Manufacturing method of high purity calcium carbonate by the crystallization method

摘要

Provided are a method for preparing high purity calcium carbonate of 99.9% or more purity by purifying calcium chloride to form an aqueous solution, growing a crystal of the solution by slow cooling and temperature difference, dissolving the crystal, and neutralizing a mixture gas of ammonia gas and carbonate gas by gas blowing, and a method for preparing a water-soluble calcium powder having amorphous phase by using the prepared high purity calcium carbonate as a starting material. The method for preparing water-soluble calcium having high purity comprises the steps of: adding ammonia water or gas to aqueous solution of calcium chloride containing no floats with stirring and removing secondarily formed impurities from the solution; heating and thickening the solution, and then growing a single crystal of the thickened solution by slow cooling and temperature difference; treating the crystal by gas blowing to form high purity of calcium carbonate slurry; and filtrating and drying the formed calcium carbonate slurry.