Holger Schnideritsch

EXTRACTION OF LANTHANIDES FROM SPENT POLISHING AGENT

Abstract The polishing of glass substrates or wafers requires fine-grained particles, frequently based on oxides of the lanthanides cerium and lanthanum. During processing the slurries become enriched with different elements depending on the specific production program and the chemical composition of the work piece. Concentrations of these impurities can reach critical values and may negatively influence the surface quality of the substrates. Therefore, the polishing agents have to be removed from the system and are sent to a landfill or recycled. This chapter describes options for processing such secondary rare earth resources using different hydrometallurgical methods including mineral acids for extraction. In some cases, the focus is also on the evaluating precipitation methods by carbonate or oxalate carriers to produce a rare earth concentrate that meets requirements for reuse in fabricating new polishing powders.

RFID-Reststoff-Anfall und Recyclingpotenziale der Metallanteile

SummaryThe RFID technology (Radio Frequency Identification) represents an extensive field of application for logistic topics.. The application of RFIDs is unlimited. Particularly the simple replacement of the established bar-code system by smart labels and also the tracking/tracing of various objects, animals and people exhibit a high market potential. Due to the estimated future market development and penetration difficulties in the supply of RFID manufacturer with silver (antenna material) could be expected. An increase in primary production of lead and copper and accordingly the recycling of this metal from consumed RFID tags alleviate this problem. For the recovery it is necessary to find technologies for the separation of smart labels from the tagged objects. The build-up of appropriate infrastructures for the RFID recycling is also a future topic. The recovery of the two antenna metals copper and silver are thereby in focus. The increased accumulation of RFIDs in the established recycling routes (glass, plastic, paper and metal) may lead to a decrease of quality of secondary products. An upstream separation of smart labels avoids problems in the subsequent recycling processes (i. e. glass melting furnace – glass bottle production).ZusammenfassungDie RFID-Technologie (Radio Frequency Identification) stellt ein weitreichendes Einsatzgebiet für logistische Themenstellungen dar. Ausgehend vom einfachen Ersatz des heute gängigen Bar-Code-Systems bis hin zur Nachverfolgung (Tracking & Tracing) diverser Gegenstände, Tiere und Personen sind die Anwendungsmöglichkeiten praktisch unbegrenzt. Aufgrund der zu erwartenden zukünftigen starken Marktentwicklung und -durchdringung könnte es zu Schwierigkeiten bei der Versorgung der RFID-Hersteller mit dem Antennenmetall Silber kommen. Der steigenden Nachfrage ist mit einer Erhöhung der primären Blei- und Kupferproduktion beizukommen. Eine alternative Lösung für dieses Versorgungsproblem stellt die Sekundärmetallurgie dar. Hierbei ist es jedoch notwendig, Verfahren für die Separation der Etiketten mit den RFIDs (Smart-Labels) von den gekennzeichneten Objekten zu finden und geeignete Infrastrukturen für das Recycling dieser Art der Elektrokleingeräte aufzubauen. Die Rückgewinnung der beiden Antennenmetalle Kupfer und Silber stehen hierbei im Fokus. Durch den vermehrten Anfall von RFIDs in den bereits etablierten Recyclingprozessen (Glas, Kunststoff, Papier und Metall) könnte es zu Qualitätseinbußen bei den jeweiligen sekundären Produkten kommen. Eine vorhergehende Abtrennung der Smart-Labels von den gekennzeichneten Objekten schützt die nachfolgenden Prozesse vor diesen Problemen.

New preparation and recycling procedure to recover rare earth elements from magnets by using a closed loop treatment

The use of critical raw materials also increases due to the higher demand on electrical and electronic equipment (EEE). The high content of valuable substances in EEE in relation to primary ores secures a potential for its use as new raw materials sources, the so-called ‘urban mining’. Positive effects of urban mining are to save existing mineral resources as well as to relieve the primary production and get a new opportunity instead of landfilling. The subsequently described research work at the Chair of Nonferrous Metallurgy at the University of Leoben is concentrated on the preparation of hard disc drives (HDDs). Currently, the main problem to recover neodymium–iron–boron (NIB) magnets is the missing technology for preparation. A disassembling of HDD by hand is not economic and a treatment by a shredding machine destroys the NIB magnets, so that they cannot be separated and fed into a proper recycling process. Therefore, the investigation leads to a thermal treatment to obtain the components of a HDD in separated form. The investigation also focuses on a metallurgical way to recover the technological metals like neodymium, copper, gold as well as a reusable aluminium alloy. Therefore, a closed loop treatment was found to clean the leaching agent and reuse it to reduce the amount of waste streams.