What do you mean by Acidic Flux and Basic Flux?
Acidic flux are those flux which comes from substances like Lewis acid such as SiO2, H3PO4, HCl etc.
Acidic flux is used in metal welding or extractive metallurgy or Smelting.
Silica (SiO2) is used to remove basic earthly impurities (gangue) such as lime (CaO) or MgO.
It is similar to Acidic flux but only difference is that we take basic substances like CaO for welding process or extractive metallurgy or Smelting.
Basic fluxes like lime (CaO), magnesium oxide (MgO) are used to remove acidic gangue such as SiO2.