Etching and pickling


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 and 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.