Promoting Nuanced Taconite Regulations Act of 2012 - Amends the Clean Air Act (CAA) to consider as approved with respect to a taconite ore processing facility, under ambient air quality standard implementation plans for a state, any implementation plan submitted by the state (including any such plan submitted prior to enactment of this Act) that specifies the best available retrofit technology for any such facility for the purpose of eliminating or reducing any impairment of visibility.
Prohibits the Administrator of the Environmental Protection Agency (EPA), if a state has submitted such a plan, from promulgating, implementing, or enforcing any requirement pursuant to a federal implementation plan under the CAA with respect to such facility for such purpose.
Makes this Act applicable until January 1, 2022.