A significant reduction in the CO2-emissions generated during the production of conventional quicklime can be achieved by avoiding the use of fossil fuels.
In this research, the use of indirect electrical heating for calcination of limestone in a laboratory plant specially adapted for this purpose is investigated. The newly developed OPTIKALK process was tested with limestone from the Ernstbrunn deposit of Profibaustoffe Austria GmbH. Systematic test series with different grain size bands were analyzed in terms of mineral processing and were further used as feed material.
It was shown that the OPTIKALK-process in the laboratory plant is capable of producing high-quality quicklime products that are in line with market requirements and is suitable for reducing CO2 emissions. In the series of tests carried out, thermal comminution was also observed, which represents a significant relief for subsequent process steps (e.g. grinding to product fineness).
Furthermore, it was shown within this work that the stockpile fine fraction of the company Profibaustoffe is also suitable as a feed for the OPTIKALK-process. This should enable optimal circular economy in the future in line with the “Zero-Waste” concept and could enable the utilization of the entire deposit content. The use of the OPTIKALK-process for other materials has already been demonstrated using the example of perlite expansion.
The findings of this work are promising for the future, both from the point of view of process technology and from ecological as well as economic perspectives. The planning work for the construction of a pilot plant is in full progress as a necessary intermediate step on the way towards the installation of a large-scale industrial plant using the OPTIKALK-process.