粉煤灰与氯化钙焙烧提取氧化铝的动力学  

Kinetics of Alumina Extraction by Calcination of Coal Fly Ash and Calcium Chloride

作　　者：叶标 郁青春[1,2,3] 邓攀 邓勇[1,2,3] 杨斌[1,2,3] YE Biao;YU Qingchun;DENG Pan;DENG Yong;YANG Bin(National Engineering Laboratory for Vacuum Metallurgy,Kunming University of Science and Technology,Kunming 650093,China;Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province,Kunming University of Science and Technology,Kunming 650093,China;Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]昆明理工大学真空冶金国家工程实验室,昆明650093 [2]昆明理工大学云南省有色金属真空冶金重点实验室,昆明650093 [3]昆明理工大学冶金与能源工程学院,昆明650093

出　　处：《有色金属工程》2019年第6期36-42,共7页Nonferrous Metals Engineering

摘　　要：我国每年产生大量的粉煤灰,从粉煤灰中提取氧化铝是一种提高资源综合利用率和解决铝资源短缺的方法。粉煤灰的活性大小直接影响氧化铝的提取,氯化钙作为焙烧助剂能够有效活化粉煤灰。将CaCl2与粉煤灰在实验设定温度和时间下进行混合焙烧,焙烧熟料用硫酸浸出,浸出液中氧化铝的含量用EDTA络合滴定法测定。分析了粉煤灰与CaCl2混合焙烧过程中实验参数对氧化铝浸出率的影响,探讨焙烧反应的动力学和机理。结果表明,优化条件为:焙烧温度900℃、焙烧时间30min、氯化钙与粉煤灰质量比1∶1,在此条件下氧化铝的浸出率为93.48%,反应主要产物为CaAl2Si2O8、CaSiO3、Ca12Al14O33和Ca3Fe2(SiO4)3。粉煤灰与CaCl2反应受内扩散控制,其表观活化能为Ea=20.13kJ/mol,反应动力学方程:1-2x/3-(1-x)2/3=0.0517exp[-20130/RT]t。A large amount of coal fly ash is produced every year in China. Extracting alumina from coal fly ash is a way to improve the comprehensive utilization rate and solve the shortage of aluminum resources. The active size of coal fly ash directly affects the extraction of alumina, and calcium chloride as a roasting aid can effectively activate the fly ash.The coal fly ash and CaCl 2 were mixed and calcined at the experimental setting temperature and time. The calcined clinker was leached with sulfuric acid, and the content of alumina in the leachate was determined by EDTA complex metric titration method. The effects of experimental parameters on the leaching rate of alumina during the mixing and roasting process of coal fly ash and CaCl 2 were analyzed, and the kinetics and mechanism of the calcination reaction were discussed. The experimental results show that the optimum conditions are: calcination temperature is 900 ℃, calcination time is 30 min, mass ratio of calcium chloride and coal fly ash is 1∶1. The Leaching rate of alumina is 93.48% under this condition, the main reaction products are CaAl 2Si 2O 8, CaSiO 3, Ca 12 Al 14 O 33 , and Ca 3Fe 2(SiO 4) 3. The reaction of coal fly ash with CaCl 2 is controlled by internal diffusion, and its apparent activation energy is E a = 20.13 kJ/mol, which accords with the reaction kinetic equation 1-2 x /3-(1- x ) 2/3 = 0.0517exp[-20130/ RT]t .

关 键 词：粉煤灰 氯化钙 焙烧 氧化铝 动力学 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]