Xella is working hard to achieve one of its 2025 circularity targets: zero AAC leftovers to landfill. Previously, the Kolubara plant sent approximately 10,000 tons of AAC leftovers — 30% of the company's total — to landfill each year. This posed a significant challenge due to the process being both cost- and labor-intensive.

Creative solutions for leftovers

Expensive investments were not the first choice. The initial idea of paying 1.5 million euros for comprehensive equipment was quickly abandoned. "We had to be creative," Kolubara plant manager Aleksandar Petrović recalls. Instead, the team reviewed the production process and realized that changing the product's recipe would make a difference. With the support of Xella Technologie & Forschungsgesellschaft mbH (T&F), the plant adopted a new mixing ratio for their products - reusing significant amounts of leftover material to produce new blocks.

Adequate Pumps for Transportation Challenges

However, the production process also needed optimization. "Now we have installed new pumps for sand slurry with crushed material," says the plant manager. He adds: "Together with the Romanian, Bosnian and Slovenian colleagues, we looked for better solutions as they have more advanced equipment, and we found one for us as well."

Savings and strategic investments

A revised investment plan provided a practical solution: only 10% of the original huge investment plan were needed. The investment now allows full use of AAC leftovers in production and reduces CO2 emissions by 415 tons of CO2 per year. "With the reduced costs, we expect the project to pay for itself in less than a year," says Petrović. He also highlights an additional benefit: "Circularity reduces the need for virgin mineral resources."

Serbia is poised to make a significant contribution to Xella's 'zero to landfill' circularity goal, driven by innovative solutions and collaboration beyond company boundaries. "It's a very interdisciplinary issue, because you really need an excellent understanding of the processes in the plant, but you also need to look more broadly in the ecosystem to see what local opportunities there are to find solutions," summarizes Antonio Grginovic, Circular Economy Development Manager at Xella Group.