The Influence of Calcination Temperature to Calcium Content in the Mangrove Crab Shells (Scylla serrata) from Merauke

Abstract

This study introduced the use of shells of the Merauke Mangrove crabs as a natural source of calcium extracted through thermal decomposition process with various temperatures. The method adopted in this study was carried out in two stages; first, shells of the crabs that have been cleansed and dried under the sun for 24 hours, were mashed and then it divided into two parts. The first section was used for the analysis of calcium composition. While the second part was calcined at three different temperatures, 900°C, 1000°C and 1100°C for 5 hours before analysis. The results of the XRF showed that the raw powder of mangrove crab shell was contained 90.46% of calcium and 9.64% of other mineral content. This study revealed that the temperature of 1000°C is the right calcination condition to produce high calcium minerals in the mangrove crab shell, in which it reached 97.76% purity. The phase form that obtained from the XRD before being calcined was CaCO3 and after the calcination process was Ca(OH)2/CaO hydration. This study also found that the calcined process has succeeded to decrease the carbon content in the shells. Therefore, it can be concluded that the mangrove crab shells from Merauke, possess basic materials as bioceramic.