Defluorination method of acidic aqueous solution containing hydrofluoric acid

Abstract

The invention discloses a defluorination method of an acidic aqueous solution containing hydrofluoric acid. The method comprises the following steps: (a) facilitating the reaction of the acidic aqueous solution containing the hydrofluoric acid and edittrialkyl chlorosilane or a mixture of edittrialkyl chlorosilane and hexaethyldisiloxane, wherein the reaction temperature is 10 to 80 DEG C, the reaction time is 5 to 100 min, separating an obtained reaction solution, wherein an upper layer is an organic silicon mixture, and a lower layer is a defluorinated acidic aqueous solution; and (b) mixing the organic silicon mixture obtained in step (a) and an alkaline solution, performing regenerative reaction, separating an obtained regenerated reaction solution, wherein the lower layer is an alkaline solution containing fluoride salt, and the upper layer is hexaethyldisiloxane. The method has the advantages of simple process, high operation flexibility, high defluorination efficiency, environmental friendliness and environmental protection.

Description

technical field

[0001] The invention relates to a treatment method for fluorine-containing hydrochloric acid, in particular to a defluorination method for an acidic aqueous solution containing hydrofluoric acid. Background technique

[0002] A large amount of acidic aqueous solution containing hydrofluoric acid, such as fluorine-containing hydrochloric acid, fluorine-containing sulfuric acid, and fluorine-containing acidic wastewater, is produced in the industrial production process. Due to the existence of hydrofluoric acid, the application value of acidic aqueous solution is greatly reduced, and it is easy to cause environmental protection problems and cause potential harm to the environment. Some enterprises even treat it as waste acid, which seriously affects economic benefits. Therefore, it is necessary to find a method for effectively removing hydrogen fluoride in acidic aqueous solution. At present, lime or carbide slag neutralization and sedimentation separation are...