One year after our first and successful try in these competitions, we were looking forward to taking part once again. So, we registered for this scientific event again but, this time, with a teammate less.
Topic of the race in 2018 was “recycling of LIBs”. Actually, we must design a process for recycling of a hydroxide precipitate excluded from an industrial, hydrometallurgical process for LIBs waste recycling. We must do this job in less than 10 hours and use normal chemicals and facilities. The following table shows the chemical compound of the material delivered to teams:
Our challenge started with studying published articles to get an idea for this purpose. At this step, I got to know about an odd, for me, separation technique called salting-out. This process is similar to the solvent extraction method but a simple organic solvent such as alcohols is used as an extractant instead of solvents with complicated formula and manufactured exclusively.
Based on this interesting method, we proposed a process for our specific waste. Unfortunately, due to lack of knowledge about it, enough time, and facilities to do some tests before the race, we failed to accomplish the process well. Therefore, on match day, we encounter problems that we had not considered before. The main one was the behaviour of manganese in leaching and precipitation steps.
Overall, our suggested process expected to work was as below:
During the salting-out mechanism, Co is extracted through an equilibrium between theses reactions causing transport of cobalt in the form of an ionic complex from aqueous to organic phase:
I got so excited when I figured out that although 2-propanol and water are soluble in each other, they will not be if water is saturated with a salt, in this case NaCl.
Finally, as we anticipated we achieved less score than other teams totally according to following criteria:
- Written proposal
- Suggested process
- Products, applicability, cost and time
- Laboratory experiments
- Efficiency and purity
- Safety and Sustainability
However, I succeeded in winning an award in another part of this period of competitions. This award went to who presented the best idea for management and collecting of domestic waste batteries. In this figure, I explained my opinion that the first step to overcome this challenge is cultural activities with a focus on schoolers.
Finally, I would like to thank my just friend Mr. Karimi for accepting my invitation to be my teammate once again. Also, some moments of this event are recorded in the pictures below.