Akademik Veri Yönetim Sistemi
JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI, 2025 (ESCI)
Rare earth elements (REE); constitutes the most important raw materials in renewable energy, aviation industry, electronics, defense industry and many other advanced technology fields. During the coal combustion (CC) in thermal power plants, huge amounts of by-products are released. These coal by-products contain a significant amount of REEs. For this reason, it is recommended to develop sustainable recycling technologies for the recovery of metals and REEs. While developing these technologies, accurate and precise analysis results in analytical chemical methods of REEs are required at every stage. The use of reference materials (RM) is a key activity to develop and maintain a consistent measurement system in the world. RM is used for various purposes such as deviation evaluation, calibration, method validation, etc. in measurement systems. RM production process is a process that includes some major multiple steps but the most important ones are Representative Sampling (RS) and assurance of Homogeneity (H) and Stability (S) of the sample. Also, this is a production process that needs to be designed with different algorithms for each different matrix. While conducting RM production activities, it is determined that RS and H have a crucial importance on the process, and this study aims to show the importance of these stages. In addition, the effects of sampling fly ash samples on different days and taking them into solution using two different dissolution methods were examined. It was observed that the REEs in the sampled coal fly ash could be taken into solution more efficiently by 3 acid dissolution method. It was seen that sampling with the accumulation method on 10 different days determined during RS was a correct approach, and that the REE analysis results of the relevant samples showed undeniable changes in the waste content according to the days and were not constant.