Feed
Feed means the prepared and mixed materials, which include but are not limited to materials such as limestone, clay, shale, sand, iron ore, mill scale, cement kiln dust and flyash, that are fed to the kiln. Feed does not include the fuels used in the kiln to produce heat to form the clinker product.
Source
40 CFR § 63.1341
Scoping language
All terms used in this subpart that are not defined in this section have the meaning given to them in the CAA and in subpart A of this part.