A traveling gate system for treating mineral ores that incorporate a cooling zone intermediate to heating zones to enable the use of a longer gate chain and additional heating zones to further refine the heat treating process of a traveling gate system. In the cooling zone the gas is forced upward to initially contact the gate chain and cool it and prevent the chain parts from exceeding their high temperature limit. Appropriate gases such as air can be selected for the cooling gas to further enhance the treatment of the material being processed on the gate chain.