Method for recleaning vanadium-titanium magnetite concentrates by using oxidation and alkaline leaching, desliming and combined magneto-gravity separation

The invention relates to a method for recleaning vanadium-titanium magnetite concentrates by using oxidation and alkaline leaching, desliming and combined magneto-gravity separation. The method comprises the following steps: vanadium-titanium magnetite concentrates are put into an alkaline solution and an oxidizing agent is added; then an alkaline leaching reaction lasts for 0.5-2 hours at the temperature of 220 DEG C-330 DEG C; reactants are filtered, so that a filtrate and an alkaline leaching filter cake A are obtained; and the filter cake A is added with water, and the mixture is prepared into ore pulp for desliming and combined magneto-gravity recleaning. The method has the advantages as follows: due to the introduction of O2 or H2O2 during oxidation and alkaline leaching, compounds containing S are oxidized, the reaction is accelerated, and the reaction temperature and the energy consumption are reduced. Besides, an iron ore concentrate with the TFe content of 65 %-70 % and a titanium concentrate with the TiO2 content of 50 %-70 % are screened, so that efficient separation of titanium and iron in vanadium-titanium magnetite concentrates is achieved, the content of impurities entering a blast furnace, such as TiO2, S, Si, Al and the like is reduced, the utilization coefficient of blast furnace is increased, and the comprehensive utilization ratio of titanium resources is increased as well.