Optibor, in combination with a sodium borate (such as neobor borax pentahydrate or dehybor u00ae anhydrous borax), can be used to adjust the sodium-to-boron ratio in glasses that require low sodium levels, such as borosilicate glass, in which boric oxide provides essential fluxing properties at low sodium and high alumina levels. for the glassy surfaces of ceramics and enamels, boric oxide u2026 Anhydrous borax is white solid crystalline product used in gold smelting as a flux. the advantages of using borax in gold smelting are: facilitates separation of the gold from gangue at lower temperatures. borax forms a structural network with rock silicates that captures metal ions which normally associate with oxides eg. Also known as: sodium borate, sodium tetraborate (decahydrate), and disodium tetraborate. borax is an important boron compound, a mineral, and a salt of boric acid u2026 There are 1,147 anhydrous borax suppliers, mainly located in asia. the top supplying countries or regions are china, south africa, and united states, which supply 95%, 1%, and 1% of anhydrous borax respectively.