Coarse and fine grading oxidizing roasting vanadium extraction system for stone coal vanadium ore and oxidizing roasting method

The invention provides a stone coal vanadium ore coarse and fine grading oxidizing roasting vanadium extraction system and an oxidizing roasting method. The system comprises a feeding system composed of a stock bin, a weightlessness scale and a spiral feeding pipe; the coarse grain material oxidizing roasting system consists of a first-stage cyclone separator, a flow sealing valve, a main furnace, a second-stage cyclone separator and a coarse grain roasting reactor; the fine particle material oxidizing roasting system consists of a three-stage cyclone separator and a fine particle roasting reactor; the negative pressure dust removal system consists of an exhaust heat exchanger, a bag-type dust remover, a Roots blower and a chimney; the heat recovery system consists of a heat exchanger, a first first-section cooler, a first second-section cooler, a second first-section cooler, a second second-section cooler and a heat exchange air inlet pipe; by arranging the coarse particle roasting reactor and the fine parti