MANUFACTURING METHOD OF CHEMICAL CALCIUM COMPOUND USING SHELL MATERIALS

摘要

A method for preparing a high-purity calcium-based compound using waste shells is provided to recycle waste resources efficiently, remove sodium and strontium ions from waste shells effectively, and to manufacture easily an ultra high purity calcium-based compound used for electronic ceramics and medicines. A method for preparing a high-purity calcium-based compound using waste shells includes the steps of: adding an aqueous solution of hydrochloric acid or nitric acid to washed shells to obtain a solution, removing impurities from the solution, adding ammonia water to the solution to provide pH 5-9, and separating a supernatant from a precipitate to prepare an aqueous solution of calcium chloride or calcium nitrate; thereto adding potassium hydroxide and ammonia water to the aqueous solution of calcium chloride or calcium nitrate and adjusting pH of the solution to 8-13 to convert sodium chloride, strontium chloride or sodium nitrate, and strontium nitrate into sodium hydroxide and strontium hydroxide; adding 0.1-0.5wt%, based on the amount of calcium ions present in calcium hydroxide, of a surfactant to the sludge of calcium hydroxide to remove the sodium hydroxide and strontium hydroxide, stirring the admixture for 1-5 hours to activate the surfaces of calcium hydroxide, sodium hydroxide, and strontium hydroxide, and filtering the resultant using a centrifuge and filter press; and carbonating the calcium hydroxide to prepare calcium carbonate.