Improved Sorting Technology For Use On Stainless Steel And Superalloy Scrap - Objective

Increase the recycling of critical and strategic materials by simplifying the indentification and segregation of scrap. Background Because the United States is dl-most totally dependent on imports of such critical metals as chromium, cobalt and nickel, Bureau of Mines research has been directed towards conserving these metals by increasing the recycling of the complex scrap materials that contain them. Experienced scrap sorters, using the traditional techniques of object recognition, spark tests, chemical spot tests, color, apparent density, and magnetic properties, can adequately sort a wide variety of alloy groups. However, the complex nature of new materials entering the scrap market has made sorting both more difficult and more important. Some new alloys contain so many components that separation by discrete alloys becomes a prerequisite for effective recycling. The Bureau has completed Investigations on two methods for rapidly sorting complex scrap mixtures. One method uses a combination of two low-cost instruments. The other uses a single sorting instrument. Both approaches are reported.