... any requirement, please contact us freely. METALLURGICAL GRADE NIOBIUM POWDER SPECIFICATIONS: GradeNb (min %)Impurity Contained (ppm max) ... 150mesh DESCRIPTION: In powder with deep-gray color.USAGE:Used in niobium mill products, additive in alloy and welding bars ... rare earth salts, metal neodymium, metal praseodymium, Pr-Nd alloy, praseodymium, neodymium and dysprosium alloys, metal lanthanum, low ...