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    The Chinese Journal of Process Engineering 2014 Vol.14
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    Optimization of Magnetic Parameters in a Continuous Casting FC-Mold
    GAO Chen ZHANG Li-feng WANG Qiang-qiang
       2014, 14 (1): 1-8.  
    Abstract （1109）      PDF （829KB）（242）       Save
    In order to optimize the operational parameters of flow control mold (FC-mold), the effects of magnetic parameters including electric current and location of the two rules on the flow pattern in a continuous casting mold were studied by numerical simulation. The results indicated that higher electric current value resulted in bigger maximum intensity of the magnetic field. When the current was approximately below 665 A, the surface velocity in the mold decreased with the increase of the current. When the current was over 665 A, the maximum surface velocity fluctuated with the increase of the current. The pressure on the narrow face by the jet from the nozzle outport reached the maximum value 1890 Pa at 665 A. And the impingement depth of the jet decreased with the increase of the current. The maximum meniscus velocity was more affected by the location of lower magnetic field rather than that of upper one. Both intensity and location of the magnetic field had great influence on the flow pattern in the continuous casting strand.
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    Flow Characteristics of Catalytic Particles in the Pre-lifting Structure with Two Strands of Catalyst Inlets
    ZHU Li-yun FAN Yi-ping LU Chun-xi
       2014, 14 (1): 9-15.  
    Abstract （898）      PDF （375KB）（189）       Save
    Solids volume fraction and particle velocity in the pre-lifting structure with two strands of catalyst inlets were studied using optical fiber on a large scale cold model experimental setup. A radial non-uniformity index was applied to describe quantitatively radial distribution of solids volume fraction and particle velocity. The experimental results in different pre-lifting structures were compared. The experimental results show that the pre-lifting structure can be divided into three zones. According to the analysis of radial non-uniformity index of solids volume fraction and particle velocity, the uniformity degree of radial distribution of solids volume fraction and particle velocity decrease in the order of riser region > bottom region > central tube region. The homogeneous distributions of solid volume fraction and particle velocity exist on one section between 1.3 and 2.3 m in the riser. Compared with the pre-lifting structure without central tube and traditional structure, the distribution of solids volume fraction is so homogenous that catalyst particles and oil can react more effectively. Then, empirical models using parameters of terminal solid volume fraction es', Froude number Fr and axial height/riser diameter h/Dr for estimating the axial distributions of averaged cross-sectional solids volume fraction in the pre-lifting structure are obtained based on the experimental data and theoretical analysis, respectively, which agree well with the experimental data.
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    Numerical Simulation of Electromagnetic, Flow and Temperature Fields in Electroslag Remelting Process
    LIU Yan-he HE Zhu LIU Shuang LIU Zheng XIA Tian WANG Fang LI Bao-kuan
       2014, 14 (1): 16-22.  
    Abstract （1015）      PDF （907KB）（490）       Save
    The magnetic and Joule-heat fields of electroslag remelting process (electrode, slag and ingot) were obtained by finite element software, and the electroslag remelting process coupled with the magnetic and Joule-heat fields was simulated by CFD software. Based on the basic control parameters, the metal pool shape, temperature distribution and velocity field were analyzed. The simulated results are in good agreement with the experimental data, especially on slag-metal interface, the maximum error does not exceed 10%. When the inserting depth is 0.015 m, an intermediate region appears between the anti-clockwise circulating eddies in the bulk of slag, which is controlled by a clockwise circulating eddy. The maximum temperature will be decreased by about 1% for each additional 0.015 m of the inserting depth.
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    Numerical Simulation on Hydrodynamic Performance of the Maxblend Impeller
    LI Jian-da SU Hong-jun ZHANG Qing XU Shi-ai
       2014, 14 (1): 23-29.  
    Abstract （962）      PDF （550KB）（557）       Save
    The hydrodynamic characterization of Maxblend impeller in the laminar regimes is studied by CFD simulation in the systems of viscous Newtonian and non-Newtonian pseudoplastic fluids. The power consumption, Metzner constant (ks), shear performance and axial pumping are examined. The results indicate that the power curve is consistent with the experimental data. ks=10 remains almost constant for a wide range of rheological behavior indices. The Maxblend impeller presents a flow pattern structure of double circulation. The region of impeller has high shear rate and large discharge quantity. And large vortex flow is generated, which results in the shear efficiency lower than 0.5. As the Reynolds number increases (Ren=1.4, 5.0, 7.6), the average shear rate (3.40, 9.91, 15.05 s-1) and pumping (0.0014, 0.0033, 0.0052 m3/s) of the tank increase, especially in the wing area at the bottom of impeller, the increase of average shear rate (3.40, 9.91, 15.05 s-1) and pumping (0.0014, 0.0033, 0.0052 m3/s) is relatively large. The mixing effect is strengthened and large junction area generated by high shear rate. Rapid cycling is induced by strong pumping between high and low areas of shear rate, and the fluid reaches high mixing efficiency as a result.
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    Research on Fluidization Characteristics of Some Typical Iron Ore Powders
    LIANG Hai-long WEN Liang-ying LU Feng ZHONG Hong
       2014, 14 (1): 30-35.  
    Abstract （1029）      PDF （286KB）（290）       Save
    Fluidization characteristics of some typical iron ore powders (Australian ore, Brazilian ore, Beifang ore, schreyerite ore) were studied using a D-type organic glass tube model with 150 mm diameter. The pressure drop as a function of the gas velocity for the iron ore powder was obtained, the minimum fluidized velocity and the largest pressure drop showed a basic agreement with the theoretically estimated values. The results indicated that the particle size was the main influential factor on the fluidization characteristics, the minimum fluidization velocity increased obviously with increasing of the particle size. The schreyerite ore with the particle size less than 0.125 mm showed a poor flowability, and channeling occurred in the process of fluidization. The particularly fine iron ore escaped from fluidized bed along with the gas flow when the powder in broader particle size was perfectly fluidized. For the four different iron ores with the same particle size, the minimum fluidized velocity was close, but the pressure drop was quite different. The bed pressure drop of Brazilian ore was much greater than other three iron ores. All the minimum value of the largest bed pressure drop appeared between 0.25 mm and 0.45 mm, which was considered as suitable particle size range in the iron ore fluidized reduction process.
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    Effect of Deflector on the Gas-Solid Separating Performance in the Cyclone Separator
    LIANG Jia-hao LI Yang KONG Xiang-gong LIU Mei-li
       2014, 14 (1): 36-41.  
    Abstract （1053）      PDF （834KB）（195）       Save
    The performance of a cyclone with deflector in annular space is studied by using numerical simulation method. Simulation results of the gas flow filed reveal that the introduction of deflector in the cyclone separator can improve the asymmetry flow greatly, when compared with traditional single inlet cyclone separator. In the cyclone with deflector, the centre of flow coincides with the geometric center, which restrains the flapping motion of vortex cone. To further study the performance of the new cyclone separator, two-phase flow is investigated by using DPM model. The simulation results show that the collection efficiency of particles is enhanced notably, especially the particles with small sizes, the efficiency of which is raised up from 53.4% to 94.6%.
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    Circulation Velocity of Fluid in Three-phase Biological Fluidized Bed Reactor with Internal Circulation
    NIU Kai-yuan HU Kun YU Meng-li HUANG Wei-xing
       2014, 14 (1): 42-46.  
    Abstract （854）      PDF （323KB）（450）       Save
    The gas hold-up in the reactor and local flow resistance at the bottom of downcomer under different operating and structural conditions were studied by experiments and CFD simulation. The results show that the gas hold-up increases with increasing of gas input velocity Ugr, while the local resistance factor increases with decreasing of Ar/Ad and increasing of d/h. Based on these results, new correlations for the gas hold-up and local flow resistance factor were developed. Then, the downcomer fluid velocity under different operating and structural conditions were measured, and the effects of local flow resistance and friction resistance analyzed with the established fluid velocity model. It is found that both the local flow resistance and friction resistance affect the downcomer fluid velocity significantly, and by using the new correlations in the fluid velocity model, the downcomer velocities predicted by the model are in good agreement with experimental measurements. The downcomer velocity reaches the largest value 0.32 m/s when Ugr is 2.29 m/s. However, the fluid velocity gets the largest value when Ar/Ad is taken as the maximum value 1.61 and d/h as the minimum value 1.75.
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    Experimental Simulation on Chemical-looping Combustion of Cold Model
    Huseyin Sozen WEI Guo-qiang LI Hai-bin HE Fang HUANG Zhen
       2014, 14 (1): 47-55.  
    Abstract （963）      PDF （252KB）（234）       Save
    The pressure profiles, gas velocities, solid circulation rate, solids flux, residence time distribution of gas and particles in chemical-looping combustion reactors and gas leakage were studied in a cold flow model unit. And these parameters in both air and fuel reactors were measured in the experimental stage. The experimental results show that gas fluidization velocity in the air reactor is 1.8 m/s, gas fluidization velocity in the fuel reactor 0.5 m/s, and the bed materials inventory of the two reactors between 1.2 to 3.15 kg. The first cold flow model results show that the solid circulation rates are sufficient. The appropriate operating conditions are optimized and the summary of final changes is made the on cold model. The proposed design solutions are currently being verified in a cold flow model simulating the actual reactor (hot) system. This paper presents an overview of the research performed on a cold flow model and highlights the current status of the technology.
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    Research on Chemical Enrichment Process of Sulfur in Sulfur-containing Slag Produced in Zinc Hydrometallurgical Production
    ZHANG Ying YU Guo-lin ZHENG Shi-li QIAO Shan WANG Xiao-hui JIANG Shao-feng WANG Shao-na
       2014, 14 (1): 56-63.  
    Abstract （979）      PDF （550KB）（255）       Save
    Aimed at recovery of sulfur by hot filtration method from sulfur-containing slag which was a by-product from the enriched-oxygen direct leaching process of zinc concentrate, chemical enrichment process of elemental sulfur was carried out. Based on physico-chemical analysis of the sulfur-containing slag, it was known that the impurities affecting the grade of elemental sulfur were SiO2 and FeS2. Then, the technical scheme of de-silication by HF solution and decomposition of FeS2 by acidic ferric sulfate solution was proposed, and the relevant conditions were studied. The optimal conditions to remove silica were HF mass concentration 20%, temperature 55℃, time 3 h, and ratio of liquid to solid 4 mL/g, and the better conditions to decompose FeS2 were Fe3+ concentration 1.5 mol/L, sulphuric acid concentration 1.5 mol/L, 2 times of theoretical amount of ferric sulfate, temperature 98℃ and time 5 h. After treatment of the sulfur-containing slag by the two steps, the elemental sulfur in the slag was enhanced form 70% to 86%. The preliminary economic evaluation for this process showed that the proposed method had certain potential in industrial application.
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    Purification of Silicon by Si-Fe Alloy Refining-High Temperature Quenching-Acid Leaching Process
    WU Jian WANG Zhi GUO Zhan-cheng;
       2014, 14 (1): 64-70.  
    Abstract （951）      PDF （1290KB）（230）       Save
    The purification of silicon was carried out by Si-Fe alloy refining, high temperature quenching and acid leaching, the morphology, structure and purification effect of the silicon were studied. The results indicated that the total removal rate of impurities in the silicon before quenching was 76.82%, and after quenching 96.05%. With the increase of quenching temperature, the removal rate of impurities in silicon material after quenching was raised gradually, the total removal rate of impurities after quenching at 1007, 1207 and 1220℃ was 91.87%, 95.19% and 96.05%, respectively. Under the cooling rate of 3℃/min, the total removal rate of impurities in silicon material after quenching was 96.05%, however when the cooling rate was 9.5℃/min, the total removal rate of impurities after quenching was 94.21%.
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    Separation of As from As and Sb Contained Smoke Dust by Selective Oxidation
    LI Lei ZHANG Ren-jie LIAO Bin XIE Xiao-feng
       2014, 14 (1): 71-77.  
    Abstract （937）      PDF （311KB）（313）       Save
    Based on the thermodynamic analysis, behavior characteristics of As and Sb in the As and Sb contained smoke dust were studied. The results showed that the volatilization rates of As and Sb deceased with the increase of oxygen concentration in the roasting system. The arsenic phase was transformed into Fe3(AsO4)2 and Pb3(AsO4)2 with the existence of lead and iron oxides in the dust, which went against increasing of the As removal rate. The main influential factor on the As removal rate was roasting temperature. After treatment through the two-stage oxidizing roasting, the As removal rate reached 60.79% with the Sb loss rate of 9.78% in the conditions of roasting temperature of 973 K, oxygen flow rate of 30 mL/min and roasting time of 30 min for the first stage roasting, and oxygen flow rate of 40 mL/min and roasting time of 60 min for the second stage roasting. As was effectively separated from the smoke dust.
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    Characteristics of Adsorption and Desorption of Copper Ion on Imprinted Chitosan/Al2O3
    CHEN Hua-jun ZENG Jian-xian GUO Qian-nan ZHANG Jin-bin YU Xie QIAN Zhao-hui
       2014, 14 (1): 78-83.  
    Abstract （994）      PDF （249KB）（185）       Save
    In order to separate selectively Cu2+, Cu2+ imprinted polymer/aluminium oxide (IIP/Al2O3) was prepared by the surface-grafting and surface imprinting techniques. Al2O3 powder modified with tetraethylorthosilicate was used as the carrier, and chitosan as the functional monomer. Dynamic adsorption of Cu2+ on IIP/Al2O3 was studied, and Thomas, Yoon-Nelson and Wolborska models were adopted to fit to the experimental data. Further, experiments were performed to optimize the parameters of dynamic desorption. The results indicated that breakthrough capacity and dynamic adsorption capacity of the IIP/Al2O3 were 4.03 and 15.68 mg/g, respectively, and removal rate of Cu2+ reached 45.55% at Cu2+ inlet concentration of 100 mg/L, IIP/Al2O3 column height of 37.25 mm, flow rate of 1.0 mL/min and pH value of 5. The Thomas and Yoon-Nelson models fit well to the experimental data of dynamic adsorption. 15 mL hydrochloric acid solution at 0.6 mol/L resulted in the desorption rate of 99.54% for Cu2+ at IIP/Al2O3 column height of 37.25 mm and flow rate of 1.0 mL/min. Desorption time was short, and Cu2+ was easily recycled.
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    Removal of Cr6+ from Contaminated Soil by Surfactants and Sulfate-reducing Bacteria
    CAO Xiao-ya CAO Jun-ya LI Yuan-yuan ZHANG Guang-ji YANG Chao XIE Qiang
       2014, 14 (1): 84-89.  
    Abstract （827）      PDF （200KB）（198）       Save
    The chemical status of Cr was analyzed by the European Community Bureau of Reference method. Cr contaminated soil was leached by surfactants and sulfate-reducing bacteria (SRB). The experimental results showed that sodium dodecyl benzene sulfonate and Tween-80 at the concentrations of 5.0 and 0.01 g/L could enhance the leaching rate. When the content of Cr in the soil was 200 mg/kg, the leaching rate of Cr6+ was 14.70% and 24.74%, when the content of Cr in the soil was 500 mg/kg, the leaching rate of Cr6+ was 35.99% and 41.42% respectively. When the microbial quantity in the reaction system was 10 mL, the leaching rate of Cr6+ at different contents of Cr (200, 500 mg/kg) reached 98.07% and 94.73% in 18 h respectively. By co-processing of surfactants and SRB, all leached Cr6+ was converted to Cr3+, the residual Cr6+ in the soil converted from availabilities into stable state, mainly in Cr2(CO3)3 and Cr(OH)3. After leaching with surfactant and SRB, the concentration of Cr6+ in the soil was up to the environment quality standards for soils.
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    Collecting Rules of High Concentration Dust in Sintering Transfer Station by Exhaust Hood
    LI Xiao-chuan CHEN Ming-jun LI Qiang JIA Bin-bin HU Ya-fei
       2014, 14 (1): 90-95.  
    Abstract （925）      PDF （427KB）（130）       Save
    Dust emission in sintering ore transfer station of belt conveyor is chosen to determine its physical and chemistry property, observe the dust flow in exhaust hood, and study the relation between the granularity or total quantity of collected dust and the suction parameters for obtaining the collecting rules of high concentration dust with exhaust hood. The result indicates that the concentration of emission dust is more than 3000 mg/m3, its true density 4.040 g/cm3, and particle sphericity 0.51~0.93, and the content of total-iron (TFe) and calcium oxide (CaO) reaches 62%~64%. With increasing of suction velocity, the dust concentration in exhaust hood rises gradually, and the dust emission processing aroused by induced air is replaced by collecting processing of suction flow. When the suction airflow increases to a certain value, it has an effect on raising motionless dust attached on materials bed. With rising of suction velocity, the total quantity and maximum granularity of collected dust increase. But, the ratio of respirable dust is obviously reduced. In order to avoid a large amount of dust being blown away from material bed, the energy-saving suction velocity should not exceed 9.20 m/s. And the sizes of 97% particles in all collected dust should be less than 112.62 μm.
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    Viscosity Reduction and Dehydration of Crude Oil by Radiation
    ZHOU Cui-hong ZENG Meng LI Qiang ZHANG Hai-long
       2014, 14 (1): 96-100.  
    Abstract （865）      PDF （228KB）（296）       Save
    Radiation techniques were used for reduction of the viscosity and dehydration of raw oil sample. The effects of temperature and time of water bath, microwave and ultrasonic wave on the viscosity and water content of raw oil sample were examined. The results indicated that ultrasonic wave and microwave showed a better efficiency than water bath. The reduction rate of viscosity was 72% by the treatment of ultrasonic wave at 60℃ for 11 min, and 64.7% by the treatment of microwave at 70℃ for 9 min. These results are better than those previously reported.
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    Kinetic Model of Collision and Growth of Al2O3 Inclusions in Liquid Steel
    YUE Qiang CHEN Huai-hao KONG Hui WANG Jian-jun
       2014, 14 (1): 101-107.  
    Abstract （1065）      PDF （556KB）（216）       Save
    The growth kinetic models of non-metallic Al2O3 inclusions in liquid steel based on population balance model are developed to simulate their molecular diffusion and growth resulting from Brownian, Stokes and turbulent collisions. Brownian collision is considered in the stage of molecular diffusion, besides, Ostwald ripening. Particle-size-grouping method is applied to simulate the aggregation and growth of inclusions. The results show that the change of inclusion number density is slight for the inclusion diameter smaller than critical size, and significant for the diameter bigger than critical size as turbulent energy dissipation rate increases from 0.1 to 10 m2/s3. The peak-value diameter is around 0.2 μm corresponding to the maximum number density during collision and growth.
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    Combustion Kinetics of Coal Char with Random Pore Model
    SHAO Jiu-gang ZHANG Jian-liang WANG Guang-wei ZUO Hai-bin
       2014, 14 (1): 108-113.  
    Abstract （946）      PDF （660KB）（228）       Save
    The non-isothermal and isothermal combustion processes of coal char were studied by thermogravimetry, and the effects of heating rate and reaction temperature on combustion behaviors analyzed. The weight loss curve of combustion process was fitted by random pore model (RPM), and kinetic parameters obtained. In non-isothermal process, with the increase of heating rate, the weight loss curve moved to high temperature zone, and the maximum weight loss rate increased. When heating rate increased from 5℃/min to 20℃/min, the maximum weight loss rate increased from 3.2%/min to 11.3%/min. In isothermal process, with the increase of combustion temperature, the maximum weight rate increased, its combustion characteristics were improved. When the combustion temperature increased form 510℃ to 630℃, the maximum weight loss rate increased from 2.1%/min to 8.3%/min. RPM could describe the combustion process of coal char with high accuracy, and the activation energy of non-isothermal process and isothermal process was calculated as 84.27 and 64.16 kJ/mol, respectively.
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    Combustion Properties and Reaction Kinetics of Coal Char Based on Non-isothermal Thermogravimetry
    SUN Hui ZHANG Jian-liang WANG Guang-wei SHAO Jiu-gang PENG Xiao-hui
       2014, 14 (1): 114-119.  
    Abstract （910）      PDF （624KB）（312）       Save
    Non-isothermal thermogravimetry was used to study the combustion properties of four kinds of coal char, which were made from Jinkai lignite (JK), Wanshou bituminous coal (WS), Jinzhong Energy anthracite (JZ) and Lidaning anthracite (LDN) under different metamorphic conditions respectively, and their combustion reaction process was simulated by using random pore model (RPM), unreacted shrinking core model and volumetric model. The results show that the combustion properties of prepared coal char are related to metamorphic degree and volatile content of the original coal, and the heating rate. Decreasing the volatile content of coal and increasing the heating rate can lead to faster combustion rate of coal char apparently with shorter combustion time. The kinetic calculation shows that the RPM model is the optimized one to describe the combustion process of coal char, and the apparent activation energy calculated by it for the four kinds of coal char is 55.74, 88.26, 84.27 and 101.30 kJ/mol, respectively.
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    Formation Process of Propane Hydrate in Different Systems
    ZHANG Xue-Min LI Jin-ping WU Qing-bai WANG Chun-long JIAO Liang
       2014, 14 (1): 120-124.  
    Abstract （896）      PDF （390KB）（290）       Save
    In order to understand the formation characteristics of C3H8 gas hydrate and accelerate the formation process, the formation experiments of C3H8 are carried out with a visualization installation in the systems of pure water, 1950′10-6(w) SDS and 400′10-6(w) SDBS, respectively. And the induction time and formation rate of C3H8 in three different systems examined. The results show that in the temperature range between 0.8 and 1.2℃, the induction time of propane hydrate is the longest in pure water among three different systems, and the average formation rate is fastest in 1950′10-6(w) SDS, up to 0.0224 mm/h. Compared with the system of pure water, surfactant can shorten the induction time of C3H8 hydrate formation process and enhance its formation rate.
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    Optimization of Distillation Operation for Coking Wastewater Treatment Based on MINLP Model
    LIAO Ming-sen ZHAO Yue-hong NING Peng-ge CAO Hong-bin WEN Hao WANG Shao-na
       2014, 14 (1): 125-132.  
    Abstract （1017）      PDF （311KB）（265）       Save
    A mixed integer nonlinear programming model for ammonia-water distillation column is set up ?based on rigorous MESH equation? in order to minimize the operation cost of the column for obtaining the corresponding optimal operating ?parameters. In this model?, utilities price?,? bio-treatment cost?,? heating type of the column and heat integration of the preheater ?are considered as the key factors affecting the column operation cost?,? while feed inlet ?temperature and location?,? and ?corresponding? utilities flow rates are defined as the key operating parameters. The results indicate that direct heating column can save 1.56 ￥/t, compared with indirect one. The sensitive analysis shows that the parameters such as inlet and outlet concentrations of ammonia?,? total stage number?,? ?utilities price?,?? and preheater efficiency have significant effect on the operation of the distillation column. For a direct heating column, the optimal operating conditions are outlet concentration at 300 mg/L, total stage number 25, preheater efficiency 65%, and feed inlet temperature 75.40℃.?
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    Co-production of 3-Hydroxypropionie Acid and 1,3-Propanediol by a Recombinant Strain of Klebsiella pneumoniae
    LI Qing HUANG Yan-na LI Zhi-min YE Qin
       2014, 14 (1): 133-138.  
    Abstract （1066）      PDF （316KB）（228）       Save
    The production of 3-hydroxypropionic acid (3-HP) and 1,3-propanediol (1,3-PDO) by recombinant Klebsiella pneumoniae over-expressed aldehyde dehydrogenase was optimized with glycerol as substrate. During the feeding stage of fermentation, glycerol concentration was controlled differently at 0~10, 10~20, 20~30 g/L and intermittent addition of glycerol for three times. The results showed that the process controlling of glycerol concentration at 20~30 g/L resulted in the highest titer, 47.20 g/L of 3-HP and 43.90 g/L of 1,3-PDO were obtained in 26 h. The intermittent addition of glycerol led to the highest yield of 3-HP and 1,3-PDO, 0.35 and 0.38 mol/mol, respectively. The co-production of 3-HP and 1,3-PDO could achieve cofactor regeneration of NAD+ and NADH balance, which enhanced the recovery of carbon.
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    Preparation of Fertility-promoting Intrauterine Infusion in situ Gel and Its in vitro Release
    LU Chao-cheng FU Hua-lin ZHOU Tao ZHANG Yan-li LIU Meng-jiao JIN Chao CAO Hang LUO Li
       2014, 14 (1): 139-144.  
    Abstract （953）      PDF （1034KB）（248）       Save
    Fertility-promoting intrauterine infusion in situ gel (FPG) was prepared by cold soluble method with Poloxamer 407 (P407) and Poloxamer 188 (P188). The effects of concentrations of P407, P188, hydroxy propyl methyl cellulose (HPMC) and sodium alginate on gelation temperature were studied, the gelation temperature of in situ gel before and after addition of fertility-promoting intrauterine infusion liquid and release behavior in vitro were investigated. The results showed that the average gelation temperature of FPG was 27.9℃ when the concentrations of P407, P188 and HPMC were 18%(w), 7.5%(w) and 0.3%(w). Average accumulated loss rate of gel and accumulated release rate of drug were 92.11% and 95.42% in 6 h. The drug in the gel was released by the gel erosion, and the release profiles accorded to zero order equation.
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    Improvement of Oxidative Stability of Rubber Seed Oil Biodiesel with Additives
    LI Fa-she LI Ming BAO Gui-rong WANG Hua DU Wei SU Cheng-shuai WANG Zheng
       2014, 14 (1): 145-150.  
    Abstract （958）      PDF （245KB）（147）       Save
    Physical and chemical properties and fatty acid composition of rubber seed oil were measured. Using Rancimat method, the influences of six antioxidants and their addition, blending with any two kinds of antioxidants, temperature and mental copper and iron on the oxidative stability of rubber seed oil biodiesel were studied. The results show that the content of unsaturated fatty acid is 82.1% and the induction period of rubber seed oil biodiesel 0.81 h. The antioxidative effect of the biodiesel is better when the six antioxidants are used. When the TBHQ addition is 4000′10-6 (w), the biodiesel can achieve the national standard of biodiesel, the induction period of thel biodiesel is 13.09 h. The antioxidative effect order of six antioxidants on the biodiesel is TBHQ>BHT>D-TBHQ>OG>PG>BHA. The best antioxidative effect is obtained with PG mixed with other antioxidants. But using TBHQ mixed with other antioxidants will reduce itself antioxidative effect. The measuring temperature and addition of 0# light diesel on the biodiesel greatly affect the oxidative stability. With the increase of measuring temperature, the induction period decreases, but with the increase of 0# light diesel, the induction period prolongs. Copper and iron affect the oxidative stability of the biodiesel.
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    Mineral Characteristics of Coal Gangue from Liupanshui in Guizhou Province
    JIN Hui-xin WU Fu-zhong ZHU MIng-yan
       2014, 14 (1): 151-156.  
    Abstract （1234）      PDF （286KB）（326）       Save
    The mineral characteristics of coal gangue from Liupanshui area in Guizhou Province were studied. The results showed that the mixed gangue samples of waste coal roadway gangue and rock gangue had low C content and low calorific value, which could not be used directly as power generation fuel. However, Al enrichment and high contents of Fe and Ca were one of the important characteristics of coal gangue. The chemical components in the coal gangue mainly included SiO2, Al2O3 and Fe2O3, and their total content was up to 70%~80%. Moreover, V, Co, Ni, Cr and Ge had high enrichment degree in the coal gangue, which should be recovered as important value metals. In addition, its mineral composition mainly consisted of quartz and kaolinite, and then siderite, pyrite, montmorillonite, plagioclase, illite, dolomite, calcite and anatase, etc. The coal gangue powder was made up of the particles with irregular shapes and different sizes in the main range 1~3 mm, and partially 0.2~1 mm. The crystalline minerals, such as quartz, siderite and pyrite, were mostly in dense block and had perfect crystalline structure, while kaolinite, montmorillonite and plagioclase, etc., were in flake or loose block, which had lower crystalline degree than quartz, the organic matter containing C was mainly in flake and amorphous structure.
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    Preparation of Magnesium Aluminum Spinel Powder with Waste Solution from Acid Leaching of Blast Furnace Slag
    CHU Liang SHEN Xing-mei WANG Lian-zhen LI Liao-sha
       2014, 14 (1): 157-161.  
    Abstract （894）      PDF （490KB）（172）       Save
    Magnesium aluminum spinel powder was prepared by homogeneous precipitation method with acid-leaching solution of blast furnace slag containing Mg2+, Al3+ and other valuable components as raw material, and urea as precipitant. According to precursor productivity and properties of magnesium aluminum spinel, the optimal technological conditions were obtained: reaction temperature 100℃, urea dosage 10 times of theoretical dosage, calcination temperature 1100℃ and isothermal treatment time 2 h. After addition of 5%(w) Na2S2O4, the content of Fe2O3 was decreased from 1.70%(w) to 0.49%(w), iron removal rate reached 71.2%, and the whiteness increased 11 degrees. The magnesium aluminum spinel particles were flower and needle-like in shape. The prepared product belonged to alumina-rich spinel series, the content of impurities in the product was below the level of national standard.
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    Analysis on Development of Iron-making Process Based on the Principle of Energy-saving and Emission Reduction
    LI Ke-jiang ZHANG Jian-liang ZHANG Ya-peng LIU Zheng-jian JIANG Xi
       2014, 14 (1): 162-172.  
    Abstract （964）      PDF （722KB）（374）       Save
    Through the basic research on current situation of iron-making industry in China, the importance of iron-making industry in sustainable development was demonstrated, and the severe problems of energy consumption and environment protection were pointed out. And the key problems on energy saving and emission reduction in steel plants were analyzed based on carbon and energy flows, from which it was clear that the main task of emission reduction was to reduce the consumption of fossil fuels, such as coal and coke, and the main task of energy saving was to take advantage of the latent and sensible heat of top gas and sensible heat of blast furnace slag. Then, several advanced energy saving technologies, such as coke oven gas injection, injection of plastic scraps into the blast furnace, pure oxygen blowing and utilization of blast furnace slag, were analyzed. They did not make fundamental change to the blast furnace ironmaking process. Their popularity was critical to the improvement of energy saving and emission reduction in iron and steel industry in China. Finally, the research prospect of energy saving and emission reduction was indicated. In the short term, the utilization efficiency of fossil fuels should be improved based on in-depth research on consumption mechanism, and the structure of energy consumption optimized to alternate fossil fuel with clean energy. In the long term, the nature of iron making, carbon deoxidization, should be thought deeply in order to conduct exploratory research on innovation of ironmaking process and eliminate the fundamental shortcoming of current ironmaking process with high energy consumption and high emission.
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    Research Advances in Inhibitors Control of Low-temperature High Magnetic Induction Grain-oriented Silicon Steel Production with Acquired Inhibitor Method
    FU Bing XIANG Li QIU Sheng-tao CHENG Guo-guang
       2014, 14 (1): 173-180.  
    Abstract （815）      PDF （332KB）（363）       Save
    The current application and exploitation on production of low-temperature high magnetic induction grain-oriented silicon steel with acquired inhibitor method at both iron and steel enterprises and research institutions in the world are reviewed. The control techniques of inhibitors, which include the composition design for inherent inhibitors, nitriding method and process, and secondary recrystallization annealing, are thoroughly analyzed and proposed. It is indicated that the design ideas for inherent inhibitors are basically identical. The main inhibitor is AlN, the auxiliary inhibitor is sulfide, and a small amount of elements can also be as the auxiliary inhibitor, such as Sn, Sb, etc. However, the content of elements consisting of inhibitors has some difference. Nitriding with NH3 after decarburization has become the main method currently, but the most appropriate selection of nitriding method, which depends on the actual production conditions, is still not definite. Meanwhile, the corresponding control conditions of nitriding and decarburization annealing have obvious differences. And there is no difference in two kinds of heating program used for secondary recrystallization annealing, but the selected N2 content in the annealing atmosphere has some difference. Finally, the key problems on the control techniques of inhibitors are analyzed, and the further research directions are pointed out.
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    Pressure Characteristics in Pulse Cleaning System of Rigid Ceramic Filter
    YANG Liang JI Zhong-li LAI Tong
       2014, 14 (2): 181-188.  
    Abstract （835）      PDF （1282KB）（243）       Save
    The dynamic pressure characteristics at different positions of pulse cleaning system were measured by high frequency dynamic pressure sensor. The effects of cleaning pressure and diameter of nozzles on pulse cleaning performance were examined. Both design proposals for the subject and filtration to verify this research conclusion were proposed. The results show that there is significant difference of pulse cleaning performance with the same diameter nozzles, the difference of pulse jet nozzles performance increases when cleaning pressure increases, the pulse cleaning intensity decreases when the nozzles diameter increases. The static pressure along cleaning direction gradually increases. By decreasing the diameter of nozzles along the pulse jet direction, the pulse cleaning effectiveness can be improved. The ratio of sectional area of nozzle (s) to sectional area of pulse jet pipe (S) is significant for pulse cleaning. In this research, the best ratio s/S is from 45% to 55%.
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    Numerical Simulation on Separation of Solid with Liquid and Sedimentation of Red Mud in a Flat Bottom Thickener
    LI Mao LI Qiu-long ZHOU Tian LEI Bo ZHOU Jie-min ZHOU Chenn-qian
       2014, 14 (2): 189-196.  
    Abstract （836）      PDF （492KB）（459）       Save
    The solid-liquid separation process in an alumina red mud flat bottom thickener with the diameter of 40 m was simulated using the commercial CFD software Fluent and combining the simplified 3-D Eulerian two-phase model, realizable k-e turbulence model and SIMPLE algorithm. The flow patterns and solid red mud distribution in the thickener were analyzed and the arrangements for the overflow weir and feed inlet for feedwell proposed. The simulation results were verified by field measurements. Further simulation was carried out based on the optimum proposal. Combined with the self-defined evaluation criteria, the obtained results indicated that the solid concentration of overflow was decreased by 84.3% when the overflow weir was removed. And the fluid volume fraction lying in 60~64 g/L in the feedwell was increased from 3.70% to 14.36% after adopting the self-sucking jet pipe in the feed pipe, which could elevate the homogeneity of solid distribution in the feedwell, and enhance the sedimentation efficiency in the red mud thickener.
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    Effects of Collisional Parameters of Rough Particles on Simulation of Gas-Solid Flow in a Bubbling Fluidized Bed
    LU Bing ZHAO Yun-hua ZHONG Ying-jie
       2014, 14 (2): 197-203.  
    Abstract （896）      PDF （468KB）（304）       Save
    A two-fluid model based on the kinetic theory of rough particles was used to study the effects of collisional parameters on the flow behaviors of gas and particles in a bubbling fluidized bed. It was found that increasing the friction coefficient or decreasing the normal restitution coefficient led to more heterogeneous distribution of particles, larger expansion of the bed surface and more intense fluctuation of gas pressure drop. The time-averaged gas-solid flow fields predicted with a proper friction coefficient agreed well with the experimental data, and the friction coefficient was recommended at 0.3~0.6 for the poppy seeds. But the variation of normal restitution coefficient did not change the overall time-averaged flow fields, so its value was less sensitive than the friction coefficient. The tangential restitution coefficient had comparatively much weaker impact on both the dynamic characteristics of the bubbling fluidized bed and the time-averaged gas-solid flow fields.
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    Impact of Baffle Space Height on the Helical Baffle Double-pipe Heat Exchanger
    WU Jing-qiu ZHU Dao-Fei WANG Hua
       2014, 14 (2): 204-210.  
    Abstract （854）      PDF （594KB）（191）       Save
    Heat transfer performance and flow resistance of shell side of the double-pipe heat exchanger with helical baffle were investigated by using CFD numerical simulation software. 5 heat exchangers with the helical baffle at the helical angle of 40o, and baffle space heights of b, 3b/4, b/2, b/4 and b/8 (b refers to the helix pitch) were simulated, and the influence of baffle space height on fluid flow and heat transfer of the shell side was examined. The results indicated that under the same volume flow rate, the heat transfer per unit area, heat transfer coefficient and friction factor increased with the increase of baffle space, but the pressure gradient decreased with the increase of baffle space. The heat exchange coefficient of heat exchangers with partition height of b, 0.75b and 0.5b was enhanced over 7.83, 3.68 and 3 times than that with partition height of 0.125b, and the pressure drop reduced by 98%, 97% and 95%, but the resistance coefficient was enhanced over 34, 15.3 and 5.3 times, respectively. In order to enhance the comprehensive heat exchange of shell side of single-tube heat exchanger with helical baffle, the partition height should be between 0.5b and 0.75b.
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    Coupled Numerical Simulation on the Flow and Temperature Fields of Molten Steel Pool in a Twin-roll Strip Caster
    DONG Jian-hong WANG Nan CHEN Min
       2014, 14 (2): 211-216.  
    Abstract （936）      PDF （705KB）（379）       Save
    Based on CFD software Fluent, a three-dimensional finite-volume model was established, and flow and temperature fields in a molten steel pool of a twin-roll strip caster were simulated. The basic characteristics of flow and temperature fields were analyzed, and the effects of delivery system, outlet angle of feeding device, casting speed, and overheating and cooling conditions on the flow and temperature fields investigated for AISI304 stainless steel casting. The results showed that the turbulent kinetic energy had the maximum value of 0.0175 J/kg and temperature gap was within 20 K at the surface when the casting system combined with submerged nozzle, multi-hole feeding device, flow guiding device and distributing device was used under the conditions of feeding inlet submerging in the distributing device pool, outlet upward angle of feeding device at 15°~18° and steel casting speed 60~80 m/min. Meanwhile, over 0.6 mm solidified shell stably formed between the pool and casting roll contacting surface.
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    Mathematical Simulation on the Heat Transfer and Solidification Process of Secondary Cooling in Bloom Steel Continuous Casting
    XIA Yun-jin FAN Ding-dong LI Jie
       2014, 14 (2): 217-222.  
    Abstract （855）      PDF （609KB）（390）       Save
    The heat transfer and solidification of secondary cooling zone in bloom continuous casting were simulated based on a fluctuated cooling approach-improved (FCA-I), and the three simulation methods, monotonic cooling approach (MCA), fluctuated cooling approach (FCA) and FCA-I, were compared. The results show that the bloom surface temperature before straightening and liquid core length calculated by the three methods have not much difference with the measurements, but FCA-I is more accurate, which can real-time predict the distribution of bloom surface temperature and the liquid core length change with casting speed. FCA-I not only retains the advantages of FCA which can accurately reflect the actual temperature change of foot-roller, but also overcome the shortcomings of FCA which is difficult to adapt to the changing of casting speed. The relationship between the solidification time (t) and shell thickness (dshell) in mold and secondary cooling zone calculated by FCA-I are regressed as dshell=19.62t1/2-2.52 and dshell=29t1/2, respectively, the simulation results basically agree with literatures.
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    Influential Factors on Dynamic Characteristics of Three-phase Fluidized Bed
    LI Hong-li LI Yang-dong LI Deng-xin YIN Chun-sheng
       2014, 14 (2): 223-228.  
    Abstract （902）      PDF （269KB）（232）       Save
    A series of conductivity at different measuring holes in a three-phase fluidized bed were measured by using conductance probe measurement technique, taking glass beads, gold concentrate and gold cyanidation tailing with different diameter particles as solid phase, air as gas phase, and different viscosity liquids as liquid phase. Through calculation, the effects of particle size (dp), density (r), mass (q), superficial gas velocity (Ug) and liquid viscosity (ml) on phase holdups were studied. The results showed that with increasing of dp of glass beads from 0.05 to 0.15 mm, local gas holdup (eg) increased 2%~3%, and local solid holdup (es) decreased 2%~4%. With increasing of r, both es and eg became smaller, and vice versa. With increasing of q, eg decreased, but es increased, with each addition of 100 g glass beads, es increased about 1.5%, eg decreased about 2.5%. With increasing of Ug, both eg and es increased. With increasing or decreasing of ml, eg and es constantly increased or decreased.
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    Experimental Investigation on Solid-Liquid Suspension in a New Self-aeration Monolayer Multiphase Stirred Tank
    HAO Hui-di CHENG Tian-qi QIN Pei-pei ZHU Na LEI Jian-yong ZHAI Tian
       2014, 14 (2): 229-233.  
    Abstract （1019）      PDF （226KB）（206）       Save
    A new self-made tornado flow stirred tank was used to carry out experiments without ventilation, the relationship of critical suspension rotational speed (Nc) with the solid content w, particle density r, and inner diameter (D) of the suspension stirred tank was obtained. Under the same geometrical conditions, the new stirred tank was compared with a standard stirred tank in Nc. The results show that Nc increases with the increase of solid phase fraction j and particle size dp, which is not conducive to good suspension. With the increase of solid particle density, Nc goes up. With the increase of the tank diameter, Nc decreases. An expression for Nc of the new stirred tank is obtained, Nc=6.3dp0.21(gDr/rL)0.45w0.19/D0.55. At the same solid phase fraction, Nc in the new stirred tank is below 30% of that in a standard suspension stirred tank, which means that the particles can be suspended at a lower stirring speed.
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    Treatment of High Content Manganese-containing Wastewater by O3-H2O2 Oxidation Based on Optimal Redox Potential
    LI Tian-xin LIU Xiang WU SAhi-ling GU Wei-min UWIZEYIMANA Herman
       2014, 14 (2): 234-240.  
    Abstract （1103）      PDF （248KB）（281）       Save
    Ozonation and H2O2-NaOH advanced oxidation processes were used to treat high content manganese-containing wastewater based on optimal redox potential (ORP). The effects of oxidizer (ozone, H2O2 and NaOH) dosages, and the oxidation kinetics were investigated. Experimental results indicated that the ORP was 296~299.7 mV in the ozonation oxidation, under addition of ozone at 0.13~0.15 g/L in both first and second ozonation oxidation processes, the removal rate of Mn2+ reached 91.57%. The ORP was 12.40~12.80 mV in the H2O2-NaOH oxidation, when the dosages of H2O2 and NaOH were 2.0 and 2.6 g/L respectively, their molar ratio was 0.9:1 and H2O2 was added first, the removal rate of Mn2+ reached 99.31%. The treated wastewater had the Mn2+ concentration of 1.2 mg/L which was lower than the first level standard (2.0 mg/L) specified in the National Wastewater Discharge Standard GB 8978-1996. The oxidation kinetics indicated that the oxidation processes obeyed first order reaction kinetics. The rate constant k was 0.0762 min-1 for the first ozonation oxidation and 0.0822 min-1 for the second one at set ORP, otherwise k was 0.0279 and 0.0508 min-1, respectively. k was 0.4758 min-1 for the H2O2-NaOH oxidation at set ORP, otherwise k was 0.3594 min-1.
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    Extraction and Separation of Indium and Iron Ions from Synthetic Sulphuric Acid Leaching Solution of Blast Furnace Sludge by Ultrasonic Methods
    SHEN Xing-mei LI Liao-sha WU Xing-rong GAO Zhi-fang LV Jia
       2014, 14 (2): 242-246.  
    Abstract （1032）      PDF （222KB）（150）       Save
    Probe ultrasound and vibrating-plate ultrasound methods were used to enhance the extraction and separation of indium and iron ions from synthetic sulphuric acid leaching solution of blast furnace sludge. Compared with traditional solvent extraction method, the ultrasonic methods could obtain higher extraction and back-extraction rates of indium ion, shorten extraction and back-extraction time, and improve the efficiency. The results showed that vibrating-plate ultrasound method was suitable for extraction process of indium ion, and probe ultrasound method was appropriate to the back-extraction process. The optimal conditions with two ultrasonic methods to extract and separate indium and iron ions from the synthetic solution were 1 mol/L sulphuric acid and vibrating-plate ultrasound extraction for 1 min, which resulted in 96.5% and 8.5% extraction rates of indium and iron ions, and 2 mol/L hydrochloric acid and probe ultrasound back-extraction for 2.5 min, which resulted in 71.0% and 3.8% back-extraction rates of indium and iron ions, respectively.
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    Characteristics of Treating Carboxymethyl Cellulose Condensate with Upflow Blanket Filter and Biological Aeration Filter
    ZHANG Wen-yi LIU Fang LI Wen-yu FENG Guo-yong LIU Yu-chong ZHU Zheng-wei
       2014, 14 (2): 247-252.  
    Abstract （825）      PDF （284KB）（178）       Save
    Aiming at the problem of acidic condensate treatment, which was generated by using multi-effect evaporation of food additive carboxymethyl cellulose (CMC) wastewater, the combined reactor of upflow blanket filter (UBF) with biological aeration filter (BAF) was adopted for biodegradation. Its technological parameters were investigated with hydraulic loading as control parameter. Based on COD removal, the UBF kinetic model was established. Biological phases in UBF and BAF reactors were also analyzed to reveal the characteristics of CMC condensate. The optimum parameters of UBF-BAF reactor were obtained: hydraulic retention time (HRT) of 24 h in UBF reactor, HRT of 5 h in BAF reactor, temperature 20~40℃, pH value 6.5~7.5, and BAF backwashing cycle 5~7 d. When the influent COD concentration was 2388~4000 mg/L, COD removal rates were up to 84.26% and 80.53% in UBF and BAF reactors, respectively. The effluent water could meet Grade I discharge demands of integrated wastewater discharge standard (GB 8978-2002).
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    Adsorption of Naphthalene at Low Concentration on Activated Carbon
    MEI Lei HE Lu FAN Chui-gang HAO Li-fang LI Song-geng SONG Wen-li
       2014, 14 (2): 253-257.  
    Abstract （1024）      PDF （271KB）（246）       Save
    Adsorption performance of naphthalene on activated carbon GH-8 at different temperatures and superficial velocities was studied with a fixed bed reactor. Model parameters were obtained by fitting to Yoon-Nelson model, kYN=0.20 h-1 and kYNt=51.404-0.166T+0.292/u. Mass transfer model was used to predict the length and moving velocity of mass transfer zone. The calculation results showed that the maximum relative deviation between the calculated and experimental values was less than 10%.
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    Preparation of Hydrated Sodium Metaborate from Boron Concentrate via Pressure Alkaline Leaching
    YIN Bao-wen QIN Shi-yue ZHANG Yi-fei ZHANG Yi
       2014, 14 (2): 258-265.  
    Abstract （902）      PDF （625KB）（184）       Save
    Pressure alkaline leaching was used to prepare hydrated sodium metaborate from boron concentrate in NaOH-H2O system. Orthogonal experiments indicated that the most significant influential factor was NaOH concentration, and order of the factors was initial NaOH concentration > reaction time > mass ratio of liquid to solid > temperature. The effects of initial NaOH concentration, reaction time, temperature, mass ratio of liquid to solid, stirring speed and particle size of ore on leaching of boron were examined. Under the optimal conditions (mass fraction of NaOH of 25%, mass ratio of liquid to solid of 4:1, reaction temperature of 140℃, time of 2 h, stirring speed of 500 r/min and gauge pressure of 0.2 MPa), 95.91% of boron was leached out. Na2O and B2O3 in wet boric sludge could be effectively recycled by three-stage countercurrent slurry washing (washing temperature of 90℃, mass ratio of liquid to solid of 3:1, and time of 1 h), dropping to 0.35% and 0.45%, respectively. Final boric sludge containing 42.91% MgO was good raw material for extraction of Mg. After purification, the leachate was crystallized isothermally at 25~30℃ for 6 h and the crystallization rate reached over 70%. Washed with anhydrous ethanol and saturated sodium metaborate solution and dried under 40℃ for 12 h, reulting crystal was analyzed by XRD and proved to be NaB(OH)4, its purity was nearly 90%.
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