Thermal decomposition of three types of copper clad laminates considering the influence of an iron-clay catalyst in the production of pollutants

Abstract

Metal recovering through decomposition in the presence of steam of different wastes has been demonstrated to be an effective method. In the present work, three different types of copper clad laminates (FR4, CEM3 and ROGERS) were subjected to high temperature decomposition, analyzing their performance. Firstly, the samples were analyzed by thermogravimetry, both in the absence and in the presence of oxygen in the atmosphere; FR4 and CEM3 showed a very strong interaction with oxygen, in contrast to ROGERS. Secondly, the laminates underwent oxidative pyrolysis in the presence of steam at 900°C in a horizontal laboratory furnace; the experiments °were carried out in the presence and in the absence of an iron-clay catalyst, in order to evaluate its effect on the production of pollutants. Analyses of the produced gas and semivolatile species are shown, including polycyclic aromatic hydrocarbons (PAHs), bromophenols (BrPhs) and brominated dioxins and furans (PBDD/Fs). The gaseous emissions are almost limited to methane, hexane, toluene and xylene, and the production of PAHs and other semivolatile compounds is considerably reduced with the use of the iron-clay catalyst. The emissions of BrPhs and PBDD/Fs are also very limited. Comparing among the behavior of the three types of laminates, the emission of brominated compounds is much lower in the gasification of ROGERS, compared to FR4 and CEM3.