Endless casting and rolling operations right from the first heat
On December 18th, thanks to the joint efforts of Danieli and Nucor teams, Nucor Steel Florida safely started on schedule, melting, casting and rolling in endless mode from the first heat.
Located in Frostproof, Florida, USA, the new MIDA minimill has a rated capacity of 380,000 shtpy and will produce rebar ranging from #3 to #11 (9.5 to 35.8 mm) in straight bars up to 60 ft, and spooled coils up to 5 tons. Featuring the latest energy-saving and environmentally friendly melting, the MIDA casting and rolling technologies significantly reduce the overall CO2 emissions thanks to the absence of the reheating furnace.
With the Florida minimill, Nucor will satisfy the regional demand of steel rebar, recycling the scrap available in the area and reconfirming the Endless Casting and Rolling solution as a proven solution for a sustainable steel production.
Nucor Steel Florida (NSFL) is the fourteenth Danieli MIDA minimill featuring Endless Casting-Rolling ECR technology for long products in operation worldwide - second for the Nucor group - and fourth in the USA.
In January 2020, the first MIDA minimill for Nucor, Sedalia, Missouri also started up quickly, having the endless casting and rolling operations in place on third day and a “more than 1 km” long billet produced on the fifth day.
The consistent start-up of this plant validates once more the full reliability of the MIDA endless casting and rolling process, which gives steelmakers the possibility to achieve a total transformation costs from 5 to 10 % lower than a traditional minimill.
The Nucor Florida minimill composition:
The MIDA endless casting-rolling process route includes the Danieli ECS® scrap preheating and continuous charging system, able to feed hot scrap continuously into a 40-t, side-charging, Fastarc AC EAF; and then a ladle furnace ensures the proper refining of the steel.
A single-strand, high-speed continuous casting machine is the core of the endless casting-rolling section. It is equipped with the Danieli Fast Cast Cube (FCC) and a 130 x 130 mm square section Power-mould copper tube directly connected, through a 4 MW induction furnace, to an 8 + 8 stands ultra-compact rolling mill.
The finishing facilities consist of an apron roller line, for the larger sizes, the Danieli-patented Direct Rolling and Bundling system (DRB) for the smaller range and a spooler line based on the “K-Spool” technologies, able to produce coils from rebar #3 to #8 in coils up to 5 tons.
The latest Danieli technologies for an environmentally friendly and energy saving plant are also applied to the auxiliary units, which include the Fumes Treatment Plant, based on a Pulse-jet bag filter, the Water Treatment Plant, and the Danieli heavy duty technological and maintenance cranes serving the whole plant, from the scrap yard to finished products handling.