Some of the earliest evidence for the use of lime dates back roughly 10,000 years. An excavation in Cajenu in Eastern Turkey revealed a Terrazzo floor that had been laid with lime mortar. Lime stabilisation of clay was also used about 5,000 years ago in Tibet for the construction of the pyramids of Shersi. It was also used in conjunction with limestone by the Egyptians in the construction of the pyramids and by the Chinese when they built the Great Wall of China. By 1,000 B.C., there is evidence that both quick and hydrated lime has been used for building in numerous civilizations, including the Greeks, Egyptians, Romans, Incas, Mayas, Chinese and Mogul Indians.
The earliest ever excavated lime kiln was dated to 2,400 BC and was found at Khafaje in Mesopotamia, an era which almost marks the beginning of human civilisation.
The Romans employed hydraulic lime and lime pozzolan mixtures in many construction projects, including the Appian Way. They developed the technology of lime burning and the use of mortar, cement and concrete, using lime as the binder. They built the first lime factories and discovered that lime also acts as a chemical reagent. In 350 BC Xenophon referred to the use of lime for bleaching linen. Almost all of the Mediterranean peoples were familiar with lime as a paint. Lime was also used for tanning leather, and was mixed with organic substances to produce putty and glue.
When the Roman Empire fell, however, the Romans took the majority of their technology with them (including the burning of stone) and as a result, the Saxons who followed tended to use large amounts of timber for construction, meaning there was a significant period of time when stones/rocks/lime were rarely used. Lime was finally re-introduced when the Normans arrived and used it for the construction of a number of religious buildings.
In 1824 Portland cement was established and soon dominated the construction market, slowly edging out the use of lime. The use of lime in building and construction is now widely recognised to give important benefits in flexibility, breathability and overall sustainability of the building and its use is back in vogue for both building restoration and new build.
Lime is the cheapest and most widely used alkali. Global production of lime products is now estimated to be well in excess of 200 million tonnes per annum.
Lime is regarded by many as one of the most heavily used chemicals in the world. In the USA for example approximately 15 million tpa of lime is produced, making it the 5th largest selling chemical on a tonnage basis (just behind sulphuric acid, nitrogen, oxygen and ethylene).
In the majority of industrial countries, the major uses of lime products are in steel making (38%), and the construction and building industry (36%). Growing markets for lime include environmental clean-up, where it is used to remove or "lock in" pollutants from soil, water and air. The remaining lime is used in a wide array of industries (see 'A-Z of Applications' for more detail), many of which you will encounter in everyday life.
If you add up the number of times during the day that you use, touch, eat or drink something in which lime is used, you might be surprised at just how much we all rely on this amazing chemical.