic liquids including 1-methoxyethyl-3-methyl imidazole chloride ([MOEMIM]Cl), 1-methoxyethyl-3-methyl imidazole bromide ([MOEMIM]Br), N,N,N-trimethyl-N-(2- methoxyethyl) ammonium bromide ([N111,1O2]Br), N,N,N-triethyl-N-(2-methoxyethyl) ammonium bromide ([N222,1O2]Br), were synthesized and applied as co-catalyst of triethylamine hydrochloride chloroaluminate ionic liquids for isobutane alkylation. The effect of four kinds of ionic liquids and the addition amounts on the catalytic performance of chloroaluminate ionic liquids had been systematically investigated. The results showed that addition of 6%(?) [MOEMIM]Cl into triethylamine hydrochloride chloroaluminate ionic liquids improved the C8 selectivity from 47.7% to 63.6% and research octane number (RON) from 83.5 to 93.2 at 25℃, 500 mL/h feed rate, 20:60 the volume ratio of acid to hydrocarbon. The optimized ether-functionalized composited ionic liquids catalyst could be reused for at least 20 times without loss activity. These enhancement is believed to result from the increased isobutane solubility, the inhibited acidity and improved interfacial properties.

Preparation of Mesophase Pitch from Petroleum Pitch

Chengyou HE Yi NIE Peipei LI Lu BAI Qibao WANG

Chin. J. Process Eng.. 2017, 17(5):  1023-1027.  DOI: 10.12034/j.issn.1009-606X.217112

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The petroleum asphalt was used to prepare the mesophase pitch through three steps treatment including polymerization, hydrogenation and heat treatment. The mesophase content in the obtained product is more than 80%. The composition and structure of asphalt in the three-step process were characterized. Besides, the influence of heat treatment conditions, like low temperature with a long time and high temperature with a short time, on mesophase pitch morphology was investigated. The results showed that the content of toluene insoluble and the number of aromatic rings in the asphalt were improved by thermal polymerization. After modified by hydrogenation, the alicyclic hydrocarbons in the asphalt molecules was increased and the mobility was improved. Finally, after thermal treatment, the polycyclic aromatic molecules were formed with side chains or naphthenic structure. The treatment by low temperature with long time was favorable to the development of mesophase molecules and obtaining wide-area streamlined mesophase.

Respective and High Value-added Utilization of the Valuable Components in BOF Steel Slag

Yanbo HE Zhaojin WU Zhifang GAO Haifeng YUE Weiming LIU Ping WANG

Chin. J. Process Eng.. 2017, 17(5):  1028-1034.  DOI: 10.12034/j.issn.1009-606X.217124

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A new method for respective and high value-added utilization of the valuable components in BOF steel slag was proposed. Using the selective carbothermic method, the reduction behavior of the valuable elements Fe, P, Mn, Cr etc in BOF steel slag and the composition of the ferroalloy (target phase) precipitated from the slag effected by reduction temperature and time were investigated. Target phase and residues were obtained from the reduced slag by milling and magnetic separation. The metals-doped LiFePO4/C, a cathode material of lithium ion battery was synthesized by using the target phase recovered from the slag as main raw material. The results showed that exhibiting first discharge capacity of 159.58 mA?h/g at 0.1C and excellent rate performance. The residue was fine powders with mean size of about 2.5 ?m and uniform size distribution, and its main phases include Ca(OH)2, 2CaO?SiO2 and 3CaO?SiO2, showing significantly improved resource characteristics and utilization value.

Calculation Model for Turnover Number of Multi-functional Hot Metal Ladle

Zongxi GU Anjun XU Dongfeng HE Wei WU Jingbo LIU Weigang HAN3

Chin. J. Process Eng.. 2017, 17(5):  1035-1040.  DOI: 10.12034/j.issn.1009-606X.217147

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Calculation model for turnover number of multifunctional hot metal ladle was proposed based on comprehensive consideration of ladle preparation and ladle allocation method for blast furnace. Ladle number was composed of three parts which were loaded ladle number for processing needs, required preparation and unloaded ladle number for excessive allocated for blast furnace. Ladle turnover number in 2 blast furnace?2 basic oxygen furnace production mode in Chongqing steel plant was obtained as 16 by applying the model. The results showed that decreasing the buffer capacity of loaded and unloaded ladle should be a crucial step to reduce the ladle turnover number. Therefore optimizing ladle allocation method and continuous casting heats were supposed to be adopted as feasible measures. Individual optimization of ladle allocation method and casting heats can both contribute to the decrease of 2 in ladle number. In addition, ladle number can be reduced by 4 with joint optimization according to the model.

Dissolution Behavior of Lime Particles in CaO-FeO-SiO₂-P₂O₅ Slag

Yunjin XIA Xiaopan LI Jie LI Dingdong FAN Xin GUO

Chin. J. Process Eng.. 2017, 17(5):  1041-1046.  DOI: 10.12034/j.issn.1009-606X.217121

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The dissolution behavior of lime particles in CaO?FeO?SiO2?P2O5 slag at 1400℃ was studied by putting the average size about 70 ?m lime into the CaO?SiO2 saturated slag. The results showed that six areas were formed along calcium oxide around after the lime particles were adding into the slag, namely unmelted calcium oxide region, transition layer of lime dissolution transformation to calcium ferrite, calcium ferrite layer, discontinuous solid solution layer, dense solid solution layer and original slag. The C2S?C3P solid solution was formed in 5 s, its P2O5 content reached the maximum about 120 s, then the size of solid solution increased and P2O5 content decreased with time. When P2O5 was in slag, the xC2S?C3P layer was formed in the reaction interface of lime, instead of C2S, the formation of C2S?C3P solid solution layer prevented the dissolution of lime.

Mineral Phase Transformation during Oxidation Roasting of Low-grade Sulfide and Oxide Mixed Zinc Ore with High Calcium

Xiaobing GAO Yixin HUA Yun WANG Cunying XU Jian LI Wenhao KUANG Zhen ZHANG Zhen LEI Donghui LU

Chin. J. Process Eng.. 2017, 17(5):  1047-1053.  DOI: 10.12034/j.issn.1009-606X.217151

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Based on the characteristics of high calcium content, the low-grade sulfide and oxide mixed zinc ore was treated via an oxidation roasting at low temperatures by controlling the sulfur and oxygen potentials in the gas phase to make the transformation of zinc-bearing mineral phases and promote the dissolution of zinc in the ammonia system. At the same time, sulfur in the ore could be transformed into CaSO4 in the presence of CaCO3 and the pollution of SO2 to environment could be effectively avoid. The results showed that when the mixed zinc ore with a Zn content of 5.45% roasting at 300℃ for 3 h, the hemimorphite and sphalerite in the ore were transformed into easily soluble ZnO, while the galena, pyrite and calcite were transformed into PbSO4, Fe2O3 and CaSO4, respectively. The obtained calcine was leached with NH3?(NH4)2SO4?H2O system at 45℃ and the zinc leaching rate was up to 73.27%. When the temperature was higher than 300℃, however, a large amount of franklinite would be produced in the calcine, resulting in a decrease in the leaching rate of zinc.

Biochemical Engineering

Expression of CRM197 in E. coli System and Its Application in Universal Influenza Vaccine

Lu XU Jing ZHANG Rong YU Zhiguo SU

Chin. J. Process Eng.. 2017, 17(5):  1054-1058.  DOI: 10.12034/j.issn.1009-606X.217132

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Express the nontoxic mutant of diphtheria toxin (CRM197) in E. coli BL21 (DE3) by gene engineering technique and purify the protein by affinity chromatography under denaturation. As the carrier protein, recombinant CRM197 was conjugated with influenza antigen M2e via BMPH to prepare the conjugate vaccine to immune BALB/c mice. Determine the M2e specific IgG in sera by indirect ELISA. The results showed that rCRM197 was expressed in E. coli system successfully with optimized level (250±30 mg/L) and high purity (>95%). The conjugate vaccine CRM197?M2e prepared by chemical coupling in denaturation could effectively immunize BALB/c mice. And the M2e-specific IgG antibody titer elicited by CRM197?M2e conjugate vaccine was significantly higher than that in healthy, M2e, CRM197 and M2e+CRM197 mixed groups by 430.5, 32, 181 and 215 times.

Pretreatment Method of Lessonia trabeculata Stipe

Chuanfeng AN Zhihui WANG Bin WANG Fengji HUI Wei CONG

Chin. J. Process Eng.. 2017, 17(5):  1059-1065.  DOI: 10.12034/j.issn.1009-606X.217152

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The water absorption characteristics of Lessonia trabeculata stipe and the effects of smashing and squeezing pretreatment methods on water absorption were investigated. The results showed that the critical penetration distance of water in the stipe was about 2 mm. When the size of stipe particles was twice times less than the critical penetration distance, the algal particles could be sufficiently penetrated and saturated by water in 6 h. As the crack of stipe was grown and enlarged with the increase of squeezing pressure, the water absorption rate increased to 250% at 149 MPa in 6 h. Since stipe was sufficiently soaked in water after pretreatment, the alkaline extraction speed could be remarkably raised. Especially when some cell walls were destroyed by squeezing, the extraction speed was the highest during the earlier 3 h of extraction.

Materials Engineering

Characterization of Activated Carbon from Capsicum Straw under Optimum Carbonization Process

Haihong LI Yuqian LIU Ning WANG

Chin. J. Process Eng.. 2017, 17(5):  1066-1071.  DOI: 10.12034/j.issn.1009-606X.217113

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The activated carbon was prepared by capsicum straw as the research object. The carbonization temperature, carbonization time and heating rate were taken as the influencing factors, and the specific surface area and char yield were taken as the test indexes of orthogonal experiment. The pore structure and surface chemical properties of activated carbon were characterized, which was prepared under the optimum carbonization process. The results showed that the optimum carbonization conditions were as follows: the carbonization temperature of 400℃, coking time of 50 min, heating rate of 5℃/min. Under these conditions, the char yield of activated charcoal was 39.900%, the BET specific surface area was 966.003 m2/g, the total pore volume was 0.544 cm3/g and the average pore diameter was 2.252 nm. Besides, rich pore structure and the functional groups such as phenol, alcohol hydroxyl, carboxyl, ether etc. existed in the surface of activated carbon.

Preparation of Mg-Al Alloys via Electrochemical Co-deposition Using AlCl₃-NaCl Double Salt as Al Source

Yang LIU Xuchen LU Zhimin ZHANG Shiwei CHEN

Chin. J. Process Eng.. 2017, 17(5):  1072-1077.  DOI: 10.12034/j.issn.1009-606X.217140

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Mg?Al alloy was prepared using electrochemical co-deposition method with AlCl3?NaCl double salt as Al source and molten salt prepared by the dehydration of MgCl2?6H2O as the electrolyte. The results showed that the AlCl3?NaCl double salt was relatively stable at high temperature when AlCl3 molar fraction was less than 0.4. The volatile loss of AlCl3 could be effectively reduced when using AlCl3?NaCl double salt as Al source to feed into molten system of high temperature. When the mole fraction of AlCl3 in the double salts was less than 0.5, the usage efficiency of AlCl3 was high in the process of preparation Mg?Al alloy, and Al content in Mg?Al alloy was increased by 9.5% at least compare with those alloys prepared by using AlCl3 as Al source, the deviation from theoretical value of Al content in Mg?Al alloy reduced. Al content in Mg?Al alloy increased linearly with the increase of the AlCl3 content in the molten salt, and the Mg?13%Al alloy has relatively uniform element distribution at macro level, and the grain size of alloy was 50?100 ?m.

Synthesis of Sodium Titanate by Crystallization of Amorphous Phase and Crystalline Structure Transition

Yan PENG Zhi WANG Dong WANG Xuzhong GONG Jianwei CAO Tao QI

Chin. J. Process Eng.. 2017, 17(5):  1078-1084.  DOI: 10.12034/j.issn.1009-606X.217130

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The method of crystallization of amorphous phase was applied to synthesize the different sodium titanate and the rules of crystalline structure transition to find the ways to synthesize different sodium titanates with single-phase and high crystallinity was studied. The crystallization of amorphous phase contains two parts, namely preparing amorphous phase and its crystallization. Preparation of amorphous sodium titanate is obtained by sintering TiO2 and Na2CO3 at 1200℃ for 1 h and then water-quenching. Crystallization of amorphous phase is carried out to synthesize sodium titanate by controlling the temperature, holding time and heating program. The results showed that single-phase Na2TiO3 and Na16Ti10O28 can be synthesize at 626℃ for 0 min and 811℃ for 120 min, respectively. The single-phase Na16Ti10O28, Na2TiO3, Na2Ti3O7 were synthesized at 897℃ for 0, 30 and 120 min, respectively. The average crystallinity at 626, 811 and 897℃ were 45.2%, 43.8% and 86.6%, respectively. In addition, it is found that gradual transition happens from amorphous phase to Na2TiO3 during the heating process, then transition happens from Na2TiO3 to Na4Ti5O12 at 626℃, further transits to Na16Ti10O28 at 811℃ and transits to Na2Ti3O7 at 897℃.

Preparation of Graphene and its Application on the Adsorption of Cr(VI)

Zhigong ZHENG Jinbei YANG Jinchao GUO Ronghui SHI

Chin. J. Process Eng.. 2017, 17(5):  1085-1090.  DOI: 10.12034/j.issn.1009-606X.217104

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Graphene was prepared by graphite oxide reduction method. Graphene was used to remove Cr(VI) from water as an absorbent. Effects of pH, temperature and graphene dosage on the adsorption capacity, adsorption thermodynamics and kinetics were discussed. The results showed that graphen was a good adsorbent of Cr(VI). The adsorption behavior was the favourable adsorption, conformed the Langmuir isotherm equation well. The adsorption process was spontaneous and endothermic process, it corresponded with pseudo-secong-order kinetic model, the activation energy was 88.62 kJ/mol.

Environment & Energy

Research and Application of Waste Heat Recovery and Cascade Utilization for Low-grade Flue Gas in Industrial Field

Naili GUO Chunsheng YANG Peng XIAO Jianqiong HUANG

Chin. J. Process Eng.. 2017, 17(5):  1091-1096.  DOI: 10.12034/j.issn.1009-606X.217175

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To satisfy the actual demands of industrial enterprises, a comprehensive and high-efficient system based on the principle of thermodynamics, and applicable to recovery and cascade utilization of waste heat for low-grade flue gas in industrial field, has been researched and developed within modern sensor technology, automatic measurement and control technology, and high-efficient heat exchange technology. It has been applied practical production in the industrial enterprise. Modular design has been adopted, which can better adapt to the highly-variable working conditions during the productive process and then achieve automatic dynamic control for the amount of recovery and utilization of waste heat. It has gotten rid of the low efficiency of recovery and utilization for low-grade waste heat below 250℃ in the industrial enterprises. Moreover, it overcame the defects of analogous system, such as narrow range of application, low efficiency of recovery and utilization, poor level of automation, and complexity and poor precision for operation. The practical application in the industrial enterprise has demonstrated that the system can only save the energy cost beyond 300000 ￥/a, but also decrease energy waste and thermal pollution caused by direct emission of waste heat. Therefore benefit society and economy were significantly.

Simulation and Optimization of Salinity Gradient Power Generation System

Bin LI Lianying WU Weitao ZHANG Ying WANG Yangdong HU

Chin. J. Process Eng.. 2017, 17(5):  1097-1101.  DOI: 10.12034/j.issn.1009-606X.217107

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The configuration of multistage forward osmosis power generation was introduced and electricity generation performance was improved effectively compared with the single-stage forward osmosis configuration. Simulation analysis is carried out on the configuration of multistage forward osmosis power generation and the effect of concentrated brine flow and preload pressure on the power output was analyzed. The results showed that the power output increased at first and then decreased with the increasing of concentrated brine flow or preload pressure and there existed a highest value. For different energy recovery efficiency, optimization model with the maximum the power output of 100 m2 osmotic membrane as the objective and with concentrated brine flow and preload pressure as the decision variables was established. As a result, there were different optimum solutions concentrated brine flow and preload pressure for different power recovery. It showed that concentrated brine flow decreased and preload pressure increased with the increasing of power recovery.

Pyrolysis Dynamics Calculation and Pyrolysis Gases Analysis of Wood Particles

Congcong YUAN Yudong WANG Dingchuan ZHANG Bin YANG Yongnian DAI

Chin. J. Process Eng.. 2017, 17(5):  1102-1108.  DOI: 10.12034/j.issn.1009-606X.217128

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To explore the effect of atmosphere on the pyrolysis reaction of compressed wood chips particles, the thermo-gravimetric experiments with carbon dioxide and dry air as the dynamic gases under heating rates of 10, 20, 30℃/min were conducted by using synchronous thermal analyzer. Aiming at the second mass loss stage of thermo-gravimetric curves, the software of Netzsch Thermokinetics 3 was used to analyze the reaction orders, and Coats?Redfern method was used to calculate the kinetic parameters. Moreover, gas chromatography was applied to determine the composition of pyrolysis gases produced from enlarged experiment of thermo-gravimetric experiment at the heating rate of 10℃/min. The results showed that there are 3 weightless stages in the heating process of wood particle under these two kinds of atmosphere. In carbon dioxide and dry air, the second stage weight loss were 65.97% and 56.31%, the thermal decomposition reaction series were 1.23 and 1.0, the activation energies of this pyrolysis phase were117.73 and 87.4 kJ/mol, and the pre-exponential factor were 5.8×106 and 1.1×104 min?1, respectively. In the pyrolysis gases, the concentration of methane is lower in carbon dioxide than in dry air, while hydrogen and carbon monoxide are higher.