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Physical and Chemical Properties

Potassium fluoride is basis raw material of manufacturing fluoride, chemical formula is KF. Molecular weight is 58.10. It is colorless cubic crystal or white powder. It is poisonous! It is deliquescent. Taste is salty. Specific gravity is 2.48. Melting point is 858℃. Boiling point is 1505℃. It is soluble in water. It was dissolved in hydrofluoric acid and ammonia. It is insoluble in ethanol, acetone. Aqueous solution is alkaline and it can corrode glass and porcelain. It can cause irritation for human skin, mucous membrane and eye. When belows 40.2℃, it can crystallize in an aqueous solution to give dihydrate KF·2H2O, which is monoclinic, it is self-dissolved crystalline water at 41℃. It can be obtained by the thermal decomposition of potassium hydrogen fluoride or potassium carbonate (or potassium hydroxide) and hydrofluoric acid (40% or anhydrous). It can be used for glass engraving, food preservation, it can be also used as welding flux, fluoride, pesticides,etc. Figure 1 the structural formula of potassium fluoride.

Preparation

Potassium fluoride is prepared by reacting potassium carbonate (or KOH) with aqueous hydrofluoric acid. Care is necessary in handling the anhydrous salt, to prevent its hydration.

Reactivity Profile

Potassium fluoride reacts with acids to evolve corrosive and toxic hydrogen fluoride. Aqueous solutions corrode glass and consequently are prepared and stored in polyethylene containers. The pure solid may be stored in glass containers. Reacts violently with (Pt + BrF3). [NTP 1992].

Health Hazard

TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.

Fire Hazard

Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.

Safety Profile

Poison by ingestion and intraperitoneal routes. Moderately toxic by subcutaneous route. Experimental teratogenic effects. A corrosive irritant to the eyes, skin, and mucous membranes. Mutation data reported. A very reactive material. When heated to decomposition it emits toxic fumes of K2O and F-. Used in etchmg glass, as a presewative, as an insecticide, and in organic synthesis. See also FLUORIDES and HYDROFLUORIC ACID.

Potential Exposure

Potassium fluoride is used in etching glass; as a preservative and insecticide.

Shipping

UN1812 Potassium fluoride, solid, Hazard Class: 6.1; Labels: 6.1-Poisonous materials.

Incompatibilities

Incompatible with strong acids; reacts releasing hydrogen fluoride. Aqueous solutions corrode glass and consequently are prepared and stored in polyeth- ylene containers. The pure solid may be stored in glass containers. Reacts violently with (Pt 1 BrF 3 )