Research on the treatment method and production process of high-purity calcium chloride from hatching poultry eggshells waste

Tóm tắt

The rapid growth of the poultry industry generates a significant volume of eggshell by-products from hatcheries, which pose biological hazards and are often discarded, causing environmental concerns. Eggshells consist of over 93% calcium carbonate (CaCO₃), representing a valuable natural source for calcium-based products, particularly calcium chloride (CaCl₂). This study investigated pre-treated methods to reduce microbial contamination, improve membrane separation, and recover eggshells rich in CaCO₃ for CaCl₂ production. Sterilization at 121℃ for 60 min, followed by drying at 45℃ for 4 h, achieved the best microbial reduction and membrane separation efficiency (93%), the purity of CaCO₃ reaches 98%. Conversion from CaCO₃ to CaCl₂ achieved 89% recovery and 100% purity, meeting the QCVN 4-9:2010/BYT standards, with technological conditions: demembraned eggshell with (particle size >3 mm) was mixed with a 5% HCl solution at a 1:15 (mass/volume) ratio for 3.5 h. These findings demonstrate the potential for industrial-scale CaCl₂ production from eggshell waste.