A tremendous amount of rockwool slabs is currently brought in by Dutch growers who are in the middle of their crop rotation. Renewi (formerly Van Vliet Contrans) collects the rockwool slabs and processes them into new raw materials. To do that, they first need to shred the slabs, and later on the material will have to rest for two months in order to dry.
Via a drum installation the rockwool is separated from the organic and plastic materials. The remaining rockwool granulate is then suitable again for the production of stone bricks.
The green waste is being transformed into compost, as can be seen in this video:
Renewi can process about 120,000m3 of rockwool slabs every year. That's quite a lot, which can be seen in this video: