焙烧曲线调整与预焙阳极质量

为了满足满负荷生产的需要，根据实际操作条件，调整了原设计曲线。实践证明，实行新曲线后火道温差减小，中温升温速率得到控制，高温保持适度，避免了火道过烧现象，提高和稳定了阳极质量，阳极理化指标达到较好水平，同时对减少燃料消耗、延长焙烧炉使用寿命也有积极意义。还对料箱温差较大等问题提出解决措施。     

Autopsy of refractory lining in anode kilns with open and closed design

Aluminosilicate refractory lining constitutes a major part of anode baking kilns, and during anode baking the lining is exposed to harsh conditions which limits the lifetime. Here, autopsies of refractory linings from both an open and closed top furnace are reported aiming to determine the microstructural and mineralogical changes in the lining during operation. Significant variations in density and porosity were observed, both across the brick cross sections, but also for the vertical position in the lining. The chemical and mineralogical composition of the bricks were investigated by electron microscopy and X-ray diffraction. Only minor changes in the mineralogical composition of the materials were observed, and sodium originating from green anodes was only observed to a minor degree. Evidence of silicon oxide transport from the lower to the upper part of the linings was observed, reflecting the changes in reducing-oxidizing conditions during an anode baking cycle. The main degradation mechanisms in these linings were due to densification of the material over time, particularly the uneven densification across a lining wall. The present findings are discussed and related to the main differences in the two furnace designs.     

影响预焙阳极质量因素分析及改进途径探讨

结合国外预焙阳极生产和质量控制的研究成果，从原料、生阳极生产、焙烧工艺以及检测手段方面，分析了影响预焙阳极质量的主要因素。指出原料质量等级的下降，糊料混捏未达到最佳条件，配方与国产原料及工艺选择不相适应，生产的稳定控制程度较低，焙烧温度欠佳以及缺乏必要的检测手段是影响和制约国内阳极质量的主要原因。文中对相应的改进措施和途径进行了探讨，包括原料掺和、优化配方、改善混捏条件、精细控制配料各元素、改善焙烧条件、完善工艺生产线配置、引进先进的检测手段和设备。     

净化处理在预焙阳极生产中的应用

介绍了预焙阳极生产过程中废气产生的主要工段～原料破碎、石油焦煅烧、煅后料冷却、配料、混捏成型、阳极焙烧,主要废气污染物为粉尘、煅烧废气、沥青烟气。结合国内外现有的烟气治理措施,阳极生产中设计出不同类型的粉尘、沥青烟尘治理的方法,使我公司的粉尘、沥青烟尘实现达标排放。     

提高出口大型开槽阳极质量的探讨

从阳极成型工艺和焙烧工艺等重要环节对改进和提高大型开槽阳极的生产质量进行了探讨.     

硅石—碳化硅窑具砖

针对硅砖使用过程中易断裂的弊病,在其生产工艺的基础上,以碳化硅代替部分硅石克服之。碳化硅的加入量为15％。初见成效,30％效果明显,1100℃的水冷次数高达13次。硅石—碳化硅砖集硅砖和碳化硅砖之优点而兼具荷重变形温度高,热震稳定好的特点。作为耐火材料烧成用的高温窑具,使用寿命比硅砖提高五倍以上。     

浅谈静电除尘在炭素焙烧烟气净化中的应用

在电解铝用炭素阳极焙烧过程中产生含有大量沥青焦油、氟化物和粉尘等的有毒有害烟气,烟气的净化极为重要。本文就国内现主要采用的干法吸附和电捕处理焙烧烟气方法进行对比,重点对中国铝业公司青海分公司现有的电捕净化方式在实际运行中存在的问题进行探讨,从而找出改进的方法和措施。     

多品种炭阳极焙烧的工艺研究

面对国内外阳极市场千差万别的阳极尺寸要求，大多数阳极生产厂家的焙烧生产线都比较固定。本文针对车间的实际，就如何改变原有的固定生产模式，建立适应多品种阳极焙烧的柔性化生产线进行了总结，重点对生产过程各环节的管理提出了许多切实可行的办法。表明现阶段对于基层的生产管理，还必须以科学管理的思想为指导，实行制度化管理为主；同时在管理、技术等方面必须不断的创新，对相关生产企业也有一定的参考价值。     

PECHINEY阳极焙烧炉结构特点分析

分析了法国ＰＥＣＨＩＮＥＹ焙烧炉的结构特点及自动控制技术对焙烧过程的影响，该焙烧焙烧的阳极质量与普通的焙炉相比大大提高，能耗降低了近一半。     

水泥回转窑用含ZrO2耐火材料

含ZrO2耐火材料在水泥窑上的应用不断增加,水泥窑用含ZrO2耐火材料包括含锆白云石砖、含锆镁砖、含锆镁尖晶石砖、含锆高铝砖等.本文从材料的抗化学侵蚀性、热震稳定性、导热性和力学性能等方面讨论了ZrO2的引入对耐火材料使用性能的影响.     

15000m3/h耐火材料厂焙烧窑炉烟气低温脱硝工程实验

耐火材料是一种必要的工业炉衬基础材料,经过高温煅烧制得,空气中的N₂高温氧化形成NO_x,且窑炉烟气中NO_x浓度根据生产工段的变化而波动。目前国内在耐火材料焙烧窑炉烟气NO_x脱除方面的工艺少有报道。为解决这一问题,本文首次提出将选择性催化还原（SCR）法运用到耐火材料焙烧窑炉烟气脱硝工程实验中,根据特定工况烟气参数,通过调整反应参数得到了最佳工艺条件。系统地考察了烟气温度、氨氮比和空速对脱硝效率的影响。研究结果表明,当烟气温度为165°C、氨氮比为1.3、空速为2000h^-1时,脱硝效果最佳,脱硝率可达到90%。对于耐火材料焙烧窑炉烟气脱硝治理推广具有较好的前瞻性。     

NiFe2O4/Ag惰性阳极的熔盐腐蚀性能

以Fe2O3,NiO和Ag粉为主要原料,采用固相烧结工艺制备了NiFe2O4/Ag惰性阳极.采用X射线衍射和扫描电子显微镜对材料的组成和微观结构进行了研究,并测量了样品抗热震性、抗折强度、在冰晶石熔盐中的静态热腐蚀以及电解腐蚀速率,对其腐蚀过程作了初步探讨.结果表明:惰性阳极由NiO,NiFe2O4尖晶石和Ag三相组成.随着金属Ag含量的增多,惰性阳极样品在冰晶石熔盐中的静态热腐蚀速率增加,由于抗热震性和抗折强度有了大幅提高,电解腐蚀速率降低.静态热腐蚀和电解腐蚀呈现出物理化学溶解过程,而且由于金属银对晶界的强化作用,电解腐蚀由晶粒开始.     

Fabrication of low to high duty fireclay refractory bricks from lignite fly ash

The development of refractory bricks made of new materials has recently drawn a lot of interest to address sustainability issues. So, in this study, the recycling of lignite fly ash produced by coal-fired thermal power plants has been investigated to make fireclay refractory bricks. The lignite fly ash and ball clay are the primary raw materials characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray fluorescence (XRF), and differential thermal analysis (DTA). The samples were prepared using a uniaxial hydraulic press, and firing was done in the range of 1000–1200 °C for 2 h. The fired samples were characterized in terms of chemical composition, mineralogical phase, and microstructural using different characterization tools such as XRF, XRD, and SEM. The physical, mechanical, and thermal properties such as linear firing shrinkage, apparent porosity (AP), bulk density (BD), cold crushing strength (CCS), cold modulus of rupture (CMOR), and thermal conductivity of the fired sample were investigated. The linear firing shrinkage, AP, BD, and CCS values were achieved estimated to be 5.32%, 2.10 g m/cc, 15%, and 52 MPa, respectively. The SEM analysis shows dense, rod-like mullite structure and interlocking microstructure of the fired samples. The results were well matched with ASTM standards and commercially available products. So, this promising result indicates lignite fly ash can be used as a potential raw material to produce fireclay refractory bricks.     

Forsterite refractory brick produced by talc and magnesite from Thailand

This research focuses on refractory material synthesized from precursors of talc and magnesite in Thailand. They were mixed at a molar ratio of 1:5 with mechanical activation at 5 h and calcined at 1300 °C for 1 h to create forsterite. The resulting forsterite crystals were round with less than 1-μm particle size. Synthetic forsterite refractory was formed into refractory bricks and studied at various sintering temperatures of 1200, 1300, and 1400 °C with a dwell time of 2 h. The characteristics and properties of refractory samples were tested in physical properties, cold crushing strength, thermal conductivity, thermal shock, and corrosion resistance from various substances. The results showed that increasing the sintering temperature increases the physical properties and cold crushing strength values. Also, the sintering temperature increases will increase thermal conductivity. The best condition of forsterite refractory brick sintering was 1400 °C for 2 h (FB-14), which showed the following desirable properties: firing shrinkage of 18%, bulk density of 3.03 g/cm³, the apparent density of 3.26 g/cm³, both apparent porous and water absorption values of zero, and cold crushing strength of 72.18 MPa. The FB-14 brick has excellent resistance to corrosion and penetration from lead silicate frit and copper slag. There was minor weight loss from the corrosion of the chemical solutions used in sodium hexametaphosphate production, whereby weight loss will begin on the 18^th cycle. Consequently, the FB-14 brick can be used for blast furnace walls to slow down corrosion, which will allow the blast furnace to have a longer life cycle.     

Degradation mechanisms and use of refractory linings in copper production processes: A critical review

The use and degradation of refractory linings in copper furnaces are discussed, thereby describing the main steps taken at the research, development and industrial level to minimize refractory wear. Which combination of chemical, thermal and mechanical degradation mechanisms is dominant depends on many factors such as the furnace type, the lining design, including the selection of the refractory type, and the process conditions. Magnesia-chrome bricks are widely used to line copper furnaces, despite the potential risk for the formation of hexavalent Cr under specific conditions, typically in the presence of alkali or alkaline earth oxides. To understand and predict refractory degradation, both post-mortem investigations and lab scale tests are considered to be helpful tools, thereby supported by phase diagram investigations and thermodynamic and kinetic calculations. This review concludes with refractory selection and use on the industrial level, including the waste and recycling management of spent refractories.     

Performance of a ceramic frit anti-oxidation coating on a MgO-C refractory brick

In steel production, ladles must be preheated to minimize the heat loss of the steel melt, prevent thermal shock of refractory bricks (MgO-C), and to maximize the lining life of ladle. Partial oxidation of MgO-C bricks begins in the graphite bond during the preheating. Oxidation of graphite bond also causes a decrease in performance of the bricks because of an increase in the brick porosity. In this article, coating on a MgO-C brick surface by a ceramic film to protect against carbon oxidation was studied. Coated and un-coated bricks were heated at 1200 °C, cooled to room temperature, then the brick properties investigated. The oxidization resistance properties of brick with coating were much better than those without coating, which should lead to longer refractory service life.     

耐火预制件在烧成系统改造中的应用

在烧成系统使用的传统耐火材料,由于受到水泥窑恶劣工艺条件和窑内风速、烟气成分及含尘量、颗粒硬度、温度波动等因素的影响,再加上相应的化学侵蚀、冲刷磨损、机械应力及热剥落,使用寿命一般不长。耐火预制件具有整体质量可控、安装方便、维修时间短、无需再现场烘烤可直接投入使用等优点。将耐火预制件用于水泥熟料生产线的窑尾烟室及分解炉锥体、三次风闸阀、篦冷机喉部、篦冷机矮墙等部位,使用效果良好,大大提高了烧成系统的运转率,降低了系统的运行成本,在节能改造中取得了良好的效益。     

水煤浆水冷壁气化工艺及生产运行

以水煤浆水冷壁气化技术在山西阳煤丰喜集团临猗分公司应用为例,主要介绍了水煤浆水冷壁气化的工艺及设计特点,总结了水煤浆水冷壁气化炉的优势,运用该技术可解决现有耐火砖炉存在的炉体易损耗、工作效率低等问题,具有良好的应用前景。     

阳极双电层电容对微生物燃料电池性能的影响

采用3种活性炭粉制备具有不同电容的阳极,研究了双电层电容阳极对单室空气阴极微生物燃料电池启动、运行、性能、阳极生物膜附着的影响。结果表明:当电极表面积相近的情况下,阳极双电层电容从0.0012 F增加到22.72 F时,微生物燃料电池启动时间缩短了68.0%,电池的最大功率密度增加了16.8倍,达到546.1 m W·m-2。扫描电子显微镜的结果表明高电容的阳极表面附着的微生物量比低电容电极的高1倍。因此,微生物燃料电池性能受阳极双电层电容的影响,而与阳极表面积的相关性小。     

Modification of petroleum coke by different additives and the impact on anode properties

Anodes, which provide the carbon required for aluminum production, are made from dry aggregates (petroleum coke, rejected anodes, and butts) with coal tar pitch as the binder. Good quality anodes require good interaction between coke and pitch, and this relies on good wetting properties. The objectives of this work are to analyze the wetting properties of four different cokes with and without modification using an additive and to test the effect of the modified coke on anode properties. A FTIR study was done to identify functional groups in non‐modified and modified coke samples since they play an important role on coke‐pitch interactions. The wetting tests were done using the sessile‐drop method to measure the contact angle between coke and pitch. The results showed that the additive improved the wettability of all four cokes by pitch. The least wettable coke was chosen to produce anodes. For anode production, the entire dry aggregate is modified. The additive was mixed with the dry aggregate using two different approaches (one day earlier and 5 min before mixing). The anodes were characterized before and after baking. The early treatment with the additive was found to be better for the modification of dry aggregate.