# Supply Chain Data Analytics for Digital Twins:
## 4 Case Studies
### Pilot Descriptions/Demonstration
#### 4.1.2 Spanish Pilot  
The analytics service applied in Spain focuses on recovering and recycling End-Of-Life (EOL) Permanent Magnets (PMs) from Waste Electronic and Electric Equipment (WEEE). It has three organizations covering different steps from the recovering, recycling and manufacturing of magnets. Together, they cover different steps in a supply chain that requires the exchange of information in order to optimize their production, analyze their costs and be aware of the materials that they will receive. On the supply chain scale, the first organization is a recycling company that receives the home appliances collected at recycling points in Spain. They process each appliance based on the current European regulations, dismantling harmful components and recovering recycling materials. Within these materials, they extract magnets that otherwise will be mixed with scrap metals and sent to melt. These recovered magnets are sent to a lab specialized in magnet processing and capable of recycling sintered magnets. The magnets are analyzed, processed and transformed into magnetic pellets that can be injected into new magnets by a magnet producer. Finally, there is a magnet producer that can manufacture new magnets and internally recover scraps from their production. It is estimated that each year, 30-50 million tons of Waste Electrical and Electronic Equipment (WEEE) is produced. This waste contains a significant amount of end-of-life (EOL) magnets, which are often not recovered and are mixed with other metallic recycling streams. Due to the presence of rare-earth elements in these magnets, the European Commission has emphasized the importance of recovering EOL magnets [26]. This importance is expected to grow as the first large wind turbines and mass-produced electric cars reach the end of their operational life. PMs can be divided into two main groups: those based on Ferrite alloys and those based on Neodymium alloys. The demonstrator has focused its efforts on Ferrite magnets due to their more widespread use. The objective of this pilot is to ensure that recycling end-of-life (EOL) magnets is a viable option, considering both the technical processes and economic viability. This can be achieved by sharing crucial data among key partners, enabling organizations to make data-driven decisions. To meet this objective, the involved companies agreed to share information through an external digital twin service. This service provides data-sharing capabilities and includes the data-sharing agreement between the partners. The analysis of the various processes at each organization identified three critical points in production that required the implementation of analytics. The first was the need to gather statistics about the types of magnets used in different waste items received by the recycling company. The second was to analyze whether all recycling steps were necessary. Finally, an estimation for the total energy consumed by the recycling process was provided. The first point is crucial because magnets in home appliances represent a small fraction of the total device and extracting them can require significant time for minimal yield. Using historical data to estimate the probability of extracting a specific type of magnet from a given device helped the recycling company focus on relevant equipment. The second critical area is the recycling process itself. The current lab-scale recycling process includes the following:  
_Crushing_: The received end-of-life (EOL) magnets are crushed and transformed into powder. _Ball Milling_: This process reduces the grain size of the magnetic powder to a few micrometers. _Thermal Treatment_: The magnetic powder undergoes annealing, where it is heated and cooled at a controlled rate to modify its crystallographic structure and enhance magnetic properties. _Homogenizing_: The magnetic powder is mixed with a polymer. _Extrusion_: The mixture of magnetic powder and polymer is heated to form pellets.