RU1828845C - Method for producing metal fluoride - Google Patents

Abstract

The invention relates to preparative chemistry, and in particular to methods for producing metal fluoride. Polytetrafluoroethylene is placed in a container, which is connected by a container in which the corresponding metal is placed, after which the tanks are vacuumized, sealed and the container with polytetrafluoroethylene is heated to a temperature of 450-600 ° C, and the container with metal is up to 200-600 ° C . The synthesis time is 2-4 hours. 1 tab.

Description

The invention relates to preparative chemistry and can be used for the synthesis of metal fluorides.

The aim of the invention is to increase the speed of the process.

To achieve the goal in a method for producing metal fluoride, which includes loading the corresponding metal with the thermal decomposition products of polytetrafluoroethylene, removing the gaseous product and condensing it, loading the metal and polytetrafluoroethylene separately in two interconnected containers, both tanks are evacuated, sealed and heated, moreover capacity with metal - up to 200-600 ° С, and capacity with polytetrafluoroethylene - 400-600 ° С.

The placement of polytetrafluoroethylene in a separate container, its connection with the reaction chamber containing metal, ensures maximum access of gaseous decomposition products to the reaction chamber, eliminates the ingress of solid fine carbon into it

thereby eliminating the screening of the solid decomposition product of the polytetrafluoroethylene metal-gaseous decomposition product.

The placement of polytetrafluoroethylene in a separate vessel allows controlling the rate of decomposition of polytetrafluoroethylene depending on the temperature of the vessel and thereby controlling the rate of supply of gaseous decomposition products to the reaction chamber.

The decomposition rate of polytetrafluoroethylene increases with heating. Thus, for example, at a temperature of 450 ° C it is 5-10% / s, at temperatures of 500, 550, 600 ° C, respectively 5 -10, 4-, 4,5.

Evacuation of the container with polytetrafluoroethylene and the reaction chamber with the metal removes oxygen and moisture adsorbed by the charge components, accelerates the decomposition of polytetrafluoroethylene and the synthesis process.

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The fundamental difference between the proposed metal fluorination operation and that used in the prototype is that the separate heating of the chamber with the metal and the container with polytetrafluoroethylene to temperatures of 450-600 ° C eliminates the screening of the metal-gaseous decomposition product by carbon and allows you to vary the pyrolysis rate of polytetrafluoroethylene , as well as the rate of interaction of the products of its decomposition with the metal, achieving the optimum process speed.

The distinguishing feature is essential and allows you to achieve your goal.

Example. To obtain 20 g of GeF4, tank 1 was filled with 13.46 g of polytetrafluoroethylene (fluoroplast-4). The vessel 1 was connected to the vessel 2 (reaction chamber), in which 9.77 g of germanium was placed. The vessels 1 and 2 were evacuated to a pressure of 10 mmHg, sealed and the vessel with germanium was heated to 450 ° C, and the vessel with polytetrafluoroethylene up to 600 ° C. The resulting GeF4 was condensed in a vessel 3 cooled by ice water. The time of synthesis of GeF4 at a given temperature of heating the vessel with polytetrafluoroethylene and the reaction chamber with germanium was 2 hours. The yield of GeF4 is 85% based on germanium. The coincidence of the melting point of the obtained product (mp-15 ° C) with published data indicated high quality GeF4.

The time of synthesis of metal fluorides at a given temperature of heating the tank and

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chambers, as well as the temperature of condensation of fluorides are given in the table.

Using the proposed method for the synthesis of metal fluoride provides, in comparison with the prototype, the following advantages:

1. Acceleration of the metal fluoride synthesis process by 5-6 times (see table), due to elimination of carbon screening of the interface of reacting substances, by increasing the rate of decomposition of polytetrafluoroethylene in vacuum.

(2) The synthesis process is controlled by separately heating the chamber with metal and the vessel with polytetrafluoroethylene, which allows one to vary both the pyrolysis rate of polytetrafluoroethylene and the rate of interaction of its decomposition products with the metal to achieve the optimum rate of the synthesis process.

Claims (1)

The claims A method of producing metal fluoride, including loading the corresponding metal and polytetrafluoroethylene, reacting the metal with the products of thermal decomposition of polytetrafluoroethylene, removing the gaseous product and condensing it, characterized in that, in order to increase the speed of the process, the loading of metal and polytetrafluoroethylene is carried out separately in two interconnected containers both containers are evacuated, sealed and heated, with a container with metal up to 200-600 ° C, and a container with polytetrafluoroethylene up to 450-600 ° C.