宁夏高灰煤与向日葵秸秆的混合灰的熔融行为  

Melting Behavior of Mixed Ash of High Ash Coal and Sunflower Straw in Ningxia

作　　者：孙冬 徐荣声 徐炜 王萍 史小红 李梅[1] SUN Dong;XU Rong-Sheng;XU Wei;WANG Ping;SHI Xiao-Hong;LI Mei(School of Chemistry and Chemical Engineering,North Minzu University,Yinchuan 750021,China;Key Laboratory for Chemical Engineering and Technology,State Ethnic Affairs Commission,North Minzu University,Yinchuan 750021,China;Ningxia Key Laboratory of Solar Chemical Conversion Technology,North Minzu University,Yinchuan 750021,China)

机构地区：[1]北方民族大学化学与化学工程学院,银川750021 [2]北方民族大学国家民委化工技术基础重点实验室,银川750021 [3]北方民族大学宁夏太阳能化学转化技术重点实验室,银川750021

出　　处：《应用化学》2024年第10期1457-1468,共12页Chinese Journal of Applied Chemistry

基　　金：国家自然科学基金联合基金(No.U20A20125)资助。

摘　　要：生物质与煤共燃烧是能源清洁利用的主要方向之一。研究了宁夏高灰煤灰(WWA)、向日葵秸秆灰(SSA)及不同质量比的WWA与SSA的混合灰(W_(3)S_(1)、W_(2)S_(1)、W_(1)S_(1)、W_(1)S_(2)和W_(1)S_(3))在高温下的熔融温度特性,并通过X射线荧光衍射(XRF)分析灰的化学组成、X射线衍射(XRD)分析矿物质演化行为、扫描电子显微镜(SEM)分析高温下灰渣的微观形貌,以及Factsage热力学软件计算灰在高温下的液相含量,阐明影响灰熔融过程的影响因素,阐释灰的熔融机制。结果表明:添加少量的SSA后,混合灰的4种熔融特征温度开始减小。当SSA添加质量分数为33%(W_(2)S_(1))时,灰熔融温度最低,其变形温度(DT)降低至1228℃,比WWA降低了约50℃;随着SSA质量分数的继续增加,混合灰的DT和软化温度(ST)略有升高,但半球温度(HT)和流动温度(FT)升高明显。高温下,灰中碱性组分形成白榴石、透辉石、钾霞石和镁黄长石等硅铝酸盐,是灰熔融温度降低的主要原因;而随着SSA比例的增加,部分碱性组分以高熔点的单体氧化物或无定形物质存在,造成灰的FT升高。WWA中添加少量SSA后,混合灰的起始液相温度降低,熔融过程与煤灰相似,主要熔融过程(液相含量超过80%)发生在1300℃之前。当SSA的质量分数超过50%时,起始液相温度增加,主要熔融过程发生在1400℃。本文为解决向日葵秸秆与煤共燃烧过程中的结渣问题提供一定理论参考。Co-combustion of biomass and coal is one of the main directions of clean energy utilization.The melting temperature characteristics of Ningxia high ash(WWA),sunflower straw ash(SSA)and mixed ash of WWA and SSA with different mass ratios(W_(3)S_(1),W_(2)S_(1),W_(1)S_(1),W_(1)S_(2),W_(1)S_(3))at high temperature were studied.The chemical composition of ash was analyzed by X-ray fluorescence diffraction(XRF),the mineral evolution behavior was analyzed by X-ray diffraction(XRD),the microscopic morphology of ash at high temperature was analyzed by scanning electron microscopy(SEM),and the liquid phase content of ash at high temperature was calculated by Factsage thermodynamic software to clarify the influencing factors of ash melting process and explain the melting mechanism of ash.The results show that with the increase of SSA content,the four melting characteristic temperatures of mixed ash begin to decrease,and the melting temperature of W_(2)S_(1) is the lowest,and its deformation temperature is reduced to 1228℃,which is about 50℃lower than WWA.With the continuous increase of SSA content,the deformation temperature(DT)and softening temperature(ST)of mixed ash increased slightly,but the hemisphere temperature(HT)and flow temperature(FT)increased significantly.At high temperature,the formation of alkaline components such as leucite,diopside,potassium nepheline and magnesium feldspar in ash is the main reason for the decrease of ash melting temperature.With the increase of the proportion of SSA,some alkaline components exist in the form of oxides with high melting point or amorphous substances with high melting point,resulting in an increase in the flow temperature of ash.When a small amount of SSA is added to WWA,the initial liquid phase temperature of the mixed ash is reduced,and the melting process is similar to that of coal ash,with the main melting process(liquid phase content exceeding 80%)occurring before 1300℃.When the content of SSA exceeds 50%,the initial liquid phase temperature increases,and the mai

关 键 词：煤灰 向日葵秸秆灰 灰熔融特性 矿物质演变 结渣机理 

分 类 号：O611.6[理学—无机化学]