System and process for purifying waste water by using waste heat of acid making from smelting flue gas

Abstract

The invention discloses a system and a process for purifying waste water by using waste heat of acid making from smelting flue gas. The system comprises a washing tower, an outlet of the washing tower is connected with a storage tank, the storage tank is connected with a cooling tower, a top outlet of the cooling tower is connected with an electric demister, a bottom outlet of the electric demister is connected with a second dilute acid circulating pump, and the cooling tower is further connected with the second dilute acid circulating pump. The second dilute acid circulating pump is respectively connected with the plate heat exchanger and the storage tank, the plate heat exchanger is connected with the cooling tower, the bottom outlet of the storage tank is further connected with the first dilute acid circulating pump, the top outlet of the degassing tower is connected with the storage tank, the bottom outlet of the degassing tower is connected with the neutralization tank, and the bottom outlet of the neutralization tank is connected with the plate-and-frame filter press through the slurry pump. An outlet of the plate-and-frame filter press is connected with a neutralizing water tank which is connected with a clean water pump which is connected with a cooling tower. According to the system disclosed by the invention, limited heat energy carried by low-temperature flue gas is fully utilized, so that the lime neutralized calcium sulfite wastewater is evaporated and purified, and the energy consumption for treating the calcium sulfite wastewater is saved.

Description

technical field [0001] The invention belongs to the technical field of waste water purification technology, and in particular relates to a system and a technology for purifying waste water by utilizing waste heat of acid production from smelting flue gas. Background technique [0002] Acid production from sulfur-containing flue gas is a classic process for flue gas desulfurization treatment. The acid production process mainly includes four processes: flue gas purification, sulfur dioxide conversion, sulfuric acid condensation and tail gas treatment. In addition to sulfur dioxide, sulfur-containing flue gas usually contains a small amount of fluoride, arsenide and other metal compounds. It usually also contains a small amount of sulfur trioxide, fluoride, arsenide and other metal compounds. Although these substances are very small, However, it will cause great harm to the sulfur dioxide conversion catalyst and the metal and non-metal equipment and facilities in the acid produ...

AI Technical Summary

Problems solved by technology

In addition to sulfur dioxide, sulfur-containing flue gas usually contains a small amount of fluoride, arsenide and other metal compounds. It usually also contains a small amount of sulfur trioxide, fluoride, arsenide and other metal compounds. Although these substances are very small, However, it will cause great harm to the sulfur dioxide conversion catalyst and the metal and non-metal equipment and facilities in the acid production process, so it is necessary to purify the sulfur-containing flue gas

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