Project Background

The desulfurization system of the original sintering plant is not equipped with desulfurization wastewater treatment system. The desulfurization wastewater is discharged into the sewage treatment system of the whole plant after comprehensive treatment. Due to the high content of suspended solids, high TDS content and serious excessive heavy metals in the desulfurization wastewater, the original sewage treatment system of the whole plant has a great impact. In order to meet the treatment requirements and reduce the environmental protection risk, the company will carry out the renovation project of ultra-clean emission of electrolytic aluminum flue gas desulfurization flue gas in 2022, construction of a desulfurization wastewater treatment system.

The heavy metal thallium content in the raw water of the newly-built desulfurization wastewater system is relatively high. The designed effluent quality index meets the desulfurization wastewater discharge standard of the iron and steel smelting industry, in which the thallium content is required to be ≤ 0.05mg/L. Beijing Huade Chuangye Environmental Protection Equipment Co., Ltd. has designed a two-stage thallium removal system composed of HDCY integrated desulfurization wastewater treatment system according to its water quality characteristics and discharge requirements. The overall process is shown in the following figure.

Process Flow Diagram

To achieve the effect

The effect of the modified desulfurization wastewater treatment system:

• Through the two-stage process configuration, all kinds of heavy metals in the raw water are guaranteed to be qualified, and the treatment demand for thallium (Tl) can reach 0.05mg/L.

The first level is equipped with an efficient cyclone clarification system, which not only meets the removal of regular heavy metals (except heavy metal thallium), but also adapts to the characteristics of high suspension of desulfurization wastewater and improves the impact resistance of the system to the influent as a whole;

With the help of the thallium removal agent for the target depth capture of heavy metal thallium, and the formation of a stable chelate precipitation, to obtain a more reliable thallium removal efficiency, according to different water thallium content requirements, flexible adjustment of the dosage;

The end is loaded with a clarification system, with the help of heavy medium powder, to improve the flocculation efficiency, increase the proportion of flocs, to ensure the quality of the effluent, and to prevent the effluent from exceeding the standard caused by the escape of thallium-containing suspended substances after the removal of thallium.