A small coal mine with a 600mm narrow gauge railway at work near Mamiao in Sichuan Province, China in 2009. A 'health and safety' nightmare...
This added in 2022. There are broadly two kinds of coal mines in China.
Small scale ones like this are almost entirely operating without official permission typically the owners will be bribing local authorities to turn a blind eye to their operation. Overall they actually produce a tiny amount of coal but try as they can the central government has insufficient control to enforce their policy of closure. It's very much 'whackamole' stuff.
The larger ones are usually (but not always) better regulated with a fair degree of safety measures but they are still among the most dangerous such in the world.