The discovery of silver predated the Spring and Autumn Period and the Warring States Period. According to historical records, as early as the late Neolithic Age, the working people in ancient China knew about silver mines and collected, refined and processed silver into ornaments. It is generally believed that silver is a precious metal, and then in later dynasties, kings began to use silver as a reward, and some people began to pay bribes with silver. With the progress of the times, people began to use silver slowly, and silver began to be converted into money. From Wei Jin to Sui Dynasty, silver began to circulate in the form of coins, and the court made silver into copper coins as currency. Then in the Jin Dynasty, silver began to appear in the form of ingots and began to improve its quality. Then with the development of the times, silver began to be made into ingots. Official silver is the silver with the imperial court logo, which is not allowed for private use. Most of the folk silver is broken silver, and there are some unmarked silver. Smelting method is adopted in the early stage of silver processing, and smelting method or soot blowing method is adopted in the later stage, that is, silver is melted and stirred with iron bars, and the impurities inside will be oxidized and attached to the iron bars to be taken out. The soot blowing method of tribute melting method is to add lead and manganese to the broken silver ore to melt and remove impurities such as floating iron to make expensive lead (silver-lead alloy). Expensive lead is heated and melted on the "soot-blowing bed", and lead penetrates into the ash, leaving only silver on the ash, thus achieving the purpose of separation. Then repeat the same process to improve the purity of silver soot blowing.