Calcium fluoride is an inorganic compound with the chemical formula CaF2, a colorless crystal or white powder. It is insoluble in water, slightly soluble in inorganic acids, and acts with hot concentrated sulfuric acid to produce hydrofluoric acid. Experiments generally use calcium carbonate and hydrofluoric acid or concentrated hydrochloric acid or hydrofluoric acid repeatedly treated fluorite powder to prepare calcium fluoride. Nature's calcium fluoride mineral fluorite or fluorite, often gray, yellow, green, purple and other colors, sometimes colorless, transparent, glassy, brittle, with significant fluorescence phenomenon. Very pure fluorite is used to make special lenses. Fluorite is mainly used as a flux for smelting metals; when drinking water contains 1-1.5ppm calcium fluoride, it can prevent and control dental disease.

Basic information

Properties

White powder or colorless cubic crystal, luminous when heated. Melting point 1402℃; Boiling point 2500℃; Relative density 3.18; Refractive index 1.434; Almost insoluble in water, 0.0017g/lOOmL water at 25℃. Soluble in concentrated inorganic acid, and decomposition of hydrogen fluoride. Slightly soluble in dilute inorganic acid.

Preparation method

Fluorite deposits have been found in China, because the ore body is mostly sharply inclined vein-like, the extension depth is also larger, so most mines use underground mining method, or shallow open-pit mining, deep underground mining. The mining method is based on the shallow hole mining method. See "Phosphorite" for the mining process. Beneficiation

There are generally two kinds of beneficiation methods, one is the production of qualified concentrates by hand-election of raw ores, and the other is the hand-election of tailings and poor ores. Fluorite is enriched by flotation. Beneficiation principle process varies according to the type of ore, such as quartz and fluorite ore, the principle process is as follows: raw ore, a crushing, a grinding, a rough selection of a rough selection again and again grinding, a number of selection of a fluorite concentrate.

Usage

It is a new type of electric light source material, which can be directly used as phosphor material for fluorescent screen and fluorescent lamp. It is also the main material of single crystal of optical instruments such as infrared laser system optical lens and rectifier. It can also be used in the manufacture of optical glass, optical fiber, enamel, medicine and as a catalyst for dehydration and dehydrogenation reaction and metallurgical flux.

Safety

Toxic! Mouse intraperitoneal injection LD5.: 2638. 27mg/kg. irritating to eyes and skin. Irritating to mucous membranes and upper respiratory tract. Ingestion causes abdominal pain and may cause death. Store in cool, ventilated warehouse. Keep away from fire and heat. Keep container sealed. Store separately from acids. Handle gently, keep package intact and prevent spillage.