Al Smith on sun 3 jan 99
Sea shells supply calcium with minimal traces of other elements. They are
just a substitute for whiting. When calcined, they convert to calcium
oxide which is caustic. The calcined shells can be easily crushed to a
powder, called quick lime, or added to water (slaked), to form calcium
hydroxide. The hydroxide reacts with carbon dioxide in the air to form
calcuium carbonate - whiting. In addition to being caustic, when the
hydroxide converts to the carbonate, it can set up like a brick. This is
how plaster is made if you live near a source of free sea shells.
This process works exactly the same with limestone but the end product is
likely to contain a fair amount of magnesium.
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Al Smith in California's Mojave desert
aosmith@ridgecrest.ca.us
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