黄铁矿流化床还原磷石膏制备SO_(2)的实验及机理分析  

Experimental and mechanistic analysis of SO_(2) preparation from pyrite reduction of phosphogypsum in fluidized bed

作　　者：田治华 马栋 王勤辉[1] 章斌 解桂林[1] TIAN Zhihua;MA Dong;WANG Qinhui;ZHANG Bin;XIE Guilin(State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学能源高效清洁利用全国重点实验室,浙江杭州310027

出　　处：《高校化学工程学报》2025年第1期119-130,共12页Journal of Chemical Engineering of Chinese Universities

基　　金：中央高校基本科研业务费专项资金(2022ZFJH004)。

摘　　要：为了将黄铁矿和磷石膏(PG)中的元素S尽可能地转化为SO_(2),同时明晰该过程的反应机理,通过流化床实验结合热重和热力学计算,系统研究了黄铁矿添加量、反应温度等对PG分解过程的影响。结果表明黄铁矿的加入降低了PG的分解温度,并且提高了PG的分解率。该过程的最慨然机理函数为G(α)=1-(1-α)^(1/3),表明反应受相边界控制。优化的反应条件:温度为1100℃,黄铁矿添加量为30%,反应时间为20 min,黄铁矿粒径为0~0.075 mm,在该条件下PG分解率和SO_(2)收率分别为99.95%和95.95%。当黄铁矿添加量为30%~70%,会产生副产物CaS。当添加量超过70%,会产生固熔体Ca_(3)Fe_(4)S_(3)O_(6)。按照黄铁矿添加量的不同,该过程主要有两种不同的机理路径。本研究丰富了黄铁矿还原PG制备SO_(2)的工艺理论。In order to convert as much as possible S in pyrite and phosphogypsum(PG)into SO_(2),effects of pyrite addition and reaction temperature on PG decomposition were systematically investigated using fluidized bed combined with thermogravimetric and thermodynamic calculations.The results show that the addition of pyrite decreases PG decomposition temperature and increases PG decomposition ratio.The most probabilistic mechanism function of the process is G(α)=1-(1-α)^(1/3),which indicates that the reaction is controlled by phase boundary.The optimized reaction condition is 30%pyrite addition at 1100℃for 20 min,under which the PG decomposition ratio and SO_(2)yield are 99.95%and 95.95%,respectively.The by-product CaS was produced when the pyrite addition was 30%~70%.When the addition was more than 70%,solid melt Ca_(3)Fe_(4)S_(3)O_(6)was produced.There are mainly two different mechanistic paths in this process according to different pyrite additions.This study enriches the process theory of SO_(2)preparation from reduced PG of pyrite.

关 键 词：磷石膏 黄铁矿 二氧化硫 流化床 动力学 机理 

分 类 号：X705[环境科学与工程—环境工程]