CFB锅炉粉煤灰摩擦荷电特性及分选脱炭研究  

Study on tribocharge characteristics and triboelectric separation of fly ash from circulating fluidized-bed boiler

作　　者：杨勇 邓雨生[2] 郑文凯[2] 卢晓斌[2] 张真兴 王海锋 YANG Yong;DENG Yusheng;ZHENG Wenkai;LU Xiaobin;ZHANG Zhenxing;WANG Haifeng(School of Environmental Science and Engineering,Guangdong University of Technology,Guangzhou 510006,China;Utilities Division,SINOPEC Corp.Maoming Company,Maoming525000,China;School of Chemical Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]广东工业大学环境科学与工程学院,广东广州510006 [2]中国石化集团茂名石油化工有限公司热电分部,广东茂名525000 [3]中国矿业大学化工学院,江苏徐州221116

出　　处：《选煤技术》2023年第1期15-23,共9页Coal Preparation Technology

基　　金：国家自然科学基金面上项目(51674257);江苏省科技计划专项资金项目(BE2022717)。

摘　　要：脱炭是粉煤灰综合利用的前提,摩擦电选是粉煤灰脱炭的有效方式。为了探索粉煤灰摩擦荷电特性和分选脱炭的最佳操作条件,以CFB锅炉粉煤灰为研究对象,基于其物理化学、工艺矿物学特性分析,采用不锈钢、铜、铝和PVC四种材质,通过摩擦荷电试验,对焦炭和粉煤灰主要成分(SiO_(2),CaO,CaSO_(4))进行了摩擦荷电特性研究;通过摩擦电选试验,探究了给料速度、风量、分选电压对粉煤灰摩擦电选脱炭效果的影响;并采用Box-Behnken响应曲面法,对粉煤灰摩擦电选的操作参数进行了优化。试验结果表明:PVC的摩擦荷电效果较好,能使焦炭与粉煤灰主要成分的摩擦荷电量差异较大,可作为摩擦荷电器的摩擦材料;粉煤灰烧失量随给料速度的增加呈先降低后增加的趋势,随着风量的升高呈现逐渐降低的趋势,分选电压提高有利于降低粉煤灰烧失量,三个因素之中以风量对粉煤灰烧失量的影响最为显著;优化得出粉煤灰摩擦电选的最佳操作条件,即风量为70 m^(3)/h、分选电压为20 kV、给料速度为10.8 kg/h,在此条件下,粉煤灰烧失量最低,为8.45%。研究可为粉煤灰摩擦电选脱炭工业生产条件的优化提供有益参考。Removal of unburnt carbon from fly ash is the prerequisite for comprehensive utilization of fly ash,and triboelectric separation is an effective method for use in this respect.In order to determine tribocharge charactristics of fly ash and the optimum separation conditions,the fly ash produced by the circulating fluidized-bed boiler is selected as the object of study.Based on results of analysis of physiochemical property and mineralogical characteristics of the fly ash,test on tribocharge characteristics of coke and the main components in fly ash(SiO_(2),CaO,CaSO_(4))is conducted using stainless steel,copper,aluminum and PvC as friction materials.The effect of carbon removal that can be obtained through triboelectric separation,with an aim to explore the law governing the effect on carbon removal efficiency produced by feed rate,airflow rate and voltage.The operating parameters involved in the separation process are then optimized using the Box-Behnken response surface method.As revealed by test result,a best result can be expected in separation of coke and the main components in fly ash with the use of PVC as the friction material;the loss on ignition of fly ash shows the tendency of first going up and then dropping down with the increase of airflow rate,and tends to gradually fall with increase of airflow rate,the rise of voltage is beneficial to decrease of loss ignition of fly ash,among the three operating parameters,the airflow rate can exert the most noticeable impact on loss on ignition of fly ash;when separation is made under the optimum operating conditions with an airflow rate of 70 m^(3)/h,a voltage of 20 kV and a feed rate of 10.8 kg/h,the loss on ignition of fly ash can be reduced to a lowest level of 8.45%.The results of the study made in the paper may serve as a valuable reference for optimization of the carbon removal process using this separation method under industrial conditions.

关 键 词：粉煤灰脱炭 CFB锅炉粉煤灰 荷电特性 摩擦电选 粉煤灰烧失量 

分 类 号：TQ536[化学工程—煤化学工程]