Image source, Reuters
Image caption,British Steel's Scunthorpe plant looms large on the skyline of the town
British Steel plans to close down its blast furnace in Scunthorpe, putting up to 2,000 jobs at risk.
The business, owned by China's Jingye Group, wants to replace it with two electric arc furnaces (EAFs) - one at Scunthorpe and one at Teeside.
The construction is expected to take between two and three years.
British Steel said it aimed to transform the firm into a "green and sustainable company" and had to look at different scenarios to help it do this.
Unions estimate the shift could ultimately lead to the loss of 1,500 to 2,000 jobs, predominantly at Scunthorpe.