冶炼烟气洗涤污酸废水气液硫化除锌

采用气液硫化法对模拟含锌污酸废水进行处理,考察pH值、H2S气体分压、反应温度、反应时间、Zn~(2+)初始浓度等条件对Zn~(2+)去除效果的影响。在单因素实验的基础上进行五因素五水平的正交实验,并对采用该工艺处理冶炼烟气洗涤污酸废水效果进行验证。研究Zn~(2+)硫化分离的热力学,及其气液反应动力学过程,并对锌沉渣进行分析与表征。结果表明:在最佳工艺条件为模拟溶液初始pH值3、反应时间80 min、温度35℃、H2S气体的体积分数为30%、Zn~(2+)初始浓度100 mg/L时,Zn~(2+)脱除率为99.54%,沉渣主要物相为ZnS,锌的质量分数达63.84%;实际污酸废水锌浓度为569和216.7 mg/L时,去除率分别达到99.79%和99.49%。     

石墨负载纳米零价铁去除溶液中U(Ⅵ)

以液相还原法制备纳米零价铁,将其负载于石墨表面制备负载型纳米零价铁复合材料(G-nZVI),并用来去除溶液中的U(Ⅵ),考察初始溶液的pH、反应温度、反应时间、U(Ⅵ)的初始浓度以及固液比等因素对复合材料(G-nZVI)去除U(Ⅵ)影响。用扫描电镜(SEM)和X射线衍射(XRD)技术对反应前后的材料进行表征,分析其去除U(Ⅵ)的机理。结果表明:纳米零价铁颗粒分散在石墨粉的表面,没有产生团聚。反应后溶液中主要生成UO_2和U(Ⅳ)氢氧化物沉淀。石墨负载型纳米零价铁对U(Ⅵ)有很好的去除效果,在pH为4.0,温度为30℃,反应时间为60 min,固液比为0.25 g/L,初始U(Ⅵ)浓度为10 mg/L条件下,U(Ⅵ)的去除率和吸附容量分别达到99.67%和43.2 mg/g,说明该复合材料(G-nZVI)在含铀放射性废水的处理与环境修复中具有潜在的应用价值。     

铝钙粉浸出渣制备沸石及其对锌冶炼废水的吸附性能

以聚合氯化铝(PAC)生产过程中铝钙粉浸出渣为原料,通过酸浸-焙烧-水热晶化工艺制备沸石,并研究其对锌冶炼废水中重金属的去除效果。结果表明:铝钙粉浸出渣通过酸浸-焙烧-水热晶化过程,当原料n(SiO_2)/n(Al_2O_3)=2时,产物物相为结构完整的A型沸石;当原料n(SiO_2)/n(Al_2O_3)=6时,产物物相为结构完整的P型沸石。拟二级动力学方程计算得到A型沸石对Zn~(2+)、Cd~(2+)的平衡吸附量分别为97.09、12.39 mg/g,P型沸石对Zn~(2+)、Cd~(2+)的平衡吸附量分别为57.84、10.82mg/g。Freundlich吸附等温线拟合结果表明,A型沸石和P型沸石吸附Zn~(2+)、Cd~(2+)机理均为非均相表面的复杂吸附。当废水pH为8、吸附温度为25℃、吸附时间为150 min时,采用A型沸石处理锌冶炼废水,产渣量为1.1 g/L,废水中Cu~(2+)、Pb~(2+)、Zn~(2+)、Cd~(2+)、总砷(AsT)浓度分别由1.68、13.12、147.00、15.14、4.06 mg/L降至0.06、0.05、0.52、0.03、0.01 mg/L,达到《铅、锌污染物排放标准》(GB25466—2010)。     

羊栖菜对水环境中Cd~(2+)的吸附特性

以非活性羊栖菜粉为吸附剂,研究羊栖菜对水溶液中Cd~(2+)的吸附特性。结果发现:在最佳吸附pH为5,温度为313.15K,吸附剂浓度为1g/L,Cd~(2+)初始浓度为40mg/L左右时,羊栖菜对镉离子的去除率的最大值为92.54%,且吸附10 min时,即达到最大去除率93.95%;在60 min时,基本达到吸附平衡,羊栖菜对Cd~(2+)的去除具有快速、去除率高的特点。动力学实验数据符合准二级动力学模型,Langmuir对热力学实验平衡数据的拟合较高,最大理论吸附容量为68.49 mg/g。通过方程拟合和SEM分析发现吸附过程发生了离子交换。FTIR分析显示,羟基、羧基等官能团在吸附过程中发挥了作用,通过解吸可以实现羊栖菜粉的再生和循环利用。     

污酸废水中铜和砷的气-液梯级硫化与分离（英文）

通过气-液硫化反应初步分离污酸废水中的铜和砷,并将一级铜、砷分离渣按一定比例加入污酸原液中实现溶液中铜和渣中砷的置换分离。考察反应时间、温度和H2S用量对铜、砷去除率的影响,同时考察固液比、时间和温度对铜、砷置换反应的影响。当在50℃时加入20mmol/L的H2S时,在0.5min时间内即可使铜的去除率达到80%以上,且砷的去除率约为20%。将铜、砷一级分离渣按照10%以上的固液比例加入污酸废水中,在20℃下10min后由于铜、砷置换作用,废酸中铜和砷分离率达到99%以上。沉渣中主要物相为CuS,富集的铜渣中铜的质量分数为63.38%。     

活性硅酸钙吸附铝酸钠粗液中铁化合物的试验研究

本文以高铝粉煤灰提铝过程中产生的副产物活性硅酸钙为吸附剂,研究了活性硅酸钙添加量、吸附温度及吸附时间对活性硅酸钙吸附铝酸钠粗液中铁化合物效果的影响。试验结果表明:活性硅酸钙加入量为10g/L、吸附温度70℃、吸附时间60min的条件下,铝酸钠粗液中Fe2O3质量浓度由8.6mg/L降低至2.53mg/L,除铁率达70.59%。吸附过程对铝酸钠粗液成分及活性硅酸钙固相组成影响很小;吸附过程更符合Freundlich方程,其吸附机制为化学吸附。     

生物法制备聚合硫酸铁及其应用研究

研究生物法制备铁系絮凝剂及其影响因素。以FeSO4·7H2O为原料,利用驯化后的氧化亚铁硫杆菌（T·f）在酸性条件下的催化氧化作用制备生物聚合硫酸铁（PFS）,并确定最佳制备条件。实验表明：在反应液初始pH值1.5、硫酸铵用量0.5g/L、初始Fe2＋浓度45g/L、接种量10%、温度30℃时,在转速为120r/min的恒温水浴摇床中连续培养5～6d、可以制出pH1.5～2.2、盐基度17.5%～22.7%、全铁含量43.87～45.24g/L的产品。实验通过处理3种废水来考察其絮凝性能,结果表明：当PFS投加量一定时,COD去除率可达70%以上,脱色率达90%,Zn2＋去除率达99%,说明PFS是一种絮凝效果优异的水处理剂。     

硅藻土-钨渣基陶粒对废水溶液中铜离子的吸附（英文）

为了在中国南方有色矿冶区同时实现工业钨渣的资源化利用和重金属废水的处理,以钨渣和硅藻土为主要原料制备一种新型陶粒,对其与溶液中重金属Cu~(2+)的吸附规律进行研究。结果表明:新制备的近球形陶粒表面粗糙多孔,内部有许多贯穿性孔道与外部相连通;陶粒的主要物相组成含有MnFe_2O_4。在303 K、铜离子初始浓度100 mg/L、陶粒投加量0.5 g和300 min条件下,陶粒对Cu~(2+)的吸附量为9.421 mg/g,吸附去除率达94.21%。随着陶粒投加量的增大,其对溶液中Cu~(2+)的总吸附量增大,单位吸附量降低;陶粒对Cu~(2+)的吸附量随试验pH值的增大而增大。陶粒对Cu~(2+)的等温吸附更符合Freundlich模型,吸附主要发生在非均质表面,为优惠吸附;陶粒对铜离子的吸附动力学符合准二级动力学方程,吸附过程主要受液膜扩散、表面吸附以及颗粒内扩散因素控制。对于实际重金属废水的处理,陶粒对重金属离子的吸附初始阶段受扩散控制,此时,可通过加强搅拌的方式提高Cu~(2+)的去除率。     

离子交换吸附富集红土镍矿浸出液中的镍

研究高镁铁质红土镍矿硫酸浸出液中镍的高效提取方法。通过在d 150 mm×1800 mm PVC柱中填充12 L CN27离子交换树脂,对高镁铁质红土镍矿硫酸浸出液进行动态吸附。研究初始液pH、Ni2+和Fe2+的质量浓度、流速、吸附时间等参数对树脂有效吸附量和吸附效率的影响。结果表明:初始液中Ni2+质量浓度2.5 g/L、pH 3~5、流速1.0 L/min、树脂饱和吸附时的有效利用率达85%~93%,树脂吸附Ni2+的最高有效吸附量可达58.0 g/kg;初始液中Ni2+质量浓度2.5 g/L、pH 4.5、流速1.0 L/min时,吸附后液Ni2+质量浓度1.0 mg/L时,树脂吸附Ni2+的有效吸附量可达41.8~42.0 g/kg,富集液中Ni2+的富集倍数达到25以上,镍离子的质量浓度提高到54 g/L以上;初始液中Fe2+的质量浓度增加,树脂对镍的吸附量降低,不仅会导致富集液中Ni2+的质量浓度降低,富集液中Fe2+的质量浓度也会增加。离子交换吸附不但能使低浓度含镍溶液富集到满足镍电积工艺的要求,且能对杂质进行有效分离。     

锌湿法冶金过程中臭氧氧化沉淀除去微量钴

为有效去除锌湿法冶金过程中的微量钴,探索采用臭氧氧化净化ZnSO4溶液中钴的可行性,考察搅拌速度、反应温度、气体流量、溶液pH值、钴离子浓度、锌离子浓度等因素对除钴效果的影响。结果表明:在锌离子初始浓度100 g/L、钴离子初始浓度20 mg/L、温度30℃、气体流量800 mL/min、pH=5.0、搅拌速度800 r/min等条件下,反应30 min后,钴浓度可降至0.2 mg/L,除钴率高达99%。     

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.