PRODUCTION DEVELOPMENT: Volvo Group and Lyrestad First in the World With Groundbreaking Technology for Casting in Molding Sand Without Carbon

Volvo's TORE NILSSON'S IDEA REDUCED CO2 EMISSIONS by 85 PERCENT. Tore Nilsson, Foundry Process Engineer at Volvo Group Skövde Foundry, had an idea for a new mineral mix that could make it possible to remove all carbon in the molding sand, but this was not something they had the opportunity to test in their machines.
"We have 700 tons of molding sand in our main plant and it is not easy to replace if something goes wrong. It is like an ecosystem; if there is the slightest disturbance, the risk of destroying it is very high. What Lyrestads Gjuteri did, which works with significantly smaller volumes, is unique and something similar has not happened since the 1960s. They were brave and took the risk when we asked if they could help us do what is also extremely difficult to achieve during hot production. That was the starting point for our collaboration,” says Tore Nilsson. The result is that carbon dioxide emissions during casting have been reduced by over 85 percent with the help of the jointly developed and implemented groundbreaking technology. It even means that Lyrestads Gjuteri will be the first iron foundry in the world to use soot-free molding sand.
The background is that all foundries' molding sand contains a couple of percent carbon at best, but it can be even larger amounts. Molding sand is used when casting metal in molds. It consists of quartz sand mixed with clay in varying amounts to increase its strength, toughness and permeability. A distinction is made between raw sand with less than 10% clay, dry sand with up to 20% clay and clay sand with more than 20% clay. The mixing of coal powder is done to prevent the sand from burning to the casting.
The goal of this project, and Volvo's driving force, has been to completely remove the coal. The project was started two years ago.
"The coal is the culprit," sums up Andreas Stridkvist at Lyrestads Gjuteri: "Exactly, coal is the biggest cause of emissions, but it is also the coal that makes it black, dirty and unpleasant in these industrial environments and it is simply the culprit when the goal is to strive to be able to see itself as a clean industry."
Lyrestads Gjuteri has had full production with the new technology since August 2023 and noticed early positive effects on the working environment. In addition to the fact that they have relatively immediately managed to reduce carbon dioxide emissions during casting by over 85 percent, almost only water vapor is formed when pouring iron into sand molds. Instead of the previous situation where lots of harmful gases were formed.