The iron and steel scrap stream has always been full of chemistry considerations, and a portfolio of emerging high-strength types of steel is poised to add other processing question marks, according to Dean Kanelos of Charlotte, North Carolina-based Nucor Corp.
Kanelos was part of a panel at the ISRI2019 convention, held in Los Angeles in April, that addressed the topic of “How what you’ll be recycling in five years will be radically different than today.” He pointed to ultra-high strength steel (UHSS) and advanced high-strength steel (AHSS) products as having a growing presence in the automotive sector.
According to Kanelos, the average vehicle right now has about 75 pounds of UHSS steel, but that figure is poised to grow to 320 pounds per vehicle by 2025. Regarding this pace of change, Kanelos stated, “It’s not gradual.”
Kanelos described some of these as “press-hardened steels” that have a low-alloy content but that are “difficult to shred, shear or bale.” These types of steel comprise up to 10 percent of the sheet metal in a typical car now, but that percentage “is going to continue to increase” he commented.
AHSS steels are more commonly used in frames and impact-bearing panels. Kanelos described these steels as light-gauge steels that contain some nickel and manganese, but not enough to be problematic for scrap processors.
Steelmakers in the United States are likely to produce some 800,000 tons of AHSS steel by 2027, said Kanelos, with recyclers eventually encountering this “difficult to cut, shred and bale” steel in hybrid and electric vehicles (EVs).
The EV sector may also begin to yield some carbon fiber scrap, although Alistair Gledhill, who works from Pennsylvania for Germany-based ELG Haniel, says the aerospace sector has been the pioneer in using this material.
Gledhill said ELG’s Carbon Fibre Ltd. recycling facility in the United Kingdom was established in 2011 and is now handling some 150 tons per year of the increasingly popular material. At the plant, carbon fiber components may require some disassembly before they are shredded and put through what Gledhill called a modified pyrolysis process.
That process, according to Gledhill, burns off any attached plastic. The raw fiber remaining is chopped and then either milled into a powder or the chops can be molded into a product, such as a nonwoven mat.
Gledhill said he sees a bright future for carbon fiber recycling, with demand for virgin material currently exceeding supply. The recycled carbon fiber can be produced at half the cost of virgin material, he said, and he added that “there also is a good green story” to tell with carbon fiber recycling, involving lower carbon emissions.
The recycled material still “has to be validated as a specification raw material” Gledhill remarked, and the supply chain expanded, but having companies such as Boeing on board should help address both needs.
At the same session, Mark Wilde of BMO Capital Markets provided an overview of changes to the recovered fiber stream in North America, including the decline of printing and writing papers in the stream and the volatile nature of recent old corrugated containers (OCC) pricing.
ISRI2019, the annual convention of the Washington-based Institute of Scrap Recycling Industries (ISRI), was April 8-11 at the Los Angeles Convention Center in Los Angeles.