Importance of lime and limestone

Because limestone deposits are widely distributed throughout the world, a high proportion of humanity has ready access to the material. No reliable figures 

In most countries, the major uses of limestone are as an aggregate in construction and building and as the primary raw material for the production of cement. 

The amount of limestone used in construction and building varies widely from one locality to another and depends on its availability and cost relative to other aggregates, such as gravel and crushed hard rocks. In the USA, for example, limestone sales amounted to about 800 million tonnes in 1994 — about 72 % of the crushed rock sales. 

The proportion of limestone quarried that is used in construction and building is also affected by availability and cost. In many countries, the level is around 40 to 50 %, whereas in the USA and the UK, where limestone is widely available and relatively inexpensive, the level is over 70 %. 

While limestone is not an essential raw material for the production of cement, it is generally the cheapest source of calcium oxide. On the basis of the global production of cement, the limestone used in its production probably amounts to about 1,500 million tpa, or one third of the total extracted. 

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