This Chapter shall not apply to a salvage yard regulated pursuant to Chapter 20 of the N.C. Gen. Stat., unless the salvage yard is engaged in the business of gathering or obtaining ferrous or nonferrous metals that have served their original economic purpose and is in the business of performing the manufacturing process by which ferrous metals or nonferrous metals are converted into raw material products consisting of prepared grades and having an existing or potential economic value. (2013-410, s. 30.5.)