Borax Molecular formula: Na2B4O7.10H2O CAS No. : 1303-96-4 Specification: Items Guaranteed Patameters Purity 95% min Water Insolunle Matter 0.04% max Carbonate 0.2% max Sulphate 0.2% max Chloride 0.05% max Fe 0.005% max Packing: 25kg woven bag with PE liner or 1000kg big bag Application: Mainly used in biochemical and chemical laboratories to make buffers. A mixture of borax and ammonium chloride is used as a flux when welding iron and steel . It is also uesd as food additive and in manufacture of putty, glass, pottery, enamel glazes and so on.