Eco-design for recycled products: Rejuvenating mullite from coal fly ash

Secondary pollution exists extensively in the utilization of industrial solid waste. To reduce environmental risks of building material products recycled from industrial solid waste, a framework of eco-design strategy is established based on the existing eco-design method and life cycle thinking. It focuses on controlling of chemical components by integrating tracking and controlling of toxic components introduced by industrial solid waste. The framework consists of four steps: analysis of raw material applicability, analysis of process control conditions, and safety analysis during product use and final disposal. Raw material requirements are designed including effective components, quality disturbance components, and environmental risk components. Operating condition requirements are given to control flows of selected components in key procedures. Environmental safety of products during use and final disposal under these requirements are tested by simulation experiments. Then a series of eco-design requirements are proposed. The framework is applied in a case study of mullite recycled from coal fly ash and the result shows that the established framework could be feasible for products recycled from industrial solid waste. Nevertheless, the method needs expansion with industrial solid waste properties and product requirements, and steps need optimization if applied in other wastes.