Exemption for rock phosphate removes excise duty where used as fertiliser or as an input in fertiliser manufacture. Exemption relieves rock phosphate under sub heading 2505.00 from the whole of excise duty specified in the Schedule, provided the material is used as a fertiliser or as an input in the manufacture of fertilisers, issued under sub rule (1) of rule 8 of the Central Excise Rules, 1944.