The polluted limestone generated at Audi Hungaria painting plant is transported to Lafarge Cement Factory where it is used for cement production.
Audi Hungary Ltd. has the will to reduce the waste they produce with the effective environmental and energy management systems and state-of-the-art technologies. For example at their production site uneasily recycled waste stream was directed back to circular economy recently thanks to the help of Saubermacher Hungary Ltd., waste management company. The pure limestone powder – thanks to its special physical characteristics - is used as a filtermaterial to filter out the paint and lacquer particles from the air of the painting cabin of Audi. The paint and lacquer particles are captured by the limestone powder, when the clean air is removed from the system, this polluted limestone accumulates.The used and contaminated, but not hazardous limestone powder was previously landfilled, but now it is taken to the LAFARGE Cement Factory, where they use it as a substance (accessory agent) during cement production. LAFARGE Cement Factory Ltd. decided to invest in the technology a few years ago which makes this synergy work - it is able to receive this by-product and to introduce it to the production.
More than 2000 tons of contaminated limestone powder is generated per year at the site of the paint shop and 100% is transported to the cement factory, where the arrived secondary material can replace 50% of the primary raw material.
Constant flow of the used and contaminated limestone powder from the painting plant.
Technology which can make the factory ready to receive the incoming material and to use it for cement production.
Worked out system and place which can store the incoming material.
Evidence of success
The technology is successful, 50% of the primary raw material could be replaced per year during cement production.
In this way less waste goes to landfill, contaminated limestone powder is being used as a by-product. This material stream is 100% redirected to circular economy which means 100% of waste reduction occurs.
Waste treatment costs are saved, even some revenue is being realised by the sales of the by-products.
Quantity issues: securing the sufficient amount of used limestone powder being transported to the cement factory constantly and having the enough storage place for the incoming material.
Transport issues: based on the distance, transport cost might become too high or the GHG emission can rise.
Potential for learning or transfer
Other factories (car manufacturers, other producers of painted items) can use the same technology for dry separation using limestone powder for filtration of contaminated air and utilize their own used limestone powder as a by-product for producing cement.