摘要
湿法磷酸浸出过程中,传统刚性搅拌桨的作用方式主要是剪切作用,容易形成对称性流场结构,降低搅拌效率。实验考察了桨叶类型、离底高度、搅拌速度、柔性钢丝绳长度、柔性钢丝直径对磷矿浸出率及最大Lyapunov指数(LLE)的影响。实验结果表明:刚柔组合桨通过刚-柔-流的耦合作用,改善流场的结构,提高了流体混沌混合效果。当搅拌转速225 r/min,浸出时间120 min,离底高度h=T/4,柔性钢丝绳直径d=0.42r,柔性钢丝绳长度L=1.3T时,刚柔组合桨的最大Lyapunov指数达到0.09071,磷矿浸出率提高了10.8%。另外,在相同的功耗(Pv=9890 W/m3)条件下,刚柔组合桨使反应器内的悬浮均匀度和渣中磷含量分别降低了40.8%和17.67%,有效地改善了晶体的形貌,提高了磷石膏的过滤性能,强化了颗粒的混合与浸出。
In the process of wet-process phosphoric acid leaching, the mode of action of the traditional rigid stirring paddle is mainly shearing, and it is easy to form a symmetrical flow field structure and reduce the stirring efficiency. The effects of impeller type, impeller off-bottom clearance, stirring speed, length of flexible wire, diameter of flexible wire on leaching rate and largest Lyapunov exponent (LLE) were investigated experimentally. The results showed that rigid-flexible impeller changed structure of flow field and improved the fluid chaos mixing degree through coupling interaction of rigid-flexible-fluid. At leaching time 120 min, agitation speed 225 r / min, off-bottom clearance h=T/4, diameter of wire d=0.42r and length of wire L=1.3T, LLE of rigid-flexible impeller reached 0.9071 and leaching rate of phosphate rock increased by 10.8%. At the same power consumption (P v =9860 W/m 3 ), the suspension uniformity and the slag phosphorus content were reduced by 40.8% and 17.67% with the rigid-flexible impeller, respectively. In addition, the morphology of the crystal was improved when the rigid-flexible impeller was used. Meanwhile, the filtration performance of phosphogypsum was enhanced.
作者
李兵
杨义
刘作华
陶长元
谷德银
许传林
王运东
LI Bing;YANG Yi;LIU Zuohua;TAO Changyuan;GU Deyin;XU Chuanlin;WANG Yundong(School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China;Sinochem Fuling Chongqing Chemical Industry Co., Ltd, Chongqing 408100, China;Department of Chemical Engineering,Tsinghua University, Beijing 100084, China)
出处
《化工学报》
EI
CAS
CSCD
北大核心
2019年第5期1742-1749,共8页
CIESC Journal
基金
国家重点研发计划项目(2017YFB0603105)
国家自然科学基金项目(21576033
21621636004)
国家科技支撑计划项目(2015BAB17B01)
中央高校基本科研业务费专项资金(106112017CDJQJ228808)
重庆市科技创新领军人才支持计划项目(CSTCCXLJRC201703)
关键词
湿法磷酸
刚柔组合桨
两相流
浸取
结晶
最大LYAPUNOV指数
wet-process phosphoric acid
rigid-flexible impeller
two-phase flow
leaching
crystallization
largest Lyapunov exponent
