Synthesis of Aragonite from Calcined Scallop Shells at Ambient Temperatures and Their Morphological Characterization by FE-SEM

Abstract

Pure aragonite was synthesized from calcined scallop shells in a single step in the presence of Mg²⁺ ions at ambient temperatures under the controled CO₂ flow rates. The Mg²⁺ ions seem to behave like a catalyst to form aragonite, since most of the Mg²⁺ ions remained in the solution. However, very small amounts of Mg²⁺ ions was selectively adsorbed onto the surface of fine calcite crystals to inhibit further growth of calcite. The morphologies and sizes of aragonite was strictly controlled by the reaction temperature. It was a characteristic property of calcined scallop shells to produce the aggregated aragonite. This study possibly would contribute to a better utilization of waste scallop shells and to establish a "soft process" for producing fine particles of aragonite.