Gypsum
Softest Mineral Ever!
Background Info
Chemical Formula: (CaSO42H2O)
- Physical Properties: Appears in nature as a mineral or rock. As a mineral, it can form attractive and sometimes extremely large, crystals. As a rock, gypsum is sedimentary usually found in thick beds or layers with halite, anhydrite, sulfur, calcite and dolomite. It can also have different appearances such as clear, colorless, white, gray, yellow, red, and brown. This mineral is also known for its flexibility and extreme softness (2 on Mohs’ hardness scale).
- Chemical Properties: Gypsum is the most common sulfate mineral and belongs in the sulfate group. In chemical composition it is very similar to Anhydrite (CaSO4). The chemical difference is that gypsum contains two waters and anhydrite is without water.
Top Locations for the Most Gypsum
Mining Method: Open Pit Quarry
First, the gypsum on the surface is broken by drilling and blasting. Then the fractured gypsum is loaded onto trucks and transported to a processing plant. Open-pit mines are normally used when deposits of minerals or rock are found close to the surface; where layer material covering the valuable deposit is comparatively thin or the material of interest is inappropriate for tunneling.
Processing Gypsum
Processing Plants
- At the processing plant, the large gypsum ore is reduced in size by passing through a large crusher. Crushing the ore generates a mixture of smaller rocks that can be cleaned and sorted by size. Sorting is accomplished by passing the gypsum through a series of vibrating screens. The end product is loaded for distribution to be further processed by the end user.
Marketing
Primarily sold through importing companies (mainly in India, like IndiaMart) as a powder-like form or drywall.
Prices:
- Retail: $24.97 (wallboard) $10 per. Lb (powder),
- Wholesale: $18.99 for 10 lbs (powder), $27.99 for 2 lbs (powder), $29.99 for 20 lbs (powder), $65.99 for 50 lbs (powder)
Uses Throughout the Ages
Past Uses
- Building pyramids
- Soil additive to improve crop yields in agriculture
- "Sackett Board" as a replacement for wood and as a base for the application of plaster
Ancient Pyramid
Present Uses
- Wallboard and plaster products (most significant)
- Make Portland cement
- Plaster of paris
- Agricultural applications such as soil conditioning
Environmental Issues
The process of obtaining gypsum can cause environmental degradation. According to the Global Press Institute, gypsum mines in India leave disfigurements on the landscape causing a rather unappealing look. The structure has also been removed from the landscape and deposits of gypsum are then exposed to the climate. Exposed gypsum dissolves easily in the rain and leaves gaping holes that both contribute to the erosion and pose a physical danger. The lack of rock or vegetation in the landscape can even lead to soil erosion and cause sinkholes and landslides.
Soultion
"Reclaiming"
This process involves returning the land to a state that is better than it was before the mineral was removed. A reclaimed mine can be beautiful, with many ponds and open fields. Some companies such as the Harrison Gypsum Company make an effort in returning mine sites to a state of usefulness.
Sources
- http://www.mineralseducationcoalition.org/minerals/gypsum
- http://www.minerals.net/mineral/gypsum.aspx
- http://minerals-n-more.com/Gypsum_Info.html
- http://www.harrisongypsum.com/facts/
- http://www.greatmining.com/open-pit-mining.html
- http://dir.indiamart.com/search.mp?ss=gypsum+powder&biz=20
- http://www.gypsum.org/about/gypsum-101/history-gypsum/
- http://www.gypsum.org/about/gypsum-101/what-is-gypsum/
- http://www.ehow.com/info_8535057_dangers-gypsum-mining-processing-use.html