Method of Recycling Hazardous Waste (Inventions and Innovation)
The production of primary metal from ores has long been a necessary, but environmentally devastating process. Over the past 20 years, in an effort to lessen environmental impacts, the metal processing industry has developed methods for recovering metal values from certain hazardous wastes. However, these processes leave residual molten slag that requires disposal in hazardous waste landfills.
A new process recovers valuable metals, metal alloys, and metal oxides from hazardous wastes, such as electric arc furnace (EAF) dust from steel mills, mill scale, spent aluminum pot liners, and wastewater treatment sludge from electroplating. At the same time, the process does not create residual waste for disposal. This new method uses all wastes from metal production processes. These hazardous materials are converted to three valuable products – mineral wool, zinc oxide, and high-grade pig iron.