The price is primarily driven by the Calcium Fluoride (CaF2) content, typically ranging from 60% to 85% for metallurgical grade. Other critical factors include the Silica (SiO2) content, which should ideally be below 5% to ensure effective fluxing, and the levels of impurities like Sulfur (S) and Phosphorus (P), which must be kept at a minimum to avoid contaminating the steel. Additionally, the physical size (lumps vs. fines) affects the price, as lumps (10-50mm) are preferred for better permeability in blast furnaces.