General requirements for technical conditions for mining of facing stone mines

Available thickness m

Stone removal thickness m

Minimum mining elevation

Open-air mine field

Slope angle

Open pit minimum chassis width m

Stripping ratio

m ³ /m ³

3

Not lower than the local erosion datum, such as technically economically feasible, the erosion datum can be reduced accordingly

Rocky rock mass 50-90o, loose rock mass no more than 45o

≤30～40

Depending on the overall economic benefits of mining may be