**4. Metal recovery from waste/contaminated plastics through MAP**

Metal containing plastic has been treated with MAP to recover the metal and recycle all the other components like a solid, a liquid and a gas.

a.Several metals are present in waste or contaminated plastics, for instance, lead is present in the envelope of lead-acid battery realized using HDPE as the material of the container. At the end of life of the lead-acid battery the Pb of the electrodes and H2SO4 are recovered and recycled while the envelope must be disposed of as a contaminated HDPE because it contains Pb. This contaminated plastic may be pyrolyzed using a MAP process using carbon as an MW absorber. In the course of the process gas is formed (containing hydrogen and

low molecular weight hydrocarbons) together with a liquid (containing a small amount of water, and aliphatic hydrocarbons close to those reported in paragraph 3.1.1 on the MAP of HDPE). The char contains the MW absorber, the low amount of carbon formed from HDPE, and the lead present as a contaminant [51] and this char may be recycled as an MW absorber. For each recycle of the char, the concentration of lead is slightly increased every time. When an appropriate concentration of lead was reached the MW absorber was sent to a process for the extraction of the lead present, for instance through acid or metallurgical treatment, then the MW absorber may be recycled or in the case of carbon, used as a solid fuel together with the carbon formed from HDPE. In **Figure 2** is reported a schematic representation of the process.


*A schematic representation on the MAP of lead containing HDPE to recover lead. MWA: Microwave absorber.*

magnet and sent to a metallurgical process to enter in a new cycle of utilization. The char formed during the pyrolysis of tyre (recycled carbon, rCB) may be used to prepare new tyres or may be employed to prepare anode for Oxygen Reduction Reaction (ORR) [40] as previously suggested in paragraph 3.3.1.
