Authored By:
Bev Christian, Irina Romanova and Laura Turbini
Research In Motion
Summary
Twenty-nine different cells phones have been disassembled, ground up, dissolved and analyzed for elemental content, mainly for information about the metals present in the phones, but also for some metalloids and non-metals. The following elements were detected in some or all of the phones: Be, Mg, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, As, Nb, Ag, Sn, Sb, Ba, Ta, W, Au and Pb. The following elements were not detected: Se, Cd, In, Te, Pt, Tl or Bi. The paper will discuss the method used and propose possible sources in the telephones for certain elements of interest and the reasons for the interest in some of the elements.
Conclusions
Although laborious and requiring hundred thousand dollar equipment, it is possible to measure elemental composition of electronic devices. It is acknowledged that the work could be done with an AA instead of an ICP, however the cost of the individual elemental lamps and the labor involved in making the lamp changes for each element would be onerous at best. The question still remains how accurate are the results for any analytical technique.
There are possibilities for very complex reactions among all the elements present and the dissolving acids. There is no guarantee that these are all broken down, even in the 8000°C argon plasma flame. Without complete elemental disclosure of every component of every subassembly from all suppliers, there will be no way to know for sure of the level of accuracy of the results. Certainly more work can easily be done on the accuracy and precision of the results.
In this work it has been shown that for the cell phone collection examined; there is a continuing, slow rise in the use of copper, gold and silver, irrespective of the rising cost of the latter two.
The elements that potentially are coming from illegal mines in the DRC are certainly present. Tantalum was found in all but one. Tin was found in all those tested and gold and especially tunsten were found in every cell phone, where tested. How exactly the industry will deal with the dilemma of tracking the source of these elements when their ultimate source may be buried in six to ten layers of a supply chain must be worked out in the coming months. One suggestion has been to "follow the money", not the ore itself.
Although cadmium was not found, lead certainly was, although usually in small amounts that can probably be tied to the RoHS exemptions. Two cases were mentioned where this might not be the case.
Additional testing is most likely going to be necessary to detail the end use of the lanthanide elements.
Initially Published in the IPC Proceedings
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