技术设备

铝电解烟气逆向二段干法吸附净化新技术应用了铝电解含氟烟气干法净化原理,将国内外通用的氧化铝和载氟氧化铝一次加入反应段进行一次吸附,改为逆向二段吸附,首先用活性较差的载氟氧化铝与含氟浓度高的铝电解初始烟气进行吸附,然后用活性强的新氧化铝吸附烟气中剩余的氟化物,优化了干法吸附机制,以较低的反     

减少氧化铝超浓相输送运行阻力的分析

氧化铝超浓相输送是近几年兴起的新技术,如何既能使往烟气中添加吸附用的新鲜氧化铝达到输送方便可控制,又能保证低的氧化铝破损率,改善吸附效果、提高烟气净化效率,是氧化铝超浓相输送的关键,我公司几年来在生产实践中总结了氧化铝输送过程中存在的问题,进行了多项改进效果良好。     

电解烟气净化氧化铝流量计量新技术与应用

概述电解烟气净化过程中,氧化铝流量的准确计量对氟盐回收效率的影响。综合分析了电解烟气净化过程中影响氧化铝准确计量的主要因素,提出了新型流量计的解决方案。简单说明了在电解烟气净化工艺中合理配置流量计,针对氧化铝流量实施在线动态准确计量,间接提高了电解烟气净化过程中的氟盐回收效率。     

电解铝烟气净化系统的应用——小区域单台电解槽净化

小区域——单台电解槽净化系统是针对每台电解槽单独设置一台除尘器,以几台电解槽为单位设置一个小区域的净化系统。该系统在每台电解槽上布置一台除尘器,在小区域范围内布置一台引风机,除尘器下部连接氧化铝输送支溜槽,支溜槽先输送载氟氧化铝,后输送新鲜氧化铝。此系统不需要载氟氧化铝料仓、反料溜槽、反料气提机等。所以一次性建设费用较低,净化运行费用低,除尘器安装在平台上无需建设场地。     

铝电解槽烟气干法净化—新型气/固反应器的设计和运行特性

序言干法净化电解车间烟气用的氧化铝,吸附有烟气中的杂质。如很细的金属化合物粒子、二氧化硫和由阳极带入的碳素材料。当净化器捕集的氧化铝返回电解槽时,这些固体杂质也进入电解槽,其中有的成份能使铝的纯度降低。如果生产用的氧化铝百分之百用于净化,这些     

焙烧炉烟气净化方法和效果的述评

阳极焙烧炉的烟气中含有３．４－苯并芘等强致癌物质，属于一级危险毒物。“白法”净化的载焦油氧化铝应与新鲜氧化铝或干法净化的载氟氧化铝混匀后使用；“黑法”净化的阳极原料中掺入的残阳极头要用喷砂彻底清理；净化后的烟囱排放高度应为３０－５０ｍ；“黑白”联合净化法要增加辅助储仓，增加投资和运行费，且管理复杂；净化系统中设备和管道里的焦油结疤应当定期用蒸汽吹洗 ；湿法和干法净化投资相近，但干法净化成本较低、交     

浅谈干法净化的运行参数

用氧化铝吸附氟化氢,已在预焙槽和部分上插槽烟气净化中得到广泛应用。近几年,国内有关设计、科研和生产单位做了大量试验研究工作,并在工程设计中予以实践。探索提高净化效率和净化回收的经济效益,几乎是所有     

铝电解烟气干法净化系统的研究——加料混合

介绍了铝电解烟气干法净化加料混合方法的研究,使氧化铝(A12O3)和烟气充分均匀混合,为氧化铝吸附烟气中的氟化氢提供有利条件.通过对烟气中氧化铝颗粒的受力分析.氧化铝颗粒在烟气中的运动分析,确定径向喷射氧化铝加料的方法进行氧化铝加料混合.同时设计了中心径向喷射加料和四周径向喷射加料两种不同方式的加料方案.通过对中心喷射加料方案的加料简略计算,确定试验的初始设定参数,并对试验装置进行试验.通过对两个喷射加料方案的试验观察,发现氧化铝颗粒在气流中运动时,惯性力的作用很大,当输送管的方向发生改变,气流中的氧化铝颗粒物偏向喷管弯曲部分及其后面一段距离的外侧运动,导致氧化铝在喷嘴喷出时就存在不均匀的现象,使烟道中气固混合不均匀.试验采取在中心喷射加料方案的加料立管上增加膨胀管的办法对该加料方案进行改进,使氧化铝和输送气体在膨胀管内产生回流并进行二次混合,取得了预期的效果,达到了使氧化铝和烟气混合均匀的目的.     

阳极焙烧炉烟气联合式干法净化技术的研发和应用

论述了焙烧炉烟气净化系统广泛采用电捕焦油器净化技术和氧化铝吸附净化技术在国内铝用阳极炭素厂实际生产中暴露的问题,提出了联合式干法净化技术的开发理念和运行效果,说明了联合式干法净化技术的成功应用为焙烧炉烟气治理提供了高效可靠的净化方法.     

上插自焙槽电解烟气净化问题的分析探讨

西方国家９０％自焙槽电解烟气净化由湿法改为干法。青铜峡铝厂１０６ｋＡ上插槽系列由湿法净化改为干法净化，氟的净化效率可达９９％以上，沥青烟的净化效率可达９７％以上，吨铝排氟降到２ｋｇ／ｔ－Ａｌ以下，粉尘排放量降到１５ｍｇ／Ｎｍ＾３以下，每年可回收氟化铝８８０ｔ，氧化铝２０ｔ。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.