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1h,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.%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 °C ,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 t, and the decoloring time is 30 min; under those conditions, the color of wet rare phosphoric acid is from black to colorless.
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