The scientists of Tallinn University of Technology and the University of Tartu and the team of Ragn-Sells AS have developed an industrial technology for the climate neutral separation and recovery of the elements found in oil shale ash, following the example of similar circular economy projects implemented in Sweden. Recycling a large waste segment by way of valorisation has two benefits from the viewpoint of environmental sustainability because the quantity of waste and CO2 emissions is reduced and the primary production of several virgin materials can thereby be reduced as well.