REUSE OF WASTE CRAB SHELLS FOR SYNTHESIS OF CALCIUM CARBONATE AS A CANDIDATE BIOMATERIAL

Abstract

The crab shell (Portunus Pelagicus) wastes are constituted of major calcium carbonate (account for 70 wt. %) and have the potential to reuse as a starting biomaterial for precipitated calcium carbonate (PCC) products. The purpose of the present work was to synthesize PCC powder using crab shells based on the gas-solid-liquid carbonation route. In this experiment, crab shell powder was prepared by washing, drying, and subsequent grinding. The resulting powder was then calcined at 900 ℃ for 5 h before being used for the synthesis of the PCC product. Later, the calcined crab shell powder was dissolved with 2M HNO3 solution in a glass beaker with the pH solution of 12 set up by adding NH4OH. The solution was subsequently stirred magnetically for 30 min. The carbonation process ended when the PCC solid was obtained at a pH of 7. The crab shell powder, crab shell powder after calcination, and the obtained PCC solid were then characterized using XRD, SEM-EDX, and FTIR methods, respectively. The resulting PCC product has been shown to have calcium carbonate with the major vaterite phase. This experimental work demonstrated the potential application of crab shells for a low-cost biomaterial of future medical applications.