The first Global Landfill Mining Conference took place on 9 October 2008 in London, with 105 delegates from 20 countries in attendance. As well as papers on the regulatory and economic prospects for future landfill mining, a number of case studies of both integrated and material-specific landfill mining were presented. What came out most forcefully at the event was that 'there are landfills, and there are landfills.'
Conference convenor Robert McCaffrey started the day by pointing out that not all landfills are the same - that there are landfills and there are landfills. To be exploited as a resource, a landfill must have sufficient concentrations of commodities (metals, plastics, potential fuels, construction materials) and have them in economic quantities. As subsequent speakers pointed out, there are other significant barriers in the way of successful landfill mining.
Peter Jones, seen left, a well-know industry consultant, pointed out that although there were 500 significant active landfill sites in the UK in 2005, by 2007 this had reduced to on 250, and that the trend towards fewer and larger landfills will continue. A total of around 3.2 billion tonnes of materials will have been landfilled between 1975 and 2015, probably including around 160 million tonnes of plastic.
Professor William Hogland (seen right) and colleagues from Sweden then spoke on the financial aspects of landfill mining. He concluded that the economic potential of a landfill mining project is directly related to capital costs such as site preparation, rental or purchase of machinery, operation costs and regulatory compliance. Potential revenues include sales of metals, plastics, construction materials, secondary fuels, CO2 credits, increased land values. The increase in aesthetic value of the site, and the elimination of the potential for future pollution are also of value, but are difficult to quantify.
Stuart Hayward-Higham of UK landfill operator Sita subsequently spoke about his experiences in opening up and moving waste from three UK landfill sites for regulatory and compliance reasons. Although various technical difficulties were encountered - including the intermittent uncovering of bags of asbestos - all were overcome, and the three sites were successfully mined, transported and remediated. Stuart conculed, "Landfill mining is practical, technically possible and potentially commercially viable, but it is far more complext than you may initially think."
Joeri Jacobs from NV Afvalzorg detailed his organisation's capabilities in managing methane production from landfills. By producing conditions conducive to growth of methanogenic organisms (by recirculating landfill liquids), methane production can be accelerated dramatically, so that production can be concentrated in a shorter period. Conversely, methane production can be halted entirely by aerating the landfill using 'air-lances' to pump air into the waste body. Caution must be ensured to avoid auto-ignition in this case. Both accelerated methane production and the ability to cease methane production are potentially important prior to mining.
Makr Johnson of Biffa, another major UK waste company, then gave details of a new approach to sustainable landfilling. In this case, the landfills would be used as bio-reactors, and would be structured from the start to enable them to be mined at the end of their working life. The approach would be applicable now, but might only result in future minable landfills in 20, 30 or more years in the future.
In a major section of the conference, three presenters gave details of landfill mining projects around the world. William Hogland and Dirk Lechtenberg looks at landfills in Asia, and pointed out that in poor countries, waste is already scavenged for valuable materials such as metals and plastics, so that the material that is eventually landfilled is of very low value indeed. However, both speakers gave examples of successful landfill mining projects. Jelle Frölich of MPI from the Netherlands next spoke on his company's plans to start integrated landfill mining in Holland, where there are already 4000 closed landfills. As well as generating electricity from methane, MPI would utilise all material-streams from mining, including metals, plastics, biomass fuels, construction materials, as well as increasing the value of the land. MPI is pioneering an approach whereby it will take over a landfill from the current user for Euro1 - including all liabilities - and aims to make the project pay. The first full project should be underway in 2009.
The final trio of papers looked at material-specific landfill mining projects. Stuart Foster of Recoup spoke about the possibility of recycling plastics from landfill. He concluded that it is possible (after all, it is already being done from some domestic waste streams) but that potential technical problems are significant. Separation of plastics from other landfill materials is difficult, and then cleaning and identifying plastic types (recyclable versus non-recyclable) is another hurdle to overcome. However, the potential tonnages that would become available if these technical barriers could be overcome are very significant. Guy Robinson of Wellington Green Ltd gave details of several different technologies that could be used to recycle plastics, and gave details of companies that are putting these technologies into practice.
The final paper, by Patrick Davison of Mayer Environmental, was a case study of a material-specific landfill mining project for metals. The project involved the excavation and processing of 66,000 tonnes of materials from a landfill in the UK, using a two-stage dense-media separation scheme. The project was deemed a success and the metals yields were high enough to fund a significant part of the project. If the project had been completed at a time of higher metals prices, then the project would have been very profitable.
The final summary of the event might be that landfill mining has already been successfully undertaken in many parts of the world, including the UK, not only for specific materials like plastic or metals, for also for integrated projects where multiple materials streams are profitably utilised. The technical barriers to landfill mining (particularly separation of material types) are well on their way to being overcome, and the final economic feasibility of any project depends on the size of the landfill, its composition, the cost of mining and the price that can be gained for mined constituents.
The following companies registered their interest in attending the first meeting in London:
Adelaide Brighton Cement Ltd, Akmenas Cementas AB, Alma College, American Air Filter Manufacturing Sdn. Bhd., Ashworth, BAA, Barnes Kavelle, Biffa, Bilhaq Trading & Construction System, Blue Circle Southern Cement, Bournemouth International Airport, Box International Consulting, C.A.Blackwell (Contracts) Ltd, Cambridge University, Capita Symonds, Cayman Islands Government, Cementos Progreso, S.A., Cemex Egypt, Cemex, Ci.a Ind. El Volcan S.A., Ciments Calcia, Cimpor Cimentos do Brasil, Cimpor, CIMPOR-Cimentos de Portugal, SGPS, SA, CLASSI ENVIRONMENTAL LLC, Claudius Peters Project GmbH, CRIC, Defra, Dudman Group Limited, Duna-Drava Cement Kft., ECODECO, Econic Ltd, Edmund Nuttall Ltd, Ends Report, Envirnoment Media Group, Environment Agency Wales, ENVIRONMENTAL CRISIS CENTER, ETS, European Parliament, Fairport Engineering Limited, Fars Nov Cement Co, FL Smidth, FLSmidth Automation, Foresight Group, Four Rivers Trading, German Contratc Services Ltd, Getraco Ltd, Girac Limited, GLT-Avfall, Golder Associates (UK) Ltd, Group DML, Groupe Sch/Trdi, H.J. Hansen Genvindingsindustri A/S, H.S.E MANAGEMENT LTD, Hexion Specialty Chemicals, HJ Hansen, Hobart & William Smith Colleges, Holcim US Inc, Imperial College London, INFINIS Ltd., Ingeneria y Mantenimiento SA, Iowa State University, Island Waste Services, JACC Allen Holdings Ltd, JBMI, Kier Construction, Kier Mining, Knauf Gips KG, Lafarge Aggregates Ltd, Lafarge Cementos Mexico, Lafarge CTEC, Lafarge, LAING O'ROURKE, Land & Mineral Management Ltd, Land and Mineral Management Ltd, Latitude 18, Lester Franks Survey and Geographic, LIEBHERR RENTAL LTD, Lifecycle Renewables Ltd, LINDNER Recyclingtech & MVW Lechtenberg , Lucky Cement Limited, MAPEI, Masry Innovation Centre PTE LTD, Medtronic, Metro international, mi2g Ltd, Microcem, Minerals Resource Management Ltd, Ministry of Environment and Water Resources, Mississippi lime Company, Modus Comunicazione, Mongolyn Alt (MAK) Corp, Mpendulo Mining, MPI Multi Purpose Industries, MRLIZ Consultoria, MSV Limited, MT Hojgaard, Multi Purpose Industries (MPI) , MURLI INDUSTRIES LTD, National University of Colombia, NV Afvalzorg NL, Oakdene Hollins Ltd, Orchid Environmental Ltd (part of Fairport), Ormonde Import Export Services, Ovam, Pakistan Agricutural Research Council, Peel Environmental Ltd, Pegase International SA, Pembridge Consulting Ltd, Peninsula Environmental Solutions, Pfister GmbH, Pishro pey Jam, Prolec Ltd, PT Gikoko Kogyo Indonesia, PT. Godang Tua Jaya, Queen Mary, University of London, Ravenblack, Resource Media, Rexnord Industries, Rock inc., S&B Industrial Minerals S.A., SC. ROMAIR CONSULTING LTD, Schreiber Yonley & Associates, Singareni Collieries Company, Singh (UK) Ltd., SITA FRANCE, SITA Power, SITA UK LTD., SLR Consulting Limited, Smiths (Gloucester) Ltd., SORPA bs., Sougueta Engineering AG, SRC Ltd, SRM Ltd, STANDARD INDUSTRIE, Steetley Dolomite Ltd, Stena Metall AB, Storefield Group, Swindon Borough Council, Tarmac, TEPUI, Toxicology Research Laboratories Ltd, Ultratech Cement Limited, University of Kalmar, University of Sheffield, VEOLIA PROPRETE, Viridor Waste Management, Volta Foundation, Votorantim Cimentos, Vulcan Materials Company, W. Clifford Watts Ltd, Waste Recycling Group, WASTECH CONSULTORIA E SERVIOS AMBIENTAIS LTDA, West Sussex County Council, WRG, Zuari Cement Ltd.