Method for depleting low-grade copper concentrate smelting slag

The invention discloses a dilution method for low-grade copper concentrate smelting slag. The method comprises the steps that liquid copper smelting slag flows into the furnace from the upper middle portion of the oxygen-enriched side-blown depletion smelting furnace through a launder, a cold material is added, high-sulfur pulverized coal and oxygen-enriched air are blown into the furnace from the two sides of the smelting furnace at the same time for a depletion reaction, copper matte and slag are obtained, copper matte is collected in a siphon mode, the slag is collected after being crushed with water, and then the copper-rich side-blown depletion smelting furnace is obtained. The cold charge comprises low-grade copper concentrate and quartz sand. According to the method, based on the synergistic effect of all raw material components, high-sulfur coal serves as fuel, low-grade copper concentrate and quartz sand serve as cold materials, the high-sulfur coal and oxygen-enriched air are blown in from tuyeres i