Determination of W, Mo and 11 Other Elements in Tungsten-Molybdenum Ores by Inductively Coupled Plasma Optical Emission Spectrometry with Lithium Metaborate Fusion

BACKGROUND Tungsten molybdenum ores are strategic mineral resources. China is a large producer and consumer of tungsten and molybdenum ore. Accurate and efficient analysis of tungsten and molybdenum and its associated beneficial and harmful elements is of great significance for the evaluation and comprehensive utilization of tungsten and molybdenum ore deposits. Acid dissolution and alkali fusion are the general digestion methods in tungsten molybdenum ore analysis. However, the acid solution method cannot be used to overcome the hydrolysis problem when treating samples with high content of tungsten and molybdenum, whereas the alkali fusion method such as sodium peroxide and sodium hydroxide usually introduces a large content of alkali metals, so the determination of potassium and sodium cannot be finished. OBJECTIVES To find an efficient method for the determination of tungsten, molybdenum and 11 other elements in tungsten molybdenum ore. METHODS Lithium metaborate melting-tartaric acid ultrasonic leaching and inductively coupled plasma-optical emission spectrometry (ICP-OES) was used for the simultaneous determination of tungsten, molybdenum, copper, lead, zinc, aluminum, iron, calcium, magnesium, titanium, manganese, potassium and sodium in tungsten-molybdenum ore. The sample was completely digested by lithium metaborate fusion. No other elements were introduced except for B and Li. Tartaric acid was used to inhibit the hydrolysis of tungsten and molybdenum. Ultrasonic leaching speeds up the dissolution of the frit. RESULTS The experiment optimized the analysis spectrum and observation method of each element, compared the amount of flux and instrument conditions to obtain the best conditions, and used the matrix matching method to draw a standard curve to eliminate the influence of the matrix effect. The linear correlation coefficient of the standard curve of each element was greater than 0.9990, the detection limit of the method was 1.34-46.2μg/g, the relative error of measured results was 0.14%-8.7%, the relative standard deviation (RSD, n=10) of the measured results was 1.4%-7.6%. CONCLUSIONS This method can accurately and efficiently complete the simultaneous determination of multiple elements in tungsten and molybdenum ore samples.