11:00 Mark Conedera, P.E., U.S. Steel Company
Applications of AMD Sludge for the Steel Industry
Mark A. Conedera, P.E.
Because acid mine drainage (AMD) sludge contains iron in an oxide rather than metallic form, its potential use in integrated steelmaking is limited to iron production in blast furnaces. In order to charge AMD sludge into a blast furnace, it must first be agglomerated. Accepted agglomeration methods include pellitizing, sintering, and briquetting. The United States Steel Corporation (U. S. Steel) Edgar Thomson Plant located in Braddock, Pennsylvania has the last two operating blast furnaces in the state of Pennsylvania and utilizes a briquetting plant to agglomerate fine materials containing iron oxides for subsequent charging into the blast furnaces. A sample of AMD sludge provided to U. S. Steel by the Pennsylvania Department of Environmental Protection was evaluated as a potential feed material to the Edgar Thomson Plant blast furnaces. The iron content of the sample proved insufficient to justify its use. In addition, other metallic components of the sludge were at concentrations detrimental to the steelmaking process. Based on a technical analysis conducted by U. S. Steel Research personnel, use of AMD sludge in blast furnaces cannot be justified unless the total iron content is greater than about 55% and the sulfur content does not exceed 0.1%. More sulfur can be tolerated provided that the total iron content exceeds 55%. The economic value of suitable AMD solids will depend on the actual cost of agglomeration. For the Edgar Thomson Plant briquetting facility, AMD sludge impacts on drying costs, binder costs, and briquette plant productivity must be evaluated. The physical and metallurgical properties of the briquetted product must also be considered. Continued evaluation of AMD sludge for steelmaking will require both laboratory and full-scale plant testing.
Mark Conedera is a Senior Environmental Engineer in the corporate Environmental Affairs Department of United States Steel Corporation (USS), Pittsburgh, Pennsylvania. In his position, he is responsible for managing the corporate Hazardous Materials Storage and Toxics Release Inventory (TRI) reporting programs. These programs were mandated under the federal Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA) and expanded by the Pollution Prevention Act of 1990. In addition, Mark is the liaison between the Environmental Affairs Department and Research Division of USS for projects involving the use of steelmaking byproducts. Prior to his current position, Mark held positions in the Environmental Control Departments of the USS Edgar Thomson Plant and Gary Works and has been with USS for over fourteen years. He holds a B.S. degree in Environmental Engineering from Pennsylvania State University and M.S. degree in Civil Engineering from Carnegie Mellon University, and is a registered Professional Engineer in Pennsylvania.