New research explores how granite-processing sludge can be transformed into high-performance ceramic materials through additive manufacturing, contributing to more circular and resource-efficient industrial production.
Granite processing generates significant quantities of mineral sludge, a by-product that is often discarded despite its potential as a secondary raw material. Recovering and reusing this waste offers an opportunity to reduce dependence on virgin resources while supporting more sustainable manufacturing practices.
A study presented in the scientific poster Resource Recovery of Granite-Processing Sludge for Extrusion-Based 3D Printing of Ceramic Products investigates how granite sludge can be incorporated into ceramic formulations suitable for extrusion-based 3D printing, using a technique known as Slurry Deposition Modelling (SDM).
From industrial waste to valuable materials
The research focused on developing and optimising ceramic mixtures combining granite sludge, clay, water and additives. Different formulations were evaluated to determine their suitability for 3D printing and their mechanical and physical performance after firing.
The findings demonstrate the potential of granite sludge as a valuable alternative to conventional ceramic raw materials.
Key research findings
Up to 50% granite sludge incorporation: The optimised formulation incorporated 50% granite sludge by weight while maintaining suitable printing behaviour.
Improved mechanical strength: Bending strength increased from 6.8 MPa to 43.4 MPa as granite sludge content increased, exceeding the 20 MPa construction target from 30% sludge incorporation onwards.
Reduced water absorption: Water absorption decreased by approximately 44%, from 5.3% to 3.0%, indicating improved material densification.
Optimised printability: A water content of 25% enabled stable extrusion and suitable paste behaviour for additive manufacturing.
Reduced material waste: The SDM approach reduced machining waste from approximately 45% to 6%, highlighting the potential for more resource-efficient production.
Advancing circular manufacturing
These results demonstrate how industrial by-products can be recovered and transformed into functional materials for new manufacturing applications.
By combining waste valorisation, material optimisation and additive manufacturing, the research contributes to the broader objectives of the CIRCULOOS project, which promotes circular manufacturing practices and more efficient resource use across European industry.
Further research will explore lower-temperature processing and firing-free formulations to improve the environmental performance of the manufacturing process.
Research poster: Resource Recovery of Granite-Processing Sludge for Extrusion-Based 3D Printing of Ceramic Products
Authors: Ioannis Kakogiannos, Georgios Chalkias, Marija Veskova, Laura De Breuk, Claude Schneider and Luc Segonne.
This work was carried out in the context of CIRCULOOS, funded by the European Union’s Horizon Europe programme under Grant Agreement No. 101092295.