3. (1) There shall be levied and collected as a cess for the purposes of this Act a duty of excise on all minerals specified in the Schedule despatched from the mines, at such rate not less than fifty ¹[Poisha] and not more than one Taka per ton as may be fixed by the Government by notification in the official Gazette: Provided that the Government may, by notification in the official Gazette, exempt from liability to the duty any of such minerals or any class thereof. (2) The duty levied under sub-section (1) shall, subject to and in accordance with rules made in this behalf under this Act, be collected by such agencies (hereinafter referred to as the collecting agencies) and in such manner as may be prescribed.