Production of purified calcium carbonate

摘要: A method of producing relatively pure calcium carbonate from a impure source oxide, characterised in that the comprises steps slaking oxide water to produce an aqueous hydrated lime slurry; treating slurry by addition thereto soluble anions which are capable forming salt with ions has dissociation constant greater than hydroxide; separating solid content liquid fraction thereof obtain substantially solids-free solution and anions; intimately contacting carbon dioxide gas at selected rate maintain temperature within specific range lower pH pre-set value conducive for formation precipitate one crystalline forms, group consisting calcite, vaterite aragonite, predominates; and separating precipitated mother liquor.