How to prepare refined fluorosilicic acid

How to prepare refined fluorosilicic acid

1. The acid hydrolysis of silica powder is carried out in a lead lined acid hydrolysis equipment by first adding hydrofluoric acid, and then gradually adding silica powder to make it react. After the reaction is completed, rice bran ash is added to neutralize the free hydrofluoric acid and act as a bleaching solution. The solution is filtered, and an appropriate amount of yellow lead powder (PbO) is added to the filtered clear liquid to remove the sulfate ions brought in by hydrofluoric acid. After filtration, the fluorosilicic acid product is obtained.

6HF+SiO2→H2SiF6+2H2O

2. Produced by absorbing silicon tetrafluoride released from wet process phosphoric acid production through water absorption. It can also be prepared by reacting silica sand with hydrofluoric acid or by heating a mixture of silica sand, calcium fluoride, and concentrated sulfuric acid.

Evacuate personnel from the contaminated area to a safe zone and prohibit unrelated personnel from entering the contaminated area. It is recommended that emergency responders wear self-contained breathing apparatus and chemical protective clothing. Do not come into direct contact with the leaked material and seal the leak while ensuring safety. Mix and absorb with sand or other non combustible adsorbents, then collect and transport to waste disposal sites for disposal. You can also rinse with a large amount of water, and dilute the washing water into the wastewater system. If there is a large amount of leakage, use embankments to contain it, and then collect, transfer, recycle or dispose of it harmlessly before disposal.

This product is toxic. Operators must wear necessary protective equipment. See sodium fluorosilicate for the rest. Packaged in plastic woven bags lined with polyethylene plastic bags, with a net weight of 50kg per bag. There should be a clear "drug" label on the packaging. It should be stored in a cool and dry warehouse. The packaging must be tight. Do not store or mix with edible or acidic materials. Toxic substances. Hazard code: GB6.1 class 61514. UNNO.2855; IMDGCODE6250 page, Class 6.1. Water and sand can be used to extinguish fires.

Skin contact: Remove contaminated clothing and immediately rinse with water for at least 15 minutes. If there are burns, seek medical treatment.

Eye contact: Immediately lift the eyelids and rinse with flowing water or saline solution for at least 15 minutes.

Inhalation: Quickly leave the scene and move to a place with fresh air. Keep the respiratory tract unobstructed. Administer oxygen when experiencing difficulty breathing. When breathing stops, immediately perform artificial respiration. Seek medical attention.

Ingestion: Those who accidentally consume it should drink milk or egg white. Seek medical attention immediately.