摘要
耐火材料作为高温窑炉的内衬,对其节能降耗起着至关重要的作用。陶瓷行业中,使用轻质隔热材料砌筑的窑炉和窑车具有较好的节能效果,且实现了快速烧成。但对于工作衬与金属液、熔渣直接接触或与物料间有侵损反应的窑炉,要求工作衬致密度较高,以保证窑炉具有较好的抗侵蚀性能和长的使用寿命,这导致该类窑炉热容量大、热耗散大,热效率较低。高温窑炉工作衬用耐火材料一般由致密骨料和基质组成(熔铸耐火材料除外),骨料相对致密,而基质较为疏松。通常侵蚀和损毁首先从基质开始,无论骨料是否损毁都会因变质层热物理性能变化而发生剥落,造成材料整体损毁,故重质骨料适当轻量化应该不会大幅降低耐火材料的强度和抗介质侵蚀性能。轻量耐火材料是指引入具有较高气孔率(尤其是闭气孔率)的骨料代替致密骨料,制备的致密度介于轻质和重质耐火材料之间的一类耐火材料,它的开发旨在不严重影响耐火材料高温使用性能的前提下,通过降低耐火材料的热容量和导热系数达到保温隔热、节能降耗的目的。基于上述原因,轻量骨料对轻量耐火材料的制备工艺过程、显微结构和使用性能具有决定性的影响。本文首先介绍了轻量耐火骨料的制备方法、材料体系和相关性能,包括部分烧结法、造孔剂烧失法、反应物原位分解造孔法、发泡法、引入纳米粒子烧结法、放电等离子体烧结法等。进而给出轻量骨料在耐火浇注料、不烧含碳耐火材料以及烧成定形制品中的应用、相关性能和使用效果。已有研究发现,在制备轻量骨料的过程中,在追求降低其热导率和体积密度的同时,很难获得令人满意的显气孔率和吸水率,该矛盾成为目前轻量耐火材料获得广泛推广和使用的技术瓶颈。文章还介绍了氧化镁碳热还原输运氧化结合反应烧结的方法,其无需制备
Refractory,as a high-temperature furnace lining,exerts a crucial role for energy saving in industry.The ceramic industry already have gained a better energy-saving and rapid firing by means of building lightweight kiln and kiln car with light insulating material.However,the furnaces,in which working lining contacts or even reacts with the molten metal,slag,raw materials or intermediate products,require a higher density so as to ensure better corrosion resistance and longer service life,and in consequence,often have large heat capacity,high energy consumption and low thermal efficiency.Working lining refractory used in high-temperature furnaces usually consists of aggregate and matrix（except casting refractories）,and aggregate has a high density while the matrix is relatively loose and more vulnerable to slag attack.With the change of thermal physical properties,the metamorphic layer will be spalled,whether the aggregate is damaged or not.Thus properly lightweight aggregates should not significantly reduce the strength or anti-media erosion resistance of refractory.Lightweight refractories refer to a class of refractories with density between light and heavy refractories.In this kind of refractories,aggregates with higher porosity（especially closed porosity）substitute for dense aggregates.Under the premise of retaining high-temperature performance,the use of lightweight refractories with lower heat capacity and thermal conductivity can achieve the purpose of thermal insulation and energy saving.Therefore,lightweight aggregates have a dominant impact on the preparation process,microstructure and performance of lightweight refractory.In this paper,material systems,related properties and the preparation methods of lightweight refractory aggregate are summarized,including partial sintering method,sintering agent loss by pore-forming agent,in situ decomposition pore-forming technique,foaming method,nanoparticle-assisted sintering method,discharge plasma sintering method and so on.And then it reviews the applica
作者
尹洪峰
党娟灵
辛亚楼
高魁
汤云
袁蝴蝶
YIN Hongfeng;DANG Juanling;XIN Yalou;GAO Kui;TANG Yun;YUAN Hudie(College of Materials and Mineral Resources,Xi＇an University of Architecture and Technology,Xi＇an 710055)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2018年第15期2618-2625,2639,共9页
Materials Reports
基金
国家自然科学基金(51572213)
关键词
轻量耐火材料
骨料
浇注料
低导热率
密度梯度
lightweight refractory
aggregate
castable
lower thermal conductivity
density gradient
