The lime kilns of Fuerteventura

The lime kilns are one of the heritage elements with the greatest ethnographic value on the island. We find examples throughout the territory 

These lime kilns are testimony to a flourishing past. The production of lime, the best in the Canary Islands, was one of the most important economic engines on the island for a long time. 

Lime kilns were operating in Fuerteventura from the 16th century until the second third of the 20th century. Thousands of tons of lime left the ports of Fuerteventura towards the other islands of the archipelago. Also to Madeira and the Iberian Peninsula. 

The greatest demand for Majorera lime occurred between the end of the 19th century and the beginning of the 20th, coinciding with the construction of large works and infrastructure on other islands.

Where is lime extracted from? 

Lime is basically obtained from the combustion of rocks rich in calcium carbonate. This process was carried out in a lime oven, either artisanal or industrial. In both cases the elaboration of the lime was similar. The presence of calcium carbonate in certain areas can have two main origins: organic and sedimentary deposition. On the one hand, there are certain aquatic organisms capable of precipitating calcium carbonate in the form of shells, rhodoliths, etc. Over time, the accumulation of these organic remains form limestone or dolomite rocks.

In addition, the erosion produced by water in certain rocks makes it possible to transport existing carbonates and deposition in other places, giving rise to new sediments. Stalactites and stalagmites are a clear example of this. At other times, the water seeps into the soil, dissolving the carbonates and redepositing them when the water evaporates. More or less thick crusts of a whitish material called caliche form. Caliche has been the essential raw material in the production of lime in Fuerteventura.

Where were the lime kilns built? 

The lime kilns were built mainly in the coastal areas, in coves that allowed the shelter of the boats. The caliche stones were transported several kilometers to the ovens on donkeys and camels. Once the lime was made, it was taken to the ships. But, we can also see lime kilns in areas of the interior of the island. In these cases, the ovens were erected next to roads that had good communication with a nearby port.

What are traditional lime kilns like? 

Lime kilns have a slightly ovoid cylindrical chamber open at the top, with another side opening at ground level, like a door. The structure of traditional Majorero ovens is very simple. The largest and most solid are built with basaltic rocks, and do not exceed eight meters in height or four in diameter. There are also smaller ovens made from caliche covered with mud cake. These do not exceed four meters in height. 

The lower door was oriented against the prevailing winds, thus controlling the combustion process. The lower hole also allowed the quicklime to be removed once it was cooked. A grill that was placed inside, just above the opening, facilitated the work of extracting the lime. You just had to move it so that the already burned caliche fell out.

The lime kilns were fueled with anthracite coal, sometimes brought from the United Kingdom. In times of scarcity, peninsular coal was used, and even, in the first moments, the thermophilic forest of the island was used. 

How was caliche extracted? 

After having chosen the right place to extract the caliche, the extensive layer of caliche was broken into manageable pieces. The process was very rudimentary and hard. To do this, the workers used pickaxes, wedges, hammers and augers. When stones about 15 centimeters thick and weighing no more than 10 kg were obtained, they were carried on pack animals and taken to the ovens.

How were the ovens loaded? 

The process of filling the furnace was carried out from the upper hole. A layer of caliche stone was interspersed with another of fuel, until the cone of the furnace was completely filled. Dry gorse was placed at the bottom. Then the ignition started. In this way the fire was transmitted to the different layers of fuel and turning the caliche into quicklime. 

The caliche cooking process took several days, sometimes even more than a week. Everything depended on the speed of combustion of the furnace and its characteristics. The first indication of its end occurs when the smoke that comes out of the oven is whitish in color. After finishing cooking, water was added to the lime stone, obtaining the so-called slaked lime, easy to transport in wooden boats.

Lime Kilns Interpretation Center. 

The Lime Kilns Interpretation Center (CIHC) is a project that will be installed in the El Charco Lime Kiln complex, in the capital of Fuerteventura. In 2017, work began for the remodeling and rehabilitation of the Lime Kilns and their surroundings. The surrounding areas have been partially conditioned with pedestrian spaces. Next to the industrial oven built in 1946, the CIHC has been built, an exhibition space open to the city, which will have explanatory murals, panels and lecterns, where, in addition to making the history of the lime industry known, it could function as a classroom -workshop, auditorium or audiovisual projection room



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