氧化锌矿物浸出渣中铅、锶的提取及动力学分析

NH₄HCO₃ conversion followed by HCl leaching was performed and proven to be effective in extracting Pb and Sr from zinc extracted residual. The mechanism and operating conditions of NH₄HCO₃ conversion, including molar ratio of NH₄HCO₃ to zinc extracted residual, NH₄HCO₃ concentration, conversion temperature, conversion time, and stirring velocity, were discussed, and operating conditions were optimized by the orthogonal test. Experimental results indicate that NH₄HCO₃ conversion at temperatures ranging from 25 to 85°C follows the shrinking unreacted core model and is controlled by inner diffusion through the product layer. The extraction ratios of Pb and Sr under optimized conditions reached 85.15% and 87.08%, respectively. Moreover, the apparent activation energies of Pb and Sr were 13.85 and 13.67 kJ·mol?1, respectively.     

皮秒Nd:YAG激光对生物金属纯Ti和Ti–13Nb–13Zr合金的表面改性

The effects of picosecond Nd:YAG laser irradiation on chemical and morphological surface characteristics of the commercially pure titanium and Ti–13Nb–13Zr alloy in air and argon atmospheres were studied under different laser output energy values. During the interaction of laser irradiation with the investigated materials, a part of the energy was absorbed on the target surface, influencing surface modifications. Laser beam interaction with the target surface resulted in various morphological alterations, resulting in crater formation and the presence of microcracks and hydrodynamic structures. Moreover, different chemical changes were induced on the target materials’ surfaces, resulting in the titanium oxide formation in the irradiation-affected area and consequently increasing the irradiation energy absorption. Given the high energy absorption at the site of interaction, the dimensions of the surface damaged area increased. Consequently, surface roughness increased. The appearance of surface oxides also led to the increased material hardness in the surface-modified area. Observed chemical and morphological changes were pronounced after laser irradiation of the Ti–13Nb–13Zr alloy surface.     

基于响应曲面法的铁焦冶金性能多目标协同优化

Iron carbon agglomerates (ICA) are used to realize low-carbon blast furnace ironmaking. In this study, the central composite design based on response surface methodology was used to synergistically optimize the compressive strength, reactivity, and post-reaction strength of ICA. Results show that the iron ore addition ratio significantly influences the compressive strength, reactivity, and post-reaction strength of ICA. The iron ore addition ratio and carbonization temperature or the iron ore addition ratio and carbonization time exert significant interaction effects on the compressive strength and reactivity of ICA, but it has no interaction effects on the post-reaction strength of ICA. In addition, the optimal process parameters are as follows: iron ore addition ratio of 15.30wt%, carbonization temperature of 1000°C, and carbonization time of 4.27 h. The model prediction results of compressive strength, reactivity, and post-reaction strength are 4026 N, 55.03%, and 38.24%, respectively, which are close to the experimental results and further verify the accuracy and reliability of the models.     

汽车用废弃锂离子电池的减量化、再生及回收研究进展

The demand for Li-ion batteries (LIBs) for vehicles is increasing. However, LIBs use valuable rare metals, such as Co and Li, as well as environmentally toxic reagents. LIBs are also necessary to utilize for a long period and to recycle useful materials. The reduction, reuse, and recycle (3R) of spent LIBs is an important consideration in constructing a circular economy. In this paper, a flowsheet of the 3R of LIBs is proposed and methods to reduce the utilization of valuable rare metals and the amount of spent LIBs by remanufacturing used parts and designing new batteries considering the concept of 3R are described. Next, several technological processes for the reuse and recycling of LIBs are introduced. These technologies include discharge, sorting, crushing, binder removal, physical separation, and pyrometallurgical and hydrometallurgical processing. Each process, as well as the related physical, chemical, and biological treatments, are discussed. Finally, the problem of developed technologies and future subjects for 3R of LIBs are described.     

传统加热和微波加热下氧化锰矿的碳热还原行为研究

For the purpose of exploring a potential process to produce FeMn, the effects of microwave heating on the carbothermal reduction characteristics of oxidized Mn ore was investigated. The microwave heating curve of the mixture of oxidized Mn ore and coke was analyzed in association with the characterization of dielectric properties. The comparative experiments were conducted on the carbothermal reductions through conventional and microwave heatings at temperatures ranging from 973 to 1373 K. The thermogravimetric analysis showed that carbothermal reactions under microwave heating proceeded to a greater extent and at a faster pace compared with those under conventional heating. The metal phases were observed in the microstructures only under microwave heating. The carbothermal reduction process under microwave heating was discussed. The electric and magnetic susceptibility differences were introduced into the thermodynamics analysis for the formation of metal Mn. The developed thermodynamics considered that microwave heating could make the reduction of MnO to Mn more accessible and increase the reduction extent.     

机械合金化法制备的Cu/SiC纳米复合材料的组织、热性能和力学性能评估

Nano-sized silicon carbide (SiC: 0wt%, 1wt%, 2wt%, 4wt%, and 8wt%) reinforced copper (Cu) matrix nanocomposites were manufactured, pressed, and sintered at 775 and 875°C in an argon atmosphere. X-ray diffraction (XRD) and scanning electron microscopy were performed to characterize the microstructural evolution. The density, thermal expansion, mechanical, and electrical properties were studied. XRD analyses showed that with increasing SiC content, the microstrain and dislocation density increased, while the crystal size decreased. The coefficient of thermal expansion (CTE) of the nanocomposites was less than that of the Cu matrix. The improvement in the CTE with increasing sintering temperature may be because of densification of the microstructure. Moreover, the mechanical properties of these nanocomposites showed noticeable enhancements with the addition of SiC and sintering temperatures, where the microhardness and apparent strengthening efficiency of nanocomposites containing 8wt% SiC and sintered at 875°C were 958.7 MPa and 1.07 vol%?1, respectively. The electrical conductivity of the sample slightly decreased with additional SiC and increased with sintering temperature. The prepared Cu/SiC nanocomposites possessed good electrical conductivity, high thermal stability, and excellent mechanical properties.     

空冷条件下钛渣颗粒的氧化路径及氧化动力学

The oxidation pathway and kinetics of titania slag powders in air were analyzed using differential scanning calorimetry (DSC) andthermogravimetry (TG). The oxidation pathway of titania slag powder in air was divided into three stages according to their three exothermic peaks and three corresponding mass gain stages indicated by the respective non-isothermal DSC and TG curves. The isothermal oxidation kin-etics of high titania slag powders of different sizes were analyzed using the ln-ln analysis method. The results revealed that the entire isotherm-al oxidation process comprises two stages. The kinetic mechanism of the first stage can be described as f (α)=1.77 (1?α) [?ln (1?α)](1.77?1)/1.77 , f (α)=1.97 (1?α) [?ln (1?α)](1.97?1)/1.97 , and f (α)=1.18 (1?α) [?ln (1?α)](1.18?1)/1.18 . The kinetic mechanism of the second stage for all samples can be described as f (α)=1.5(1?α)2/3[1?(1?α)1/3]?1 . The activation energies of titania slag powders with different sizes (d1 < 0.075 mm, 0.125 mm < d2 < 0.150 mm, and 0.425 mm < d3 < 0.600 mm) for different reaction degrees were calculated. For the given experimental conditions, the rate-controlling step in the first oxidation stage of all the samples is a chemical reaction. The rate-controlling steps of the second oxidation stage are a chemical reaction and internal diffusion (for powders d1 < 0.075 mm) and internal diffusion (for powders 0.125 mm < d2 <0.150 mm and 0.425 mm < d3 < 0.600 mm).     

烧结铁矿中FeO含量对其在富氢高炉中还原行为的影响

Japan started the national project “COURSE 50” for CO₂ reduction in the 2000s. This project aimed to establish novel technologies to reduce CO₂ emissions with partially utilization of hydrogen in blast furnace-based ironmaking by 30% by around 2030 and use it for practical applications by 2050. The idea is that instead of coke, hydrogen is used as the reducing agent, leading to lower fossil fuel consumption in the process. It has been reported that the reduction behavior of hematite, magnetite, calcium ferrite, and slag in the sinter is different, and it is also considerably influenced by the sinter morphology. This study aimed to investigate the reduction behavior of sinters in hydrogen enriched blast furnace with different mineral morphologies in CO–CO₂–H₂ mixed gas. As an experimental sample, two sinter samples with significantly different hematite and magnetite ratios were prepared to compare their reduction behaviors. The reduction of wustite to iron was carried out at 1000, 900, and 800°C in a CO–CO₂–H₂ atmosphere for the mineral morphology-controlled sinter, and the following findings were obtained. The reduction rate of smaller amount of FeO led to faster increase of the reduction rate curve at the initial stage of reduction. Macro-observations of reduced samples showed that the reaction proceeded from the outer periphery of the sample toward the inside, and a reaction interface was observed where reduced iron and wustite coexisted. Micro-observations revealed three layers, namely, wustite single phase in the center zone of the sample, iron single phase in the outer periphery zone of the sample, and iron oxide-derived wustite FeO and iron, or calcium ferrite-derived wustite 'FeO' and iron in the reaction interface zone. A two-interface unreacted core model was successfully applied for the kinetic analysis of the reduction reaction, and obtained temperature dependent expressions of the chemical reaction coefficients from each mineral phases.     

Mg和La对Ca–Ti 处理钢中夹杂物演变和组织的影响

The evolution of inclusions and the formation of acicular ferrite (AF) in Ca–Ti treated steel was systematically investigated after Mg and La addition. The inclusions in the molten steel were Ca–Al–O, Ca–Al–Mg–O, and La–Mg–Ca–Al–O after Ca, Mg, and La addition, respectively. The type of oxide inclusion in the final quenched samples was the same as that in the molten steel. However, unlike those in molten steel, the inclusions were Ca–Al–Ti–O + MnS, Ca–Mg–Al–Ti–O + MnS, and La–Ca–Mg–Al–Ti–O + MnS in Mg-free, Mg-containing, and La-containing samples, respectively. The inclusions distributed dispersedly in the La-containing sample. In addition, the average size of the inclusions in the La-containing sample was the smallest, while the number density of inclusions was the highest. The size of effective inclusions (nucleus of AF formation) was mainly in the range of 1–3 μm. In addition, the content of ferrite side plates (FSP) decreased, while the percentage of AF increased by 16.2% due to the increase in the number of effective inclusions in the La-containing sample in this study.     

铁酸锌焙烧后的还原行为及氨浸特性

A novel method for recovering zinc from zinc ferrite by reduction roasting–ammonia leaching was studied in this paper. The reduction thermodynamic of zinc ferrite by CO was analyzed. The effects of roasting parameters on the phase transformation and conversion rate of zinc ferrite, and the leaching behavior of zinc from the reductive roasted samples by ammonia leaching, were experimentally investigated. The mineralogical phase compositions and chemical compositions of the samples were characterized by X-ray diffraction and chemical titration methods, respectively. The results showed that most of the zinc ferrite was transformed to zinc oxide and magnetite after weak reduction roasting. 86.43% of the zinc ferrite was transformed to zinc oxide under the optimum conditions: CO partial pressure of 25%, roasting temperature of 750°C, and roasting duration of 45 min. Finally, under the optimal leaching conditions, 78.12% of zinc was leached into the solution from the roasted zinc ferrite while all iron-bearing materials were kept in the leaching residue. The leaching conditions are listed as follows: leaching duration of 90 min, ammonia solution with 6 mol/L concentration, leaching temperature of 50°C, solid-to-liquid ratio of 40 g/L, and stirring speed of 200 r/min.     

机械零件的可靠性优化设计

在分析传统设计方法与可靠性设计方法在设计思想、设计原理上的区别的基础上,将可靠性设计与优化设计结合起来,对机械零件的可靠性优化设计方法进行研究。在满足可靠度约束及结构几何约束的条件下,以机械零件具体情况最小作为优化目标函数进行可靠性优化设计,得到了比常规设计更为合理的设计结果。     

浅析概念设计

概念设计是利用设计概念并以其为主线贯穿全部设计过程的设计方法。概念设计是完整而全面的设计过程，它通过设计概念将设计者繁复的感性和瞬间思维上升到统一的理性思维从而完成整个设计。概念设计围绕设计概念而展开，设计概念则联系着概念设计的方方面面。     

桥梁全寿命设计总体框架研究

提出把桥梁全寿命设计概括为使用寿命设计、美学设计、性能设计、环境生态设计、监测养护与维修设计及成本分析等六大过程的设计,提出一种包括三大设计阶段、六大设计过程的桥梁全寿命设计总体框架.     

生态牛仔服装的绿色设计

以生态牛仔服装的绿色设计为例,利用产品生命周期并行的绿色设计技术,从设计策划、产品设计、清洁化生产、消费使用、回收处理等环境和质量影响因素对生态牛仔服装的绿色设计方法进行研究。结果表明,由设计、环境、工艺等多学科专业组成的设计小组是完成绿色设计任务的保证,纺织材料的选择和漂洗后整理工序采用节能减排新工艺是控制产品生态质量标准和产品生产对环境污染的关键环节。因此,采用传统设计与生态设计相结合的设计理念和整体优化闭环控制系统来诠释生态牛仔服装的绿色设计,可以更有效地简化设计程序。     

普通民用建筑基础隔震技术研究

文章主要介绍了隔震设计与传统抗震设计的不同原理和减震效果,隔震基础的设计原则,特别是叠层橡胶支座的设计方案;最后以某建筑的具体设计和施工为实例对采用叠层橡胶支座的基础隔震设计进行相关总结,为基础隔震技术的普及和应用提供工程借鉴和参考的依据.     

多学科优化设计在柴油机设计上的应用

多学科设计优化方法是一种新的针对复杂工程系统设计的获得整体最优设计方案的方法.本文研究如何在柴油机的设计中采用协调优化方法对系统进行建模和多学科综合设计优化,并通过实际的设计应用,证明协调优化方法可以通过合理配置设计参数,实现柴油机的优化设计,综合提高柴油机的经济性、技术性能、可靠性及使用寿命.     

在城市快速发展背景下的建筑设计策略

为了解决我国城市化进程的加快所带来的建筑设计层面上的问题,提出了建筑设计观念的革新,建议采用可持续的设计方法、弹性的设计过程、标准化的设计以及采用开放式的建筑结构设计,同时强调融入情感的建筑设计方法以及建筑师的责任感和使命感,从而提高了建筑设计在城市快速扩张时期的适应性,最终实现人、建筑、环境的和谐发展,达到城市的可持续发展.     

低碳理念下的包装设计

阐述低碳设计与传统设计的不同之处及低碳包装设计理念，分析当前低碳时代包装设计面临的改革与挑战。提出包装材料的低碳设计途径，并以包装材料再利用案例具体说明。     

2021年创新设计热点回眸

 面向知识网络时代的创新设计呈现绿色低碳、网络智能、开放融合、共创分享的新特征。2021年，创新设计研究在理论方法、技术手段及应用拓展等方面取得了重要进展。从生物启发创新设计、数据驱动创新设计、可持续创新设计、基于人工智能的创新设计以及面向疫情的创新设计等视角回顾了创新设计年度研究热点和代表性成果，并展望了创新设计未来的研究热点。     

砂井地基固结概率设计的中心设计系数方法

将概率统计理论引入砂井地基固结问题的分析中，提出了砂井地基固结概率设计的中心设计系数方法，该方法用设计系数将砂井地基固结概率设计与常规设计联系起来。径向固结系数的设计值等于其均值与中心设计系数乘积。推导了径向固结系数为伽玛分布时中心设计系数的计算公式，并据此研究了中心设计系数的变化规律。提出了砂井地基固结概率设计的一般步骤，并用算例说明了该法在实际工程中的应用。