Ultramarine Blue Inorganic Pigment Production from locally available Raw Materials

Abstract

Synthetic ultramarine inorganic blue pigment is one of common type of blue pigment which can be easily produced from locally available geomaterials. The chemical composition of these geo-materials (sulphur and clay) was investigated by the silicate analysis method and Synthetic ultramarine blue pigment was synthesized by a solid state calcination process. A literature review was used to select and investigate the effect of reaction temperature (750, 800 and 850 0C), residence time (4, 5, and 6 hours), and sulfur weight amount (20.56, 21.34 and 22,06w %) on the blue pigment production process. The main blue coloring strength was identified by Commission Internationale de l'éclairage laboratory coordinate value (L*, a*, b*) where L* is the lightness value starting from 0 up to 100, a* and b* are correlation coordinates which show the coloring value between +60 and-60. The optimum process parameters for the production of blue color pigment were determined by a design expert. The optimal process parameters were a reaction time of 4.87hr. (4 hours and 52 minutes), reaction temperature (799.840C), sulfur concentration (22.06 wt. %), and blue color value (b*=-13.13). The pigment properties were characterized by density, moisture content and color value, resistance to heat, detergent, acid, alkali and light. The crystalline nature structure and the functional group were determined by X-ray diffraction and infrared spectroscope. The quality of the blue color strength was also examined by spectrophotometer CM- 600d. According to the results of the research, there's an opportunity to produced ultramarine pigment material by using local geo-minerals.