Steel Dynamics Inc. (SDI)

This is a topic that I remember researching, but I evidently never wrote any notes. From memory, SDI started with a greenfield plant near Butler, IN, that produces steel coils. It expanded with another plant near Columbia City to produce structural and rail products. And its headquarters is in Fort Wayne, IN.

They have obviously expanded considerably from those two plants. Their steel mills use electric arc furnaces (EAF) and continuous casting. OmniSource is a wholly-owned subsidiary that handles scrap metals and Millennium Building Systems is their fabrication operation that "produces trusses, girders, steel joist and steel decking products" that are used in the building industry. [SDI-history] Given the Minnesota Operations, I presume they now also make HBI to feed their EAFs. That makes EAF steel competitive with blast furnace steel in terms of purity. (Each time scrap steel is used, more impurities are added to the next generation of steel.)  I could not find much information on their Iron Dynamics.

SDI-products

I've noticed that most of  the information on their web site is stale because it stops at 2014. 

SDI-history

SDI-product-guide, p15

A good video. Specifically, it is a professionally narrated video of equipment operationing within the factories. And it starts with no background music. When they did add background music, at least they kept it in the background. The concern about safety is needed. They have had five workers killed since 2001. [WANE] 

Screenshot
[I presume these are the two Electric Arc Furnaces (EAF) in their Butler mill.]

In addition to their original plant in Butler, they bought a flat-roll plant in Columbus, MS from Severstal when they exited the North American market, and they are building a new one in Sinton, TX.

2019 Annual Report, p13