生态产业科学与磷氟工程

常规湿法磷酸净化过程中，液-液两相采用“分散-连续”传质模式，存在“混合越好则分相越难”的结构性矛盾，导致传质效率低、设备体积庞大、投资与运行成本高昂。针对这一问题，本文提出在微尺度空间内引入旋流场，实现液-液两相“连续-连续”传递的思路，以规避“混合-分相”的矛盾，并据此设计了微型旋流反应器。系统评估该反应器在湿法磷酸净化的萃取、脱硫和反萃等主要单元操作中的传质与分相性能，并与常规反应槽进行对比。结果表明：在微型旋流反应器中，达到一级传质理论平衡所需的传质时间在0.2 min以内，比常规反应槽减少1～2个数量级，分相时间缩短至1/10～1/5，时空产率提高1～2个数量级。对于萃取和反萃过程，仅需3级即可满足工业化要求，脱硫过程仅需1级，相比常规反应槽，传质级数和设备体积均显著减少。该研究为湿法磷酸净化过程强化与设备微型化提供了新思路，也为涉及液-液传质与反应的过程提供了新的技术支撑。

In conventional wet-process phosphoric acid purification, the liquid-liquid two phases adopt a“dispersion-continuous” mass transfer mode, which suffers from the structural contradiction that “better mixing leads to more difficult phase separation”, resulting in low mass transfer efficiency, bulky equipment, and high investment and operating costs. To address this issue, a rotating field at the microscale is introduced to achieve a “continuous-continuous” mass transfer mode between the two liquid phases, thereby circumventing the“mixing-separation” contradiction. A micro-rotating reactor is designed accordingly. The mass transfer and phase separation performances of the micro-rotating reactor in the main unit operations of wet-process phosphoric acid purification, namely extraction, desulfurization, and stripping, are systematically investigated and compared with those of a conventional reaction tank. The results show that in the micro-rotating reactor, the mass transfer time required to reach the first-stage theoretical equilibrium is within 0.2 min, which is 1-2 orders of magnitude lower than that in the conventional tank; The phase separation time is reduced to 1/10-1/5, and the space-time yield is increased by 1-2 orders of magnitude. Only three stages are needed for extraction and stripping, and one stage for desulfurization in the micro-rotating reactor to meet industrial production requirements, representing significant reductions in both the number of mass transfer stages and equipment volume compared with the conventional tank. The study provides a new idea for process intensification in wet-process phosphoric acid purification and equipment miniaturization, and offers new technical support for processes involving liquid-liquid mass transfer and reactions.