law: 7[8. Periods for which mining leases may be granted or renewed.
  (1) The provisions of this
  section shall apply to minerals specified in Part A of the First Schedule.
  (2) The maximum period for which a mining lease may be granted shall not exceed thirty years:
  Provided that the minimum period for which any such mining lease may be granted shall not be less than twenty years.
  (3) A mining lease may be renewed for a period not exceeding twenty years with the previous approval of the Central Government.]