水泥窑用低儿优质镁铬砖的研制

本文介绍了结合我国国情彩 增铝，增铁的技术路线研制的低铬优质镁铬砖色代替普通镁铬砖，当Ｃｒ２ｏＣ〈４％时仍具有优良的热震稳定性和粘挂窑皮性。该砖已经在徨丹江水泌厂１＾＃窑烧成带使用了两个窑交俱有良好有使用性能。     

回转窑烧成带镁铬砖的使用与窑衬寿命的关系

根据回转窑烧成带镁铬砖的损坏机理，找出提高窑衬周期的具体措施，阐明水泥生产过程中回转窑烧成带镁铬砖的使用与窑衬寿命的关系。     

水泥窑用耐火材料及其选择匹配

水泥窑用耐火材料有粘土砖、高铝砖、磷酸盐结合高铝质窑衬砖、镁砖、镁铝尖晶石砖、普通镁铬砖、直接结合镁铬砖等等，根据它们不同性能分别匹配于窑系统的不同部位。     

抗剥落高铝砖在湿法短窑烧成带的使用

我厂有７台湿法短窑，长径比在１８～２５之间，分别使用喷入法和蒸发机喂料。这２种喂料方式的优点是将水分蒸发移至窑外或采用喷雾干燥，使筒体长度能够缩短，从而减少了投资。但由于窑预烧能力不足，生料在烧成带需高温慢窑煅烧（窑速在１r／min），因而烧成带热负荷高，窑衬周期短，多年来，烧成带耐火材料使用过高铝砖、不烧镁铬砖和普通烧结镁铬砖，使用寿命为１２０～１８０d左右，与湿法长窑和干法窑相比差距较大。２０００年，我厂工程技术人员结合本厂工艺设备状况多方论证，在３号、４号水泥窑烧成带用抗剥落高铝砖代替镁铬砖，…     

白云石砖在窑外分解窑上的试用

白云石砖在窑外分解窑上的试用梁忠博辽宁省本溪水泥厂（１１７０１９）我厂３号窑为１２００ｔ／ｄΦ３．７ｍ×５３ｍ的窑外分解窑，窑内烧成带衬料长期使用普通烧结镁铬砖。由于镁铬砖在水泥窑内使用中砖内Ｃｒ２Ｏ３组分与窑气、窑料中的碱、硫等相结合，形成有毒的Ｃ...     

合理选择和使用耐火砖消除铬对环境的危害

水泥窑用镁铬砖的残砖中铬含量较高，对环境危害大。为降低铬盐对环境的危害，牡丹江新材料科技股份有限公司在水泥窑上进行了使用低铬砖和无铬砖的试验。试验表明，加锆改性尖晶石砖的使用情况较直接结合镁铬砖差，而加铬方镁石复合尖晶石砖(LYC砖)的使用效果好于直接结合镁铬砖。LYC砖不仅铬含量低，对环境的危害小，且其使用寿命是普通镁铬砖的5倍，是直接结合镁铬砖的1．72倍。使用LYC砖对提高窑运转率，降低生产成本有利。     

新型干法水泥窑高温带用无铬砖的研制及应用

<正>镁铬砖在水泥窑高温带使用后会产生致癌物质六价铬盐化合物,西方发达国家已限制或禁止镁铬砖在水泥窑上使用,国内由于没有合适的无铬砖替代镁铬砖,所以镁铬砖仍在国内水泥窑高温带大量使用     

影响回转窑镁铬砖窑衬周期的因素探讨

镁铬砖属于碱性耐火材料，一般使用在水泥回转窑的烧成带，它直接影响回转窑窑衬周期的长短，认识镁铬砖使用的损坏机理，找出提高窑衬周期的具体措施与对策，对回转窑的安全平稳运转，减少耐火材料的用量，提高回转窑的产量和稳定熟料质量均具有非常重要的意义。     

使用镁铬砖窑衬延长窑的运转周期

我厂从推广水泥回转窑烧成带镶砌镁铬砖开始,先是在5号窑上使用。由于在运输和保管上没有注意镁铬砖的防雨防潮;在镶砌上忽视质量赶进度;在设备上窑胴体水冷却门处漏水;在使用上抢着开窑也未重视保温、挂窑皮和保护窑皮。因此,影响了镁铬砖窑衬的使用寿命。通过一段时间的实践,初步掌握了烧成带正确使用镁铬砖的规律,并相继在五台窑上全面推广,使窑衬的使用寿命延长,窑的运转     

国产耐火材料在5000t／d水泥窑烧成带上的使用

在大型窑外分解窑上，国产镁铬砖可代替进口砖，使用周期可达1年，阐述了烧成带窑衬损坏的机理，选用依据、砌筑方法及操作手段。     

The Effect of Sintering Temperature on Microstructure of High Chrome Bricks

The microstructure of high chrome bricks made at dif-ferent sintering temperature are analyzed by SEM. The re-sults indicate that the sintering temperature of high chromebricks has an optimum range, it is not the higher, the ber-ter. The high chrome. bricks made at this sintering temper-ature have the moderate crystal size in the matrix and ofdense structure. The closed bonding structure could be ob-tained between grains and matrix and no crackle occurred.The high chrome bricks with this microstructure have thebest dynamic properties.     

Slag Resistance of Magnesite-chrome Brick Impregnated with Chrome-bearing Sols

Cr2O3 has eminent slag corrosion resistance.So,the magnesite-chrome brick is thought as an important refractory material used in RH refining furnace in the process of steel-making around the world.After chromebearing sots being prepared by sol-gel method,single sol (Cr(OH)3)and mixed sol(Mg(OH)2-Cr(OH)3)were impregnated into magnesite-chrome bricks by vacuum impregnation.The corrosion resistance of the impregnated bricks to silicon steel slag was studied by porosimetric analysis and fiactal dimension calculation.The results showed that the corrosion resistance of impregnated magnesite-chrome brick was better than that of the unimpregnated brick and the brick impregnated by MgSO4 solution,and the one which has surface-treated by Mg(OH)2-Cr(OH)3 sol was the best,mainly because of lower apparent porosity,smaller pores diameter and their smoother inner suoface.     

铬砖在蓝色浮法玻璃液中的耐侵蚀机制

用广东石井特种耐火材料厂生产的铬砖(Cr2O3>94%)和洛阳浮法玻璃有限公司生产的蓝色浮法玻璃为实验材料,参照GB 1020488<玻璃熔窑用耐火材料在静态下抗玻璃液侵蚀实验方法>,使用扫描电子显微镜测试分析手段.研究了侵蚀前后铬砖显微结构和侵蚀界面附近元素组成的变化,探索了铬砖的耐侵蚀机制.实验结果表明:铬砖的耐侵蚀性与其显微结构有关,也与玻璃的组成有关,碱金属氧化物能降低其耐侵蚀性.     

锆英石对铝铬锆砖抗侵蚀性能及六价铬形成的影响

铝铬锆砖因具有优异的抗渣侵蚀性能,被作为炉衬材料广泛应用于工作环境恶劣的危废焚烧炉。然而,铝铬锆砖在制备和服役过程中可能形成有毒的水溶性Cr(VI),相关研究工作却未见报道。本研究分别以单斜氧化锆和锆英石为氧化锆源制备了两种铝铬锆砖,研究了铝铬锆砖在四种不同组成危废焚烧炉渣中的侵蚀行为及熔渣侵蚀前后砖中Cr(VI)的含量。结果表明,锆英石高温下分解形成单斜氧化锆和无定形的二氧化硅,促进化学稳定性较好的(Al,Cr)₂O₃固溶体的形成,提高了铝铬锆砖的致密化程度,同时改善了铝铬锆砖的抗渣侵蚀性能。此外,生成的二氧化硅可以还原砖中Cr(VI)化合物,降低铝铬锆砖中的Cr(VI)含量。熔渣侵蚀后,铝铬锆砖渗透层中Cr(VI)含量与熔渣成分密切相关。在被高碱性氧化物含量的熔渣侵蚀后,铝铬锆砖渗透层中的Cr(VI)含量较高,但锆英石作为氧化锆源的铝铬锆砖在不同熔渣中侵蚀前后的原砖层和渗透层内的Cr(VI)含量均低于欧盟限制标准。     

Effects of Resins with Different Molecular Structures on Properties of MgO-C Bricks

Resins PFG-4,PFG-8 and a reference resin( resin A) were used as binders of Mg O-C bricks,effects of the resins with different molecular structures on wettability of magnesia,on physical properties,mechanical properties,oxidation resistance and thermal expansion properties of Mg O-C bricks were researched. The results show that the microstructures of solidified resins with different molecular structures are different,which have obvious effect on the cold mechanical properties of Mg O-C brick,but little effect on the oxidation resistance,thermal performance and expansion properties.     

水煤浆加压气化炉用Cr2O3-Al2O3-ZrO2砖的损毁模式

详细分析了陕西渭河煤化工集团有限责任公司的德士古(Texaco)水煤浆加压气化炉用Cr2O3-Al2O3-ZtO2砖的损毁模式及影响因素,并提出了降低耐火砖损毁的方法.认为块状剥落、烧蚀损伤、冲蚀损伤和机械损坏是造成耐火砖损毁的主要原因;提高耐火砖自身的抗侵蚀能力,改善炉衬砌筑结构和炉内工况气氛,控制适当的炉渣特性,以及采用正确的修理维护方法,是提高德士古水煤浆加压气化炉用Cr2O3-Al2O3-ZrO2砖使用寿命的主要途径.经过几年的反复试验和技术改进,特别是采用中钢集团洛阳耐火材料研究院生产的Cr2O3-Al2O3-ZrO2砖后,渭河煤化工集团有限责任公司的德士古水煤浆加压气化炉用Cr2O3-Al2O3-ZrO2砖的使用寿命已从原设计的8000 h提高到现在的23000 h.     

Study on Microstructure and Slag Corrosion Mechanism of High Chrome Bricks for Gasifier

1 Introduction The gasifier like Texaco style is of important tech- nical equipment for ammonia synthesis and production of carbamide, carbinol and ethylene etc. Due to differ- ent energy resource structure, petroleum coke is adopt- ed as rawmaterial in A…     

水煤浆加压气化炉用高铬砖的优化

通过调整高铬砖中α-Al2O3微粉粒度分布和Cr2O3微粉的加入量,对水煤浆加压气化炉用高铬砖进行性能优化。结果表明,优化后的高铬砖显气孔率明显降低,抗热震性和抗侵蚀性显著提高。     

Discussion on Wear Mechanism of High Chrome Brick Used in Coal Slurry Gasifier

The microstructure and phase composition of high chrome brick used in coal slurry gasifier has been analyzed by means of SEM and Energy Spectrum. The results indicate that the used brick can be divided into different zones as slag-adhered zone, reaction zone, penetration zone and unaltered zone. The phase composition and microstructure are different and cracks occurred in different degree at these zones. A dense ring belt was formed with complex spinel ( Mg, Fe)( Cr,Al, Fe2O4) in the reaction zone near the hot face. The wear mechanism of the brick during its employment has been discussed. It is considered that the reaction and penetration of coal slag and strong reduetant bring about the composition change of the brick and destroys its original network inlayed structure and consequently result in its structure spalling and weakening strength, which is the main wear mechanism of the brick and followed by temperature fluctuation and high mechanical im-pact of flowing fluid with high-speed.     

Chrome dyeing using anionic bivalent chromium complexes as mordants

Chrome dyeings are normally produced by first applying an acid dye containing ligand groups and then afterchroming with hexavalent chromium derivatives such as dichromate salts. The latter can damage wool fibres and also are toxic components in dyehouse effluents, so afterchroming with mixtures of Cr(III) salts and organic acids has been studied. It has been shown that the anionic complexes that form from trivalent chromium and the organic acids are fibre substantive at pH 2–4 and have the correct stability profile for exchanging ligands to bind the chromium with ligand groups in the dye. Dyeings produced generally show colour yields and fastness properties similar to the normal Cr(VI) dyeing process; the exception are these chromophores which undergo oxidative change in the dichromate process.