Updated with time frame for expansion, new production figures
North Star BlueScope has filed a new air permit for its proposed 800,000t-900,000t (882,000st-992,000st) expansion of its Delta, Ohio, flat-rolled mill.
The permit was filed with Ohio's Environmental Protection Agency (EPA) months after the mill's owner, Australia-based steel producer Bluescope, said it would make its final investment decision in the second half of 2019.
The company has said the expansion will cost $700mn and would increase the mill's current steel production from 2.1mn t/yr to 2.9mn-3mn t/yr. The expansion is expected to take two to three years to complete.
The expansion will add a third electric arc furnace (EAF) and a second slab caster.
The air permit with Ohio's EPA says emission testing for the new equipment will be conducted by 12 June 12 2020.

