Closing the Loop: Designing an Advanced Hydrometallurgical Lithium-Ion Battery Recycling Facility; Navigating the Role Companies and Politicians Play in Cobalt Source Tracking within the Democratic Republic of Congo

Cobalt is an increasingly important raw material for the global market. Everything from smartphones to laptops depends on cobalt for their batteries. Growing populations and continuous technological industrialization mean that the need for cobalt will not slow down unless significant advancements in battery technology are made. This dependence stresses the need for not only a circular economy but also stricter standards for cobalt mining. This thesis portfolio offers insights into a solution for both of these issues.

The technical portion of this thesis addresses the need for recycling lithium-ion batteries. The primary feed source for this plant is black mass, which comprises of ground-up lithium-ion batteries removed from the plastic casing. The proposed plant aims to process 100,000 tons of black mass per year using hydrometallurgy and pH-controlled precipitation.

The plant will produce valuable metals used in battery production, including MnCO3, Co(OH)2, Ni(OH)2, and Li2CO3. This particular plant design does not produce Li2CO3 due to an excess of Na+, which results in Na2SO4 forming with the desired product. With this approach, the plant is projected to produce 27,773,016 kg/yr of MnCO3, 19,213,615 kg/yr of Co(OH)2, and 31,336,111 kg/yr of Ni(OH)2. This results in a potential revenue of $756,277,173. The capital investment for this proposed plant is $284,587,576, which, when compiled with a Lang factor of 3.63 for solid and liquid handling plants, comes out to a total capital cost of $1,033,052,901. This, coupled with an annual raw material cost of $903,226,465, results in a yearly operating profit of -$918,679,604. Due to this yearly economic loss, we do not recommend going through with this design in its current state. However, there are some clear improvements that could be made to make this project viable. By increasing the concentration of acid or utilizing a different base, the overall scale of the process could be reduced significantly while still processing 100,000 tons yearly. This would, in turn, reduce both the capital cost and the annual operating costs.

Furthermore, this project provides an opportunity to close the loop and contribute to a circular economy. One where electrical waste is repurposed and given new life. Through careful planning, creative engineering, and substantial financial buy-in, this plant serves as a way to use a valuable resource currently left to rot.

The socio-technical portion of this thesis portfolio explores the relationship between cobalt and the Democratic Republic of Congo (DRC) with a particular focus on source tracking, which is the process of tracking where cobalt or other raw materials originate from and where they go. These relationships are influenced by complexities within the DRC surrounding ethical, economic, and political factors. This study uses the Social Construction of Technology (SCOT) framework to analyze these relationships.

Throughout this thesis, it was found that the problem was not so cut and dry. Plenty of relevant social groups, including the state-run Entreprise Generale du Cobalt, and private companies like Sud South were actively trying to improve source tracking and, in turn, improve the living and working conditions of Congolese within the mining sector. Even though these relevant social groups are trying to solve the problem, there are also groups taking advantage of source tracking’s youth. These relevant social groups included individual people like ex-president Joseph Kabila, and larger organizations like Gecamines and the China Railway Group. These groups have consistently stolen large amounts of money from the Congolese people, which is slowing down the development of these mining communities, thus keeping them in poverty.

Overall, it was found that this ethical issue will require continuous and collaborative efforts from many groups. The principal issue, being government corruption, would need to be rooted out before substantial change can be made. After the overarching system is cured, revenue from the cobalt industry can be reinvested into the mining communities and improve the lives of millions of Congolese.

In conclusion, my technical project of a lithium-ion battery recycling plant provides a unique opportunity to take a currently useless waste product and repurpose it into the next generation of batteries. Additionally, my socio-technical report provides insight into the current landscape of cobalt mining within the DRC and how it can be shifted in a positive direction. A combination of these efforts could result in the improvement of how cobalt is viewed around the world.

School of Engineering and Applied Science

Bachelor of Science in Chemical Engineering

Technical Advisor: Eric Anderson

STS Advisor: Karina Rider

Technical Team Members: Joseph Fink, Benson Harlan, Gaurav Kapoor, Nikolai Kosinski