Fluorine gas application and use safety

(1) Isotope separation

The most powerful driver of the large-scale industrial application of elemental fluorine is uranium isotope separation, which is the most important use of fluorine. The separation of uranium-235 isotopes from natural uranium is the basis of the atomic energy industry, uranium hexafluoride is the key material for the separation of uranium-235 isotopes, and the production technology of uranium hexafluorine can only use elemental fluorine as a fluorine agent.

After the Second World War, the demand for nuclear fuel in various countries increased rapidly, resulting in rapid growth in the production of fluorine.

(2) Oxidizing agent of rocket propellant

With the rapid development of space technology and the increasingly frequent activities of human exploration in space, rockets play an indispensable and important role as a vehicle for the delivery of space vehicles. Rocket liftoff requires power, which comes from the combustion of propellant, and elemental fluorine acts as the strongest oxidant in the combustion process of propulsion.

(3) For chemical preparation

1. Synthesis of fluorinating agents with special purposes

Using the properties of elemental fluorine that can react with almost all elements, a variety of fluorinating agents with different uses can be made. Such as chlorine trifluoride, chlorine pentafluoride, bromide trifluoride, iodine pentafluoride, cobalt trifluoride, antimony pentafluoride, silver difluoride, boron trifluoride, arsenic trifluoride, arsenic macrofluoride, etc., these fluorinated agents are milder than elemental fluorine and can be used for the preparation of many organic and inorganic fluorides that need to control the degree of fluoride.

2. Production of sulfur hexafluoride gas

Elemental fluorine reacts with elemental sulfur to obtain sulfur hexafluoride, sulfur hexafluoride has good heat resistance and chemical stability, very high electrical insulation, and is widely used as an arc extinguishing medium on high-voltage electrical appliances and electronic equipment.

3. Preparation of organic fluoride

Perfluorocarbon oils or perfluorolipides made from thorough fluoridation of hydrocarbons from fluorine are key materials in the production of nuclear fuel. Using fluorine diluted with nitrogen, the control reaction can produce many fluorine-containing organics, such as hexafluoroethane, octafluoropropane and other pharmaceuticals and pesticides are intermers, refrigerants, fluoroplastics, plasma etc.

4. Production of nitrogen trifluorideFluorine gas reacts with nitrogen-containing compounds such as NH3, NH4F, xHF, (NH4) 3AIF6, etc. under certain conditions to form a trifluorinizing agent. The special physico-chemical properties of nitrogen trifluoride make it available as a rocket propellant, etching agent and cleaning agent for semiconductor chip manufacturing processes.

(4) Preparation of fluorinated fossil ink

This is a class of solid fluorocarbons of non-stoichiometry composition that can be produced by direct fluoridation of graphite or carbon. Fluorinated chemical ink is an excellent solid lubricant and cathode material for the manufacture of high-energy batteries.

(5) Preparation of fluorinated asphalt

Inspired by the study of organic fluoridation and fluorinated fossil ink, the researchers began research on the modification of fluoride of asphalt. Asphalt fluoridation is given many new special, some properties better than the related organic fluoride, it has a lower surface energy than polytetrafluoroethylene, is an excellent hydrophobic, oil-resistant material, and maintains the softenability of asphalt and solubility in the phase semi-solvent, which provides the necessary processability for its scale utilization, is a product with great development and utilization value.

(f) Surface fluorineation of polymers

With a low concentration of fluorine - nitrogen mixture instead of air to make polyolefin plastic containers, so that the inner wall of the product formed a layer of fluorocarbon film, the transmittance of organic solvents can be greatly reduced, can be used as a vehicle fuel tank, flavor and fragrance packaging container and strong corrosive chemical packaging container.

(7) The working medium of excimer lasers

Fluorine and inert gases such as argon, krypton, etc. can be used as the working medium of excimer lasers, which can be used for myopia treatment and have been promoted and applied in hospitals.

(8) Used for cleaning the CVD chamber in the semiconductor manufacturing process

Because fluorine gas does not cause a greenhouse effect, replacing fluoride or bottled fluoride with on-site fluoride production to clean the CVD reaction chamber has great market potential in the semiconductor field. The fluorine-based removal method does not cause the fluorine compounds emitted when the chemical depositor cavity is removed, and it is also convenient to produce fluorine gas, which makes the selection of fluorine gas in the new generation of removal substances attract wide attention. Previously, fluorine gas was transported to the site of use via high-pressure cylinders, but it could not be promoted due to cost, handling and safety issues. Field fluorine generators produce fluorine gas at low pressures, which can solve the problem of safe and stable supply, providing a viable alternative to the semiconductor industry.Safe to use

Since fluoride is a highly toxic element, it has a strong corrosive effect on the eyes and respiratory mucosa. Therefore, when using equipment equipped with fluorine, operators should wear gloves, coats and boots made of neoprene, as well as transparent masks made of highly fluorinated polymers, and at the same time, the workshop should have a good ventilation system.

Leak treatment: Quickly evacuate the leak-contaminated area, the personnel to the upper hand, and immediately isolate, strictly restrict access. Cut off the source of fire. Emergency responders are advised to wear self-contained positive pressure respirators and gas suits. Enter the scene from the upper hand. Cut off the source of the leak as much as possible. Rational ventilation to accelerate diffusion. Dilute and dissolve with spray-like water. Construct embankments or dig pits to contain large amounts of wastewater generated. If possible, residual or leaky air is sent by an exhaust fan to the wash tower or to the fume hood connected to the tower. The leaky container should be properly handled, repaired, and used after inspection. If the leakage comes from the user system, the cylinder valve should be closed, and the pressure must be relieved and purged with inertness before repair, and the exhaust gas is diluted and emptied with a large amount of air after detoxification.

Evacuation distance in the event of a spill

In the case of hazardous chemical leakage accidents, the emergency evacuation of surrounding personnel and residents must be done in a timely manner.

The evacuation distance is divided into two types: the emergency isolation belt is a circle with emergency isolation as the radius, and non-accident handling personnel are not allowed to enter; Downwind evacuation distance refers to the range of protective measures that must be taken, that is, residents within the range are in danger of harmful contact, and effective measures such as evacuation, sealing the windows of the residence can be taken, and communication is kept open to obey the command. Because the mixed effect of night meteorological conditions on poison gas clouds is smaller than during the day, poison gas clouds are not easy to disperse, so the downwind evacuation distance is relatively farther than during the day. The distinction between night and day is based on the rise and fall of the sun.