1. Defining opencut mining area is the key link of opencut design and construction.

2. Opencut mining will destroy the ecological environment to a certain extent.

3. These opencut, containing shed-tunnel and opencut in the shape of arch, were often destroyed in the earthquake disaster, and makes more difficulties for the disaster relief officials.

4. Defining opencut mining area is the key link of opencut design and construction. Defining final mining area is equal to defining the mining and stripping quantity.

5. On the basis of analyzing the cause of producing big block base in explosion in Fengjiayu Opencut Iron Mine, an effective method has been developed to reduce big block and overcome the base.

6. A great deal of dust and poisonous gas produced in the process of opencut mining pollutes the environment seriously.