Method for pretreating wet-process dilute phosphoric acid for improving operation rate of concentration equipment

• Main Authors: YANG XING, ZHOU GUIMIN, ZHAO LEI, ZHU DAIQUAN, LIU SHUFU
• Format: Patent
• Language: Chinese; English
• Published: 08.09.2017
• Subjects: CHEMISTRY; COMPOUNDS THEREOF; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS

The invention discloses a method for pretreating wet-process dilute phosphoric acid for improving the operation rate of concentration equipment. The method comprises the following steps: adding concentrated sulfuric acid to the wet-process dilute phosphoric acid to be concentrated until the content of SO4<2-> in the wet-process dilute phosphoric acid reaches 45-50g/L, then conducting stirring for 15-30min for conducting grain growing, standing the wet-process dilute phosphoric acid for aging for 48h, conducting gravity free settling separation, returning solid residue to a wet-process phosphoric acid extraction system, and delivering the clear solution to the concentration equipment for conducting concentration. According to the method, the concentrated sulfuric acid is added to the dilute phosphoric acid for reducing the content of Ca<2+> in the dilute phosphoric acid, thereby reducing the separation of post precipitation in the concentration process, prolonging the usage time of the concentration equipment