Hydrogen chloride gas has a wide range of uses i […]
Hydrogen chloride gas has a wide range of uses in industrial production. Today I will introduce you to several industries commonly used in hydrogen chloride, which are also often used in our industry. Especially the production of inorganic and organic medicines. Let's take a look below:
At a temperature of 180 ℃ to 200 ℃ and a mercury salt (such as HgCl2) as a catalyst, hydrogen chloride and acetylene undergo an addition reaction to form vinyl chloride, which is then polymerized into polyvinyl chloride under the action of an initiator.
2. Bleaching and Dyeing Industry
Acid pickling after bleaching of cotton cloth and neutralization of residual alkali after mercerizing treatment of cotton cloth must use hydrochloric acid. In the printing and dyeing process, some dyes are insoluble in water and need to be treated with hydrochloric acid to make them into soluble hydrochloride before they can be applied.
3. Metal processing
Pre-plating treatment of iron and steel parts, first wash with caustic soda solution to remove oil stains, and then soak with hydrochloric acid; before metal welding, you need to apply a little hydrochloric acid to the welded joints, etc., all use hydrochloric acid to dissolve metal oxides. To remove rust. In this way, the metal surface can be plated and welded firmly. The purpose of removing materials can also be achieved by performing a dissolution reaction with some metals (such as aluminum) by means of corrosion.
4. Food industry
In the production of chemical soy sauce, the cooked bean cake and other raw materials are immersed in a solution containing a certain amount of hydrochloric acid and maintained at a certain temperature. Hydrochloric acid has a catalytic effect and can promote the hydrolysis of complex proteins therein. After a certain period of time, it has an umami taste. The amino acid is neutralized with caustic soda (or soda ash) to obtain sodium amino acid. The principle of making MSG is similar.
5. Production of inorganic drugs and organic drugs
Hydrochloric acid is a strong acid that can react with certain metals, metal oxides, metal hydroxides, and most metal salts (such as carbonates, sulfites, etc.) to form hydrochloride. Therefore, hydrochloric acid is used in the production of many inorganic drugs. In medicine, many organic drugs, such as norfocaine, thiamine hydrochloride (vitamin B1 preparation), etc., are also made with hydrochloric acid.