Phosphate is a prevalent chemical element in the Earth's crust, and its presence in water can lead to eutrophication. To address this issue, researchers have explored various methods for removing phosphate from water and wastewater. Filtration methods have been shown to be effective, but they can be costly due to the materials used. Recent studies have focused on finding more cost-effective alternatives. This study examines the potential of using furnace bottom ashes (FBAs) from the iron industry to remove phosphate from synthetic water. The study considers different operational conditions, such as detention times, FBA doses, and phosphate concentrations, to identify the most effective and affordable removal approach. The results indicate that FBAs can be a highly efficient alternative for phosphate removal, with an optimum removal of 97.1% at 120 minutes retention time, 10 mg/L phosphate concentration, 10 mg/L FBA doses, and pH of 7.5. The findings are used to develop a highly reliable model with an R² value of 0.97.