新型半连续电内热法竖式炼镁炉的研制

针对原镁生产过程中存在的技术水平低、能源消耗大、环境污染严重等共性技术难题,研究并设计了新型半连续电内热法竖式炼镁炉。该炉型具有竖式大容积炉体、多热源发热体内部加热、自动控制实现机械化作业和电能加热等特点。试验结果表明,其具有高能效、高效率、低污染等优点。     

新型竖式电内热法半连续炼镁炉的研发

针对原镁生产现状,研制成功了新型竖式电内热法半连续炼镁炉。该炉为电能加热、大容积竖式炉体、多热源发热体、内部加热、机械化作业、自动控制与监测,已完成多批次投料试验,获取了重要的技术参数。试验表明,其具有高效、节能、清洁生产等特点。     

长铝4#竖式石灰炉技术改造

本文论述了长城铝业公司氧化铝厂4#竖式石灰炉存在的问题,介绍了竖式石灰炉物料混配的新方法和新型布料器的原理.以及4#竖式石灰炉实现计算机集中监控改造的情况,具有一定的推广和指导意义.     

蒸馏镁对海绵钛质量的影响及其应采取的措施

1工艺简介海绵钛现行生产工艺有两种方法，即分离法和联合法．分离法是还原与真空蒸馏分开进行的，且未实现蒸馏镁闭路循环．此法还原产物蒸馏后，冷凝物冷凝在冷凝套街上，经打取熔炼后回收镁，故存在电耗与镁耗高等缺点．联合法克服了分离法的缺点，是还原和蒸馏在一台炉里进行，并实现了蒸馏镁闭路循环、此法还原产物蒸馏后冷凝在反应器上，不经打取，二次补充饶直接返回还原，但是拆炉时仍有部分蒸馏镁暴露在大气中，包括还原大盖、隔热屏及隔热板等处．生产实践证明，电耗和镁耗都较分离法低得多，具有节能效果显著等优点．但由于蒸馏…     

竖式中频炉连续工业化生产氮化钒

对电加热隧道窑、工业微波炉等生产氮化钒的工艺作了比较,研究了竖式中频炉连续工业化生产氮化钒技术,介绍了竖式中频炉的生产过程,生产过程中遇到的问题以及解决办法.与推板窑生产氮化钒相比,在产能相同条件下,竖式中频炉的能源、耗材等损耗更低.     

钛渣熔分电炉炉衬结构设计探讨

对比分析传统保温式炉衬和新型强化散热冷凝式炉衬的结构特点,提出采用冷凝式炉衬能够有效解决钛渣熔分电炉炉衬使用寿命的问题。计算了钛渣熔分电炉采用冷凝式炉衬炉墙的温度梯度以及热流密度,以25 500 k VA钛渣熔分电炉为例,相比保温式炉衬的维修费及停炉损失,冷凝式炉衬增加的2.4%散热损失可以接受。给出一种冷凝渣壳层最小厚度的确定方法,计算得出镁砖材质冷凝式炉衬厚度为600 mm时,钛渣渣壳层厚度最小为109 mm。     

安钢100t竖式电炉炼钢技术

本文以安钢100t竖式电炉为例，分析了竖式电炉炼钢中废钢预热、铁水热装等核心技术，总结了竖式电炉在生产中的应用情况，对这种炉型的发展提出了一些看法。     

竖式中频炉加工氮化钒VN16技术研究

研究了利用竖式中频炉加工氮化钒VN16产品的技术。通过对氮化钒合成过程中的反应机理、反应条件等试验分析,结合工业化试验,实现了利用竖式中频炉将VN12以低成本加工成VN16产品,使氮化钒产品达到了增值的目标。     

镁板带卷式法生产现状与分析

文章对目前国内外镁板带卷式法生产的技术特点、现状和局限性等进行了论述、分析和探讨。通过对炉卷轧机工艺设备特点的分析,重点对利用炉卷轧机进行镁板带卷式法热温连续轧制以及后续带式法精整工序的技术和设备需求、特点和可能性进行了分析,并给出了生产线建设的一些建议。     

铋银锌壳真空提取银和铋锌

铋银锌壳真空提取银、铋和锌是一种采用真空冶金分离三元合金铋银锌壳使之直接获取粗银,粗铋和粗锌。铋银锌壳是铋精炼加锌除银工艺的产物,该物料经熔化后加入真空蒸馏炉中,控制炉内温度在910～1 120℃,真空度在26～53巴,锌和铋依次蒸发,并在冷凝器上冷凝,得到粗铋、粗锌,银基本上     

Histological study of the tracheal adventitia, perichondrium and annular ligament

The trachea begins at the lower border of the cricoid cartilage and passes down to bifurcate into the left and right mainstem bronchi. The presence of tracheal invasion is crucial factor influencing the prognosis for patients with cancers of the thyroid gland, hypopharynx, esophagus, etc. In order to understand the manner of invasion of the above tumors, precise knowledge of the normal tracheal structure is indispensable. This study was undertaken to clarify the normal microscopic structure of the trachea. Five normal tracheal specimens obtained at surgery were examined histologically and immunohistochemically. The loose connective tissue around the trachea, known as adventitia, was divided into a loose outer and a dense inner layer by hematoxylin and eosin (HE) staining. This two-layer pattern was clearly seen near the annular ligament but was obscured away from it. The connective tissue of the inner layer ran obliquely to joint the connective tissue of the annular ligament and ended in the submucosal layer. This arrangement of connective fibers seems to play a role in allowing the trachea to stretch and bend. Tracheal cartilage is covered with a dense fibrous membrane known as the perichoundrium. Between the superficial fibrous membrane and mature cartilage cells lies zone of immature cartilage made up of oval or spindle cells, and the inclusion of this zone in the perichondrium has long been a subject of controversy. In our study, the zone was homogeneously stained red by the elastica van Gieson's stain and was clearly distinguished from other structures. Immunohistochemical staining revealed a wide distribution of type I and type III collagen on the fibrous membrane and the zone of immature cartilage cells, while mature cartilage cells did not show such collagen. Based on these findings, we conclude that the zone of immature cartilage cells belongs to the periochondrium, which thus contains two layers, an outer fibrous layer and an inner transitional layer of immature cartilage cells. Our conclusions are as follows: 1. Tracheal adventitia is divided into two layers, an outer loose and an inner dense fibrous layer. 2. Tracheal perichondrium also consists of two layers, an outer fibrous layer and an inner transitional layer. 3. The fibrous bundle originating from the adventitia joins the connective tissue of the annular ligament, probably in order to allow the trachea to stretch and bend.     

高炉炉缸富钛保护层的解剖分析

通过对长期加钛护炉高炉的炉缸进行解剖获得了富钛保护层的样品,并推测了富钛保护层在高炉中的形成过程。研究发现Ti(C, N)晶粒最初从铁水中析出,然后通过晶界迁移在炉渣中长大,最后Ti(C, N)晶粒与熔渣和铁水一起凝结形成保护层。此外,采用酸蚀法观察了Ti(C, N)晶粒的微观形貌,发现Ti(C, N)晶粒表面相对平整且具有大量环形层状结构,另外还有少量立方体式堆砌形式存在,Ti(C, N)晶粒内部并不致密。     

微孔MgO耐火材料对钢液洁净度的影响

摘要：通过浸泡实验研究了3种镁质（致密镁质、微孔MgO质、镁碳质）耐火材料与超低碳钢液(1560℃)的相互作用,考察了不同浸泡时间(0～35min)钢中O、N、C和Al、Si、Mn含量及钢中夹杂物的成分、数量、分布等特征的变化,并对耐火材料与钢的界面层进行了观测和分析。结果表明,随着浸泡时间的延长,3组钢中氧含量均先升高再降低,均对钢液有一定的污染,钢中夹杂物的数量增加,夹杂物种类由Al2O3-MnO夹杂逐渐转变为Al-Mg-Si-Mn-O复合夹杂。与致密镁质耐火材料相比,微孔MgO质和镁碳质耐火材料与钢的界面处分别能形成连续的镁铝尖晶石层和致密的MgO层,有助于降低耐火材料的侵蚀以及对钢液的污染。此外,与不含碳的镁质耐火材料相比,镁碳质耐火材料对钢液增碳严重。因此,微孔MgO质耐火材料不仅对钢液的二次污染小、不会向钢液增碳,而且还可以吸附钢中氧化铝夹杂,更有利于超低碳洁净钢的生产。     

Structure Analysis of Oxidation Film of Ignition-Inhibition AZ91D Magnesium Alloy Added with Cerium

The effect of cerium on ignition temperature of AZ91D magnesium alloy was studied. By the addition of cerium of 1%, the ignition temperature is raised by 180℃, so the magnesium alloy added with cerium can be melted in air. The burning temperature increases with the increasing of cerium. The structure and chemical compositions of the surface oxide film were investigated by XRD and Auger electron spectrometry(AES). The results of XRD indicate that the oxide film of the surface of ignition-inhibition magnesium alloy can change from loose structure of simple magnesia to compact composite structure consisting of magnesia, cerium oxide, Mgl7 A112 and aluminum oxide, which has excellent ignition-inhibition effect. AES depth profile analysis shows that the oxide film can be divided into three layers. The outside layer is mainly made up of magnesia, the middle layer, which consists of cerium oxide, magnesia, and aluminum oxide, is compound and compact. Thermodynamic analysis indicates that the structure of the surface oxide film is accordant to the change of free energy and high vapor pressure of magnesium.     

Effects of Different Processes on Phases and Service Performance of FeSiMg8RE5 Alloy

The difference of nodularizer in phase morphology and service performance by three processes was introduced.The three processes include directly pressing magnesium into molten alloy stirring by nitrogen gas and no stirring from 5 t arc furnace and melting magnesium in the intermediate frequency furnace.The microstructure patterns were observed by scanning electron microscope, and composition of phases was measured by energy dispersive spectrometer method.X-ray diffraction method was used to determine the phase structure of the nodularizer.The results show that spheroidizing reaction time and violent degree of nodularizers are influenced by grain size and distribution uniformity of siliconizing magnesium phase; spheroidizing reaction degree can be mitigated and spheroidizing time be increased by using N2 stirring in pressing magnesium from arc furnace.     

金属基体上YSZ过渡层及YBCO薄膜结构与沉积条件的关系

研究了两种在金属基体（ＨａｓｔｅｌｏｙＣ）上沉积的、以钇稳定的ＺｒＯ２（ＹＳＺ）为过渡层的ＹＢａ２Ｃｕ３Ｏ７－ｙ薄膜结构，并讨论了结构与沉积条件的关系。当沉积速率低时，ＹＳＺ层致密、均匀，存在织构取向，且与基体连接良好；而高速率沉积的ＹＳＺ层疏松，与基体结合差。ＹＢＣＯ薄膜的结构和性能与沉积时的基体温度相关。     

大型蓄热式金属镁还原炉炉内热过程的模拟与应用

将蓄热燃烧技术的优点与金属镁还原工艺的特点相结合,开发了具有66支还原罐的大型蓄热式金属镁还原炉。应用FLUENT软件对炉膛内流动、燃烧及耦合换热过程进行模拟。结果表明,将蓄热燃烧技术应用于金属镁还原炉,可以形成均匀的流场和温度场,从根本上解决了传统倒焰式还原炉炉内流场不均匀及上下排还原罐温度不一致的问题。将新型还原炉应用于工程实际,取得了良好的应用效果,较传统还原炉炉温均匀性提高70%,单炉产量提高1倍以上,还原周期缩短1.5h,还原罐的使用寿命延长30天,吨镁能耗降低60%。     

蓄热式脉冲燃烧控制技术的开发及应用

分析了蓄热式燃烧技术在镁还原炉应用实践中产生的问题及其成因,针对金属镁还原工艺具有保温时间长及温度均匀性要求高的特点,开发了蓄热式脉冲燃烧控制技术,改善了炉温均匀性,提高了镁成品质量,可有效降低热还原法制备金属镁的成本.通过在镁还原炉中的实际应用,介绍了其系统组成,对蓄热式技术在镁还原炉中的应用与改进具有参考价值和指导意义.     

带式机镁质球团热工制度仿真及优化

摘要：镁质球团矿冶金性能好,是一种优质炼铁炉料,其生产最适宜的设备是带式焙烧机,但镁质球团对焙烧均匀性要求高。针对带式机生产镁质球团,采用Fluent工具对焙烧过程进行了模拟仿真,以获得均匀的温度场。建模考虑了碳酸镁的分解、氧化镁含量对磁铁矿氧化的影响,仿真结果通过链篦杯实验进行了验证,模型模拟的温度准确率大于90%。随后利用仿真模拟,获得了镁质球团生产的适宜热工条件,优化后料层上、中、下3层的最高温度分别为1179、1202和1166℃,且温度高于1000℃的保持时间分别为17. 5、15.4和15.5min,料层温差明显减少,3层球团的强度分别为3630、3422和3296N/个,料层平均强度为3449N/个,相比实验室管炉试验确定的热工制度,其球团强度更均匀且平均强度增加842N/个。     

S355海洋钢表面微弧氧化复合膜层耐蚀性能

采用激光熔覆与微弧氧化技术相结合在海洋钢表面制备了复合膜层.运用扫描电子显微镜（SEM）、能谱仪（EDS）和X射线衍射仪（XRD）表征复合膜层的微观结构，采用极化曲线、电化学阻抗谱、腐蚀磨损实验和浸泡腐蚀实验等测试方法研究膜层在质量分数3.5%的NaCl水溶液中腐蚀行为，并与熔覆涂层和基体进行对比.结果表明:复合膜层主要分为内致密层和外疏松层，疏松层主要由γ-Al₂O₃组成，致密层主要由α-Al₂O₃组成，与基底层结合较好，复合膜层表面硬度最大能达到HV_0.2 1423.3，比熔覆涂层高47.6%，其硬度较S355海洋钢有显著提升.基体在腐蚀和磨损交互作用中主要以腐蚀加速磨损为主，涂层在交互作用中主要以磨损加速腐蚀为主，在经过微弧氧化处理后，膜层的自腐蚀电位负移，钝态电流密度上升，抗磨蚀性能明显提高.熔覆涂层的浸泡腐蚀方式以点蚀为主，复合膜层腐蚀较轻微，阻抗模值最大能达到105.3 Ω·cm2，比熔覆层提高两个数量级，这表明复合处理可进一步提高涂层的耐腐蚀性.