14/04/2023

The Nova technology: Retrieving Value from Old Electronic Devices Through the Recycling of Precious Metals

The GeMMe Research Group at University of Liege (ULiège) (BE), led Task 3.1, which aimed to optimise the NOVA technology. This particular task focused on designing and enhancing the process to make better use of mid and low-grade Printed Circuit Board Assemblies (PCBAs) that are typically sent outside of Europe due to low interest from smelters. Specifically, the researchers from ULiège conducted experiments on two types of PCBAs: one retrieved from end-of-life (EoL) Cathode-ray tube Television (CRT TVs) and the other from Liquid-crystal-display Television (LCD TVs). As part of the small-scale optimisation phase, the research team processed over 100 kg of PCBAs using the NOVA technology.  

Using a combination of electrochemistry and mechanical activation, NOVA technology enables the detachment of electronic components soldered on the PCBA. Experimental work showed precious metals (PMs) can be concentrated mostly in the electronic components while few remain in the tin (Sn) concentrate and the copper-rich (Cu) depopulated PCBAs obtained from the NOVA process. These fractions can be further processed to valorise gold (Au) – from electronic components – and silver (Ag), Cu and Sn – from the Sn concentrate and depopulated PCBAs.  

After evaluating various pre-processing methods and reactor designs, researchers have concluded that the “rotary screen reactor” is the most effective design to support the NOVA process’s further scaling, due to its increased recovery rates. 

Results reported at the end of the small-scale optimisation phase demonstrate promising routes capable of unlocking the domestic extraction of all remaining PMs along with important societal metals such as Sn and Cu available in the “lower grade” PCBAs.  

Economic factors were analysed, considering the purchase costs of PCBAs, product revenues, and processing costs. The evaluation was conducted for a standard production of 3t/day. The findings indicate that the NOVA process is a profitable option for both types of PCBAs, with projecting earnings reaching 805 to 965 €/t for LCD TVs, while reaching 115 €/t for CRT TVs. 

Related article: Upscaling the NOVA technology with a large capacity prototype