The worldwide demand for lithium-ion batteries is higher than ever before and only growing. One result of this demand is greater investment in improved lithium-ion battery recycling processes and facilities to reduce environmental impact, conserve high-demand resources, help reduce supply chain strain for critical metals and reduce fire hazards from disposal.
Typically, the process of recycling lithium-ion batteries involves three steps:
- Collection of batteries at the end of their usable life
- Pre-Treatment to sort, discharge, dismantle, deactivate, shred and separate the different battery parts (such as separating plastics)
- Metal Recovery using one or a combination of two processes—pyrometallurgy and hydrometallurgy—to yield slags, alloys and metal concentrates. Hydrometallurgy is often used in combination with pyrometallurgy to separate key elements after the incineration process and is increasingly used in modern recycling facilities.
These recycling methods rely heavily on brines, strong bases and strong acids, all of which can take an incredible toll on metallic piping materials. Corroded piping is a threat not only to the quality of recycled material produced but also to the uptime of the recycling center.
Integrating Corzan® CPVC can contribute to lithium-ion battery recycling facilities’ long-lasting performance. Corzan CPVC’s record of industrial performance and reliability proves it can stand up to the harsh chemicals of lithium-ion battery recycling, often better than most metals and other plastics.
Lithium-Ion Battery Recycling Chemicals and Metal Pipes
Many of the chemicals and compounds needed for lithium-ion battery recycling are highly corrosive to metal piping.
Brine and water are essential to many pre-treatment processes. Discharging, for example, can be done by submerging the batteries in brine, a mix of sodium chloride and water. Especially when dissolved in water, sodium chloride forms an electrolyte solution that fosters the flow of electrons from one electrode to another. Metal atoms in the pipe break free and attach to free-floating ions in the fluid. This causes corrosion, weakens the metal piping and can cause leaks. The fragments pulled from the pipe can also contaminate the liquid in the pipe.
The metal recovery stage uses strong acids to reclaim valuable materials from lithium-ion batteries. Strong acids—such as nitric, hydrochloric, sulfuric and phosphoric acid—almost immediately attack metal, oxidizing and corroding it. Like brine, corrosion from acids can cause weaknesses and leaks.
Stainless steels and other high-quality metals can offer better resistance than carbon steel but at a substantially higher initial cost and necessary annual maintenance. As lithium-ion battery recycling facilities increase and expand, an affordable, reliable piping option becomes even more important.
The Chemical Resistance of Corzan CPVC
Chlorinated polyvinyl chloride (CPVC) is a homopolymer with greater chlorine content than regular polyvinyl chloride (PVC). This additional chlorine delivers greater chemical resistance, with the chlorine atoms protecting the polymer chain from attack from acids, bases and salts.
Often more affordable in both total and initial cost than industrial-quality materials, like stainless steel, Corzan CPVC delivers inherent chemical resistance and excellent temperature and pressure resistance compared to many other plastics. Corzan CPVC’s inertness to brines means it isn’t susceptible to ion loss like metals experience, and its additional chlorine atoms protect the material from the corrosive effects of acids necessary for lithium-ion battery recycling. Every batch of Corzan CPVC is consistent and traceable and has been extensively tested to meet exacting performance characteristics.
CPVC and Lithium-Ion Battery Recycling
CPVC can be utilized in many places in a lithium-ion battery recycling facility.
Note: Corzan CPVC can also be used to handle corrosive acid exhaust in the process steps that require ventilation.
Pre-Treatment
Before batteries can be dismantled for metal recovery, they must be discharged of their remaining energy for safety reasons. This usually involves submersion in brine, a conductive liquid that will act as an electrolyte and draw the remaining energy from the batteries.
Corzan CPVC is inherently resistant to salts and all types of water, making it an excellent choice for pipe and fittings along the discharge process as well as for brine tank lining.
Metal Recovery
Every lithium-ion battery recycler will have their proprietary method for metal recovery. Generally speaking, the recovery process will include strong acids and bases to leach valuable materials—such as lithium, nickel, cobalt, aluminum and copper—from the “black mass” produced in the pre-treatment stage and to precipitate these desirable metals from the leaching solution.
Providing the same excellent resistance as for brine, pipe, valves and fittings made of Corzan CPVC can transport chemicals used in both leaching and precipitation reactions. In addition to pipe, valves and fittings, Corzan CPVC sheet can be used to line the tanks where the reactions occur and the tanks that store these chemicals. The Corzan CPVC compound can also be used to mold fittings and other custom components needed for various mixing equipment and skid systems.
Throughout the Facility
CPVC’s chemical resistance, especially to water, makes it an ideal choice for process water piping, chemical waste and industrial HVAC systems. Corzan CPVC is also suitable for acid exhaust ducting as corrosive acid fumes are vented away from the recycling process.
Corzan CPVC Delivers Superior Performance for Lithium-Ion Battery Recycling Plants
Demand for lithium-ion batteries will only rise, and dependable recycling practices are an important part of strengthening this supply chain. Lithium-ion battery recycling facilities can use Corzan CPVC as a strategic alternative to conventional materials to maximize uptime and withstand highly corrosive chemicals for longer.
Corzan CPVC has become the non-metallic material of choice due to the science backing it. The pioneer of the CPVC compound, Lubrizol, puts the compound through extensive material tests in-house and sends it for third-party testing, which show that Corzan CPVC meets and often exceeds industry standards for dimensional tolerances, burn resistance and much more. The Chemical Resistance Table provides data on the suitability of over 500 chemicals and compounds for use with Corzan CPVC. Furthermore, pipe and fittings made from consistent, traceable Corzan CPVC are manufactured only by approved, industry-leading partners and is backed by the expert support of Lubrizol.
To learn more about how Corzan CPVC can advance lithium-ion mining, processing and recycling, read the white paper, “Conveying Process Chemicals Safely in the Lithium-Ion Supply Chain with Corzan® CPVC.”