Orientational Separation of Sulfur in Petroleum Coke by Alkali Calcining and Reflux Washing

The application of high-sulfur petroleum coke after desulfurization in aluminum electrolysis anodes is an important development trend. However, removing sulfur from high-sulfur petroleum coke is still a significant challenge.This study proposes alkali calcining and reflux washing to examine the impacts of temperature, particle size, the mass ratio of Na_(2)CO_(3) to NaOH, and total sodium addition on the desulfurization efficiency and mechanism. The results show that the desulfurization rate increases with increasing temperature, increasing total sodium content, and decreasing particle size. The addition of alkali can significantly reduce the opening-ring reaction temperature of thiophene and convert organic sulfur into inorganic sulfur(Na_(2)S). Three washing methods were compared, and reflux washing was selected to separate inorganic sulfur(Na_(2)S) from calcined petroleum coke. The sulfur content in petroleum coke decreased from 7.29% to 1.90%, with a desulfurization rate of 80.13% under optimal conditions. The petroleum coke was analyzed before and after desulfurization using X-Ray diffraction(XRD), Scanning Electron Microscopy(SEM), Infrared Spectroscopy(IR), Thermogravimetric Analysis and Differential Scanning Calorimetry(TG-DSC), Gaschromatography-mass Spectrometry(GC-MS). The results show that thiophene and benzothiophene in petroleum coke are decomposed and converted into octane and ethyl cyclohexane. These new observations are expected to provide further understanding and guidance for the utilization of highsulfur petroleum coke.

Anodic behavior and microstructure of Al/Pb-Ag-Co anode during zinc electrowinning

In order to study the anodic behavior and microstmctures of A1/Pb-Ag-Co anode during zinc electrowinning, by means of potentiodynamic investigations, scanning electron microscopy （SEM） and X-ray diffraction （XRD） analyses, the mechanism of the anodic processes playing on the surface of A1/Pb-0.8%Ag and A1/Pb-0.75%Ag-0.03%Co anodes prepared by electro-deposition from methyl sulfonic acid bath for zinc electrowinning from model sulphate electrolytes have been measured. On the basis of the cyclic voltammograms obtained, information about the corrosion rate of the composite in PbO2 region has been concluded. The microstructures were also observed by means of SEM and XRD which showed Pb-0.75%Ag-0.03%Co alloy composite coating has uniform and chaotic orientation tetragonal symmetry crystallites of PbSO4, but Pb-0.8%Ag alloy composite coating has well-organized orientation crystallites of PbSO4 concentrated in the certain zones after 24 h of anodic polarization. It is important that Al/Pb-0.75%Ag-0.03%Co anode oxide film consists of non-conductive dense MnO2 and PbSO4 and a, fl-PbO2 penetrated into which, in fact, are the active centers of the oxygen evolution after 24 h of anodic polarization.

Purification of indium by vacuum distillation and its analysis

High purity （99.999% or 5N, mass fraction） indium （In） was obtained through vacuum distillation using a 2N （99%） In as input material under a dynamic vacuum of 5 Pa. The glow discharge mass spectrometry （GDMS） was applied for the analysis of input material and the distilled indium. The results indicate that high-volatile impurities namely Cd, Zn, T1 and Pb can be removed from the indium matrix at the low fraction stage of 1 223 K for 120 min; Low-volatile impurities such as Fe, Ni, Cu, Sn can be reduced at the high fraction stage of 1 323 K for 120 min. The separation coefficient ,8i and activity coefficient Yi of impurities are calculated according to the experiments to fill the inadequate data of the thermodynamics.

Carbothermal reduction-chlorination-disproportionation of alumina in vacuum

The carbothermal reduction-chlorination-disproportionation of alumina in vacuum was investigated by XRD and thermodynamic analysis. The experiments on alumina and graphite at 1643-1843 K in vacuum were carried out. The results demonstrate that AlCl3（g） reacts with Al2O（g） or Al（g） generated from the carbothermal reduction of alumina to form AlCl（g）, and the AlCl（g） disproportionates to aluminum and AlCl3（g） at a lower temperature and the reaction rate of AlCl（g） reaches 90% at 980 K and 100 Pa. The aluminum can absorb CO to catalyze its disproportionation to C and CO2, and react backward with CO to form Al4C3, Al2O3, C and CO2, resulting in the aluminum product containing C, Al4C3 and Al2O3. The impurities in the aluminum product decrease as the AlCl（g） disproportionation temperature decreases. AlCl3 condenses at a temperature approximated to the room temperature.

Preparation of titanium powders by calciothermic reduction of titanium dioxide

To develop an effective process for titanium powders production, a calciothermic reduction process of pigment titanium dioxide （w（TiO2）〉98%）, based on the preform reduction process （PRP）, was investigated by means of XRD, SEM and EDS. In this process, the mixture of TiO2 powder and CaC12 was pressed into pieces as feed preform and was reduced by calcium vapor. Titanium powders was recovered after leaching from the reduced preform with hydrochloric acid and deionized water. The results indicate when the mass ratio of CaC12 to TiO2 is about 1：4 and at a constant temperature of 1 273 K for 6 h in vacuum furnace, titanium powders with 99.55% purity by EDS analysis and irregular shape （8-15 μm in particle size） are obtained.

High-temperature oxidation behavior of CeO_2-SiO_2/Ni-W-P composites

Ni-W-P matrix composites containing CeO2 and SiO2 nano-particles were prepared on common carbon steel surface by means of pulse electrodeposition,and the high-temperature oxidation behavior was investigated.The results show that when the oxidation time is controlled in 1 h,oxidation kinetics curve between oxidation mass gain rate and oxidation temperature of CeO2-SiO2/Ni-W-P composites accords with the index increasing law.When the oxidation temperature is controlled at 300℃,the kinetics curve between oxidation mass gain rate and oxidation time accords with the linear increasing law.The composites as-deposited are in the amorphous state and turn into the crystal state at 400℃.The microstructures of oxidation film on the composites will change from the compact state to the loose state with increasing oxidation temperature to 800℃.They are still continuous and compact,and there are no crackle,strip and falling-out.CeO2 and SiO2 nano-particles co-deposited into Ni-W-P alloy can improve the high-temperature oxidation resistance.

Electrochemical migration behavior of Ag-plated Cu-filled electrically conductive adhesives

The electrochemical migration (ECM) behavior of the electrically conductive adhesives (ECAs) filled with pure Ag powder or Ag-plated Cu composite powder with varied Ag:Cu ratios was investigated under the condition of applying constant voltage and distilled water environment.ECM resistance was determined from the current-time curves.The microstructure and composition of ECM dendrite products were analyzed by SEM/EDS and XRD.It was found that the ECM resistance of Ag-plated Cu composite powder-filled ECAs was evidently higher than that of pure Ag powder-filled ECAs.The Ag:Cu ratio of composite powder in ECAs had notable influence on ECM resistance,which was enhanced with the decrease of Ag:Cu ratios.The composition of dendrites formed between cathode and anode during ECM process was not uniform for Ag-plated Cu-filled ECAs.An ECM inhibiting mechanism of Ag-plated Cu composite powder was proposed according to analysis of the electrochemical impedance spectroscopy,Tafel plot and dendrite composition.

Regeneration of waste activated carbon after extracting gold with steam under microwave heating:Optimization using response surface methodology

The technology that waste activated carbon after extracting gold is regenerated with steam under microwave heating was studied. The influence of the activation temperature, activation duration and steam flow rate on iodine adsorption value and regeneration yield of activated carbon was investigated. The response surface methodology （RSM） technique was utilized to optimize the process conditions. The optimum conditions for the preparation of activated carbon are identified to be activation temperature of 831 ℃, activation duration of 40 min and steam flow rate of 2.67 mL/min. The optimum conditions result in an activated carbon with an iodine number of 1048 mg/g and a yield of 40%, and the BET surface area evaluated using nitrogen adsorption isotherm is 1493 m2/g, with total pore volume of 1.242 cm3/g. And the pore structure of activated carbon regenerated is mainly composed of micropores and a small amount of mesopores.

Process optimization for treatment of methyltin mercaptide effluents using modified semi-coke

The central composite process optimization was performed by response surface methodology technique using a design for the treatment of methyltin mercaptide with modified semi-coke. The semi-coke from the coal industry was suitably modified by treating it with phosphoric acid, with a thermal activation process. The objective of the process optimization is to reduce the chemical oxygen demand （COD） and NH4＋-N in the methyltin mercaptide industrial effluent. The process variables considered for process optimization are the semi-coke dosage, adsorption time and effluent pH. The optimized process conditions are identified to be a semi-coke dosage of 80 g/L, adsorption time of 90 min and a pH value of 8.34. The ANOVA results indicate that the adsorbent dosage and pH are the significant parameters, while the adsorption time is insignificant, possibly owing to the large range of adsorption time chosen. The textural characteristics of modified semi-coke were analyzed using scanning electron microscopy and nitrogen adsorption isotherm. The average BET surface area of modified semi-coke is estimated to be 915 mE/g, with the average pore volume of 0.71 cm3/g and a average pore diameter of 3.09 nm, with micropore volume contributing to 52.36%.

The mean first passage time of a three-level atomic optical bistable system subjected to noise

The transient properties of a three-level atomic optical bistable system in the presence of multiplicative and additive noises are investigated. The explicit expressions of the mean first-passage time （MFPT） of the transition from the high intracavity intensity state to the low one are obtained by numerical computations. The impacts of the intensities of the multiplicative noise DM and the additive noise DA, the intensity of correlation between two noises λ, and the intensity of the incident light y on the MFPT are discussed, respectively. Our results show： （i） for the case of no correlation between two noises （2, = 0.0）, the increase in DM and DA can lead to an increase in the probability of the transition to the low intracavity intensity state, while the increase in y can lead to a retardation of the transition; and （ii） for the case of correlation between two noises （λ≠ 0.0）, the increase in λ can cause an increase in the probability of the transition, and the increase in DA can cause a retardation of the transition firstly and then an increase in the probability of the transition, i.e., the noise-enhanced stability is observed for the case of correlation between two noises.

Dual-site lattice co-doping strategy regulated crystal-structure and microstructure for enhanced cycling stability of Co-free Ni-rich layered cathode

Affected by cobalt(Co)supply bottlenecks and high costs,Co-free Ni-rich layered cathodes are considered the most promising option for economical and sustainable development of lithium-ion batteries(LIBs).Low-cost LiNi_(x)Al_(1-x)O_(2)(x≥0.9)cathode are rarely reported due to their chemo-mechanical instabilities and poor cycle life.Herein,we employ a strategy of Mg/W Li/Ni dualsite co-doping LiNi_(0.9)Al_(0.1)O_(2)(named as LNA90)cathodes to enhance cycling stability by modifying the crystal structure and forming a center radially aligned microstructure.The Mg/W co-doped LiNi_(0.9)Al_(0.1)O_(2)cathode(named as LNAMW)exhibits high capacity retention of 94.9%at 1 C and 3.0-4.5 V after 100 cycles with 22.0%increase over the pristine cathode LNA90 and maintains the intact particle morphology.Meanwhile,the cycling performance of LNAMW cathode exceeds that of most reported Ni-rich cathodes(Ni mol%>80%).Our work offers a straightforward,efficient,and scalable strategy for the future design of Cofree Ni-rich cathodes to facilitate the development of economical lithium-ion batteries.

In situ anchoring in carbon matrix of Bi_(2)O_(2)CO_(3) as a high-performance anode material for Li-ion batteries

Bismuth-based anode materials have been regarded as promising Li-ion batteries due to their high theoretical capacity.However,their low conductivity and associated volume expansion inhabited their commercialization.In this work,Bi_(2)O_(2)CO_(3)@C composites were successfully synthesized by in situ anchoring of flower-like Bi_(2)O_(2)CO_(3) nanosheets on a carbon-based substrate via hydrothermal.The unique composited structure of Bi_2O_(2)-CO_(3)@C leads to a stable specific capacity of 547 mAh·g^(-1)after 100 cycles at a current density of 0.1 A·g^(-1).Notably,it demonstrates excellent rate capability with a specific capacity of 210 mAh·g^(-1)at 5 A·g^(-1).After 550 cycles at a current density of 0.5 A·g^(-1),a high reversible capacity of nearly 400 mAh·g^(-1)was observed.Additionally,in situ X-ray diffraction measurements clearly demonstrate the conversion between Bi and Li_(3)Bi during alloying/dealloying,confirming the good electrochemical reversibility of the materials for Li storage.The reaction kinetics of Bi_(2)O_(2)CO_(3)@C were further investigated using galvanostatic intermittent titration technique.Furthermore,Bi_2O_(2)-CO_(3)@C exhibited excellent long-term stability,maintaining its high reversible capacity for over 200 cycles at a current density of 0.5 A·g^(-1)in a full cell configuration using Li_(1.20)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2) as the cathode material.This result further underscores its promising potential for lithium-ion batteries.This work may provide inspiration for the design of alloy-type negative electrode materials for high-performance rechargeable batteries.

Improved performance of LiMn_(0.8)Fe_(0.2)PO_(4) by addition of fluoroethylene carbonate electrolyte additive

The addition of electrolyte additives is an effective strategy for tuning the property of the electrolyte to engineer the electrode/electrolyte interface,and there exist obvious discrepancies regarding the effect of fluoroethylene carbonate(FEC)as an electrolyte additive on the performance of cathodes.Herein FEC is introduced into the electrolyte of the LiMn_(0.8)Fe_(0.2)PO_(4)/Li cell and its effect on the properties of the LiMn_(0.8)Fe_(0.2)PO_(4) is investigated.It is found that the addition of FEC in the electrolyte has a positive effect on the performance of the LiMn_(0.8)Fe_(0.2)PO_(4) cathode,which can be attributed to the reduced products generated by the interfacial side-reactions on the LiMn_(0.8)Fe_(0.2)PO_(4) cathode surface and the decreased metal dissolution in the FEC-containing electrolyte,thanks to the higher oxidation resistance of FEC and the easier and stronger binding of FEC and PF_6^(-).

Preparation and characterization of Ce-Fe-Zr-O(x)/MgO complex oxides for selective oxidation of methane to synthesize gas

A series of Ce-Fe-Zr-O(x)/MgO(x denotes the mass fraction of Ce-Fe-Zr-O,x=10%,15%,20%,25%,30%) complex oxide oxygen carriers for selective oxidation of methane to synthesis gas were prepared by the co-precipitation method.The catalysts were characterized by means of X-ray diffraction and H2-TPR.The XRD measurements showed that MgFeO4 particles were formed and Fe2O3 particles well dispersed on the oxygen carriers.The reactions between methane diluted by argon(10% CH4) and oxygen carriers were investigated.Suitable content of CeO2/Fe2O3/ZrO2 mixed oxides could promote the reaction between methane and oxygen carriers.There are mainly two kinds of oxygen of carriers:surface lattice oxygen which had higher activity but lower selectivity,and bulk lattice oxygen which had lower activity but higher selectivity.Among all the catalysts,Ce-Fe-Zr-O(20%)/MgO exhibited the best catalytic performance.The conversion of the methane was above 56%,and the selectivity of the H2 and CO were both above 93%,the ratio of H2/CO was stable and approached to 2 for a long time.

Electrochemical Properties and Microstructure of Al/Pb–Ag and Al/Pb–Ag–Co Anodes for Zinc Electrowinning

The Al/Pb-0.8%Ag and Al/Pb-0.75%Ag-0.03%Co （in mass fraction） anodes used in zinc electrowinning are prepared through the electrodeposition of lead methanesulfonate electrolyte onto an aluminum matrix. The results of anode polarization curves, Tafel curves, and EIS characterizations indicated that the Al/Pb-0.75%Ag-0.03%Co anode has higher electrocatalytic activity and corrosion resistance than the Al/Pb-0.8%Ag anode. SEM observations on the fruit surfaces demonstrated the crystals on the Al/Pb-0.8%Ag anode are larger than on the Al/Pb-0.75%Ag-0.03%Co anode. After 24 h of anodic polarization, SEM observations and XRD analysis showed that the MnO2-PbO2 layer on the Al/Pb-0.75%Ag- 0.03%Co anode surface is characterized by dendritic crystals, and the PbSO4-PbO2 layer under the MnO2-PbO2 layer is characterized by uniform and chaotic orientation tetragonal symmetry crystallites of PbSO4. However, the MnO2-PbO2 layer on the Al/Pb-0.8%Ag anode surface is characterized by granular crystals, and the PbSO4-PbO2 layer under the MnO2 PbO2 layer is characterized by well-organized orientation crystallites of PbSO4, which are concentrated in certain zones.

Morphology and activity relationships of macroporous CuO-ZnO-ZrO_2 catalysts for methanol synthesis from CO_2 hydrogenation

A series of macroporous CuO-ZnO-ZrO2 （CZZ） catalysts with different Zn/Zr ratios were successfully prepared by template method and characterized by X-ray diffraction （XRD）, N2 adsorption, reactive N2O adsorption, scanning electron microscopy （SEM）, H2 temperature-pro- grammed reduction （H2-TPR）, and transmission electron microscopy （TEM）. The activity of the catalysts was tested for methanol synthesis from CO2 hydrogenation. It is found that the increase in the Zn/Zr ratio could lead to the sintering of the catalysts, destroying the macroporous structure integrity. The macroporous CZZ catalysts own lower Zn/Zr ratio, exhibiting a better morphology and activity. For comparison, the conventional nonporous CZZ catalysts were also investigated. The results show that the CZZ catalysts with macroporous structure own smaller particles, higher CO2 conversion, and CH3OH yield. It reveals that the macroporous structure could inhibit the growth of the par- ticle size, and the special porous structure is favorable for diffusion and penetration of CO2, which could improve the catalytic activities.

Ce-Fe-O mixed oxide as oxygen carrier for the direct partial oxidation of methane to syngas

The Ce-Fe-O mixed oxide with a ratio of Ce/Fe=7:3, which was prepared by coprecipitation method and employed as oxygen carrier, for direct partial oxidation of methane to syngas in the absence of gaseous oxygen was explored. The mixed oxide was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), and the catalytic performances were studied in a fixed-bed quartz reactor and a thermogravimetric reactor, respectively. Approximately 99.4% H2 se...

Synergistic extraction of zinc from ammoniacal solutions using a β-diketone mixed with trialkylphosphine oxide

A simple comparative study of synergistic extraction of zinc from ammonium sulfate and ammonium chloride systems with mixtures of Mextral54-100 and tri-nalkylphosphine oxide(TRPO) dissolved in n-heptane was described. Various parameters affecting the extraction process were investigated. Experimental results show that extraction from ammonium sulfate is better than that from ammonium chloride under the same conditions owing to the additional complexation between zinc and chloride ions. Total ammonium concentration and pH have a significant effect on zinc extraction efficiency because of the formation of zinc ammine complexes. The synergistic effect is explained by the formation of adduct between zinc chelates and trialkylphosphine oxide. The thermodynamic data show that the extraction reaction is exothermic and stripping is endothermic. Infrared(IR) spectra of the zincloaded organic phases were also examined.

Numerical Simulation for Induction Refining Process of Metallurgical-Grade Silicon in Vacuum Furnace

The temperature and velocity distribution of melting pool fields is very important effect to the silicon purification in vacuum induction furnace.A numerical model for the electromagnetic-thermal-hydrodynamic coupling fields have been developed by using the finite element method(FEM)and a 2D numerical simulation for electromagnetic、 temperature and velocity fields of metallurgical-grade silicon melting in vacuum induction furnace were performed with a software Multi-physics Comsol 3.5a in this paper.The results showed that the temperature field was dependent observably on input power of coils and induction heating times and the maximum temperature gradient in melting pool was 215K in holding time.With the silicon molted gradually a clockwise vortex was come into being for electromagnetic stirring in the smelting poor.The variation of velocity field in melting silicon is mainly influenced with the change of the current intensity and power frequency.The numerical predications of temperature distribution are in good agreement with experiments.

Dimethyl ether synthesis from CO_2 hydrogenation on La-modified CuO-ZnO-Al_2O_3 /HZSM-5 bifunctional catalysts

A series of CuO-ZnO-Al2O3-La2O3/HZSM-5 biftmctional catalysts with various La loadings for dimethyl ether （DME） directly synthesized from CO2 hydrogenation were prepared. The catalysts were characterized with N2 adsorption-desorption, X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, NH3 temperature-programmed desorption （NH3-TPD） and N2O titration techniques, and tested for the synthesis of DME directly from CO2 hydrogenation in a fixed-bed reactor. The results showed that the reducibility, dispersion ofbifunctional catalysts were strongly dependent on the addition of La. With the addition of appropri- ate amount of La, the crystaUite size of CuO was decreased and the dispersion of Cu on the surface was enhanced, which resulted in the increased conversion of CO2. It was also found that the selectivity to DME was related to the intensity and amount of strong acid site on the catalyst surface. The presence of La favored the production of DME, and the optimum catalytic activity was obtained when the amount of La was 2.0 wt.%.