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.     

论管理劳动在价值创造中的作用

基于马克思劳动价值论，阐述了管理劳动创造价值的作用，即管理劳动是一种参与创造价值的活劳动，是一种参与创造价值的复杂劳动，是参与创造价值的创新活动，指出在社会主义经济建设中，深化对管理劳动在价值创造中的作用的认识，就是为了提高其在现代化建设实践中的应用性和生命力。     

试论化学研究性学习课题的选择

研究性学习是一种全新的教学方式，它有助于学生主动探究、自主学习，化学研究性学习有利于培养学生的创新能力、实践能力、问题意识、合作意识以及关注化学与自然、社会、生活的联系，研究性学习的选题是在化学教学中实施研究性学习的关键，是化学研究性学习实施的前提，课题的选择必须符合研究性学习的开放性、探究性、实践性，遵循问题性、可行性和创新性原则，化学研究性学习课题应从化学课堂教学，化学实验教学，化学与自然、生活、社会的联系以及化学学科发展前沿中选择。     

新世纪以来底层文学的困境与美学出路——以短篇小说中对女性情感的书写为例

苦难是新世纪以来底层文学关注的主题，这其中底层女性的情感困境得到有力的书写，但有批评者指责底层文学夸大苦难及缺乏文学性。对此一些创作者和论者则提出各自反驳的理由。底层文学主要问题在于思想资源的匮乏。强化现代性眼光，并且结合形式突破，这是新世纪底层文学的关学出路。     

运输问题理论体系的改进

本文根据运输问题的特殊性,直接利用运输表给出了它的三个基本概念和两个基本定理,并以此为基础导出了其理论与算法上的一系列重要结论,从而改进和完善了运输问题的理论体系。     

略论模态语境中指称的隐晦性问题

模态语境中指称的隐晦性问题一直是模态逻辑研究的重点。迄今为止,逻辑学家已经提出了两种解决的方案:一是CHURCH方案,一是通过将专名和摹状词加以区分并论证专名是否有涵义的方案。着重讨论和分析第二种方案,从专名是否有涵义与语境关系角度审视模态语境中指称隐晦性问题,并且在此基础上提出主张和观点。     

Change in the tilting of the ridgeline surface of the subtropical anticyclone and the predictability of the onset of the Asian summer monsoon

The NCEP/NCAR reanalysis data are used to study the relationships among the change in the tilting of the ridgeline surface of the subtropical anticyclone, the establishment of the so-called "seasonal transition axis (STA)" and the onset of the Asian summer monsoon. It is shown that the monsoon onset is characterized by the overturning of the meridional temperature gradient (MTG) in the vicinity of the ridgeline surface. A MTG index is then constructed to investigate the predictability of the Asian summer monsoon onset conceptually. Data diagnoses show that if the initial MTG is known and the meridional gradient across the ridgeline surface of the local temperature tendency can be estimated, a late or early onset of the summer monsoon can be qualitatively predicted in advance.     

公共新闻事业与公共领域的建构和发展

公共新闻(Pub lic Journalism)是1990年前后在美国兴起的新闻改革运动。它的兴起并非是单独的现象,而是欧美在政治经济困局下复兴的公民社会热潮中的一个环节。哈贝马斯的公共领域理论是公共新闻的理论来源之一,公共新闻事业对于社会公共领域的建构和发展有着重要的意义。     

论《水浒传》思想的墨学渊源

《水浒传》忠义观所蕴含的社会理想与墨学有相通之处,一是“八方共域,异姓一家”与墨家的“兼爱”;二是向往“快活”与墨家的“喜利恶害”;三是“以贤为能,纪律严明”与墨家尚贤、尚同;四是“替天行道”与墨家天志。但水泊梁山作为古代中国乌托邦的一种形式,同墨家兼爱社会一样都是虚幻的,在封建社会的汪洋大海中,只能在被八百里水泊隔开的孤岛中暂时地有限地存在。     

基于风机学和空气动力学对密封空气管道中气球高度控制的建模

针对一个特殊的系统进行建模。此特殊性可描叙为:控制系统为对密封管道中质量轻的物体(以乒乓球为例)高度的控制。与密封管道密封相连接的是风机,需要控制模型底部的风扇来控制物体在管道中悬浮的高度,其中非线性红外线作为系统的测量仪器。即:输入为风扇的工作电压U;输出为物体的高度。先后对PWM调压、风扇、空气管道和非线性红外线等环节建模,并且提出了各个参量的获取方法。鉴于系统中涉及到多个小系统的非线性化建模和多个参量的获取,采用对系统进行线性化处理和利用外围仪器对参量的测取。主要对系统建模提供了一种方法,其中对于各个小系统的建模都有可取之处。     

补零对削减伪逆滤波畸变的影响

逆滤波是一种比较简单的卷积反演方法 ,在小噪声的情况下其效果相当好。但是在系统冲击响应频谱有零点时逆滤波失效 ,为此有各种不同的改进方法 ,伪逆滤波是其中之一。伪逆滤波保留了逆滤波的优点 ,但是滤波结果有畸变。该文从理论上分析通过补零增加数据长度对伪逆滤波的结果的影响 ,并对结果进行数值模拟计算 ,与已有的算法进行比较 ,发现在数据长度足够长而冲击响应频谱零点有限时 ,伪逆滤波可取得较好的效果