A method for resource processing non-ferro metals processing wastewater containing ammonia and sulfate radical

Abstract

The invention relates to a novel process for recycling treatment for waste water which contains ammonia and sulfate radicals and is produced in the process of non-ferrous metal processing. The invention is characterized in that: sodium hydroxide is added into the waste water to convert ammonium ions in the waste water into molecular ammonia; then the waste water is heated by heat resource in a rectification tower; the ammonia in the waste water enters into a condenser in the form of gas from the top of the tower to be cooled into liquid ammonia and partial liquid ammonia returns, thus the remainder becomes the product; the water removed of ammonia exchanges heat with the waste water to be treated and then continues to be cooled, thus sodium sulfate crystals are obtained; the water removed of sodium sulfate removed is removed also sulfate radicals and ammonia, and can directly return to a production plant. The invention has a combined process of ammonia rectification recycle and sodium sulfate cooling crystallization, ensures the recycling use of the water as the ammonia in the water is reclaimed in the form of liquid ammonia or ammonia water as well as the sulfate radicals are reclaimed in the form of sodium sulfate, retains valuable metal ions in the water, and improves the recycling rate of the resource. In a word, the process can realize the recycling utilization of ammonia-nitrogen waste water produced by non-ferrous metal processing, has a simple process flow, is suitable for large-scale industrial production, and has both economic and environmental benefits.

Description

technical field [0001] The invention belongs to the field of waste resource treatment or metallurgy, and relates to a method for resource treatment of waste water containing ammonia and sulfate radicals produced in the process of non-ferrous metal processing, in particular to a process of rectification-low temperature crystallization from waste water A method of recovering ammonia and sodium sulfate and reusing the treated water in metalworking processes. Background technique [0002] Sulfuric acid and ammonia are commonly used acids and alkalis in the processing of non-ferrous metals. However, in the production process, these substances often enter the waste water together with some ionic non-ferrous metal ions. If they are not effectively treated, they will not only waste resources, and may cause serious environmental pollution, such as ammonia entering the water body can easily cause "algae proliferation", resulting in the death of fish and shrimp due to lack of oxygen; s...

AI Technical Summary

Problems solved by technology

[0005] Water is a precious non-renewable resource, but the waste water produced by some metal processing processes cannot be reused in the metal processing process because it contains high concentrations of ammonia and sulfate. The water treatment technology that introduces impurity ions is of great significance to improve the water reuse rate of metal processing engineering

[0006] However, so far there is no one that can treat industrial wastewater containing ammonia, sulfate radicals, and heavy metal ions. Simply combining the above-mentioned treatment technologies not only requires high equipment investment and complicated treatment processes, but also easily causes resource loss.

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