1. RuiKe National Engineering Research Centre of Rare Earth Metallurgy and Function Materials Co. Ltd., Baotou 014030, Nei Mongol, China 2. Baotou Research Institute of Rare Earths, Baotou 014030, Nei Mongol, China
Abstract：The samples were dissolved by aqua regia and evaporated to about 2 mL of the volume. Hydrochloric acid was extracted. The silicon molybdenum heteropoly acid was formed with silicon and ammonium molybdate at pH=1.Phosphorus and arsenic were masked with oxalic acid. The determination method of silicon in rare earth system hydrogen alloys by silicon molybdenum blue spectrophotometery was established after being reduced to silicon molybdenum blue with ascorbic acid. The proposed method was applied to the determine silicon in rare earth system hydrogen alloys. The detection range of silicon is 0.0050%-0.50%.The detection limit and lower limit of silicon in the method was 0.000 50% and 0.005 0%(mass fraction),Method with low, medium and high grade three samples covering the detection range of silicon. The relative standard deviations(RSD,n=11) of found results was 2.04%（low），3.81%（medium），2.08%（high）.The recoveries were between 97.26%-102.02%.The content of silicon in rare earth system hydrogen alloys actual sample was determined according to the experimental method, and the found results were consistent with consistent with those obtained by inductively coupled plasma atomic emission spectrometry.
2017, Vol. 24 
