Rare Earth Elements (REE) recycling analysis of patents' data

The patent dataset analyzed is based on search criteria aimed at differentiating worldwide patent data regarding applications dealing with REE recycling, and a ‘control’ sample where patent data concern a more generical technical context dealing with recycling. Such differentiation is essentially achieved by two different selections of patent data from the EPO database Patstat (Spring 2022 ed.), each selection based on IPC/CPC classification codes with the addition of keywords specific for Rare Earth Elements/Lanthanoid in case the REE specific patent documents are looked for.
In a first phase a dataset has been obtained by means of a pool of classification codes devoid of the CPC “green” code Y02P10/20, while in a second search the CPC Y02P10/20 has been included in the search query.
This code concerns specifically the metal recycling methodologies, thus determining a consistent increase of the patent documents retrieved. When the search strategy is subsequently modified, i.e. by simply replacing the CPC code Y02P10/20 with the combination of IPC/CPC C22B59, specifically referring to the Rare Earth Elements, almost 86% of the data are present in both patent collections, even though the C22B59 is not recognised as a “green” classification code.

Further information can be gathered from the trend of patent applications filed worldwide (i.e. including either national authorities or supranational authorities, such as the EPO or the WIPO) considering the timeframe starting from yr. 2010 to yr. 2022. Such trends can also be assessed in order to normalize the amount of filing events, i.e. by comparing, for each of the most representative patent authorities, the trend of REE specific applications with the trend resulting from the control sample. Additional information is based on proxies that have been dealt with in an earlier publication regarding a similar approach used to investigate about the WEEE/RAEE recycling (“WEEE recycling patents' dataset”, Mendeley Data, V2, doi: 10.17632/4ysw32c9fy.2). The assessment in the ‘REE’ dataset entails the analysis of the patent families based on the ranking of IPC and CPC codes, respectively, to detect those most frequently assigned considering each of the two classification’s systems. Subsequently, qualitative and quantitative information is retrieved concerning the most frequently addressed patent authorities, the most representative players and their affiliation kind, as well as the technology concepts ranking, performed using the Orbit Intelligence patent database (available from Questel). Moreover, such source of patent data has been used to either focus the search on specific technical procedures aimed at recovering the REE from waste materials or to select the patent documents specifically regarding the recovery of chemical elements such as Yttrium and Samarium.