Abstract:The desulfurization system of one copper smelter in China treats smelting secondary off-gas and refining process off-gas. The two kinds of off-gas above are sent into the off-gas desulfurization system with limestone-gypsum method for treatment. The secondary off-gas includes: the gas from MO furnace and SCF, the gas from the converter furnace, the gas from the main plant building, and the gas from the refining furnace. In order to improve the desulfurization efficiency to meet the increasing emission standards, the existing desulfurization process adopts the limestone method + hydrogen peroxide method. The existing primary reverse jet scrubber is changed to the one-stage desulfurization (dust removal) tower with the lime-gypsum method for treatment. The existing desulfurization tower is used as the two-stage desulfurization tower (dust removal) with the hydrogen peroxide method for treatment. After the transformation, the desulfurization system has reached the design index, producing qualified gypsum and meeting the requirements of the off-gas emission standard.