NEWS A transition to electrified quicklime production could significantly reduce carbon dioxide emissions. However, process modifications may impact product quality. New research from Umeå University and the Industrial Doctoral School explores how different process conditions affect quicklime quality and offers insights for a more sustainable industry.
Jutjärn limestone quarry located in Dalarna, Sweden.
ImageKatarzyna OlovssonQuicklime is an essential material used in various industries, including steel production, where its quality is crucial. Currently, the process of quicklime production takes place in fuel-fired high-temperature kilns, emitting large quantities of carbon dioxide. Most of these emissions come from the decomposition of limestone, while the rest originate from the burning of the fossil fuels.
A possible route for carbon dioxide mitigation is electrification of the production process, which, in combination with carbon capture, could enable net-zero emissions in the long run. However, this would lead to altering the process conditions, which in turn could affect the quicklime quality.
Katarzyna Olovsson, doctoral student at the Department of Applied Physics and Electronics at Umeå University, has investigated several quality measures of quicklime. One important quality measure is slaking reactivity. Especially in steel production, high reactivity quicklime is required.
Katarzyna Olovsson, doctoral student at the Department of Applied Physics and Electronics.
ImageJonas Olovsson“In the experiments simulating an electrified heating process, we tested how different burning temperatures and durations affect the slaking reactivity. Our results showed that all quicklime samples had medium to high reactivity, demonstrating the possibility of achieving this quality in an electrically heated process,” says Katarzyna Olovsson.
Another important quality aspect is carbonation, which can occur in the cooling zone of a kiln and lowers the quality of the quicklime product.
In her research, Katarzyna Olovsson found substantial variations in carbonation depending on the type of limestone and the atmosphere in which it is processed. She studied the microstructure of two different types of limestone, sedimentary and metamorphic, and how it changed during heating and carbonation in three different atmospheres, representing conventional combustion and electrically headed kilns.
“The quality of limestone and of quicklime is important for the suppliers, producers and their customers. Depending on the industrial application, requirements can vary, and increased knowledge of the factors that affect the quality is very important. Our results should be taken into consideration while designing a cooling zone of an electrified quicklime production kiln,” says Katarzyna Olovsson.
Currently, the process of quicklime production takes place in fuel-fired high-temperature kilns, emitting large quantities of carbon dioxide.
ImageKatarzyna OlovssonThe study provides useful insights for industries looking to make quicklime production more sustainable. As the focus on cutting carbon dioxide emissions increases, electrifying high-temperature processes is emerging as a promising solution.
Katarzyna Olovsson’s doctoral project has been funded by the Industrial Doctoral School at Umeå University, SMA Mineral, Heidelberg Materials, Nordkalk och Swedish Mineral Processing Research Association – MinFo.
On Friday 11 April, Katarzyna Olovsson, Department of Applied Physics and Electronics, will defend her thesis entitled “Thermochemical properties and quality measures of limestone and quicklime”. The defence will take place at 09.00 in Aula Biologica (BIO.E.203). The faculty opponent is Professor Henrik Leion, Chalmers University of Technology.
The Industrial Doctoral School is based on collaboration between the University, researchers and businesses or organisations. The aim is to combine benefits for both society and the external party while training new high-quality researchers. The doctoral student also receives a tailored academic course package. The doctoral school is open to all disciplines and the doctoral student is employed at Umeå University.
