Crushed stone

Despite the low value of its basic products, the crushed stone industry is a major contributor to and an indicator of the economic well-being of a nation.

Substitutes for crushed stone used as construction aggregates include sand and gravel, iron and steel slag, sintered or expanded clay or shale, and perlite or vermiculite.

The industry is highly competitive and is characterized by many operations serving local or regional markets.

These costs vary depending on geographic location, the nature of the deposit, and the number and type of products produced.

Because of the high cost of transportation and the large quantities of bulk material that have to be shipped, crushed stone is usually marketed locally.

Crushed marble sold or used totaled 11.8 million tons, the majority of which was ground very fine and used as calcium carbonate.

In 2006, 5.29 million tons of crushed stone (mostly limestone or dolomite) was used as a flux in blast furnaces and in certain steel furnaces to react with gangue minerals (i.e. silica and silicate impurities) to produce liquid slag that floats and can be poured off from the much denser molten metal (i.e., iron).