A system for resource recycling of sulfur dioxide includes a charcoal reduction furnace, a high temperature dust remover, a cooling separator A, a liquid sulfur tank, a cooling separator, a tail gas absorption tower, a gas stripping tower, a hypo reactor, a centrifuge, a mother liquor tank and a thickener. And a method for resource recycling of sulfur dioxide includes the following steps: (1) preparing elemental sulfur, (2) removing dust from a process gas containing gaseous sulfur, (3) separating elemental sulfur, (4) reabsorbing residual SO.sub.2 gas, (5) purifying sulfur powder, (6) preparing a slurry of cured hypo, (7) performing liquid-solid separation, and (8) preparing an absorption slurry. According to the method, SO.sub.2 gas is reduced into liquid sulfur and sulfur powder, and sodium thiosulfate is coproduced.

A system for resource recycling of sulfur dioxide includes a charcoal reduction furnace, a high temperature dust remover, a cooling separator A, a liquid sulfur tank, a cooling separator, a tail gas absorption tower, a gas stripping tower, a hypo reactor, a centrifuge, a mother liquor tank and a thickener. And a method for resource recycling of sulfur dioxide includes the following steps: (1) preparing elemental sulfur, (2) removing dust from a process gas containing gaseous sulfur, (3) separating elemental sulfur, (4) reabsorbing residual SO.sub.2 gas, (5) purifying sulfur powder, (6) preparing a slurry of cured hypo, (7) performing liquid-solid separation, and (8) preparing an absorption slurry. According to the method, SO.sub.2 gas is reduced into liquid sulfur and sulfur powder, and sodium thiosulfate is coproduced.

A system and method for recovering sulfur in a copper smelting process includes removing fine dust from high-concentration SO.sub.2 flue gas from a matte smelting furnace, introducing the flue gas into a fluidized bed carbothermic reduction tower to be reduced by a carbon-based reducing agent to obtain reducing gas, passing the reducing gas through a high temperature separator to separate down unsaturated powder coke contained in the reducing gas, and condensing the reducing gas to obtain sulfur. The saturated powder coke entrained in the reducing gas enters a desorption tower to desorb SO.sub.2 gas therein, and the desorbed powder coke enters a fluidized bed sulfur reduction tower to continue to participate in the reduction reaction. Part of the SO.sub.2 gas discharged from the desorption tower is discharged to the fluidized bed carbothermic reduction tower to produce sulfur, and the other part enters a desulfurization tower.

The present invention discloses a process for preparing sulfur from reduction of sulfate/nitrate by iron-carbon and recovering desulfurization/denitration agents. High-concentration SO.sub.2 flue gas produced by calcination of a sulfate and NOx produced by heating decomposition of a nitrate can be directly reduced to elemental sulfur vapor and N.sub.2 through reaction with an iron-carbon material at a high temperature. Then, after dust removal, cooling and fine dust removal, sulfur is recovered by a sulfur recovery device, and metal oxides can replace alkaline mineral resources such as limestone as raw materials of desulfurization (denitration) agents. This process can recycle the desulfurization and denitration agents.

A system and method for recovering sulfur in a copper smelting process, in which fine dust is removed from high-concentration SO.sub.2 flue gas from a matte smelting furnace, the flue gas is introduced into a fluidized bed carbothermic reduction tower and reduced by a carbon-based reducing agent to obtain reducing gas, which is introduced into a high temperature separator. The separated reducing gas contains unsaturated powder coke, and the reducing gas is condensed to obtain sulfur. The saturated powder coke entrained enters a desorption tower to desorb SO.sub.2 gas, and the desorbed powder coke enters a fluidized bed sulfur reduction tower. Part of the SO.sub.2 gas discharged from the desorption tower is discharged to the fluidized bed carbothermic reduction tower to produce sulfur, and the other part is introduced into a desulfurization tower.

The present invention discloses a process for preparing sulfur from reduction of sulfate/nitrate by iron-carbon and recovering desulfurization/denitration agents. High-concentration SO.sub.2 flue gas produced by calcination of a sulfate and NOx produced by heating decomposition of a nitrate can be directly reduced to elemental sulfur vapor and N.sub.2 through reaction with an iron-carbon material at a high temperature. Then, after dust removal, cooling and fine dust removal, sulfur is recovered by a sulfur recovery device, and metal oxides can replace alkaline mineral resources such as limestone as raw materials of desulfurization (denitration) agents. This process can recycle the desulfurization and denitration agents.