Multi-stage utilization method for nickel-iron smelting waste heat of RKEF process

The invention relates to ferronickel smelting, in particular to an RKEF process ferronickel smelting waste heat multi-stage utilization method. High-temperature slag generated by a smelting furnace is subjected to dry granulation, heat energy of the high-temperature slag is recycled, and high-temperature gas is formed and conveyed to a heat energy heat exchange distributor to be subjected to multi-stage distribution; the first-stage hot air enters the rotary kiln for roasting sequentially through the first air mixing chamber and the combustion chamber of the rotary roasting kiln, the second-stage hot air enters the rotary drying kiln through the second air mixing chamber, and the third-stage hot air enters the hot-blast stove. According to the method, high-quality heat energy of the ferronickel slag is recycled, heat energy resources are efficiently and reasonably distributed and directly applied to RKEF process smelting production, loss of secondary energy exchange is reduced, the heat energy utilization rat