Scrap tire wire is gaining momentum as a recycled commodity, but steel makers remain wary as they try to resolve quality concerns.
Scrap tire processors remove steel belts and beads from tires to recover the rubber. Until recently, their only option was to dispose of the steel in landfills.
``This is an evolved process, but I can tell you it's a process that's critically important to scrap tire processors,'' said Mark Rannie, vice president of Emanuel Tire Co. in Baltimore.
Steel mills' main challenge of using tire wire in electric-arc furnaces is the rubber left on the wire, which impacts the steel's chemistry, causing increased levels of sulfur and phosphorous, said Jim McNicholas, strategic sourcing manager for Bethlehem Lukens Plate Products in Coatesville, Pa., a division of Bethlehem Steel Corp.
Steel makers prefer less than 2 percent rubber left on the wire. Density also is an issue, said Vicki Roche, raw materials director for Gerdau AmeriSteel Corp. in Tampa, Fla. The low density of scrap tire wire makes it difficult to handle and less attractive than other grades of scrap steel.
To solve the density issue, steel mills have experimented with using baled wire and even using whole tires on the rim. By using whole tires, the rubber can replace some of the charge coal used in some processes, Mr. McNicholas said. But using whole tires presents another set of problems, including methods of feeding the tires into the furnace.
Baling the wire also can solve the problem of the total yield of the product. Loose tire wire rusts and disintegrates quickly compared with other scrap steel. A mill buying a ton of wire may find it has much less than that after the material sits for as little as a few weeks.
``If we can overcome these issues, and I think we're close to doing that, there could be some real potential,'' Ms. Roche said.