Methods for controlling airborne dissemination of lead and lead- contaminated fines during the storage and processing of lead-contaminated materials

摘要

The present invention is directed to improved methods for processing battery wastes, batter casing debris and other lead contaminated materials. The improved processes of the present invention provide less environmentally stressful methods for recovering lead from such materials while at the same time producing scrap or recyclable ebonite and plastics having reduced and environmentally acceptable lead and leachable lead levels. Most of the lead is first removed by trommel scrubbing. In another aspect of the present invention ebonite and other hard surface materials to which are adhered lead contaminants are mixed with water and abraded in a high energy scrubber to remove the adhered contaminants prior to separation of the cleaned ebonite from solution. This simple and environmentally preferred hydromechanical process provides clean scrap or recyclable ebonite. In another aspect of the present invention, plastic and other soft materials contaminated with lead are mixed with a solution having a pH greater than about 7, preferably about 1-5 percent-by-weight alkali hydroxide solution, to dissolve lead contaminants. Separation of particulates produces clean scrap or recyclable plastic while carbonation of the wash water permits recovery of lead carbonate. Finally, the present invention provides methods for controlling dust contamination prior to and during processing by spraying the fine, raw materials with an aqueous solution of a wetting agent, preferably about 2 percent-by- weight alkali carbonate, bicarbonate or sesquicarbonate in water.