Determination of 10 Elements in Zirconium Ores of Hard-Rock Type by Inductively Coupled Plasma Atomic Emission Spectrometry with Lithium Metborate Fusion, Tartaric Acid Complexation, and Ultrasonic Extraction

In order to accurately determine 10 elements such as zirconium, hafnium, potassium, calcium, sodium, magnesium, aluminum, iron, titanium, and manganese in zirconium ore samples of hard-rock type, test conditions of melting and extraction were optimized, and the method mentioned by the title was proposed. The 0.1 g of the dried sample was placed into a platinum crucible, and 0.5 g of lithium metaborate was added. The mixture was mixed well, covered by the crucible lid, and melted at 1 000 ℃ for 30 min. After cooling, the platinum crucible was placed into the 25 mL of 20% (volume fraction) hydrochloric acid solution containing 20 g·L^-1 tartaric acid, and ultrasonic extraction was performed until the frit was completely dissolved. The solution obtained was made its volume up to 100 mL by water, and analyzed by the inductively coupled plasma atomic emission spectrometer. It was shown that linear relationships between values of the mass concentration and the spectral line intensity of the above 10 elements were kept in definite ranges, with detection limits（3s）in the range of 1.90-40.8 μg·g^-1. The proposed method was used for the analysis of zirconium ore samples of hard-rock type composed mainly of zircon or baddeleyite, which were consisted of basic rock reference materials with low zirconium content and zirconium concentrate reference materials. The relative errors of the determined values were in the range of -1.9%-4.0%, and RSDs (n=12) of the determined values were in the range of 0.46%-4.5%. The absolute values of accuracy and precision results were better than the control indicators specified in DZ/T 0130.3-2006, and the proposed method could also be applied to the accurate determination of zirconium ores of sand type.