Gas-solid fluidized bed dry beneficiation process using beneficiation density gradient

A gas-solid fluidized bed dry beneficiation process using a beneficiation density gradient, comprising:

• in a dry beneficiation system of a gas-solid fluidized bed, selecting coarse particles and fine particles as beneficiation medium particles, wherein an aerodynamic diameter of the coarse particles is greater than an aerodynamic diameter of the fine particles, and an aerodynamic diameter ratio of the coarse particles to the fine particles is not greater than 10;
• placing the coarse particles at a bottom of the dry beneficiation system of the gas-solid fluidized bed, and placing the fine particles above the coarse particles, wherein the coarse particles and the fine particles are in a completely separated state under an initial condition;
• under an effect of a gas flow, the coarse particles and the fine particles beginning to be fluidized to form a high-density beneficiation region and a low-density beneficiation region, respectively, and the coarse particles and the fine particles being in a mixed state at a contact interface to form an intermediate-density beneficiation region;
• and feeding minerals to be beneficiated from an upper portion of the dry beneficiation system of the gas-solid fluidized bed to pass through the low-density beneficiation region, the intermediate-density beneficiation region, and the high-density beneficiation region in sequence, to complete a beneficiation of the minerals.