[Chemical Knowledge]：The nature, use, upstream and downstream raw materials, storage methods, basic information of nitric acid.

Nitric acid properties

Nitric acid (HNO3) is a kind of inorganic acid, which is strongly acidic and has strong oxidizing and corrosive properties. Pure nitric acid is a colorless liquid, but it decomposes to produce nitrogen dioxide (NO2) in the presence of light, giving it a yellow color. Nitric acid has a density of about 1.51g/cm³, a boiling point of 83°C, and is miscible with water in any proportion. Due to its strong oxidizing properties, nitric acid is capable of oxidizing most metals, forming metal nitrates, and releasing nitrogen oxide gases. These properties make nitric acid useful in chemical reactions, but also require special care in handling.

Nitric acid use

Nitric acid has a wide range of uses in industry and laboratories. Nitric acid is an important raw material for the production of fertilizers, especially ammonium nitrate (NH4NO3), which is one of the commonly used nitrogen fertilizers. Nitric acid is used to make explosives, such as trinitrotoluene (TNT) and nitroglycerine, which play a key role in the military and mining industries. Nitric acid is also used in the production of chemicals, dyes, plastics and intermediates required in the pharmaceutical industry. In the laboratory, nitric acid is used as a strong oxidant and acidic reagent for various chemical analysis and synthesis reactions.

Upstream raw materials

The production of nitric acid depends mainly on ammonia (NH3) and oxygen (O2) in the air. Industrially, the most common production method is the Ostwald process (Ostwald process), in which ammonia reacts with oxygen over a catalyst at high temperature to produce nitric oxide (NO), which is then further oxidized to nitrogen dioxide and finally absorbed in water to produce nitric acid. The core raw material of this process is ammonia, so the production and supply of ammonia is an important part of nitric acid production. Ammonia is mainly synthesized from natural gas through the Haber process, so the supply and price fluctuations of natural gas will affect the cost structure of nitric acid.

Downstream Products

The downstream products of nitric acid cover many industries, the most important ones include fertilizers, explosives, chemical intermediates and metal surface treatment agents. Ammonium nitrate in fertilizers is the most important downstream product for nitrogen supplementation in agriculture. In the explosives industry, nitric acid is used to produce high energy materials such as TNT, nitroglycerin and nitrocellulose. In the chemical industry, nitric acid participates in the synthesis of various organic and inorganic compounds to produce important intermediates such as adipic acid and nitrobenzene. Nitric acid is also used in metal surface treatment, such as passivation of stainless steel, to improve its corrosion resistance.

Nitric acid storage method

Because nitric acid is highly corrosive and oxidizing, special attention is required during storage. Nitric acid should be stored in a cool, well-ventilated place, away from heat and fire sources. Common storage container materials include glass, plastic and some acid-resistant alloys, but ordinary metal containers must not be used to prevent corrosion and dangerous reactions. The storage container should be sealed to prevent nitric acid from volatilizing and absorbing moisture and impurities in the air. For mass storage, double-layer containers or additional safety measures are usually used, such as secondary protection tanks outside to prevent leakage accidents.

Safe handling and environmental impact

Strict safety measures must be followed when handling and using nitric acid. Operators are required to wear protective equipment, including gloves, goggles and acid suits, to avoid skin and eye contact with nitric acid. In case of leakage, personnel should be evacuated immediately, and the leaked nitric acid should be neutralized with lime or soda powder, and then cleaned up. Nitric acid is potentially harmful to the environment, especially to aquatic ecosystems. Therefore, the waste nitric acid and its solution must be neutralized before it can be discharged to prevent pollution of water source and soil.

Market and Economic Analysis

The market demand for nitric acid is affected by many factors, including agricultural production, infrastructure construction, and the development of the chemical industry. In recent years, with the increase of global population growth and agricultural demand, the demand of nitric acid in fertilizer production has maintained a steady growth. The infrastructure construction and the demand for chemical products in the process of industrialization have also promoted the development of the nitric acid market. The nitric acid market is also facing the challenges of raw material price fluctuations and environmental protection policies, especially the increasingly stringent regulations on limiting nitrogen oxide emissions and promoting green chemistry.

Conclusion

As an important chemical raw material, nitric acid is widely used in agriculture, industry and laboratory. Its production is dependent on ammonia and oxygen, mainly by the Ostwald process. Downstream products cover fertilizers, explosives and various chemicals, showing their key position in the modern chemical industry. The strong corrosive and oxidizing properties of nitric acid impose strict requirements on its storage and handling, while environmental and safety regulations also have an important impact on its market development. In the future, with the improvement of technology and environmental awareness, the production and application of nitric acid will be more efficient and sustainable.