Multicriteria optimization of copper scrap management strategy

• A model of copper scrap management at country level is proposed.
• The method is applied to the treatment of printed wiring boards.
• Several flowsheets are constructed for the production of refined copper.
• Three bi-objective optimizations are conducted based on a genetic algorithm.
• A decision support tool is used to find the best compromise solution.

A model of copper scrap management at country level is proposed, taking all copper scrap collection streams into account, with their associated environmental impacts and costs. The method is applied to the treatment of printed wiring boards (PWB) in France. Considering the initial physical properties and composition of this scrap, seven flowsheets are constructed for the production of refined copper. Then, depending on the number of PWB treated in each processing chain, the production rate, energy consumption, operating cost and environmental impacts are evaluated. Three bi-objective optimizations are conducted based on the NSGA II multi-objective genetic algorithm: production versus energy consumption, production versus operating cost and production versus environmental impacts. Pareto fronts are obtained for each optimization, giving the set of non-dominated solutions. Then the decision support tool TOPSIS is used to find the best compromise solution for waste management.