82. Decision of question whether a mine is under this Act. If any question arises as to whether any excavation or working 2[ or premises in or adjacent to and belonging to a mine, on which any process ancillary to the getting, dressing or preparation for sale of minerals or of coke is being carried on] is a mine within the meaning of this Act, the Central Government may decide the question, and a certificate signed by a Secretary to the Central Government shall be conclusive on the point.