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Primitive Technology: Making Lime from Snail Shells


Lime has several applications. For example, it's used in the production of concrete.

Continuing his experiments in primitive technology, our man in the jungle is now exploring the production of lime. And, these projects truly do qualify as primitive technology, as they straddle the line between bushcraft and advanced experiments in producing more refined chemical products.

Here, he collects empty snail shells from the jungle floor and fires them in a kiln. He then adds water and forms a slurry, before adding another aggregate and molding the putty into a brick. Once the brick dries, you can then pulverize it and add it to other aggregates to produce concrete or mortar.

It's a fascinating process that gives you an idea of what early man must have done to create a product that ultimately had some very influential uses.

The chemical composition of lime undergoes a couple of changes during the processing.

Rather than turning to limestone, he used snail shells, a source of lime he had readily available in the forest. Burning converts the shells into a material called calcium oxide or quicklime. He collected the fired shells and added water, thereby creating a product called slaked lime or hydrated lime. This process is called "slaking of lime," and changes the chemical composition of the lime yet again. 

"What I created is actually lime mortar, typically used for mortaring bricks and tiles together," he says. "It's basically the 'glue' that holds together the building blocks of masonry structures."

It's a great experiment. The applications could be used in building a more sturdy, resilient structure in place of his mud brick or wattle and daub hut.

The biggest challenge is finding enough shells in the area. However, he was able to prove that making lime in a land without limestone is possible. The trick will be trying to find enough raw material to produce lime on a larger scale.

Like what you see here? You can read more great articles by David Smith at his Facebook page, Stumpjack Outdoors.


Primitive Technology: Making Lime from Snail Shells