Mineral ascorbates are salts of ascorbic acid (aka vitamin C). They are powders manufactured by reacting ascorbic acid with mineral carbonates in aqueous solutions, venting the carbon dioxide, drying the reaction product, and then milling the dried product to the desired particle size.
A study found ascorbates (as magnesium or calcium ascorbate) to be a very effective chelator of aluminium, especially when the aluminium was bound to brain cell DNA.citation needed Taking higher doses of ascorbate with magnesium citramate increased the removal of aluminium.citation needed