Coprocessing of Industrial and Hazardous Wastes in Cement Kilns: A Review of Current Status and Future Needs in China

Abstract

Abstract

Coprocessing of wastes in cement kilns has just started in China. With approximately 50% of the world's production, the potential for saving nonrenewable fossil fuel and virgin raw materials by implementing this practice is enormous. No regulatory framework, legal requirements, or standards are, however, in place. Draft technical guidelines and background documents have recently been developed, but these need to be adapted to specific Chinese conditions and regulatory requirements. Twelve cement plants, with 18 production lines, have recently been evaluated based on their capabilities to implement coprocessing on a large-scale basis. Results reflect the variability found in the Chinese cement sector, from small inefficient and polluting plants to modern dry precalciner kilns with state-of-the-art performance. One common feature, however, is the general lack of coprocessing knowledge, capabilities, and infrastructure in the Chinese cement industry. China needs to establish and implement standards and requirements for coprocessing in general and for hazardous wastes in particular. Such standards need to specify waste types, transportation, acceptance and control procedures, storage requirements, pretreatment and feeding of wastes, emission limit values, and monitoring requirements for products.