Method of operating copper ore smelting reverberatory furnace

In a method of operating a reverberatory furnace for smelting copper containing ores having a relatively large proportion of sulfur therein, the furnace having a main body with long refractory side walls and transverse refractory end walls, the main body containing a melted bath of matte and slag layer overlying the matte, the furnace having a roof covering the main body with a plurality of hoppers opening through the roof along the side walls or closely adjacent thereto for wet charging the starting material copper ore into ore piles along the side walls below the hoppers, one end wall having main burner means therein for directing combustion flames in a substantially horizontal direction over the melt bath, the furnace having an exit for the matte, an exit for the slag and an exit for the waste gas containing sulfur dioxide produced during operation of the furnace, the last mentioned exit being adapted to be coupled to a sulfur dioxide recovery system, the improvement comprising inserting at least one oxygen fuel burner through the roof of the furnace directed downwardly toward the ore piles and feeding a mixture consisting essentially of oxygen and hydrocarbon fuel through said burner with the oxygen being present in the mixture in an amount of from 100 to 150% of the theoretical amount for burning the fuel, said mixture being fed under feed conditions which cause the tip of the combustion flame from said burner just to reach the surface of said ore piles, and maintaining the oxygen partial pressure within said reverberatory furnace measured at said exit for the waste gas within the range of about 3 to 5.5 mm Hg-absolute, whereby latent heat due to CO and H.sub.2 produced in the products of combustion in the furnace is utilized so as to increase the rate at which the ore can be smelted, thereby increasing production in the furnace, to reduce the amount of fuel necessary per unit weight of smelted ore, and to increase the concentration of sulfur dioxide in the waste gas so as to make more economical the recovery of the sulfur dioxide.