Yankuang is the largest mining group in Shandong Province and the top five in the national coal industry. Yankuang has the best coalfield in Shandong Province, with easy mining and large reserves. Xinwen Mining Group and Zaozhuang Mining Group, which are also old mines in Shandong Province, once faced great pressure because of their large families. Zi Mining Group also has a history of more than one hundred years, which has made great contributions to the construction of new China. There are many similarities between sub-mines and jujube mines, and they also faced resource depletion in the 1980s and 1990s. Linyi Mining Group has made great progress in recent years. Longkuang Group develops slowly, but it is also a small group. Feicheng Group has been established for almost 50 years. Among the seven major mining groups in Shandong, the coal field of Feicheng Group is very poor. The coal quality is not good, it is not easy to mine and the reserves are low.