The industrial manufacture of ultramarine blue pigment involves a high-temperature calcination process using silica, alumina, sodium carbonate, sulfur, and a reducing agent. These raw materials are blended and heated in a kiln at temperatures between 700°C and 800°C.
During calcination, the raw materials react to form the complex aluminosilicate framework characteristic of ultramarine. The blue color is generated by polysulfide anions trapped within this framework. The process is carefully controlled to ensure consistent shade and color value.
After calcination, the crude pigment is milled to achieve the desired particle size distribution. Particle size significantly influences tinting strength, brightness, and dispersion characteristics. Wet or dry milling processes are used depending on the grade.
Surface treatment is applied to some grades to improve wettability and dispersion in specific applications such as water-based paints or masterbatches. The treated pigment is then dried, classified, and packed for shipment.
At Shree Krishna Ultramarine Pigments (P) Limited, the manufacturing process is continuously monitored by our quality team. We use state-of-the-art analytical equipment to ensure every batch meets our internal specifications and customer requirements before it leaves our facility.