Mechanical Processing of Post-Consumer Plastics for Feedstock Recycling

This paper gives an impression of the work conducted in the Research Studio Austria (RSA) “Plastic Reborn” by the Chairs of Mineral Processing, Waste Processing Technology and Waste Management, Process Technology and Industrial Environmental Protection of the Montanuniversitaet Leoben and industrial partners. Its main project objective is to make additional shares of waste polymers, especially polyolefins out of industrial and other solid waste fractions accessible for feedstock recycling by a novel wet mechanical process.
The methods of choice are test series conducted on a self-built pilot processing plant for industrial and other solid waste fractions with different polyolefin contents. Additionally, experiment based calculations and laboratory investigations were carried out.
The results show that a combination of a jig and several centrifugal force separators can separate a light fraction with a polyolefin mass content of over 90 % out of different waste fractions, which is thereby suitable for feedstock recycling. The accruing byproducts, namely the heavy and middle fractions, were found to be suitable for energy recovery.
This new type of wet mechanical process is capable of separating products for feedstock recycling and energy recovery out of mixed waste fractions of different industrial and other solid waste origins. This process can therefore be used as a bridge technology to make additional shares of post-consumer plastics available for feedstock recycling. Consequently, this technology can be a first step to achieving the intended EU goals of 55 mass percent material plastic recycling by the year 2025.