Ultrasonic Leaching Transforms Battery Recycling and Urban Mining
Used batteries and electronic waste are packed with valuable materials like lithium, nickel, manganese, and cobalt, essential for the growing demand in renewable energy and electric vehicle sectors. Urban mining — the process of reclaiming these metals from discarded batteries and other electronic waste — is a promising route to a circular economy, reducing the need for virgin mining and minimizing waste. A key technique in this field is sonication, which has shown tremendous benefits in enhancing metal recovery rates, lowering processing times, and improving sustainability.
The Power of Sonication in Battery Recycling and Urban Mining: A Game-Changer for Sustainable Resource Recovery
A recent study by Canciani et al. (2024) explores the effects of ultrasonic cavitation — tiny shock waves created by high-intensity ultrasound waves — on the leaching process for battery recycling. Their research shows that sonication is not just a modest improvement on traditional recycling; it fundamentally changes how the recycling process interacts with battery material, making it faster, more efficient, and less reliant on harsh chemicals.
Read more about the study findings below!

Ultrasonically enhanced acid leaching operates at a rate twelve times faster than conventional acid leaching, due to the beneficial mechanical action of cavitation bubbles bursting near the surface. This phenomenon improves acid solution mixing, thereby enhancing transport properties.
Image and study: © Canciani et al., 2024

The Sonicator UIP16000hdT reliably processes large throughput of metal-containing waste slurries, facilitating the leaching of precious metals and ores.
How Sonication Works in Battery Recycling
In typical battery recycling, cathode materials (which contain valuable metals) are dissolved in an acidic solution, a process called “leaching.” This approach allows for the separation and recovery of metals from the battery’s solid structure. However, conventional leaching is time-intensive, often taking hours to achieve significant metal recovery. It also requires strong acids and high temperatures, raising concerns over environmental impact.
Sonication transforms this process by adding ultrasonic waves directly into the leaching solution. In In the 2024 published study by Canciani et al., researchers tested this technique with a surrogate battery material, lithium cobalt nickel manganese oxide (NMC). By applying ultrasonic waves at a specific frequency and amplitude, they found that ultrasonic cavitation reduces the leaching time by over 80%. The process went from taking hours to a matter of minutes, offering a revolutionary improvement in efficiency.
The Role of Sonication in Enhanced Leaching: The Science Behind Mass Transfer and Speed
Sonication does not just speed up leaching; it changes the way the acidic solution interacts with the battery particles. High-power ultrasound creates millions of microscopic bubbles that rapidly collapse in the solution, a phenomenon known as cavitation. This action generates intense local forces that break down surface particles and increase the interaction between the acid and the metals within the battery material.
According to Canciani et al. (2024), this process has two primary effects on the battery materials: it increases the porosity of the particles and reduces their size, leading to a dramatic increase in surface area. With a larger surface area, the acid can interact more extensively with the material, thus facilitating faster leaching. The authors observed that the pore volume in sonicated samples increased by an order of magnitude compared to those processed conventionally, creating more pathways for the acid to dissolve the metal content.
Ultrasonic Leaching: Improved Transport Properties and Micro-Mixing
The study also suggests that ultrasonic cavitation not only enhances surface contact but also significantly improves transport properties. Essentially, this means that the distribution of acid across the battery particles becomes more uniform, with cavitation-induced micro-mixing ensuring even exposure. This leads to a homogenized reaction environment, enabling the acid to dissolve metals more effectively and evenly.
Another notable finding is that the benefits of ultrasonic cavitation extend beyond particle size reduction. The researchers found that cavitation changes the interaction mechanism between the acid and the particles, likely due to improved boundary layer transport. In simple terms, cavitation reduces the thickness of the liquid layer surrounding each particle, allowing for faster metal dissolution.

Particle size distributions after ultrasonic and conventional leaching
Image and study: © Canciani et al., 2024
Benefits for Urban Mining and Sustainability
The effectiveness of sonication in battery recycling holds enormous potential for the future of urban mining and sustainable resource recovery. The findings of Canciani et al. (2024) indicate that sonication will replace or reduce reliance on environmentally damaging practices by:
- Reducing Chemical Use: Ultrasonically enhanced leaching allows for the use of greener solvents like acetic acid rather than harsher acids typically needed for conventional leaching.
- Lowering Energy Requirements: With sonication, leaching occurs rapidly at room temperature rather than requiring prolonged heating, which reduces energy consumption and emissions.
- Increasing Material Recovery: Improved surface interaction and enhanced porosity maximize the recovery rates of valuable metals, making the recycling process economically viable and environmental-friendly.
Broader Impact on the Battery Industry
As EVs and renewable energy technologies expand, the demand for batteries and, by extension, the metals within them, is soaring. Urban mining with sonication-enhanced recycling offers a means to recover these metals sustainably, reducing the environmental burden on mining and offering a closed-loop approach to battery production and disposal.
Scaling up sonication-based recycling methods, optimizing solvent combinations, and refining the application of ultrasonic waves will further boost efficiency. Hielscher Ultrasonics will gladly recommend the ideal sonicator inline configuration for your leaching process. Contact us now!
- high efficiency
- state-of-the-art technology
- reliability & robustness
- adjustable, precise process control
- batch & inline
- for any volume
- intelligent software
- smart features (e.g., programmable, data protocolling, remote control)
- easy and safe to operate
- low maintenance
- CIP (clean-in-place)
Design, Manufacturing and Consulting – Quality Made in Germany
Hielscher ultrasonicators are well-known for their highest quality and design standards. Robustness and easy operation allow the smooth integration of our ultrasonicators into industrial facilities. Rough conditions and demanding environments are easily handled by Hielscher ultrasonicators.
Hielscher Ultrasonics is an ISO certified company and put special emphasis on high-performance ultrasonicators featuring state-of-the-art technology and user-friendliness. Of course, Hielscher ultrasonicators are CE compliant and meet the requirements of UL, CSA and RoHs.
The table below gives you an indication of the approximate processing capacity of our ultrasonicators:
Batch Volume | Flow Rate | Recommended Devices |
---|---|---|
10 to 2000mL | 20 to 400mL/min | UP200Ht, UP400St |
0.1 to 20L | 0.2 to 4L/min | UIP2000hdT |
10 to 100L | 2 to 10L/min | UIP4000hdT |
15 to 150L | 3 to 15L/min | UIP6000hdT |
n.a. | 10 to 100L/min | UIP16000 |
n.a. | larger | cluster of UIP16000 |
Literature / References
- Chiara Canciani, Elia Colleoni, Varaha P. Sarvothaman, Paolo Guida, William L. Roberts (2024): On the effect of cavitation on particles in leaching processes: implications to battery recycling. Environmental Advances, Volume 17, 2024.
- Wang, J.; Faraji, F.; Ghahreman, A. (2020): Effect of Ultrasound on the Oxidative Copper Leaching from Chalcopyrite in Acidic Ferric Sulfate Media. Minerals 2020, 10, 633.
- J.L Luque-Garcı́a, M.D Luque de Castro (2003): Ultrasound: a powerful tool for leaching. TrAC Trends in Analytical Chemistry, Volume 22, Issue 1, 2003. 41-47.
Frequently Asked Questions
What is the Leaching Process?
The leaching process is a method used to extract valuable metals from solid materials by dissolving them in a liquid solvent, typically an acidic solution. This technique breaks down the solid matrix, allowing the metal ions to enter the solution, from which they can be further purified and recovered. Leaching is widely applied in mining and recycling to recover metals from ores and waste materials.
What is the Difference between Extraction and Leaching?
Extraction and leaching both refer to processes used to separate valuable substances from a solid material, but they differ in methods and contexts. Extraction generally refers to a broader range of techniques used to remove a specific substance, often using solvents to separate it from other components, and can involve various physical, chemical, or thermal methods. Leaching, on the other hand, is a specific type of extraction that involves dissolving metals or other solutes from a solid into a liquid, typically through the use of an acidic or alkaline solution. Leaching is commonly used in mining, metallurgy, and recycling processes. While extraction can apply to a variety of substances, leaching specifically involves the selective removal of dissolved substances from solids using liquid solvents.
What are typical Substances used for Leaching?
Typical substances used for leaching include **acids**, **alkalies**, and **solvents** depending on the material being processed. Commonly used leaching agents include:
- Acids:
- Sulfuric acid: Often used in the extraction of copper, nickel, and uranium.
- Hydrochloric acid: Used in leaching of metals such as copper and gold.
- Nitric acid: Typically used in the leaching of precious metals, especially gold and silver.
- Acetic acid: Sometimes used in environmentally friendly or organic-based leaching processes.
- Alkalies:
Sodium hydroxide (caustic soda): Used in the extraction of alumina from bauxite ore or in the leaching of certain metals like gold and zinc. - Solvents:
- Cyanide: Commonly used in gold and silver mining for leaching gold from ore (cyanidation).
- Ammonia: Used in the leaching of copper and other base metals.
These substances help dissolve specific metals or minerals from ores, waste materials, or other solids, facilitating the recovery of valuable materials.

Hielscher Ultrasonics manufactures high-performance ultrasonic homogenizers from lab to industrial size.