Pini Grandi lime kiln above Cavoli

Since ancient times, all along Elba's coastline and sometimes in inland areas as well, in places where limestone rocks emerge, numerous kilns for producing lime have been built. These were large structures in which limestone was baked to produce lime, used for building, for binding construction stones together and for plastering buildings.

They featured a cylindrical structure made from heat-resistant stone, reinforced with an inner sleeve of fire clay bricks, with an opening at the top for loading the limestone and a mouth in the lower section used firstly for inserting the many bundles of kindling required to fuel the fire for baking the limestone and then, at the end of the process, for removing the lime produced. Often, the cylindrical structure was built into a hillside, making it easier to load the limestone from above and keep the kiln hot. The inner wall of the construction was also lined with fire clay.

The limestone for processing was carefully positioned in a circle inside the kiln, resting on the wall of the structure with the exception of the part where the inlet was. The stone for baking was once again positioned carefully, creating a dome-shaped combustion chamber a metre and a half tall from the base, and the kiln was then filled up to the top.

Bundles of kindling were then placed inside the combustion chamber for a baking process that could last from seven to ten days, requiring up to six or seven thousand bundles. Heating of the kiln had to be slow and gradual to prevent the stones from blackening and the inside of the limestone from remaining 'raw'. During the process, the temperature exceeded 1000 degrees, and when blue flames finally appeared at the top, this meant that the stone was baked. The quicklime produced in this way was removed, in the form of powder or still in its solid form although heavily chemically degraded, for transport to the building sites where it was to be used and subsequent 'slaking' with water.

(Antonello Marchese, translation from Italian)