Indispensability and Vulnerability of Magnesia-carbon Bricks for Steelmaking Process

The manufacturing techniques of magnesia-carbon bricks in China have been documented from raw materials,production(process and facilities)to performance and wear issues in the ladle.Magnesia-carbon bricks made of ordinary fused magnesia is the prevailing material used in the slagline of the ladle,but its service life is substantially lower than the bricks based on large-periclase-crystal fused magnesia.In two types of fused magnesia,the average values of periclase crystal size are in double for their difference.It is suggested that large-periclase-crystal fused magnesia should be used for manufacturing magnesia-carbon bricks for the slagline of the ladle by abandoning ordinary fused magnesia,in order to have a prolonged service life,increase the availability of the ladle and reduce the number of downtimes of the ladle.Free phenol in resin produced in China should be as low as that of resin made in Europe,to improve production environment and reduce smoke emission during the ladle preheating.There are large spaces to promote the productivity of magnesia-carbon bricks in China,with high intensity mixers and hydraulic presses.Expansion controlled magnesia-carbon bricks in the ladle depend on the optimized combination of sintered magnesia,Carbores and antioxidants as the matrix,to minimize the premature wear of vertical cracks and joint opening formed in the ladle lining.

Direct-bonded Magnesite-Chrome Bricks for Kilns and Furnaces of Building Materials Industry

JC 497-92 (96)1 Contents and Applied ScopeThis standard specifies the classification, shapes and dimensions, technical requirements, test methods, inspection rules, marking, packing, transportation, storage and quality certificate of direct-bonded magnesite-chrome bricks for building materials industry. This standard is applicable to the direct-bonded magnesite-chrome bricks for cement kiln, glass melting tank and other industrial furnaces.2 Normative ReferencesGB 2997: Test method for the apparent porosity, water absorption, bulk density and true porosity of dense shaped refractory productsGB 5070: Chemical analysis method for magnesite-Chrome refractoriesGB 5072: Test method for cold crushing strength of dense shaped refractory productsGB 5989: Test method for refractoriness under load of dense shaped refractory products (Differential, with rising temperature)GB 7320: Test method for thermal expansion of refractory productsGB 7321: Sample preparation for testing of dense shaped refractory productsGB 10324: Type definition of refractory productsGB 10325: Piling, sampling, acceptance, storage and transportation of refractory products

Pore Structure Characteristics of Baking-Free Slag-Sludge Bricks and Its Correlations to Mechanical Properties

In order to explore the relationship between the macroscopic properties and pore structure characteristics of baking-free slag-sludge bricks,the compressive strength and water absorption rate using aluminum industrial slag and sludge of different substitution rates were tested.Optical instruments and image analysis software were used to measure the parameters of the pore structure.Specifically,a fractal model was built based on the fractal theory,in which the fractal dimension was used as the characteristic index of the pore structure to analyze the correlation and interaction mechanism between the fractal dimension and the macroscopic mechanical properties.Based on this study,conclusions were drawn as follows:(1)The plane pore structure of baking-free bricks shows good fractal characteristics.With the increase of the aluminum industrial slag content,the fractal dimension becomes smaller and the pore structure develops well;with the increase of the sludge content,the fractal dimension becomes larger and the pore structure becomes worse;(2)As the fractal dimension of the plane pore structure increases,the compressive strength of baking-free bricks falls,and the porosity and water absorption rise;(3)The optimum content of baking-free slag-sludge bricks is aluminum industrial slag 30%and sludge 10%.After 7 days of curing,baking-free bricks boast higher performance,and fully meet the performance requirements of solid concrete bricks(MU40),which can reduce time costs,and enhance enterprise revenue.

The State-of-art of Magnesia-chrome Refractories for P-S Converter in China's Non-ferrous Industry

The state-of-art of magnesia-chrome refractories from direct-bonded magnesia chrome brick to fused-grain rebounded magnesia chrome brick for P-S converter is dis-cribed. The Cr2O3 content of the brick is continually increased with the reduction of the impurity content of brick , the pre-synthetic raw material it applied and the operating condition of convener is optimized so that the service life of convener is largely enhanced.

Properties,Performance and Quality Control of Recycled MgO-C Bricks

Properties, section structure and service results of recycled MgO-C bricks and new MgO-C bricks for ladle slag line of Baosteel were analyzed and compared, and the measures of improving stability and quality of recycled MgO-C bricks were summarized. The results show that： （1） High quality recycled MgO-C materials can be produced by scientific, meticulous and strict management for every process such as dismantling furnace, selection, removing impurity and slag, stacking and homogenization ; （2） Using high quality recycled materials and reasonable production technique, recycled MgO-C bricks with better properties and service efficiency than those of new MgO-C brick can be produced; （3） Service efficiency of recycled MgO - C bricks is good because of its high density, good oxidation resistance and reasonable structure.

Development of a Thermoplastic Magnesia Carbon Brick ——“A Cold Process Flexible System”

Conventional resin bonded MgO-C bricks, which are manufactured via cold mixing process, harden and attain brittleness during carbonization of resin due to the formation of isotropic glassy carbon. They do not exhibit thermo-plasticity, which can facilitate the release of huge amount of stresses generated during preheating or in operation. On the contrary, pitch bonded MgO-C bricks, show better pyro-plasticity due to formation of an anisotropic and graphitized coke structure during carbonization of pitch. Hence, pitch bonded bricks show a superior structural spalling resistance in comparison to resin-bonded bricks. One of the drawbacks of pitch-bonded bricks is that the manufacturing requires a hot mixing process and hot pressing facility. This paper describes how a combination of above two processes was optimized to make a MgO-C brick via cold process. These bricks exhibit a low Modulus of Elasticity and thereby facilitate release of stresses during operation. Normal coal tar pitch is considered as an environmental hazard due to the presence of polyaromatic hydrocarbons like benzopyrene B [ a ] P. So, a special binder with a low B[ a ] P was selected, which is eco-friendly in nature. Such bricks were made in our plant in China and supplied to an integrated steel plant in Europe for their ladle. The bricks supplied have given encouraging life.

四川汉代画像砖文化创意产品的叙事性设计

为更好地传播四川汉代画像砖所具有的文化内涵,发挥其文化魅力,文章对四川汉代画像砖的画像题材、艺术风格、精神内涵进行了梳理,对画像砖类文化创意产品现状展开调研与分析。提出了准确表达式、用户参与式、意境相融式三大叙事性文化创意产品设计策略,并从叙事性设计的角度提出四川汉代画像砖文化创意产品的设计方法。以设计实践验证了该方法在四川汉代画像砖文化创意产品设计中的可行性,为叙事性设计在文化创意产品中的应用提供了新思路。

清代晒盐砖池技术的管理与淮北盐业兴衰

通过分析淮北晒盐砖池技术在清代海盐生产中的应用与管理情况可知,晒盐砖池技术的使用极大地促进了清代淮北盐业的发展。然而,清朝在生产管理上秉持固定化管理的思维,以至于砖池的尺寸、形态、数量都受到了严格的控制。同时,由于淮北海岸线不断向东迁移,致使很多晒盐砖池产能逐步降低,这就需要扩建砖池、增建分段土池和沙格,甚至完全新修一整套砖池设施。但受限于固定化管理的制度,私修新盐池、私自扩建旧盐池的现象愈发普遍,私盐也由此泛滥。尽管清朝盐政当局以打击私盐为目标,但清中期以后管理越发僵化,不断扩大砖池固定化管理的范围,这种管理制度最终成为清末淮北盐业衰败的重要原因。

基于实践育人的固体废弃物资源化实验设计——以“建筑固废工业副产石膏制备免烧砖”为例

通过科研课题与企业生产实际问题结合,在“垃圾就是放错了地方的资源”环保理念基础上,于固体废弃物资源化课程实验中开设“建筑固废工业副产石膏制备免烧砖”实验。实验考察了建筑固废、工业副产石膏分别部分替代细沙、天然石膏对免烧砖品质的影响,并进行重金属浸出环境风险评价研究。实验教学设计充分注重学生科学探索研究能力的培养,同时兼顾学生优秀品格的塑造,有助于学生的创新能力和环保素养的形成。

砖瓦行业大气污染物排放控制技术及监管策略探讨

本文首先分析了砖瓦行业传统的大气污染物除尘、脱硫、脱硝和VOCs控制技术的优缺点,其次介绍了先进的电除尘、湿法石灰石脱硫、SCR脱硝技术、燃烧优化和脱硫脱硝工艺集成技术,同时探讨了砖瓦行业污染物排放监管策略,包括国家监管政策和法律法规、行业监控机制和控制要求,最后对砖瓦行业大气污染物的排放控制进行了展望,以供参考。

大宗工业固废制备烧结砖研究进展

烧结砖是一种常见的建筑材料,经过长时间发展,制砖原料由原来的粘土等不可再生材料转变为更加环保清洁的固废材料。归纳总结了目前用于制备烧结砖常用的5种大宗工业固体废弃物,并从产品特点、烧结机理和制备条件分析固体废弃物制备烧结砖的可行性并阐明产品特点。最后,对烧结砖目前存在的问题及未来行业发展提出可行性参考建议,研究可对未来烧结砖行业发展新质生产力、优化创新与实际工程应用提供理论参考。

利用拜耳法赤泥制备免烧路面砖及其性能研究

对利用拜耳法赤泥制备免烧路面砖工艺和产品性能进行研究,并提出免烧砖返碱现象解决办法。试验结果表明,利用拜耳法赤泥制备免烧路面砖是可行的,所测性能指标符合相关标准要求。

造纸苛化白泥页岩砖生产工艺研究

对某造纸厂苛化白泥的化学成分、粒度进行了测试分析,将该造纸白泥按照不同比例直接加入到页岩中,烧制出了实心砖制品。研究了原料配比及其烧成制度对制品抗压强度、吸水率、收缩率等性能的影响。结果表明,造纸白泥掺量在15%-27%、烧结温度900~1100℃并保温1~3 h时,烧结砖性能达到了页岩砖国家标准（GB5101—2003）中的各项要求,有利于实现造纸苛化白泥的资源化利用,减轻环境污染。

利用工业碱渣制备便道砖的研究

利用氨碱法生产纯碱产生的废弃物-碱渣为主要原料制备便道砖。研究表明:碱渣直接用于制备便道砖方案不可行,需对碱渣进行预处理;由碱渣、粘土和结合剂FM混合经700℃预处理,制成碱渣-粘土-FM复合料;复合料再与石粉、石渣、水泥等按复合料80%、石粉15%、石渣5%,水泥外加10%的配比,制得的便道砖7天强度为14.84 MPa,28天强度可达24.36 MPa。

工业污泥建材化利用的研究进展

综述了工业污泥在制备烧结砖、轻集料、混凝土材料和水泥等建筑材料方面的应用,总结了目前工业污泥建材化的问题并提出了发展建议。工业污泥可作为黏土等原料的替代材料通过烧结工艺生产烧结砖、烧结轻集料和水泥,也可加入到水泥等凝胶材料中通过免烧工艺制备混凝土材料、免烧轻集料等建筑材料。利用工业污泥制备建筑材料具有较大的发展潜力。

Mu15粉煤灰蒸压砖的配合比研究

建筑垃圾危害社会环境,须合理利用.研究了以建筑垃圾为骨料,利用粉煤灰等工业废渣制Mu15蒸压砖的最佳配合比.通过试验,确定3种体系蒸压砖的最佳配合比:建筑垃圾—粉煤灰—石灰体系,建筑垃圾65%,粉煤灰25%,生石灰8%;建筑垃圾—粉煤灰—电石渣体系,建筑垃圾63%,粉煤灰25%,电石渣10%;建筑垃圾—粉煤灰—石灰—水泥体系,建筑垃圾65%,粉煤灰25%,生石灰5%,水泥3%.

工业废渣再生混凝土多孔砖配合比的试验研究

试验是以工业废渣作为粗细骨料进行再生混凝土多孔砖配合比的研究.通过正交试验选定配合比,用振动挤压成型的方法制作A、B、C三类再生混凝土KP1型多孔砖,并按照《砌墙砖试验方法》(GB/T 2542-2003)规定的方法,分别对其进行抗压强度、收缩性能和冻融循环试验.试验研究结果依照《混凝土多孔砖》(JC 943-2004)进行评定,结果表明:A类的强度等级可达MU15,B、C类的可达到MU10;多孔砖的收缩性能较小,冻融循环试验结果符合要求,价格较低,可作为黏土砖的替代品用于砌体结构房屋.

工业废渣混凝土多孔砖砌体抗震性能试验研究

目的研究工业废渣混凝土多孔砖墙片抗震性能和破坏形式.方法通过3片工业废渣混凝土多孔砖墙片在低周往复水平荷载作用下试验,分析了墙片的破坏特征,得到墙片的滞回曲线、骨架曲线、延性系数.结果与其他多孔砖墙片实验研究进行比较表明破坏形态相似,变形能力较好,抗震承载力较高.结论工业废渣混凝土多孔砖墙片延性比为2.93~3.00,抗震性能较好,抗震抗剪承载力验算可按《砌体结构设计规范》（GB5003-2001）规定执行.

基于SEM和ICT的建筑垃圾再生砖细观破坏机理

以建筑垃圾再生砖为研究对象,进行了单轴压缩试验,拟合了应力-应变曲线,采用扫描电镜(SEM)对再生砖的细观结构进行观测,利用工业CT获得了再生砖压缩破坏过程中的裂纹分布特征,并借助分形理论进行分析裂纹演化特征。研究结果表明:建筑垃圾再生砖具有较大的孔隙率,存在诸多的初始缺陷,裂纹容易最先在这些薄弱环节出现。水泥石将骨料包裹起来形成筋络结构可分割破坏区,延缓裂缝的伸展及汇聚过程,可有效提高再生砖的强度。同时再生砖具显著的不均匀性,在荷载作用下不同断面的分形维数的变化规律有较大的差异,断面上平均强度越高,分形维数的变化越平缓,反之则变化要更剧烈,但整体物理性能与混凝土是相似的。CT和SEM结合可有效地对建筑材料的微观结构和破坏机理进行分析,为进一步揭示再生砖的细观损伤破裂机理奠定基础。

芦山7.0级地震单层砖柱排架厂房震害特征及抗震分析

单层砖柱排架厂房是我国中小企业生产用房的主要形式,目前此类结构仍广泛存在于经济欠发达的地区。历次地震震害资料表明,单层砖柱排架厂房在地震中比较容易损坏。本文通过对芦山地震中单层砖柱排架厂房的震害现场调查,总结了单层砖柱排架厂房的震害特征并分析其破坏原因;统计了几次地震中单层砖柱排架厂房的震害资料,给出了修正的未设防单层砖柱排架厂房地震易损性矩阵;最后,采用了逐步回归法,柱顶位移角法及模糊震害指数法分别对单层砖柱排架厂房进行震害预测,并将各种方法的震害预测结果与实际震害情况进行了对比分析。本文研究对认识该类结构的易损性、震害机理和抗震薄弱部位,指导抗震加固有着重要意义。