Recycling of Coated Abrasives - ReCAb
The production of flexible abrasives generates waste in the form of shortfall batches, chads and offcut mass. For lack of an established treatment technology, this waste cannot be utilized materially. Instead, it is treated thermally in incineration plants. Thereafter, the remains are deposited with the slag. The production waste contains abrasive grits whose material potential as a secondary raw material remains unused.
The project, supported by the German Federal Environmental Foundation, includes the enrichment of the abrasive grits through a thermal process followed by mechanical treatment. This procedure should include the following three steps:
- Thermal separation of the composite matrix of abrasive grain and binder
- Mechanical separation of the pure abrasive grain from accompanying substances
- Classification of the abrasive grits to meet the according standards
In the project, the main examinations focus on the abrasives corundum and silicon carbide. They are the most important grits according to mass. Before the abrasives can be treated thermally, they have to be preconditioned. The thermal process removes organic binders and bases. Only the purely inorganic fraction remains as powdery component, including the abrasive grain. A following mechanical process separates the grain from the accompanying substances. Subsequently, the abrasive fraction is classified into norm conforming grit classes – analogue to the primary production process.
The project’s results will be used in a following upscaling project, which should realize the construction of a plant for the recovery of waste from abrasives production.