Abstract: A process of water-granulating copper smelting slag can readily suppress elution of As from the copper smelting slag. A process of water-granulating a copper smelting slag with granulation water in a circulating system, includes granulating the copper smelting slag with the granulation water; settling suspended solids from the granulation water circulating in the system in a settling tank followed by discharging part of the granulation water through the settling tank from the system; and feeding supplementary water having a concentration of As of 0.01 mg/L or less into the system in such an amount that the total amount of the granulation water circulating in the system is kept constant; wherein the amount of granulation water discharged through the settling tank is such that As eluted from the copper smelting slag after water granulation is 0.01 mg/L or less.

Abstract: The present invention provides a process for treating a exhaust gas which is generated when slag discharged from a smelting furnace for non-ferrous metal is water-granulated. There is provided a process for treating an exhaust gas, which is generated during water granulation of slag discharged from a smelting furnace for non-ferrous metal, containing the water vapor as a major component and metal fumes, the process comprising a step of treating the exhaust gas by a wet electrostatic precipitator.

Abstract: The present invention provides a process for treating a exhaust gas which is generated when slag discharged from a smelting furnace for non-ferrous metal is water-granulated. There is provided a process for treating an exhaust gas, which is generated during water granulation of slag discharged from a smelting furnace for non-ferrous metal, containing the water vapor as a major component and metal fumes, the process comprising a step of treating the exhaust gas by a wet electrostatic precipitator.

Abstract: A process of water-granulating copper smelting slag can readily suppress elution of As from the copper smelting slag. A process of water-granulating a copper smelting slag with granulation water in a circulating system, includes granulating the copper smelting slag with the granulation water; settling suspended solids from the granulation water circulating in the system in a settling tank followed by discharging part of the granulation water through the settling tank from the system; and feeding supplementary water having a concentration of As of 0.01 mg/L or less into the system in such an amount that the total amount of the granulation water circulating in the system is kept constant; wherein the amount of granulation water discharged through the settling tank is such that As eluted from the copper smelting slag after water granulation is 0.01 mg/L or less.