Potassium salt. Baidu Encyclopedia says that the brine in Lop Nur, Xinjiang is potassium salt extracted from the desert underground, and Lop Nur is rich in potassium salt resources. Potash fertilizer is the raw material for producing agricultural potash fertilizer. Geological brine is extracted and collected in Lop Nur during the exploitation of potassium salt. The more potash is mined, the more brine is extracted underground, which gradually forms lakes.