The introduction of a trade company in Baiyin, with the relevant license, can be described as follows:

1. Company Formation: A new trade entity is established within the city limits of Baiyin. This involves selecting an appropriate business structure (such as sole proprietorship, partnership, or limited liability company) and registering it with local authorities.

2. License Acquisition: In order to legally carry out trading activities in Baiyin, the company must acquire the relevant licenses from the local government. This may include trade licenses, import/export permits, or other specialized licenses depending on the nature of the traded goods.

3. Operation and Compliance: Once the trade company is set up with a valid license, it can legally operate within the city limits of Baiyin. The company must adhere to all relevant laws, regulations, and standards, ensuring compliance and avoiding penalties.

In summary, introducing a trade company in Baiyin with the proper licenses involves setting up the business structure, acquiring licenses, operating within legal parameters, and maintaining compliance.