Reduction of Radiator Sludge to Commercial Lead Bullion

Abstract

The shop survey, conducted as part of this project, indicated a number of industry trends and concerns. Through our work in this project, there is an apparent growth in concern and industry efforts to try to comply with the U.S. Environmental Protection Agency (EPA) standards. Numerous shops continue to inquire about the project's progress and any new developments in a recycling program with Gopher Smelting and Refining Company. Many shops are now properly storing their sludge in hope of a workable disJX>sal/recycling program. When reviewing the results of the chemical analysis of radiator boil-out/ultrasonic sludge, the range of lead in the radiator sludge runs from near 0 to about 20 % on a dry basis. In discussions with shop owners, most commented that they would add their solder droppings to their sludge to raise lead levels, increasing Gopher Smelting and Refining Company's interest in developing a recycling program. Although there is an apparent increasing trend in not using a boil-out or ultrasonic cleaner, owners stated their main reason for shutting off the cleaning devices was concern about sludge disJX>sal. With some type of recycling program, it can be concluded that these shops will be using their machines again. · There is a very strong interest in participating in some type of sludge disposal/recycling program. Two issues need to be addressed before any recycling program can work: 1) the program must be user friendly--it must not be difficult to work with; and 2) it must be cost effective for a shop owner to participate. Over the past year, interest in waste reduction/recycling and compliance with the law has increased. If some type of program can be developed and continued, the state will see a definite surge in shop participation, which of course will result in less waste being dumped illegally. In addition to the mail and interview survey, there were a number of bench-scale studies on various parts of the radiator preparation process and a full-scale factory experiment to smelt and convert a 1,000 lb. lot of radiator boil-out tank sludge to bullion lead. Most of the benchscale experimentation did not seem adequately effective for adoption by the industry. However, the mist water wash down may be adapted to help minimize drag-out of caustic boil-out solution. There should be an additional benefit to maintain the caustic boil-out tank solution and minimize dilution of boil-out bath. The full-scale factory experiment to smelt down a 1,000 lb. lot of radiator boil-out sludge went well. The shipment was made by a hazardous material truck and received at the smelter. The material was processed through Gopher Smelting and Refining Company without disrupting operations, and the product lead did not vary from the nonnal analysis range. Based on favorable results of the surveys, sample analyses, and full-scale factory test, the smelter is proceeding with an internal, proprietary detennination of a fee schedule to process the boil-out sludge at various levels of lead content.