高投料量下炼铜闪速炉内熔炼过程的数值模拟

以FLUENT 6.3为计算平台,建立了铜闪速炉熔炼过程数值模型,并针对高投料量下反应塔气粒两相变物理场信息分布变化特点展开仿真研究。结果表明:工艺风入炉后迅速膨胀,并在反应塔中心形成轮廓明显的主体气流柱;主体气流柱内外的温度和氧浓分布梯度变化较大;局部低温出现在精矿喷嘴下方,而高温反应核心区域则下移至反应塔中下部。综合多场耦合仿真结果可知:高投料量条件下精矿粒子与反应配风之间混合力度欠佳是造成高投料量反应塔内熔炼过程反应效率降低的主要原因。     

铜闪速熔炼多相流模型化研究进展

铜闪速熔炼具有高处理量、高富氧浓度、高冶炼效率和低环境污染的优势,已在世界范围内广泛推广应用,深入研究闪速熔炼过程中的物理化学现象和原理具有重要意义。然而,闪速炉内多相流间相互作用及熔炼动力学行为受到多方面因素的共同影响,仅依靠生产经验、试验观测和理论分析难以全面解析炉内多相流传质传热过程、获取流体流动特性、揭示气固多相流相互作用规律,阻碍了闪速炉冶炼效能的进一步提升。当下计算流体力学数值模拟发展迅速,正为预测和分析闪速炉内多相流问题提供了高效、准确、直观的帮助。本文在介绍铜闪速炉结构、冶炼原理、理论模型的基础上,阐述了近年来铜闪速熔炼动力学反应机理、炉内流动特性方面模型化的研究成果及发展趋势,全面综述了铜闪速炉在喷嘴、沉淀池、上升烟道、锅炉优化方面的研究成果,为闪速炉生产优化及设计改进提供指导。     

底吹炼铅炉内流动的数值模拟

以工业实践的底吹炼铅炉为对象,在炉内渣相和金属相的物性参数测定的基础上,利用FLUENT软件平台,建立一个与实际体系一致的底吹炼铅炉模型,并耦合VOF三相流模型和标准κ-ε湍流模型对底吹炼铅炉内气-渣-金属三相流动过程进行模拟。通过分析数值模拟的相界面结构、速度场分布、流线分布结果,发现氧枪上方区域搅动剧烈,渣层中存在涡流,强化了传递和反应过程。另外,所建立的模型在优化底吹炉炉体结构和改善运行条件方面有着重要作用,经过分析不同条件下炉内流体流动形态,能有效地引导完善底吹炼铅炉工况。对入口流速和喷枪倾角的优化讨论中,发现增大入口流速能提高熔炼效果,最佳喷枪倾角为5°~7°。     

冶炼烟气网络治理技术

金川集团有限公司利用闪速炉、合成炉等产生的高浓度二氧化硫烟气与电炉、贫化炉产生的低浓度二氧化硫烟气进行高低搭配，通过混合室配气，经管道网络配置到5个硫酸生产系统，平衡烟气、稳定生产，消除低浓度二氧化硫的排放污染，实现清洁生产。     

大排距双层送风冲天炉的综合检测系统

本文研究了冲天炉熔炼过程中的参数(风量,风压,前炉铁水温度,炉气成份中的CO_2％含量)实行综合检测与供风控制,以保证高温优质铁水的稳定生产。最后评价控制效果。并提出进一步采用微计算机与工业自动化仪表联用,对冲天炉熔炼过程实现全面监测及最佳控制的方案。     

热镀锌机组退火炉节能优化的数值模拟

针对某钢铁公司热镀锌机组退火炉直燃加热段(DFS)内复杂的燃烧、流动、传热过程与其操作参数的关系,利用CFD技术进行建模与仿真计算,研究了烧嘴的空燃比与空气预热温度对炉内组分浓度场与温度场的影响。模拟结果表明,直燃加热段空燃比在4. 0及以下,炉段内的还原性气氛符合生产工艺的要求;模拟找出了与试验工况截面温度一致的几组优化组合操作参数(空燃比/空气预热温度),分别为3. 7/720 K、3. 8/600 K、3. 9/450 K和4. 0/300 K,此时DFS出口及中心截面的平均温度与试验工况的3. 5/600 K一致,其中4. 0/300 K工况下,煤气用量减少11. 88%,节约能源明显。     

非氧化性炉气铝合金焦炭炉的试制及应用

一般的铸造铝合金熔炼,除使用电阻炉、中频炉及工频炉、油炉,同时考滤设备投资及燃料费用外,通常较多的采用敞开式焦炭炉进行熔炼.该炉结构简单(图1),设施投入费用低,但在合金熔炼过程中,由于炉顶部是敞开的,焦炭燃烧后产生的高温炉气始终包围着坩埚,底部风机供风充足时,焦炭完全燃烧生成的炉气呈氧化性,对熔融的铝合金存在较强的氧化作用.同时焦炭炉敞开式的熔炼方法,高温及烟尘对操作者不利,对环境也有所污染.若对这种常用的敞开式焦炭炉进行改造,做成炉顶封闭式的焦炭炉,隔绝炉气对熔融铝合金的氧化,同时也利于使用者的操作,为此对原有的焦炭炉进行改造.     

冶炼烟气网络治理技术

金川集团有限公司利用闪速炉、合成炉等产生的高浓度二氧化硫烟气与电炉、贫化炉产生的低浓度二氧化硫烟气进行高低搭配，通过混合室配气，经管道网络配置到5个硫酸生产系统，平衡烟气、稳定生产，消除低浓度二氧化硫的排放污染，实现清洁生产。[编者按]     

操作技术对冲天炉熔炼的影响

冲天炉熔炼效果不但与炉型结构密切相关,而且受操作技术的直接影响。因此,正确地做好从修炉到停风、打炉全过程中每一环节的操作,是保证冲天炉良好性能、稳定熔炼的关键。本文分析了操作技术对冲天炉熔炼的影响,阐述了保证正常稳定熔炼的操作方法。     

火电厂锅炉一次风煤粉浓度对燃烧的影响

火电厂运行中锅炉燃烧系统煤粉管内的煤粉浓度即一次风煤粉浓度是一个非常重要的参数，煤粉浓度的高低直接影响风管内送粉的均匀性；炉内工况的稳定性和锅炉燃烧效率，本文着重就山西铝厂热电分厂的锅炉在目前运行过程中，运行人员的习惯性操作对炉内气流结构的影响作出定性分析。     

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.     

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.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.