... ) ,≥77.5ºC(qualified level)invalatile substance:≤ 0.04 (excellent grade), ≤ 0.06 (first level),≤ 0.08 (qualified level)ash:≤ ... 0.01(excellent grade),≤0.01(first level),≤0.02(qualified level)Melting point ... Application:used in producing phthalic anhydride and additive of concrete Top grade Industrial naphthalene flakes,crude naphthalene,technical naphthalene,