Utilization of milk of lime (MOL) originated from carbide lime waste and operating parameters optimization study for potential precipitated calcium carbonate (PCC) production

Vast amounts of carbide lime waste generated as a by-product of acetylene gas production require urgent utilization to avert handling and disposal difficulties. The carbide lime waste is often rich in calcium hydroxide (Ca(OH)(2)), rendering it an alternative potential precursor for precipitated calcium carbonate (PCC) production. The study demonstrated that suspension of carbide lime can be utilized to synthesize PCC at favorable conditions. The characteristics and crystal morphology of the lime and as-synthesized PCC were determined using X-ray fluorescence and scanning electron microscope. The influencing reaction parameters based on temperature, flow rate, total dissolved solid and carbide lime concentration were investigated. Under specific reaction conditions of 2 M carbide lime concentration, final pH of 6.98, 90 min, and 452.30 mL/min CO2 flowrate, high purity of 99 % PCC was attained. The produced PCC from carbide lime meets end user requirement on a par with conventional PCC products.