" Pursuant to the authority conferred by this provision, the Central Government has made Rule 13 which at the material time was in the following terms: Rule 13: The goods referred to in clause (b) of sub sec.(3) of section 8, which a registered dealer may purchase, shall be goods intended for use by him as raw materials, processing materials, machinery plant, equipment, tools, stores, spare parts, accessories, fuel or lubricants, in the manufacture or processing of goods for sale or in mining, or in the generation of distribution of electricity or any other form of power." " The assessee made an application to the Sales Tax Officer on 14th September 1967 for inclusion of 36 items of goods in the certificate of registration on the ground that these items of goods were being purchased by it for use in mining ore and processing it for sale in the export market, and hence they were goods falling within section 8(3) (b) and Rule 13.