Oxide of calcium is a usual not extinguished lime. But, despite so simple nature, this substance is very widely used in economic activity. From construction, as a basis for limy cement, to cookery, as E-529 nutritional supplement, oxide of calcium finds application. Both in industrial and in house conditions it is possible to receive calcium oxide from a calcium carbonate reaction of thermal decomposition.
It is required to you
- Calcium carbonate in the form of limestone or chalk. A ceramic crucible for annealing. Propane or acetylene torch.
Instruction
1. Prepare a crucible for annealing of a carbonate of calcium. Strongly establish it on fire-resistant supports or special devices. The crucible has to be strongly installed and, at an opportunity, is fixed.
2. Crush a calcium carbonate. Crushing needs to be made for the best heat transfer in masses substances. It is not obligatory to pulverize limestone or chalk. It is enough to make rough non-uniform crushing.
3. Fill a crucible for annealing with the crushed calcium carbonate. You should not fill a crucible completely as at release of carbon dioxide, a part of substance can be thrown out outside. Fill a crucible approximately on a third or less.
4. Start heating of a crucible. Well establish and fix it. Carry out smooth warming up of a crucible from different sides in order to avoid its destruction owing to uneven thermal expansion. Continue to heat a crucible on the gas burner. After a while reaction of thermal disintegration of a carbonate of calcium will begin.
5. Wait for full passing of reaction of thermal disintegration. During reaction the top layers of substance in a crucible can badly get warm. They can be mixed several times a steel shovel.
6. Cool a crucible and substance in it. Switch off the gas burner and wait for full cooling of a crucible. Now in it there is a calcium oxide.