The Use of Recycled Aggregates for Cement Production – A Second Successful Industrial Trial!

The Use of Recycled Aggregates for Cement Production – A Second Successful Industrial Trial! 

In September 2018, a first successful trial of the use of recycled aggregates - prepared by TRADECOWALL and sourced from CDW (Construction & Demolition Waste) - took place at the VICAT cement factory in Créchy, France. The recycled aggregates were introduced at a rate of 14.2% in the raw materials in in the kiln for the production of clinker, and thereby generating an extra energy consumption of 20%. With regards the quality, the analysis carried out in the laboratories of the Universities of Delft, Kaiserslautern, Lorraine and Luxembourg confirm that the “recycled” and reference clinkers have similar chemical compositions. Only small differences of the clinker mineralogy (alite and belite proportions) were observed but the “recycled” cement properties at short term are standard.  

Following the first trial, the VICAT cement plant of Créchy carried out a second trial in July 2019. This time the recycled aggregates were introduced with a lower incorporation rate of 5% in order to avoid extra energy consumption. A 5% rate is also more realistic if a cement factory were to produce such clinker all year round (≈50 000 tons of recycled aggregates per year per cement plant). TRADECOWALL delivered 271 tons of “mixed recycled aggregates” which were used together with 4750 tons of raw materials from the quarries (limestone, marl, bauxite) and 210 tons of alternative raw materials (iron oxide, foundry sand, polluted soil, etc.) for the production of 2,500 tons of clinker. The clinker will be milled during the months of September, October and November to produce CEM I 52,5 quality cement which will be shipped to the SERAMCO partners for analysis and concrete production trials.