Jun 04, 2015· Domestic production data for crushed stone were derived by the Geological Survey (USGS) from voluntary surveys of producers. In 2013, a total of 1,457 companies produced or sold crushed stone from 3,688 operations with 3,837 quarries and 204 sales and/or distribution sites.
In the production of iron, the blast furnace is charged with iron ore, fluxing agents, usually limestone and dolomite, and coke as fuel and the reducing agent. The iron ore is a mixture of iron oxides, silica, and alumina. From this and the added fluxing agents molten slag and iron are formed.