Determination of Vanadium, Iron, Aluminum and Phosphorus in Stone Coal Vanadium Ore by ICP-OES with Open Acid Dissolution

BACKGROUND The exploration, research and utilization of stone coal vanadium ore resources need accurate composition determination, while there is no standard method for the determination of its main components such as vanadium, iron, aluminum and phosphorus. At the same time, every analysis method currently used has its own shortcomings. When the sample of stone coal vanadium ore is treated by alkali fusion and determined by ICP-OES, the high concentration of soluble salt will lead to high background and interference with the determination. The acid dissolution method can avoid the above problems, but when the conventional four acid system composed of HF+HCl+HNO3+HClO4 is used to digest the sample, the components to be tested in the sample cannot be completely released, so the sample needs to be burned at high temperature to remove carbon, making the process is cumbersome. OBJECTIVES In order to establish a method for the determination of the main components in stone coal vanadium ore samples by ICP-OES using five acid systems to digest samples. METHODS A mixed acid system of H2SO4+HF+HCl+HNO3+HClO4 with electric hot plate heating and hydrochloric acid extraction were used to digest the samples. The contents of vanadium, iron, aluminum and phosphorus in stone coal vanadium were determined by ICP-OES. RESULTS Using the strong oxidizing property of sulfuric acid to oxidize a large amount of carbon in the sample into carbon dioxide, eliminated the process of burning carbon removal, eliminated the adsorption and wrapping of carbon-containing substances on the sample, and significantly enhanced the digestion effect. When the sample weight was 0.1g and the concentration of sulfuric acid was 0.30mL, the digestion rate of the sample reached more than 99%. The detection limit was 17-51mg/kg, relative standard deviation (n=11) was between 1.7%-5.1%, and relative error was -4.6%-2.7%. CONCLUSIONS The method has the advantages of low background, high efficiency and accuracy, and can meet the detection requirements of stone coal and vanadium ore samples.