... any requirement, please contact us freely. METALLURGICAL GRADE NIOBIUM POWDER SPECIFICATIONS: GradeNb (min %)Impurity Contained (ppm max) ... products contain rare earth oxides, rare earth salts, metal neodymium, metal praseodymium, Pr-Nd alloy, praseodymium, neodymium and dysprosium ... alloys, metal lanthanum, low iron, low magnesium mixed rare earth ...