Acknowledgements

I would like to acknowledge the major contribution to the work published in this book made by the co-authors of the papers listed in Appendix 1. All of their research was significant; however, particular mention must go to Esmaiel Ganjian, Juan Lizarazo Marriaga and the late Joe Cabrera.

I would also acknowledge the financial support for the work from UK Nirex, the Engineering and Physical Sciences Research Council, ENTRUST (landfill tax), the Waste Resources Action Programme, the Minerals Industry Research Organisation and the European Union.