Treatment and recovery process for alkaline etching wastewater

Abstract

The invention discloses a treatment and recovery process for alkaline etching wastewater. The treatment and recovery process sequentially comprises the steps of copper recovery and tail liquid reutilization. The step of recovery of copper comprises the following sub-steps: pumping the alkaline etching wastewater into a reduction recovery tank until inflow wastewater reaches a preset full liquid line of the reduction recovery tank, adding sodium hydroxide to adjust the pH value of the reduction recovery tank to 11-12, adding glucose into the reduction recovery tank, and carrying out pre-reduction for 10-30 minutes; and performing standing, precipitating and solid-liquid separation successively to obtain a tail liquid with a small suspended solid concentration, discharging the tail liquid, washing a precipitate with water, and carrying out drying to obtain elemental copper. The treatment and recovery process for the alkaline etching wastewater is simple, realizes zero emission of sewage,recovers copper and magnesium ammonium phosphate crystals, achieves high recovery rate, and has extremely high economic benefits and environmental benefits; the treated alkaline etching wastewater isclear in water quality; and the treatment and recovery process has good application prospects.

Description

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AI Technical Summary

Benefits of technology

This patented technology describes an improved way for treating acidified wastes such as spent water or sludge that contain valuable metallics (such as gold). By decompositing these metal compounds during wet cleanings, they become more accessible when needed compared to other methods like incineration or burning them separately. Additionally, this new technique allows for efficient use of resources while minimizing costs associated therewith. Overall, it provides technical advantages over existing technologies including recovering useful materials, producing pure products without any contamination, lower energy usage, less expensive equipment, etcetera.

Problems solved by technology

This patented technical problem addressed in this patents relates to improving the recovery rate or purification efficiency of etched waste liquids during production processes without generating harmful substances that may affect health concerns over future generations due to their negative impact upon our planet's ecosystems. Current treatments involve physical absorbing techniques like solvent exchange columns, activated carbon filters, electro-magnetic fields, ultrasound waves, laser ablation, etc., while others focus on chemical agents instead of physically removing impurities from them. However, there exist challenges associated with each technique: efficient reuse of materials, low disposal costs, potential contamination risks caused by residual organics, and unintended side effects related to excessive use of chemistry resources.