A novel method for reusing diatomaceous earth in the filtration process of aluminium cold rolling mill

Diatomaceous earth (DE), a porous sedimentary rock, is a critical component in filtering lubricating oil during aluminum cold rolling. Its high porosity allows it to trap impurities in the oil, but frequent replacement due to a limited lifespan increases costs and waste generation. This study investigated the viability of replacing fresh DE with diatomaceous earth residue (RDE), the leftover material after filtering oil. Various tests were conducted using different raw DE and RDE proportions across different filter layers. Tests showed that a 50 % RDE mixture in certain filter layers extended filtration time while maintaining oil quality. Consequently, a 30 % reduction on both costs and RDE generation was achieved. These results represent a significant advancement in terms of material conservation, cost avoidance, and waste reduction, especially because no pretreatment was applied to the diatomaceous earth.