DefinePK

Abstract

Eggshell was waste from industrial and household that was found in much amount and really easy to found. Eggshell was contained CaCO3 about 90 %w/w. CaO was main component of gypsum that could obtained from CaCO3 processing, hence eggshell could be used as an alternative raw material for gypsum manufacture. CaCO3 from eggshell could be used for gypsum manufacture by calcinations process in the furnace at temperature 900 0C in order to deform CaCO3 in the eggshell into CaO, then calcined material was mixed with aquadest and sulfuric acid solution and was stirred until precipitate was formed. Then, the precipitate must be filtered and dried in an oven until dried. The result was shown that increase the mixing concentration gave effect the increase of gypsum strenght. The maximum result was shown in variation ratio of 35% calcined material, 50% aquadest and 15% sulfuric acid, with elapse time was 5.5 minute, load was 6.5430 lbs at compressive strenght test. The composition of maximum result was shown 0.48% of SO3, 7.68% of CaO and 0.98% of H2O at XRD and SEM test.