有机溶剂在湿法磷酸脱色中的应用

为了研究有机溶剂在湿法磷酸脱色的效果,以黑色的湿法磷酸为原料,分别使用四氯化碳、氯仿、柴油对湿法磷酸进行预脱色,再用活性炭对预脱色后的酸进行脱色.实验结果表明,柴油的预脱色效果最明显;最佳脱色条件为：湿法浓磷酸和柴油的质量比为5∶1、萃取分离时间1 h,活性炭的用量为湿法磷酸质量的1.5%、活性炭脱色时的温度为60℃、脱色时间为30 min,采用目测法观察,湿法磷酸从黑色基本变成无色;湿法稀磷酸和柴油的质量比为13∶1、萃取分离时间为20 min,活性炭的用量为湿法磷酸质量的0.25%、活性炭脱色温度为60℃、脱色时间为30 min,湿法稀磷酸从黑色变成无色.

Application of organic solvent in decoloration of wet-process phosphoric acid

The black wet-process phosphoric acid was discolored by separately using carbon tetrachloride,chloroform,diesel oil,then using activated carbon.The experimental results showed that the effect of decolorization with diesel oil was the most obvious;the best decoloration conditions of wet-process phosphoric acid were：the mass ratio of wet-process phosphoric acid to diesel oil was 51∶1,the time of extraction and separation was 1 h,the amount of activated carbon was 1.5%,the temperature was 60 ℃,and the decoloring time was 30 min.Under those conditions,the color of black wet-process phosphoric acid was from black to colorless with eye-measurement observation.The best decoloration conditions of wet rare phosphoric acid are the mass ratio of wet rare phosphoric acid to diesel oil is 13∶1,the time of extraction and separation was 20 min,the dosage of activated carbon for wet-process phosphoric acid is 0.25%,the temperature is 60 ℃,and the decoloring time is 30 min;under those conditions,the color of wet rare phosphoric acid is from black to colorless.