The SOLPART project was presented in HelioCSP, the solar thermal energy news website:

Cement is the most widely used building material in the world. One of its key ingredients is calcium oxide (CaO), also called quicklime, which can be produced by calcination from naturally occurring limestone (CaCO₃).

Calcination is an energy-intensive, around-the-clock decomposition process at around 900 °C, usually powered by the combustion of coal or secondary fuels (e.g. used tires, or the burnable fraction of industrial or municipal waste). The aim of Solpart is to develop a solar reactor prototype that separates limestone into CaO and CO₂. The heat for the particles will come directly from a concentrating mirror field without being transported by any heat transfer fluid.

More information here: https://helioscsp.com/concentrated-solar-power-for-high-temperature-solar-process-heat/