Traveling grate machine is a kind of thermal equipment working under high temperature environment, and its main parts are made of heat-resistant alloy steel. The working mode is to distribute iron pellets on slow running grate bed, use the waste heat of annular cooler and hot air flow from rotary kiln to dry, preheat, oxidize and solidify green pellets, and then directly send them to rotary kiln for roasting. The powder created in the production process of traveling grate machine is collected by ash hopper and will be reused.