What is silver nitrate?

Silver nitrate, an inorganic compound with the chemical formula AgNO3, is a white crystalline powder, easily soluble in water, ammonia, glycerol and slightly soluble in ethanol. Pure silver nitrate is light-stable, but its aqueous solution and solid are often kept in brown reagent bottles due to the general lack of purity of the product. It is used in photographic emulsion, silver plating, mirror making, printing, medicine, hair dyeing, testing chlorine ion, bromine ion and iodine ion, etc. It is also used in electronic industry.

Foreign development history

In the eighth century A.D., the Arab alchemist Jabir ibn Hayyan (Jabir ibn Hayyan) in the dry distillation of saltpeter found and produced nitric acid, which is the earliest human record of nitric acid.

In 1905, a plant for the production of nitric acid by the electric arc method appeared in Norway, which was the earliest attempt in history to industrialize nitric acid.

In 1908, Germany built a platinum network as a catalyst for the daily output capacity of 3 tons of nitric acid plant .

In 1913, synthetic ammonia was introduced, and the production of nitric acid by ammonia oxidation began to enter the industrialization stage, and this method is still the main method of producing nitric acid in the world after more than one hundred years.

History of domestic development
In 1935, under the leadership of Chinese chemist Hou Deping, the first joint enterprise producing ammonia, nitric acid, sulfuric acid and ammonium sulfate was built in China - YongLiNing Plant (now Nanjing Chemical Industry Company).

In February 1937, YongLiNing Plant produced high quality nitric acid for the first time.　

In May 1951, the production of coking, ammonia synthesis, nitric acid and sulfuric acid workshops of Dalian Chemical Plant was fully restored and output of nitric acid products was produced.

Between 1952 and 1958, China successively built synthesized nitric acid plants in Jilin, Lanzhou and Taiyuan, among which the concentrated nitric acid of Lanzhou Chemical Industry Company reigned as China's largest plant in the decades before 1997.

Since 1980, the development of China's domestic nitric acid industry began to accelerate, with the total output growing at a rate of 10% to 15% per year. Especially in the late 90's, China's nitric acid industry entered into a booming period, and the annual growth rate of total output reached 15% to 20%. However, during this period, China's nitric acid production technology was still relatively backward, and the early atmospheric pressure method and comprehensive method process units were mostly obsolete production lines, and the high-pressure method units all relied on imported second-hand equipment from abroad. Soon after, Shanxi Fertilizer Plant (now Sky Ridge Group) introduced China's first double-pressurized nitric acid plant from abroad, and since then China's nitric acid industry began to move towards the international advanced ranks.　

In 1999, Xi'an Shaangu Power Co., Ltd. successfully developed China's first set of “four-in-one” unit and applied it to Yunnan Yunfeng Chemical Industry Company, which accelerated the pace of China's nitric acid double-pressurized process domestic equipment to the international advanced level. Yunnan Yunfeng Chemical Industry Company, as the first nitric acid producer to use the localized “four-in-one” unit, strengthened the confidence of Chinese domestic nitric acid producers in choosing domestic equipment.

After 2000, China's nitric acid industry entered into a period of rapid development, the total annual output of more than 18% of the rate of rapid growth, with a variety of different types and sizes of manufacturers of about 60 manufacturers.

In November 2007, China's first set of full-load production conditions to achieve by-product steam self-sufficiency, but also surplus external steam supply of localized double-pressurized nitric acid plant in Xinxiang Yongchang Chemical Co., Ltd. was born, marking China's own research and development of domestic nitric acid plant is fully capable of replacing the imports of China's domestic nitric acid industry out of the dependence on imported equipment.