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When Nucor Corp., Charlotte, North Carolina, announced the site of its first electric arc furnace (EAF) micromill in mid-November 2017, it became the latest global steelmaker to try out the micromill concept.

In North America, Dallas-based Commercial Metals Co. (CMC) has had a micromill operating in Arizona since 2009 and started up its second such mill in Oklahoma in 2015.

Globally, Italy-based steel mill equipment maker Danieli has been setting up micromills in several nations around the world, boosting their output capacities as it has gained experience installing and equipping such mills.

American acceptance

Danieli, although based in Italy, has been a supplier of melt shop equipment to North America for several decades.

When Danieli began approaching current and prospective customers about its micromill concept, it found an early adopter in CMC, whose management in 2007 approved the purchase of land in Mesa, Arizona, for construction of a micromill planned to go online in 2009. The total investment for the project was forecast at $130 million.

In early December 2009, CMC held a grand opening ceremony at the Mesa mill, which was designed to produce some 280,000 tons of steel rebar annually, using ferrous scrap as 98.5 percent of its feedstock.

“The eyes of the world are looking at this plant, which is the first of its kind in the United States,” CMC then-CEO Murray McClean said at the time. He said the new technology would allow the company to melt, cast and roll steel in one uninterrupted process, promoting higher yields and lower energy costs.

Less than six years later, in July 2015, CMC announced it had selected Durant, Oklahoma, as the location for its second micromill, noting that the new plant in Oklahoma would largely mirror its existing mill in Arizona. CMC also indicated, however, that the new long products mill would include “improved technology developed from CMC’s operating experience with the world’s first micromill.”

“The location of the mill in Durant, Oklahoma, 80 miles north of Dallas, will allow us to better serve a growing North Texas market as well as expand into markets in Oklahoma, Kansas, Nebraska, Arkansas and Missouri,” said Joe Alvarado, who was then chairman, president and CEO of CMC. “The facility will produce low-cost, high-quality steel products [that] will complement our existing manufacturing capability to better serve our customers,” he also said of the project, which carried a forecasted price tag of $250 million.

In 2017 it was Nucor’s turn to invest in the micromill concept, and the company’s executives cited similar reasons for adopting the technology.

In November 2017, Nucor announced plans to build a $250 million rebar micromill in Sedalia, Missouri, with an anticipated startup date in 2019.

“This rebar micromill project is consistent with our long-term strategy for profitable growth and builds on our position as a low-cost producer,” said John Ferriola, chairman, CEO and president of Nucor when making the micromill announcement. “Strategically positioning this micromill in the Kansas City area will give us a sustained cost advantage over other domestic steel producers supplying rebar from outside the region.”

“We are encouraged by the tremendous support received by the state and local community in Missouri, and Nucor has decided to pursue an additional micromill project.” – Dave Sumoski, Nucor

Rebar supply to the Kansas City, Upper Midwest and Plains states markets currently travels long distances, giving the micromill in Sedalia a logistical advantage, Nucor says. The company also indicated the location will allow it “to take advantage of the abundant scrap supply in the immediate area provided by Nucor’s scrap business, The David J. Joseph Co.

A Nucor executive also disclosed that the steelmaker is seeking a site for a second rebar micromill. “We are encouraged by the tremendous support received by the state and local community in Missouri, and Nucor has decided to pursue an additional micromill project,” said Dave Sumoski, executive vice president of merchant and rebar products at Nucor. He added that the company is considering locating the mill in the southeastern U.S.

According to micromill technology provider Danieli, the concept reintroduces a way to operate a regional steel mill in the face of what had been a growing trend toward larger EAF mills, which had formerly been known as minimills.

Global reach

Mills operating at a suitable scale to serve a region is one part of the micromill story but so is the mills’ ability to include several steelmaking steps under one roof.

At the SteelMint 2017 Steel Scrap & Raw Materials Conference Asia in Bangkok in the fall of 2017, Sridhar Rao, who works from Mumbai for Danieli, described the evolution of the company’s micromill technology, which he said allows steelmakers to produce steel from scrap at facilities with a small footprint.

“Micromills make minimills smaller and more profitable,” Rao said. They use Danieli’s FastArc and FastCast technologies, he said, to continually charge scrap and engage in “endless casting and rolling” to create a process that goes from scrap to finished billets to a rolling mill to (depending on the type of steel produced) spooling lines, all in a relatively small facility.

Rao said customers in Greece, the United States and Egypt have worked with Danieli to build micromills with increasing capacities. He said the Egyptian mill is achieving up to 90 tons per hour of output and he expected new Danieli micromills being built in the Middle East and Vietnam to possibly reach 100 tons per hour.

That represents a considerable productivity advance compared with an early-stage installation in Italy in the late 1990s, when one line was designed to produce 45 tons per hour of steel. By the time the CMC mill in Arizona came online in 2009, Danieli was able to achieve 55 tons per hour of production, Rao said.

Subsequent advances in output have been more rapid, he said, with the micromill in Egypt that was commissioned in 2016 able to reach 80 and then eventually 90 tons per hour of output.

Rao listed several factors in micromill technology’s long-term success and improvement:

  • The equipment was originally designed for further improvements.
  • A culture of teamwork was cultivated between customers and suppliers.
  • Danieli tries to offer the “full support” of its personnel during the stages of plant ramp-up.
  • The continuous involvement of the company’s R&D personnel before, during and after plant startup has led to ongoing improvements.
  • The overall optimization of maintenance plans allows mills to operate in peak conditions.

Rao said Danieli is targeting a 100-tons-per-hour output rate in a future installation, adding that he was convinced the concept can make scrap-fed EAF mills “smaller and more profitable for straight bars, wire rod and spooled coils.”

In addition to its established minimill and micromill concepts, Danieli also now offers what it is calling a “nanomill” concept. The company describes an EAF nanomill as suitable for “locations with an obvious local need for long products but with restrictions in power quality and investment capability, as well as initial market volume needs.”

In parts of the world where induction furnaces have been shut down because of environmental or various other regulatory concerns, Danieli says nanomills could serve as replacement compact steel plants, adding that they are “well-suited to regional and extra-low capex (capital expenditure) investments.”

On its website, Danieli says the concept “calls for a mill that exploits the particular local availability of scrap or iron ore, as well as the market for the finished product, and converts raw materials to finished products in the most efficient way, with extremely short transport requirements. The nanomill concept supports the development of areas around the world where before no one had ever thought about building a steelmaking plant at all; in such areas, a nanomill becomes very feasible.”

The company says the rated capacity of its nanomills is in the 50,000-to-150,000-tons-per-year range.

Whether such new types of EAF mills are set up in North America or farther afield, the notion of scrap-fed steel production techniques retaining and expanding overall steelmaking market share is likely to strike ferrous scrap processors and shippers as welcome news.

The author is editor of Recycling Today and can be contacted at btaylor@gie.net.