N.D. Cent. Code § 57-61-01.4
No state severance tax may be imposed on coal used in, or coal used to produce steam that is used in, agricultural commodity processing facilities as defined in subsection 4 of section 57-39.2-04.4 located within North Dakota or adjacent states or any facility owned by the state or a political subdivision of the state. No state severance tax may be imposed on coal purchased for improvement through the process of coal beneficiation defined in section 57-60-01 which is subsequently used in, or used to produce steam that is used in, agricultural commodity processing facilities located within North Dakota or adjacent states or any facility owned by the state or a political subdivision of the state. The coal mine owner or operator shall require the person purchasing the coal to certify that amount of coal purchased for use in agricultural commodity processing facilities or for beneficiation and subsequent use in agricultural commodity processing facilities or any facility owned by the state or a political subdivision of the state or to produce steam that is used in any of those facilities.
N.D.C.C. § 57-61-01.4