烧结法赤泥的絮凝沉降分离工业试验

烧结法赤泥采用絮凝沉降分离可以简化工艺流程，强化设备产能，节约能源和减少滤布消耗，减少操作工人操作劳动强度，改善岗位卫生环境，且降低浮游赤泥返回量及降低基建投资。是我国烧结法赤泥分离的一项新技术。     

利用赤泥生产硅钙复合肥料

利用烧结法赤泥制造农用肥料,是综合利用赤泥的新途径,即有利于解决赤泥治理,又可为农业提供新型肥源,具有相当重要的意义。赤泥硅钙肥料经过几年的试验研究,已于1979年12月14日在山东省科学技术委员会,淄     

赤泥脱碱的性质及其利用

利用烧结法赤泥制造水泥是我国当前处理赤泥的主要途径。但长期以来,氧化铝生产排出的大量赤泥,由于含碱的限制,利用率低,仍堆积废置,占据土地,污染环境,未得到有效地处理。赤泥脱碱是降低赤泥含碱量和提高综合利用技术水平的有效方法。1966年和1969年曾     

赤泥天然放射性水平及在建材领域制约性研究

叙述了固体样品中天然放射性水平的不同测试方法,指出常用的放射性水平检测方法包括γ能谱法和元素转换法,并对两种方法进行评述。运用上述方法对贵州某铝厂赤泥中放射性核素226Ra、232Th、40K的比活度进行对比研究。依据国家标准相关规定,针对所测赤泥放射性水平,评估其在建筑主体材料中的最大可掺入量。结果表明,赤泥的天然放射性水平较高,不可直接用于建筑主体材料,将其作为添加料用于建筑主体材料时,拜耳法赤泥与烧结法的最大掺入量分别不得高于37%和35%。     

轻质烧结法赤泥浇注材料的工程应用研究

利用烧结法赤泥密度小、颗粒细、水化活性好等特点,与水泥、粉煤灰和减水剂复配后制得高流动性、轻质的胶结性浇注材料。室内试验采用流动度、强度和密度作为浇注材料工作性与配比设计的关键评价指标,结果表明当干粉材料中烧结法赤泥用量为84%～88%、外掺加水量为65%～70%时,浇注材料的工作性能良好。在高速公路扩建工程的挡土墙墙背回填进行了工程应用,现场DCP测试结果表明浇注实体的强度和纵向匀质性良好。具有较高的实用性和应用价值。     

高铁低硅三水铝石矿综合利用工艺研究

为高效利用进口三水铝石矿资源,对一种高铁低硅三水铝石型铝土矿开展了应用技术研究,提出一条矿石常压溶出及赤泥综合利用技术路线。首先,矿石经常压溶出,由于矿石中氧化硅含量低,在溶出过程中基本不发生脱硅反应,赤泥中氧化钠含量低;溶出赤泥经过选矿,选出的高铁赤泥可用作炼铁。溶出粗液经脱硅后再种分生产氧化铝,脱硅产生的钠硅渣可并入烧结法流程,进一步回收其中的氧化铝和氧化钠;也可以单独处理或生产4A沸石。此技术方案氧化铝提取率高、综合碱耗低、赤泥排放量小,可供氧化铝生产企业参考使用。     

赤泥利用的研究

介绍了烧结法、拜耳烧结联合法的赤泥，经过处理，制成经济价值较高的含硅化工制品；应用石灰拜耳法改进传统拜耳法，改变赤泥的化学组成，使赤泥适宜利用。     

烧结法赤泥加速碳化动力学研究

利用烧结法赤泥矿物封存CO_2不仅可以缓解温室效应,同时能够制备性能优良的建材制品,实现废弃物的资源化利用。为了研究烧结法赤泥碳化反应历程,测试了烧结法赤泥碳化反应过程的温度变化、强度发展及碳化反应程度,并建立了烧结法赤泥碳化过程的动力学模型。结果表明,烧结法赤泥碳化4h抗压强度达28.9MPa;碳化过程中,0~30min内碳化反应速率最快,反应放出大量的热量;试验数据与动力学方程有很好的相关性。     

拜耳法高铁赤泥配料对烧结法技术指标的影响

研究了在６－１５万吨Ａｌ２Ｏ３排耳法与５０万吨烧结法组成的联合法生产中，不同赤泥配比的烧结法配料对烧结法技术指标的影响。结果表明，赤泥配比对烧结法的熟料溶出率、赤泥沉降性能无明显影响。但对熟料烧结温度的降低和烧结温度范围的变窄均有影响，赤泥与比越高则影响甚。在赤泥配比稳定，配料的钙比（Ｃ／Ｓ）在现有纯烧结法的生产技术指标范围内，碱比（Ｎ／Ｒ）偏中、上控制，熟料Ａ／Ｓ保持在３．５以上的条件下，采用目     

冯海燕代表:既关注铝行业发展焦点 也关注地方经济和百姓民生

全国人大代表冯海燕的职务是中国铝业股份有限公司广西分公司安全环保部主任工程师。本次“两会”,她带来了三条与铝行业息息相关的建议。加快赤泥综合利用。2020年我国氧化铝产量已达7313.2万吨,居世界第一,由此产生的固体废物赤泥将近1亿吨。当前,我国赤泥综合利用主要方向是建材、土壤改良、路基材料、铁矿物回收以及其他有价金属提取等。相比而言,赤泥资源化利用效果较好、减排量最大、最有经济价值的是赤泥中回收氧化铁,以冯海燕所在的中铝股份广西分公司为例,现已成功将赤泥中45%左右的铁以铁精矿的形式作为钢铁厂原料,每年赤泥减排量约20%。     

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).     

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.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

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.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。