1. scope of application

Non-ferrous metallurgy, new energy batteries, rare earth, coal chemical industry.

2. Brief description of technology

This technology is used for the resource treatment of wastewater containing high concentration of ammonia nitrogen containing heavy metals. The technical principle is based on the difference in the relative volatility of ammonia and water molecules. The principle of stripping and rectification is used to separate ammonia nitrogen from water in the form of molecular ammonia, and condensed at the top of the tower. After condensation, ammonia water with a concentration of 16%-25% is recovered. After deammonia, the ammonia nitrogen in the wastewater is less than 10mg/L, which can be directly discharged or reused, or can be entered into the subsequent metal recovery system for further treatment. Key technologies include agent-enhanced pyrolysis complex molecular rectification technology, high-performance special tower internals design technology, high-temperature and high-alkali scale inhibition and dispersion technology, and full-process automatic monitoring technology.

3. technical information

Intake ammonia nitrogen is 1-70g/L, effluent ammonia nitrogen is less than 10mg/L, and high-concentration ammonia water with a concentration of 16-25% is recovered.

4. comprehensive benefits

This technology adopts the principle of stripping rectification to remove ammonia nitrogen in wastewater and efficiently recover ammonia resources. The core technologies include agent-enhanced pyrolysis complexation-molecular rectification technology, high-performance special tower internals design technology, high-temperature and high-alkali scale inhibition and dispersion technology, and full-process automatic Monitoring technology, the technical treatment effects are as follows: (1) ammonia nitrogen: initial concentration is 1-70g/L, treated effluent water is< 10mg/L, and ammonia nitrogen removal rate is greater than 99%;(2) Heavy metals: initial concentration is 10-200mg/L, treated effluent water is< 1mg/L (taking nickel as an example);(3) Recovering ammonia resources: Recovering high-purity ammonia water with a concentration of 16%-25%, the ammonia recovery rate is greater than 99%;(4) Heavy metals are recovered in the form of metal hydroxides;(5) The equipment is not easy to scale and block, and the equipment maintenance cycle is extended from 15 days to 180 days;(6) The whole process is automated to ensure that the water outlet meets the standard;(7) The equipment is integrated skid design, which effectively reduces the floor area and can be quickly installed and put into operation. Taking a demonstration project with a treatment capacity of 800m3/d, influent ammonia nitrogen of 8,000 - 16,000 mg/L and nickel of 10-20mg/L, and effluent ammonia nitrogen of 10mg/L and nickel of 1mg/L as an example, normal operation can reduce emissions of high-concentration ammonia nitrogen wastewater by 240,000 tons/year, ammonia nitrogen pollutants by 2900 tons/year, and heavy metal nickel by about 4.2 tons/year. At the same time, 22000 tons/year of high-concentration ammonia water is recovered, which can be directly sold or reused for production, saving a large amount of ammonia/ammonium raw materials for enterprises.