1. Contact relevant institutions: try to contact mine owners or operators and ask them if they have mortgage loans. If they confirm that there is a mortgage loan, they may provide some detailed information about the mortgage loan, such as the loan amount, lending institutions and so on.

2. Inquire about relevant documents: obtain information by inquiring about mining right transaction records, mortgage registration records and other relevant official documents. These documents can usually be found on the websites of relevant mining management departments or local governments.

3. Ask a lawyer for assistance: A lawyer can help interpret relevant laws and regulations, guide how to inquire, and communicate with relevant institutions on your behalf when necessary.