Recycling method of fluorine , and fluorine -containing waste water treatment facilities

摘要

PROBLEM TO BE SOLVED: To provide a technology capable of recovering fluorine as high-purity calcium fluoride at a high recovery rate without diluting waste water containing fluorine and silicon, that is, even when waste water containing fluorine and silicon is treated while keeping a high concentration.;SOLUTION: The waste water containing fluorine and silicon is supplied into a pH adjusting vessel 1 and sodium hydroxide (NaOH) is added, so that sodium silicate is precipitated. Thereafter, the resulting material is supplied to a solid-liquid separation means 2, so that the sodium silicate is solid-liquid separated therefrom. Then, the separated liquid is supplied to a reaction tank 3, water-soluble calcium and a pH adjusting agent are added, and calcium fluoride (CaF₂) is precipitated (crystallized).;COPYRIGHT: (C)2010,JPO&INPIT