湿法磷酸过滤管道系统氟硅酸钾(钠)结垢沉积模型  

MODELING OF POTASSIUM (SODIUM) FLUOSILICATE SCALE FORMATION IN WET-PROCESS PHOSPHORIC ACID PRODUCTION

作　　者：杨林军[1] 张志炳[1] 张允湘[2] 李军[2] 黄青[2] 

机构地区：[1]南京大学化工系,江苏南京210093 [2]四川大学化工系,四川成都610065

出　　处：《化工学报》2003年第10期1407-1412,共6页CIESC Journal

基　　金：国家"九五"重点科技攻关项目资助(No 95 -5 2 9-0 1-0 4)

摘　　要：采用冷却模拟系统研究了湿法磷酸过滤管道系统中氟硅酸钾 (钠 )垢的形成过程 .据此采用沉积 脱除的结垢机制 ,并借助粒数衡算方程及成垢离子的质量平衡方程建立了氟硅酸钾 (钠 )过饱和溶液在管内流动中结垢析出模型 ,通过对模型的数值求解得到了管壁表面氟硅酸钾 (钠 )结垢量、结垢速率及粒度分布 。Potassium (sodium) fluosilicate scaling in pipes of filter is the main operation problem in the wet process phosphoric acid (WPA) production from phosphate ore with high potassium and sodium content At present there is no effective way to solve this problem because of lack of theoretical research In this work, pipe flow experiment of supersaturated phosphoric acid solutions of potassium (sodium) fluosilicate was used to study scaling process on the pipe wall by simulating the vacuum filter cooling system in WPA production As regards scale model, a fairly comprehensive population balance equation was used for the solid phase and a mass balance equation was used for the scaled ions Heterogeneous nucleation and subsequent crystal growth right onto the pipe wall would lead to scale formation A sufficiently accurate discretization scheme was used in the simulation algorithm The scaling rate, scaling amount and particle size distributions were predicted with the model, and the results indicated that the predictions agreed well with the experimented data The proposed model is a useful tool for scale up in practical WPA production and other scaling problem of similar systems

关 键 词：湿法磷酸 氟硅酸钾(钠) 结垢 数学模型 

分 类 号：TQ126.35[化学工程—无机化工]