Header image for Richard (Zhizhen) Liu's Week 1 Mountaintop Experience Blog Post

Richard Liu Mountaintop Experience 2023 Week 1: A First Week’s Look at Metal Recycling

     Throughout the whole first week we’ve already started to get some general information and ideas about metal recycling and sustainability. Our primary focus is on E-waste recycling like PCB, battery and wires. At the beginning of this week, we are still not sure what our specific goals are about our whole project, what is our main focus, Is our main focus only on PCB? After meeting with our instructors, we’ve confirmed our main focus which is about the whole computer components recycling. Therefore at the end of this week, my teammate started our project from recycling PCB first. I started to look for some information about the recovery of  lithium ion batteries(LiB)  as well as some PCB recycling processes. 

Internal main PCB of Chromebook.
Electric components inside the Chromebook

     I made a few clarifications about what we should consider most during the metal recycling processes. We should consider more about high efficiency, high economic return, high safety as well as high environmental benefit(environmental friendly). That’s what metal recycling is mostly about. Most of my time this week I focus on the recycling of the lithium ion batteries by incineration(Pyrometallurgical).  The higher leaching efficiency  of magnesium, cobalt and Nickel were reached at lower temperatures of incineration around(400-500 celcius). But the drawback of the pyrometallurgical method is that it produces too many noxious emissions, it’s also dangerous to operate. By the way, this method generates too much cost. From a business perspective, the revenue we earned from LiB recycling might not cover up the cost which is being used to recycle it.  The other parts of my work I’ve been working on with my teammate are general leaching methods which are Hydrometallurgy, Biometallurgy.  My focus mainly is about microbial-mediated leaching which is part of the Biometallurgical method. I found out that the 3 major principles behind microbial mediated leaching are oxidation-reduction reaction, production  of organic and inorganic acids and excretion of microbial metabolites chelators and complexing agents. But one of the biggest drawbacks of microbial-mediated leaching is that it’s very time-consuming, and it requires very specific and sophisticated conditions for bioreactors(like the pH value, temperature).

Notes on a whiteboard from the Loewy Institute team for Mountaintop Experience 2023.
Whiteboard highlighting some of the information we gathered.