Pre-reduced pellet preparation apparatus and method based on grate-rotary kiln

A pre-reduced pellet preparation device, comprising a grate-rotary kiln pellet oxidation system and a hydrogen-based shaft furnace reduction system;

• the grate-rotary kiln pellet oxidation system comprises a grate system, and a rotary kiln system connected to the grate system;
• in the grate system, iron-containing green pellets are sequentially dried and preheated to obtain preheated pellets, and in the rotary kiln system, the preheated pellets are roasted at a temperature of 1170-1300° C. to obtain roasted pellets;
• and
• the hydrogen-based shaft furnace reduction system comprises a hydrogen-based shaft furnace, a feeding system, a reducing gas system, a cooling system, and a discharging system;
• the feeding system is disposed at the upper part of the hydrogen-based shaft furnace, and the roasted pellets from the rotary kiln system are directly conveyed into the feeding system;
• the reducing gas system processes flue gas from the hydrogen-based shaft furnace, and provides reducing gas to the hydrogen-based shaft furnace;
• the roasted pellets from the feeding system are reduced in the hydrogen-based shaft furnace to obtain pre-reduced pellets;
• the cooling system cools the pre-reduced pellets in the hydrogen-based shaft furnace to obtain cooled pre-reduced pellets;
• and the discharging system is disposed at the bottom of the hydrogen-based shaft furnace, and discharges the cooled pre-reduced pellets;
• wherein the reducing gas is hydrogen gas;
• the reducing gas is not heated prior to entering the hydrogen-based shaft furnace.