Section 18 in The Mineral Conservation And Development Rules, 1988
18. Sub-grade minerals to be brought to surface.
(1)All the sub-grade ore/minerals wherever obtained in underground workings shall be brought to the surface instead of leaving or packing them in underground.(2)As far as practicable the complete width of the ore/mineral body shall be worked:Provided that the Chief Controller of Mines may permit in writing leaving of certain portions in underground if it is necessary for the support or protection to the mine workings.
