What are the key differences between magnesium chloride forms for industrial buyers?

What are the key differences between magnesium chloride forms for industrial buyers?
Magnesium chloride hexahydrate (MgCl2·6H2O) is the dominant commercial form, prized for high water solubility and near-complete ionization across a broad pH range, enabling efficient absorption in both oral and transdermal applications. Its hygroscopic nature demands strict moisture control in packaging, warehousing, and transport to prevent caking and purity loss. Anhydrous magnesium chloride, with a melting point of 712°C, serves high-temperature metallurgical processes but requires more energy-intensive production. The hexahydrate decomposes above 135°C, releasing hydrogen chloride gas, so drying and calcination steps must be precisely controlled. Buyers should verify purity, impurity profiles, and third-party test reports, as contamination can cause defects in construction materials like fireproof boards, including efflorescence and strength failure.