Determination of Tungsten, Molybdenum, Boron, Sulfur and Phosphorus in Tungsten Molybdenum Ores by Inductively Coupled Plasma Atomic Emission Spectrometry Combined with Alkali Fusion and Separation using Ion Exchange Resin

The sample (0.500 0 g) was palced in a nickel crucible, and 2.5 g of sodium hydroxide was added, and the sample was covered with 0.5 g of sodium peroxide. The crucible was covered with the lid, and then placed in a muffle furnace, warmed up to 700℃ and kept at 700℃ for 7 min. After the crucible was taken out and cooled, the molten material was dissolved with 50 mL of hot water, the solution was transferred to a 100 mL plastic volumetric flask and diluted to 100 mL with water. The solution was shaken for mixing well, and let stand. 10 mL of the supernatant was taken and 5 mL of the treated 732 resin solution was added. The mixture was shaken for 20 min, diluted to 20 mL with water, and shaken for another 10 min. After centrifuge, the supernatant was analyzed by inductively coupled plasma atomic emission spectrometry. B 249.772 nm, W 207.912 nm, Mo 203.846 nm, P 213.618 nm, and S 181.972 nm were selected as analytical lines. Linear relationships were found between the emission intensity and the mass concentrations of tungsten, molybdenum, boron, sulfur and phosphorus within definite ranges, and the detection limits (3s) were 15, 11, 6, 34, 23 μg·g^-1, respectively. The method was used for the determination of tungsten, molybdenum, boron, sulfur and phosphorus in the national primary standard materials of tungsten molybdenum ore, giving the relative error between the measured values and the certified values in the range of -3.2%-2.0%, and RSDs (n=11) less than 3.0%. The method was applied to the simultaneous determination of tungsten, molybdenum, boron, sulfur and phosphorus in tungsten molybdenum ore samples, giving results consistent with those obtained by conventional methods.