A method and system is provided to separate calcium carbonate inorganic eggshell from the inner lining of organic protein based membrane in eggshell by product. The method involves three phases: mechanical agitation/separation functional chemical digestion and refining chemical digestion. In the mechanical stage agitation and sieving are used to remove large pieces and the majority of membrane material. In the functional chemical digestion stage the by product is processed through at least one basic solution to remove additional organic membrane and impurities. In the refining chemical digestion stage the remaining organic membrane and impurities are removed. The purified calcium carbonate is then rinsed and dried in preparation for further refinement and processing to finished goods specifications.
