1. Natural products The natural calcium carbonate (CaCO3) extracted from the quarry is in reality chalk . The same type of products is used for the paper industries and the paints or as « filler » for the plastics. There is only one advantage : its low price. In return, you take a risk as regards to the quality and a possible lack of regularity in the product, this is due to a possible important content of : - impurities,
- heavy metals (due to the extraction techniques and to the composition of the quarry),
- bacterium.
The other question is the shelflife and the lack of homogeneity of the quarry where the chalk is taken. |