Study on the range of the rational enlarging production scale of the underground metal mines

The production scale of the underground metal mine is one of the decisive factors to be considered when the mine is enlarged. First, the article studied the calculating methods of the upper level production scale; second, the floor level one; third, presented the range of the rational enlarging production scale; finally, demonstrated them with a mine. It showed that the results have certain impersonality and reliability, which may provide an important reference for the mine design.