North Star Minerals
Mine and Plant,
Acton, CA

North Star Mineral's Green Clay

North star minerals has clay used for making cement that produce, on average, 785 tons fewer of CO2 emissions than standard calcium carbonate for each 1000 tons of his green clay used. This is according to Larie Richardson, President of North Star. They call this clay the Green Clay, to reflect on it's environmental friendly nature.

For background information, the cement making process involves heating limestone (CaCO3) in a kiln. This produces Calcuim Oxide (CaO) and carbon dioxide (CO2). The carbon dioxide is discharged, and is currently blamed for Global Warming. In any event, Larie looked for ways to reduce the CO2 emission from the cement process, and being a geologist, looked at finding new types of clay for producing cement - the geological approach. After kicking many rocks in the desert and conducting tons of sampling and testing, Larie found his current deposits. His clays do not have nearly as much CO2 in them as Limestone, since it has a lot of Alumina, some iron and silica in addition to the CaO. All of these are required to produce cement, but produce very little CO2 in the process.

According to Larie's calculations, "there are 785 tons of CO2 not released per 1,000 tons of CaO in his clays. The details of the calculations are as follows.

The molecular weight of CaO is 56.0774 and the molecular weight of CO2 is 44.0095 grams per mole. The molecular weight if CaCO3 is 100.0869 g/m. The ratio of CO2 to CaO is 44.0095 to 56.0774. Accordingly, the CO2 not produced per 1,000 tons of his clays burned in the cement process is that ratio (0.7848). Multiplying 0.7848 times 1000 leads to the 785 tons mentioned above."

Since everyone is currently concerned with manufacturing and producing products, while putting less carbon dioxide into the atmosphere, here is a way to reduce emissions by changing raw materials that produce much less carbon dioxide, in the first place. Who could argue with that approach?

The Low Iron Green Clay, Anorthite 
Low Iron Content Green Clay up close 
High Iron Content Green Clay 

"Lumpy Clay", as nicknamed by a cement plant using it. This is Hornblende and other minerals, and is used in the cement making process to furnish minerals required other than calcium. 
A stacking conveyor at the high iron green clay pit. 
The low iron Anorthite (Green Clay) stockpile 
Area around the mine. Most of the growth is Chapperal. It makes reclamation easy. 
Some of the front end loaders at the mine. 
The scale house, complete with a pirate flag  

More Information on the Green Clay

Mine received slight damage from 2009 Station Fire. Photos.
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