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ePaper created 2013-10-29, 15:50:53 | version 1.25.20
68 Forschungszentrum Jülich | Annual Report 201268 Analysis method for electronic waste On average, 1,000 kilograms of ore from a goldmine contains no more than 5 grams of gold, while 1,000 kilograms of mobile phones in contrast contains up to 350 grams. Electronic waste also con- tains other elements, such as silver, pal- ladium, iridium, and copper. In principle, it should pay off to mine for noble metal there. However, in practice, recycling is a complex task. The old devices must be collected as effectively as possible, sort- ed and then taken apart. They also con- tain several harmful substances that must completely removed. “For the recycling industry, it’s important to know what valuable materials are contained in a batch of waste as well as in what quantities,” says Dr. Andrea Mahr from Technology Transfer (T) at Forschungszentrum Jülich. She sounded out the market for a method originally developed by scientists at Jülich and Aachen which analyses the contents of drums with low-level radioactive waste without having to open them. These drums will be taken to Schacht Konrad near the town of Salzgitter for final disposal from 2019. A team headed by Dr. Eric Mauer- hofer at Jülich’s Institute of Energy and Climate Research started to investigate the so-called prompt-gamma neutron activation analysis as a cost-effective and nondestructive method of analysing the contents of these drums in 2007. This method involves a neutron beam that briefly activates the atomic nuclei in the material to be analysed. The activat- ed nuclei react promptly – within a maximum of a trillionth of a second – by emitting gamma radiation. The scientists developed an analysis technique that delivers numerical values for the composition of elements from the gamma spectrum obtained. They filed a patent application and named the entire method MEDINA, short for ‘Multi-Element Detection based on Instrumental Neutron Activation’. The researchers are now planning to use the method to analyse electronic waste. They are convinced that it is much more efficient than conventional meth- ods: “The latter require a lot of staff and time, not to mention the chemicals and energy that are needed for wet-chemical sample preparation,” says Mauerhofer. Above all, however, MEDINA solves the problem posed by the complex sampling process. The necessary radiation protec- tion measures are comparable to those in doctors’ surgeries and medical labora- tories when taking X-rays or handling ra- dioactive substances. In order to adapt MEDINA to the re- quirements of the recycling sector, the scientists need industry support. “The interest is there, and we’re already in concrete negotiations with one company on joint further development,” says technology transfer expert Mahr.