Knowledge

　　The drill bit plays an important role in the water well drilling rig. During the drilling process, the operator should pay attention to the usage of the dri

　　1. Drilling workers must receive professional training and have certain work experience before they can take up their positions.　　2. The driller must be f

　　After the primary gold deposits are exposed to the surface, due to mechanical and chemical weathering, the gold-bearing veins or gold-bearing parent rocks a