一种副产石膏晶须的湿法磷酸新工艺

New technology of by-producting gypsum whisker in wet-process phosphoric acid production

将传统湿法磷酸的浸取过程分为磷矿分解和石膏结晶两个过程,分别在两个化学反应器中进行。在这两个相互独立的反应器中间添加液固分离装置,不仅能使副产物磷石膏的白度提高到95%以上,而且,在结晶反应温度为90℃、硫酸质量分数为30%、加料方式采用一次性加料、陈化时间为40 min、搅拌强度为250 r/min条件下,能得到长径比达到50以上的磷石膏晶须。

Traditional wet-process phosphoric acid （WPA） leaching process was divided into two processes,i, e. phosphorite decomposition and gypsum crystallization, which were carried out in two individual chemical reactors. Liquid-solid separation devices were installed in the middle of these two independent reactors, which not only made white content of the by-product phosphogypsum increase to more than 95%, but also phosphogypsum whisker with slenderness ratio of more than 50 could be obtained under the conditions of crystallization temperature at 90 ℃ ,30% （ mass fraction） sulfuric acid,one - off feeding way, aging time of 40 min, and stirring intensity of 250 r/min.