Trends and Technologies
For the third time experts at companies from recycling economy and plant engineering, planning offices, universities, administration, associations and other institutions met in Berlin on 4th and 5th May 2010 to hear about news from the fields of politics, law, economy and technology. Approximately 250 participants were offered a varied program dealing with the developments and technologies of waste management to obtain and process secondary raw materials (Fig. 1). The event was again organized by the publishing house TK Verlag Nietwerder and scientifically managed by a high-ranking committee of professors, which, in addition to Prof. Dr.-Ing. habil. Dr. h.c. K. J. Thomé-Kozmiensky as the main protagonist, consisted of renowned technologists (Prof. em. Dr.-Ing. habil. E. Gock, Prof. Dr.-Ing. D. Goldmann, Prof. Dr.-Ing. R. Scholz, Prof. Dr. rer. nat. A. Wolter, Prof. Dr.-Ing. G. Ziegmann – all from Clausthal Technical University) and the specialist solicitor in the field of waste and environmental legislation, Prof. Dr. jur. Andrea Versteyl, from Redeker Sellner Dahs & Widmaier Rechtsanwälte, Berlin.
Not only higher world market prices for primary raw materials but also the increased environmental awareness in Germany and the EU are the driving forces for the further development of recycling management. This is expressed, amongst other things, by the European Waste Framework Directive (WFD) that rates material recycling more highly than the previous legal regulations and which is beeing currently translated into national law. As expected, the consequences resulting from the WFD for recycling economy were a major topic at the conference.
In his inaugural address, Prof. Dr. Thomé-Kozmiensky looked back on 40 years of waste handling in Germany and came to a positive conclusion. The technical development has run parallel to the legal one. Soon the realization emerged that mechanical processing alone would not be sufficient to generate high-quality recycling products. Chemical and other physical processes, such as optical, acoustic or electric processes, must also be applied. However, Prof. Thomé-Kozmiensky also outlined the limits of recycling: “Waste management without landfills will not be possible because ecological waste management must have pollution sinks, and these are, on the one hand, the combustion, and, on the other hand the underground waste dumps.” He concluded that waste management is an area of conflict between the raw material industry and the power industry. There will also be competition between recycling and combustion in the future. Mechanical engineering will also be considerably further developed, above all in the exporting countries Germany and Austria. The quality of the recycled materials will be improved and environmental and safety awareness will be increased.
1 Politics – Law – Economy
The first day of the conference focussed on present political, legal and economic aspects of waste management in general, and of the recycling economy in particular. Thus, the resource and recycling strategies of the EU were on the agenda (Dr. K. Kögler, EU Commission, Brussels) as well as the implementation of the guidelines of the WDF for the resource economy in Germany (Assistant Secretary Dr. F. Petersen, Ministry of the Environment, Nature Conservation and Nuclear Safety, Bonn). Today no national economy can afford to dispense with the valuable materials contained in waste, i.e. secondary raw materials from mineral raw materials up to metals and rare earths or the energy sources. Recycling strategies are further developed in the waste management enterprises and adapted to the raw material markets as was explained, for example, by Dr. L. Kramm, board member of BSR Berlin, (“Recycling strategy of a municipal company”) or by Dr. E. Schweitzer, board member of ALBA AG, Berlin (“Waste incineration instead of recycling – are we on the brink of a backwards trend in environmental policy?”). It should be considered that 2.9 billion t of waste are produced in the EU states every year, but only half of this is utilized.
There is still a need for discussion as regards the dividing line between waste and product – how to achieve legal security? Prof. Dr. Andrea Versteyl dealt with this topic in her lecture and Dr. R. Cosson, managing director of BDSV (Federal German Association of Steel Recycling and Waste Management Enterprises), Düsseldorf, pinpointed the problems, which are involved alone in the determination regarding when scrap-iron and steel scrap should no longer be considered as waste. P. Buchholz from the Hanover-based Federal Institute for Geosciences and Raw Materials dealt with the raw material markets and the availability of primary and secondary raw materials. There is a huge field of unknown resources, the existence of which has been proved geologically but which so far cannot be extracted for technical and/or economic reasons. They are confronted with the reserves, i.e. the quantities that can be extracted with today’s technology at today’s prices. There is a dynamic limit between them both that has often not been taken into account as regards figures. In addition to imports of predominantly metal-containing raw materials, domestic raw material extraction in Germany both from primary sources (energy and building raw materials as well as some industrial minerals) and recycling is an important basis for the domestic raw material supply (Fig. 2).
Increasing the material efficiency and substitutions are potentials that can and must be further extended by specific research activities. In his lecture “Europe on the way to the resource economy” Dipl.-Chem. H. Alwast, Prognos AG Berlin, underlined the importance of the independence of imports for the European national economies in connection with the drastic increase of the access to the worldwide raw material resources by the emerging countries, such as China, India and Brazil, and he pleaded for the implementation of a European raw material strategy. His vision for 2035: To replace the WFD by an international raw material management law. Using many examples, Prof. Dr.-Ing. D. Goldmann (“Perspectives of recycling”) showed that, from the resource point of view, those constituents are of particular interest, where the deposits are limited and the extraction is very expensive (rare-earth elements, precious metals and metals such as Cu or Al where the production requires a lot of energy). The task of processing is to develop new technologies and to facilitate the recycling of new products, which are launched at shorter and shorter intervals. Already today, some secondary raw materials can be compared with low-grade primary raw materials so that it is even possible to talk about “synthetic ores”, e.g. in the case of slags from refuse incineration plants that often contain up to 0.7% of Cu. According to Goldmann, future secondary raw material resources are photovoltaic plants (3000 t returned in Germany in 2010), aircraft (in 2025 up to 7200 aircraft are expected) or also wind power stations (one wind turbine of an offshore plant contains up to approx. 30 t of CU and 2 t of Nd).
The second day of the conference consisted of three parallel events:
• Advanced process technologies in the field of waste and metallurgy
• Recycling of plastics/mineral raw materials and secondary building materials
• Recycling of vehicles – monitoring, material flows and use of recyclates/recycling of electrical and electronic appliances as well as of batteries and photovoltaic modules
Only a few of the many interesting and informative lectures will be presented or mentioned here.
2 Advanced process technologies
In his comprehensive general lecture “From raw material to waste processing” Prof. Dr. V. Vogt, senior assistant professor at Clausthal Technical University, showed how the topics of the International Mineral Processing Congress (IMPC), in its function as a mouthpiece regarding the scientific-technical development of the raw material specific process engineering have changed from (primary) raw material processing up to the integration of waste processing (1988 Stock-holm – special section for the processing of mineral waste, 1991 Dresden – extension to domestic, commercial and industrial waste, 2008 Beijing – incorporation of the entire secondary raw material sector including biotechnology and soil management). Using various examples (domestic and commercial waste, used paper, electrical and electronic scrap) the author demonstrated which process engineering basic operations of raw material processing had to be changed, especially to
take into account the specific properties of waste. Special equipment developments for decomposition comminution, sensor-aided sorting, flow sorting as well as the eddycurrent separation and electrostatic sorting are considered
to be important fields of development. A future focus will be on the field of very fine particles (very fine comminution and flotation, e.g. extraction of precious metals from filter dust).
Dr. S. Schäfer, MeWa Recycling Maschinen und Anlagen GmbH, Freiberg (“New possibilities for decomposition comminution by means of the universal cross-flow cutter”), presented a multi-purpose machine, with which the material to be comminuted is disintegrated and comminuted by means of a flexible operating tool, e.g. chains, as a result of acceleration and motion. Low wear costs, simple and quick tool change, adaptation to different feed materials due to a rapid variation of the machine and process parameters are only a few of the advantages of the machine.
Prof. Dr. H. Flachberger, Leoben Mining University/Austria (Fig. 3), gave a lecture on the “Possibilities of use and limits of electrostatic separation when processing primary and secondary raw materials” and showed that today this processing principle has already been established in many sectors of the secondary raw material industry, e.g. metal and plastics separation. The present limits of the process are determined by the particle size that can be processed, the possible throughput, the selectivity attainable and the very strong influence of the ambient conditions. Low capital expense as well as low operating and maintenance costs warrant the assumption that the importance of the dry process will further increase.
Dipl.-Ing. M. Riggmann, managing director of TrennSo-Technik GmbH, Weißenhorn, gave a lecture on the development of pneumatic concentrators (“Use of pneumatic concentrators for waste sorting”). At first this separating technique was predominantly used for cable processing and to clean used tyre granules. Today it has proved a success in processing domestic and commercial waste, glass, wood, slag and even scrap. Using examples it was shown that sorting with pneumatic concentrators can be a reasonable step in the entire process chain of secondary raw material processing.
Dipl.-Ing. Th. Erdmann, TiTec GmbH, Mühlheim Kärlich, gave a comprehensive overview of automatic, sensor-aided sort-ing. After explaining the various functional principles, the latest technologies and trends were demonstrated by the example of different waste flows. For the future, both further development of existing technologies (e.g. improvement of the NIR resolution for plastics/flake sorting, extension of the spectral resolution and of the spectral range for used paper sorting, improvement of the sensors for the identification of black plastics, development of multi-energy detectors in X-ray transmission sorting machines in order to be able to identify small differences in thickness) and new developments of technologies (element spectroscopy by means of the X-ray fluorescence analysis or laser induced breakdown spectroscopy) are planned.
3 Metallurgy
The relatively long tradition and the great importance of recycling in metallurgy were the reason that there was an individual series of lectures dedicated to this thematic. In his lecture “Future-proof utilization of raw materials in the production of cast iron and steel” Dr. H.-B. Pillkahn, DRT Deutsche Rohstofftechnik GmbH, Mühlheim/Ruhr, described the boundary conditions and requirements that will force the metal-producing and metal-processing industry in Germany to handle the available raw material sources more carefully and intelligently then previously. One example for this is the new process for acidic dezincification of steel scrap promoted by DRT and developed at Clausthal Technical University. Prof. E. Gock presented his hydrometallurgical process. He showed in a very impressive way that preliminary dezincification of steel plates by means of cold bypass dezincification technology is extremely useful both as regards economy and ecology. Compared to the conventional recycling process by means of pyrometallurgical dezincification, the energy balance shows an energy saving by a factor of 50 with a simultaneous reduction of the CO2 emission by a factor of 40. Further topics in this series of lectures dealt with the use of high-temperature processes as well as the demands on the recycling of aluminium and rare-earth metals (Fig. 4).
4 Recycling of plastics, mineral raw materials
and secondary building materials
The contributions in this series of lectures particularly dealt with examples of application such as the use of recycled building materials in road construction, the utilization of power plant ashes for building purposes or the demands of the cement industry on suitable alternative raw materials and fuels.
5 Recycling of electrical and electronic appliances as well as of batteries and photovoltaic modules
As regards the third parallel event, the recycling of batteries and photovoltaic modules seems to be particularly worth mentioning because, apart from the recycling of lead-acid batteries that has been carried out for decades, the efforts towards sustainability are relatively new in these branches. Dipl.-GeoÖk Ch. Reckziegel, First Solar GmbH, Mainz, gave a comprehensive overview of recycling in the photovoltaic industry and its perspectives. Dr.-Ing. R. Weyhe, ACCUREC Recycling GmbH, Mühlheim/Ruhr, discussed the recycling of modern battery systems (Ni-Cd, Ni-metal hydride and Li-ion batteries). Processes have already been developed for these secondary raw materials and good results have been achieved as regards their industrial utilization.
6 Final comments
The conference showed that today recycling management already plays an important role as regards the development of raw material resources. Today, the waste removal industry already has to be considered as a raw material producing industry. In the future, recycling management will characterize an even more sustainable economy. However, there is no question that primary raw materials are still required. However, in addition to their exploration, new and, especially innovative processing methods have to be developed to make use of their valuable constituents. The same applies to secondary raw materials. As regards secondary raw materials, the progress in machine and device engineering opens up a wide field of potential cases of application that, on the one hand, will be adjusted to mass-produced goods, and, on the other hand, to rare-earth metals and precious metals.
The already traditional Berlin Recycling and Raw Materials Conference once again proved to be a platform for all those interested in these topics. At the same time there were sufficient opportunities for discussion, to establish new contacts or to strengthen existing ones.
Most of the lectures of the conference program are included in “Recycling und Rohstoffe”, vol. 3, TK Verlag Karl Thomé-Kozmiensky, Neuruppin 2009, ISBN 978-3-935317-50-4.
HF
