Spray dry scrubbing is a popular method for removing sulphur dioxide (SO₂) gas from industrial flue gases, with hydrated lime (Ca[OH]₂) being a preferred sorbent due to its high reactivity. This study investigated the feasibility of using Industrial Brine Sludge Waste (IBSW) from the chlor-alkali industry as a source of Ca[OH]₂. XRF analysis revealed that IBSW had a high content of CaO (89.05%), making it a suitable starting material for the production of a calcium-based sorbent. A laboratory-scale spray dry scrubber was used to test the performance of the prepared Ca[OH]₂ sorbent. The desulphurization efficiency was analyzed by investigating how the SO₂ capture in the spray dryer was influenced by the inlet flue gas temperature (120 °C - 180 °C), slurry pH (6 - 12), Ca:S ratio (1.0 - 2.5), and sorbent particle size (-45µm to -90µm). The highest SO₂ capture rate of 88.54% was achieved under the following conditions: inlet flue gas temperature of 120°C, Ca:S ratio of 2.5, particle size of -45µm, and a slurry pH of 12. The results suggest that IBSW can be a viable starting material for producing Ca[OH]₂ sorbent, which could then be utilized in the spray dry scrubbing process to remove SO₂ from industrial flue gases