Michigan Compiled Laws, Chapter 211. Taxation of Real and Personal Property § 211.622

Sec. 2. Before the first calendar year in which production of merchantable ore from a low grade iron ore mining property has been established on a commercial basis, or before the period of construction of the plants for the beneficiation or treatment of low grade iron ore and the period of experimental operation of the plants, the low grade iron ore mining property shall be subject to a specific tax equal to the rated annual capacity of the plant in gross tons multiplied by .55% of the mine value per gross ton, based upon the projected natural iron analysis of the iron ore pellets or of the concentrated and/or agglomerated products, multiplied by the percent of construction completion of the low grade iron ore mining property.