Preparation of Sodium Hexafluorophosphate from Battery-Grade Sodium Fluoride Crystals

The first type: Industrial grade. This is currently the most widely used type. Its application fields are very broad,

1. Sodium fluoride (NaF) is an important fluoride salt and a raw material for manufacturing other fluorides.

2. Used as an agricultural insecticide, fungicide, wood preservative, water treatment agent, ceramic pigment, manufacturing of rimmed steel, light metal fluoride treatment agent, etc.

3. In the production of sealing materials and brake pads, it increases wear resistance. In mechanical blade planer knives with steel inserts, it enhances welding strength.

4. Added in enamel, pharmaceutical industries, paper production, and as a flocculant in building materials.

5. In the coating industry, it serves as a phosphating accelerator, stabilizing the phosphating solution, refining the phosphating process, and improving the performance of the phosphating film.

The second category: Toothpaste grade

As the name implies, it is mainly added to toothpaste. Adding sodium fluoride to toothpaste can help prevent cavities because fluoride interacts with tooth enamel to form fluorapatite on the surface, enhancing the hardness and acid resistance of the enamel, reducing plaque formation, and decreasing the incidence of cavities. Fluoride toothpaste indeed has certain anti-cavity effects. As early as the mid-19th century, Europe had pregnant women take calcium fluoride orally to prevent cavities; by the 20th century, fluoride was recognized worldwide as an effective anti-cavity agent. In general fluoride toothpaste, the sodium fluoride content is 0.22-0.33%, and the sodium monofluorophosphate content is 0.76%. Such small amounts are sufficient to provide good protection for human teeth, reducing the prevalence of cavities by 28%.

The third category: Spherical or flake sodium fluoride

Used as a UF3 adsorbent in the nuclear industry. Applied in the adsorption of special gases such as fluorine gas, absorbing hydrogen fluoride impurities.

The fourth category: Optical grade sodium fluoride

Mainly used in optical fields such as optical glass, optical fibers, and optical crystals.

The fifth category: Battery grade fluoride

Primarily used as an additive in electrolytes, either as an additive or as a raw material for sodium hexafluorophosphate in sodium battery electrolytes. Currently, CATL has taken the lead in commercializing this application.

The sixth category: High-purity or reagent grade

This type mainly requires high purity and is generally used as a reagent.

The above are several common types of sodium fluoride.