正丁醇萃取磷酸的实验研究

Experimental study on extraction of phosphoric acid using n-butanol

采用微分散法研究了磷酸的萃取特性;以正丁醇/磷酸/水为实验体系,以孔径为20μm的不锈钢纤维烧结网为分散介质,在自制萃取器中研究了相比、流量、磷酸质量分数、装置横放与立放、先混合后分散与先分散后混合、有网与无网对萃取效率的影响。结果表明,萃取率随总流通量的增大而呈先增大后减小的趋势,最优总流量800 mL/min;随相比的增大而增大,最优相比为2∶1;随磷酸质量分数的升高而升高,最优磷酸质量分数为32%,且萃取率有高质量分数磷酸>低质量分数磷酸;有网萃取率大于无网;在流量较小时,装置平放大于装置立放时的萃取率,在流量较大时,萃取率差别不大;先混合后分散的进料方式下萃取率大于先分散后混合。

The feature of phosphoric acid extraction is studied by the method of micro-dispersion.The influences of phase ratio,volume flow,phosphoric acid concentration,horizontal and vertical factors,blending first dispersing later or dispersing first blending later,with or without filter membrane,on the extraction efficiency in self-made extractor,are investigated with n-butanol/phosphate/water as experimental system and 20 μm stainless steel fiber sintered membrane as dispersion media.The results show that the extraction efficiency is improved first then decreased later with the improvement of volume flow and the best volume flow is 800 mL/min.The extraction efficiency is also increased with the increase of phase ratio and phosphoric acid concentration.The optimal phase ratio and phosphoric acid concentration are 2∶1 and 32％,respectively.The efficiency with 20 μm membrane is better than without membrane.When the volume flow is low,horizontal way is better,but under high volume flow,the efficiency is similar.The efficiency of blending first dispersing later is better than dispersing first blending later.