Determination of niobium in Ni-Nb alloy by gravimetric method
The Ni-Nb alloy was completely dissolved by the synergistic oxidation of nitrosylsulfuric acid produced by sulfuric acid-nitric acid mixed acid at heating state,and the niobium was fully dissolved again by low temperature heating in concentrated hydrochloric acid bottom solution.The solution was diluted with water to a certain volume,sufficient tannic acid solution was added to precipitate niobium completely and separate it from nickel,iron,chromium and aluminum.After filtering,burning and weighing,the niobium pentoxide was obtained and the mass fraction of niobium is calculated.The dissolution conditions the amount and time of precipitant,and temperature and time of cautenization were ditermined in this method,and the determination range of niobium was 60％～80％.The relative standard deviation(RSD)of the results was less than 2.0％,the recovery rate was 98.00％～102.00％.This method is especially suitable for the accurate determination of niobium content in Ni-Nb alloy,which can meet the strict testing requirements of high temperature alloy manufacturers,it can promote the production,quality inspection and technical progress of superalloy materials in our country.
万方数据
维普
