Undoubtedly, limestone is one of the oldest materials used since long times ago. It is thought to be discovered by the tent-dwellers. Tent-dweller families who moved to cold and warm areas seeking for pastures made stove by stone and mud and made fire in it. All the limestone or a part of it which was used for making a stove was baked and changed into quicklime and the lime paste caused the adherence of the surrounding objects together. Moreover, the use of black mortar (black ash mortar) in the very old structures can be mentioned such as Choghazanbil Ziggurat, etc. The Russians learned from the Greeks how to bake the lime and the Greeks learned it from the Iranians because the oldest gauged mortar has been found in Iran. In Iran, the recognition and use of lime and foundation paste has been commenced since 3,000 years ago. The Chombatm (the grave in which the dead has been buried in sitting position) graves found in Hassanlou area have depths of 3 meters filled with foundation paste. The date of this civilization comes back to 7th and 8th centuries. The floors of Takht-e Jamshid palaces (6th century B.C) have been covered with red mortars in which lime has also been used.

In the ancient times, lime was baked in a furnace in which a position was made under the furnace by making a roof of limestone and then the top of the roof was fully covered with limestone. Then the fuel was put in that position and was heated for 4 days round-the-clock to be baked and the quick set lime was obtained.

The application of lime mortar in the stone and brick constructions as the mortar and also the wall coverage has been common since the time of Arsacides. Exploitation of lime was also developed in the era of Sassanians.

Ancient people knew well the chemical and mechanical characteristics of lime and also knew how to combin it with other materials. They had found by experience how to make strong or impenetrable materials.

How to Make Lime

1.Traditional method
2.Industrial (mechanical) method

Lime production is one of the oldest chemical processes recognized in the man’s history. In the past, lime was produced through traditional method but today it is produced by using technology and industrial achievements as well as exploitation from industrial furnaces.
The principal material in lime production is limestone or calcium carbonate (caco3). By heating it in different kinds of baking furnaces, co2 gas exits from it and calcium oxide (cao) or quick lime will be obtained.


Caco3 ---- Hot ----> Cao + co2


It is a fully alkaline compound and can be combined with all the acids (because it is an active and partly unstable compound). Keeping it causes some changes in its purity degree and creates a high temperature when being combined with water or acids.