Design and Fabrication of Plaster of Paris Recycling Machine.

I. INTRODUCTION Plaster of Paris (POP), chemically known as Calcium Sulphate Hemihydrate (CaSO4·0.5H2O), is a widely utilized material in construction, medical modelling, architectural detailing, and artistic sculptures. Derived from the calcination of Gypsum (CaSO4·2H2O) at temperatures between 100°C and 180°C, POP is favoured for its rapid setting time, fire resistance, and ability to capture intricate Mold details. In the Indian context, POP holds significant cultural and industrial importance, particularly in the manufacturing of idols for festivals such as Ganesh Chaturthi and Durga Puja, as well as in the booming real estate sector for false ceiling and wall finishing applications. Despite its versatility, the widespread use of POP has resulted in a massive environmental challenge: waste management. Unlike natural clay, POP is non-biodegradable and insoluble in water. When disposed of in landfills, it contributes to soil inorganic loading. More critically, the immersion of POP idols in water bodies—a common cultural practice—leads to severe aquatic pollution. The material settles at the bottom of lakes and rivers, forming a thick layer of sludge that blocks natural springs and reduces the oxygen carrying capacity of the water. Furthermore, the paints, varnishes, and decorative materials often applied to POP structures contain heavy metals like lead, mercury, and cadmium, which leach into the water ecosystem, posing serious health risks to marine life and humans.