Calcium chloride is a typical water-soluble inorganic salt, widely used in de-icing, snow melting, dust removal, desiccant, cooling brine, and wastewater treatment due to its strong hygroscopic and exothermic dissolution properties. As a water treatment additive, calcium chloride can adjust water hardness, promote coagulation and sedimentation, and reduce fluoride ion concentration. In oil drilling and production, it is used as an additive in drilling and completion fluids. Food-grade calcium chloride (E509) is used as a coagulant (e.g., in tofu), thickener, and electrolyte supplement. Industrial-grade products are manufactured using the hydrochloric acid-limestone method or ammonia-soda wastewater recovery method, exhibiting high purity and low water-insoluble matter content, conforming to GB/T 26520-2011 standards.