A transmittingreceiving unit for asynchronous data transmission has a CRC unit and a transmission FIFO in a transmission path. to produce an ash, converting the ash to an aqueous slurry comprising sodium hydroxide as leading agent and hydrogen peroxide as oxidizer, and extracting vanadium, nickel and molybdenum salts and oxides from the slurry. Likewise, the stripper baffle structure is supported for movement between home or standby positions to its active position where it effects separation of a portion of the imaging media beyond its lead edge. The generated digital contents are sold.