Aerial Limes

                                                                                          THE MATERIALS

 

Aerial lime Venetian Plasters-Aerial lime is obtained cooking in special ovens at the temperature of 800-900°C calcareous rocks constituted of calcium carbonate and clay for a maximum rate of 5%. After the cooking process we have quicklime, that can be ground into a powder to obtain

Hydrate lime dust-The cooked rock is deducted of water, and once dehydrated is wet again with water that it absorbs quickly giving a strong exothermic reaction which can reach 200°C. This reaction increases the volume of the mass converting it into hydrated lime, a white mush named lime grassello. Such materials harden only under the action of air.

Hydraulic lime-Hydraulic lime is obtained cooking in special ovens at the temperature of 900-1000°C calcareous rocks constituted of calcium carbonate and clay in a percentage between 5 to 22% or more. Hydraulic lime hardens even in water presence.

Cement-Cement is obtained by cooking calcareous rocks containing 20-22% of clay, at a temperature of about 1500°C. The process is more complex than the lime one, in fact the rock is crushed first, then dried at a temperature of 700°C, then calcined or decarbonated at a temperature between 900 and 1000°C, then finally clinkered at a temperature between 1000 and 1500°C.

Gypsum-Gypsum comes from sedimentary rocks made of calcium sulfate dehydrate. After cooking at 170°C, releasing water becomes Calcium sulfate anhydrous, basically gypsum stucco.

Calcium carbonate-Calcium carbonate or marble powder is obtained crushing and milling limestones. According to the amount of clay contained, it can be more or less white and has different water absorption and covering power.