Chemical Phase Analysis of Vanadium in Stone Coal

The phases of vanadium in stone coal were divided into vanadium in iron oxide minerals and clay minerals, vanadium in mica minerals, and vanadium in tourmaline and garnet. Vanadium in iron oxide minerals and clay minerals was extracted with hydrochloric acid (1+3) solution, vanadium in mica minerals was extracted with hydrofluoric acid (1+3) solution, and vanadium in tourmaline and garnet was decomposed by Na₂O₂ melting. The total amount of vanadium and the vanadium in each phase were determined by ICP-AES. Meanwhile, the total amount of vanadium and the vanadium in the first and second phases were determined by phosphorous tungstate spectrophotometry. The determination results obtained by the two methods were in agreement. The allowable limits of ralative deviation between the sum of the vanadium in each phase and the total amount of vanadium were far less than 20%, meeting the requirement of "Test quality management standard of geological laboratory" (DZ/T 0130-2006).