Fluorine compounds

21 January 2024, 19:09

1. Hydrogen fluoride (HF). It is obtained by acting sulfuric acid on natural calcium fluoride (fluorite) or on cryolite. It is purified by treatment with potassium carbonate or distillation (sometimes it contains as impurities insignificant amounts of silicates and hexafluorosilicic acid). In anhydrous state, hydrogen fluoride is a very hygroscopic liquid (boiling point 18 - 20 °C); it "fumes" in a moist atmosphere. In anhydrous state and in concentrated solution (hydrofluoric acid) it deeply burns the skin and chars organic materials. It is stored in metal bottles with lead, gutta-percha or ceresin lining

It is stored in lined containers, as well as in rubber or plastic vessels; very pure acid is stored in silver bottles.

It is used for etching glass, manufacturing ashless filter paper, obtaining tantalum and fluorides, for cleaning and etching casting products, in organic synthesis or for controlling fermentation processes.

2. Fluorinated acids. These include:

a) tetrafluoroboric acid (hydrogen tetrafluoroborate) (HBF4);

b) hexafluorosilicic acid (hydrogen hexafluorosilicate) (H2SiF6), for example, in aqueous solutions obtained as by-products in the production of superphosphates or

from silicon fluorides. Used for electrolytic purification of tin and lead, for production of fluorosilicates, etc.

Source: "Explanations to the Commodity Nomenclature of Foreign Economic Activity of the Russian Federation (HS Code of Russia)" (prepared by the Russian Federal Customs Service) (volume 1, sections I - VI, groups 1 - 29)

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Морфология

Род

Понятие «соединения фтора» среднего рода.

Склонение и число

Падеж	Единственное число	Множественное число
Р	соединения фтора	соединения фтора
Д	соединению фтора	соединению фтора
В	соединение фтора	соединение фтора
Т	соединением фтора	соединением фтора
П	соединении фтора	соединении фтора