Pickling and etching

copper recovery from etching/pickling spent bath - base case vs emew
emew operational surplus advantage in copper recovery from etching and pickling bath
traditional technology for etching and pickling spent baths treatment
traditional technology for etching and pickling spent baths treatment vs emew enhanced waste treatment process
Improved process for etching and pickling spent baths waste treatment
Financial benefits and operational surplus using enhanced emew technology for etching and pickling spent bath waste treatment

Challenges in the conventional etching/pickling process

When it comes to safe, sustainable, and cost-effective operations, there are several challenges associated with the conventional etching/pickling process:

  1. Environmental challenges are caused by hazardous waste such as spent acid solutions, metal-containing sludges, and neutralizing agents.
  2. Crystallization challenges in the etching/pickling bath because of copper concentration build-up. It leads to a reduced value of copper and labor-intensive cleanup.
  3. The high cost associated with the disposal of hazardous waste requires additional management and labor.

Enhanced etching/pickling with emew system

Utilizing the emew system provides a feasible and eco-friendly treatment approach that allows for the direct recovery of LME grade copper (green copper) cathodes from spent baths. This method eliminates the generation of copper sulfate crystals or metal sludge, thereby increasing revenue through the sale of copper cathodes. Furthermore, it facilitates the regeneration of acid, which can be reused in fresh etching/pickling baths. As a result, the consumption of fresh acid is minimized leading to a closed-loop, sustainable process. It eliminates the waste acid streams and associated solid waste disposal thus reducing scope 3 emissions.

etching pickling formula

Benefits of emew system to enhance the etching/pickling process


Eliminating the downtime required for tank dumping, cleaning and make-up Eliminating the downtime
Improved product by optimizing and stabilizing the pickling bath chemistry Improved product quality
Consistent pickling time due to constant copper concentration Consistent pickling time
Increased production throughput by maintaining lower Cu concentration Increased production
Reduced re-working of material due to surface defects Reduced re-working of material


Reduced acid purchases by regenerating the acid

Reduced acid consumption

Reduced crystallization haulage and disposal of neutralized solids

Reduced waste disposal fee

Value of the recovered metal by-product

High metal revenue

Potential reallocation of human capital

Reallocation of human capital

Reduced waste acid treatment costs

Reduced neutralization costs


No waste acid handling

No waste acid handling

Reduced fresh acid storage and management

Reduced fresh acid storage

Significantly less waste generated by the pickling line

Closed loop process

Reduced scope 3 emissions
Enabling circular economy

Integrating the emew system in your etching or pickling applications provides substantial financial and operational benefits, resulting in a quick payback and improved facility safety. If you are interested in learning more about how emew can assist with your spent bath treatment, please contact us.