Introduction Auto-dug water sump system ZQ-II is our company's patented product, which is developed under technology exploration of seven years and on the basis of over 60 sets of digging equipments applications in the mines. The system can achieve automatic operations of drainage, concentration, dehydration and loading for the diverse types of underground water sump and various traits of coal sludge, and also can be used to dehydration recovery of coal sludge in the coal washery.