The electrolytic copper waste liquid extraction purification process based on the extraction tank is a technology that efficiently recovers copper resources and purifies waste liquid. It is mainly used to treat copper-containing acidic waste liquid (such as copper sulfate waste liquid) generated during the electrolytic copper production process. The following is a detailed analysis of the process:

1. Process flow

(1) Pretreatment

Filtration: Remove suspended matter (such as anode mud) in the waste liquid to prevent clogging of the extraction equipment.

pH adjustment: If the acidity of the waste liquid is too high (such as pH < 1), it can be appropriately diluted or alkaline substances (such as lime milk) can be added to adjust it to a range suitable for extraction (pH 1.5~2.5).

(2) Extraction stage

Selection of extraction agent:

Hydroxime extraction agents (such as LIX 84, LIX 984N): High selectivity for Cu²⁺, suitable for sulfuric acid system.

Diluent: Kerosene or sulfonated kerosene as a carrier.

Extraction operation:

The waste liquid and the extraction agent are in countercurrent contact in the extraction tank, and the copper ions combine with the extraction agent to form a complex and transfer to the organic phase.

Phase separation: The raffinate (aqueous phase) and the copper-loaded organic phase are separated by gravity or centrifugation.

(3) Stripping stage

Stripping solution: Use high-concentration sulfuric acid (150-200 g/L) or electrolytic lean solution.

Copper ions are transferred from the organic phase to the aqueous phase to generate a high-concentration copper sulfate solution (which can be reused in electrolytic copper production).

Regeneration of organic phase: The organic phase after stripping is washed with water to remove residual acid and then recycled.

(4) Raffinate treatment

Neutralization precipitation: The raffinate (low copper, high sulfuric acid) is neutralized to pH 8-9 by lime milk to precipitate residual heavy metals (such as Fe³⁺, Zn²⁺).

Discharge/reuse in compliance with standards: The supernatant after neutralization can be discharged or reused in the production process.

3. Key equipment

Extraction tank: multi-stage mixing and clarification tank, centrifugal extractor or pulse sieve plate tower.

Phase separation device: gravity settling tank, centrifuge.

Stripping system: stirred reactor or continuous countercurrent tower.

4. Process advantages

Efficient copper recovery: copper recovery rate can reach 95%~99%, and copper concentration of stripping solution can reach 40-60 g/L.

Low energy consumption: compared with direct copper extraction by electrolysis, energy consumption is significantly reduced.

Environmental protection: reduce the generation of hazardous waste sludge, and the residual liquid can be harmlessly treated.

Economic efficiency: the extractant can be recycled to reduce operating costs.

Through the extraction and purification process of electrolytic copper waste liquid in the extraction tank, the copper resources in the electrolytic copper waste liquid can be efficiently recovered, and the purification and recycling of the waste liquid can be achieved at the same time, which meets the requirements of clean production and circular economy.