磷石膏循环流化床煅烧分解工艺可行性分析  

Feasibility analysis of calcination and decomposition process of phosphogypsum in circulating fluidized bed

作　　者：张磊 李蒙 向文国[3] 胡骏[3,4] 陈时熠 段伦博[3] ZHANG Lei;LI Meng;XIANG Wenguo;HU Jun;CHEN Shiyi;DUAN Lunbo(SINOPEC Nanjing Engineering&Construction Incorporation,Nanjing 210049,China;College of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310058,China;School of Energy and Environment,Southeast University,Nanjing 210096,China;School of Petroleum and Natural Gas Engineering,School of Energy,Changzhou University,Changzhou 213164,China)

机构地区：[1]中石化南京工程有限公司,江苏南京210049 [2]浙江大学化学工程与生物工程学院,浙江杭州310058 [3]东南大学能源与环境学院,江苏南京210096 [4]常州大学石油与天然气工程学院、能源学院,江苏常州213164

出　　处：《无机盐工业》2023年第6期85-91,共7页Inorganic Chemicals Industry

摘　　要：磷酸制备过程中副产的磷石膏为工业固废,将其用于制硫酸联产钙基材料是可持续发展的技术路线。提出了磷石膏煤循环流化床煅烧分解制硫酸联产钙基材料工艺,从流程的质能平衡以及不同工况下煤煅烧磷石膏分解脱硫性能方面验证了工艺的可行性。热力学计算结果表明:该工艺能够实现自热运行,煤煅烧磷石膏分解和脱硫生成CaO,O_(2)/H_(2)O和O_(2)/CO_(2)是合适的流化和氧化介质,反应器出口干气SO_(2)体积分数最高可达33%,适合硫酸生产;还原性-弱氧化性气氛的过度能够实现磷石膏在1100℃下的分解和脱硫,低于现有磷石膏分解工艺温度;在1100℃、磷石膏/煤质量比为4∶1、O_(2)体积分数为1%的O_(2)/CO_(2)或O_(2)/H_(2)O反应条件下,固体残渣的主要成分为CaO、CaO·CaSiO_(3)。该研究结果初步表明磷石膏循环流化床煅烧分解制硫酸联产钙基材料工艺可行。Phosphogypsum produced from phosphoric acid production,as industrial solid wastes,can be used for the production of sulfuric acid and calcium based materials,which is a sustainable technological route.The process of phosphogypsum decomposition in the coalfired circulating fluidized bed to produce sulfuric acid and calciumbased materials after granulation was presented.The feasibility of the process was verified from the aspects of the mass energy balance of the process and the decomposition desulfurization performance of phosphogypsum calcined from coal under different working conditions.Thermodynamic calculation results showed that the process could realize self heating operation.CaO was generated from the decomposition and desulfurization of calcined phosphogypsum.O_(2)/H_(2)O and O_(2)/CO_(2)were suitable fluidization and oxidation media.The volume fraction of SO_(2)in the dry gas at the reactor outlet could reach 33%,which was suitable for sulfuric acid production.The excessive reducing weak oxidizing atmosphere could realize the decomposition and desulfurization of phosphogypsum at 1100℃,which was lower than the existing decomposition process temperature of phosphogypsum.Under the reaction conditions of 1100℃,phosphogypsum/coal mass ratio of 4∶1,O_(2)/CO_(2)or O_(2)/H_(2)O with 1%O_(2)volume fraction,the main components of solid residue were CaO,CaO·CaSiO_(3).The research results preliminarily showed that the technology of phosphogypsum calcination and decomposition by circulating fluidized bed to produce sulfuric acid and calcium based materials was feasible.

关 键 词：磷石膏 钙基材料 分解脱硫 循环流化床 

分 类 号：TQ126.3[化学工程—无机化工]