Clay, iron ore, iron and steel slag, sand and gravel 2009 summaries

The following has been extracted from the USGS Mineral Survey, January 2010

Clays

Domestic production and use

In 2009, clay and shale production was reported in 41 States. About 190 companies operated approximately 830 clay pits or quarries. The leading 20 firms supplied about 50% of the tonnage and 80% of the value for all types of clay sold or used in the United States. In 2009, sales or use was estimated to be 25.3 million t, valued at US$1.4 billion.

Import sources (2005 - 2008)

Brazil, 84%; UK, 4%; Mexico, 3%; Canada, 2%; and other, 7%.

Iron ore

Domestic production and use

In 2009, mines in Michigan and Minnesota shipped 99% of the usable ore produced in the US, with an estimated value of US$2 billion. Twelve iron ore mines (11 open pits and one dredging operation), eight concentration plants, and eight pelletising plants operated during the year. Almost all ore was concentrated before shipment. Eight of the mines operated by three companies accounted for virtually all of the production. The US was estimated to have produced and consumed 1% of the world’s iron ore output.

Import sources (2005 - 2008)

Canada, 58%; Brazil, 34%; Chile, 2%; Trinidad and Tobago, 2%; and other, 4%.

World Resources

US resources are estimated to be about 110 billion t of ore, containing 27 billion t of iron. US resources are mainly low-grade taconite-type ores from the Lake Superior district that require beneficiation and agglomeration prior to commercial use. World resources are estimated to exceed 800 billion t of crude ore, containing more than 230 billion t of iron.

Iron and steel slag

Domestic production and use

Iron and steel slags are co-products of iron- and steelmaking. Data on US slag production are unavailable but output is estimated as having declined by nearly one-half to a range of 8 - 12 million t in 2009, as a result of numerous idlings of steel plants during the year. Slag sales are estimated to have declined less severely, based on their being largely from stockpiles. An estimated 13 million t of iron and steel slag, valued at nearly US$300 million was sold during the year. Iron or blastfurnace slag accounted for about 60% of the tonnage sold and had a value of about US$260 million; nearly 85% of this value was granulated slag. Steel slag produced from basic oxygen and electric arc furnaces accounted for the remainder. Slag was processed by about 30 companies servicing active iron and/or steel facilities or reprocessing old slag piles; iron slag at about 40 sites in about 14 States and steel slag at about 100 sites in 30 States. Included in these data are a number of facilities that grind and sell ground granulated blast furnace slag (GGBFS) based on imported unground feed.

World mine production and reserves

It is estimated that annual world iron slag output in 2009 was around 200 - 250 million t, and steel slag about 110 - 160 million t, based on typical ratios of slag to crude iron and steel output.

Sand and gravel (construction)

Domestic production and use

Construction sand and gravel valued at US$6.2 billion was produced by an estimated

4000 companies from about 6400 operations in 50 States. Leading producing States, in order of decreasing tonnage, were Texas, California, Arizona, Colorado, Wisconsin, Michigan, Minnesota, New York, Nevada, and Ohio, which together accounted for about 50% of the total output. It is estimated that about 44% of construction sand and gravel was used as concrete aggregates; 23% for road base and coverings and road stabilization; 14% as construction fill; 12% as asphaltic concrete aggregates and other bituminous mixtures; 3% for plaster and gunite sands; 1% for concrete products, such as blocks, bricks, and pipes; and the remaining 3% for filtration, golf courses, railroad ballast, roofing granules, snow and ice control, and other miscellaneous uses.

The estimated output of construction sand and gravel in the 48 conterminous States, shipped for consumption in the first six months of 2009, was about 344 million t, a decrease of 29% compared with the revised total for the same period in 2008.

Recycling

Asphalt road surface layers, cement concrete surface layers, and concrete structures were recycled on an increasing basis.

Import Sources (2005 - 2008)

Canada, 75%; Mexico, 19%; The Bahamas, 4%; and other, 2%.

World resources

Sand and gravel resources of the world are large. However, because of environmental restrictions, geographic distribution, and quality requirements for some uses, sand and gravel extraction is uneconomic in some cases. The most important commercial sources of sand and gravel have been glacial deposits, river channels, and river flood plains. Use of offshore deposits in the US is mostly restricted to beach erosion control and replenishment. Other countries routinely mine offshore deposits of aggregates for onshore construction projects.

Read the article online at: https://www.worldcement.com/the-americas/08022010/clay_iron_ore_iron_steel_slag_sand_gravel_2009_summaries/