Quarry the limestone - The land over the limestone deposit must be removed with bulldozers and scrapers, then holes are drilled into the rock and explosives are placed inside to blow the rock apart. Pastel chalks also contain clays and oils for pigment. The base component in pastel chalks is Calcium Sulfate, which is derived from a mineral evaporate of ocean brine called Gypsum. Calcium Carbonate is a form of limestone, which is formed when plankton skeletons decompose and turn into coccoliths, then the coccoliths accumulate and form sedimentary layers. Manufacturing Chalk Citations Calcium Carbonate is the main component in chalk. Chalk is also used in fingerprint powder. Toothpaste, for example, contains small amounts of chalk. Antacid properties make chalk ideal for polishing and cleaning. Chalk used to be used in agriculture to raise pH levels in soils with high acidity.
Use of Chalk Chalk Chalk didn't become a standard in a classrooms until the nineteenth century. Then, the marine salts will contribute to the other marine shells or remain undissolved which will, either way, create a new limestone or gypsum bed millions of years from now. When it returns to the ocean it will continue the calcium cycle, and contribute to the dissolved marine calcium. previous uses information When you draw with chalk on the sidewalks it will eventually be washed away by rain and go through the local sewers, and end up back in the ocean. previous uses information "Chalk." Wikipedia 28 Oct. most of chalk information "Chalk." Wikipedia 28 Oct. recycling process information Sheridan, Rob. "Sidewalk Chalk and the Calcium Cycle." Earth Science Picture of The Day 19 Oct. Transcript: Former underground chalk quarry in Meudon, France Raw Materials Reuse and Recycling "Chalk and Limestone." Science Online.
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