Leaching of calcium phosphate with sulfuric acid was carried out to study phosphogypsum (PG) crystal growth and size distributions in presence and absence of phosphogypsum seed crystals (PGSC) and sorbitol surfactant (SS) additives. PG crystallization simulates industrial Dihydrate process for phosphoric acid production. PG crystals grow in a medium containing 26±1% P₂O₅ phosphoric acid and 2±0.5 % free sulfuric acid. Better filterability of phosphoric acid can be achieved with large crystals. The formed PG crystals are larger with addition of either 100 ppm Sorbitol surfactant, 5%, 10% or 15% PGSC compared to the baseline (without additives). With addition of surfactant or increasing the % of PGSC from 5% to 15%, both the mean diameter and d₉₀ of crystalized PG are increased due to enhancing the crystallization growth rates.