The use of non-metallic piping in the lithium-ion battery supply chain is necessary due to the nature of the liquids being transported. Non-metallic piping is commonly used to transport various medias throughout the lithium-ion supply chain due to its superior chemical resistance and ability to withstand corrosion. Below you will find answers to frequently asked customer questions about non-metallic piping and Corzan® CPVC in the lithium supply chain. If you have additional questions or would like more information, please contact us to be connected with one of our piping material experts.
1. What is direct lithium extraction (DLE), and how is it different than traditional lithium mining methods?
Direct Lithium Extraction (DLE) is the selective extraction of lithium ions directly from lithium-rich solutions like brines, geothermal sources and even oilfield wastewater. A process with fewer steps than conventional methods, DLE enables faster extraction (hours versus years), reduces water use (seven times lower) and has a smaller environmental footprint. DLE is accomplished via ion exchange, adsorption or solvent extraction, and new methods continue to be developed as DLE grows in popularity. Lithium rich brine and strong chemicals used in DLE have an adverse effect on both metallic and non-metallic materials. Corzan CPVC innately resists corrosion caused by many chemicals such as lithium rich brines and acids used in the DLE process.
2. How is lithium traditionally mined and processed?
Traditional lithium extraction methods include evaporation ponds and hard rock mining. Salt flat brines account for about 80% of lithium production. This process allows the sun to evaporate water from the ponds, leaving valuable lithium salts behind. This is a months-long or sometimes years-long process. The resultant brine is then transferred and treated before lithium carbonate can be extracted. The process often includes:
- Pumping brine from underground aquifers for storage in evaporation ponds
- Solar evaporation of water over time, resulting in concentrated brine
- Precipitation of the brine solution to extract lithium salts via chemicals
- Filtering and drying of salts to produce battery-grade lithium carbonate
Far less common than evaporation, hard rock mining manually extracts lithium from other minerals via heavy crushing machinery. Typical steps include:
- Crushing and grinding
- Leaching, often using sulfuric acid and hydrochloric acid
- Filtering to remove solids and concentrating by removing excess water
- Precipitation of salts, often lithium carbonate and lithium hydroxide.
- Filtering and drying of salts, producing pure lithium
Common to both methods are chemicals and compounds highly degrading to metallic piping and many other plastics. Corzan CPVC is chemically inert to all salts, including brine, and all types of water, including process water. It also withstands strong chemicals like hydrochloric and sulfuric acid.
3. How is lithium mined and processed using Direct Lithium Extraction (DLE)?
As an improved form of lithium mining, DLE may use a variety of methods to extract lithium. This includes ion exchange, solvent extraction and adsorption, with additional methods emerging as this technology continues to advance.
Leading direct lithium extraction (DLE) technologies
Overview of different direct lithium extraction (DLE) technologies. Credits: Extantia.
DLE mining methods rely on strong chemicals to support different separation processes (e.g., ion exchange) that can quickly degrade metallic piping. An inherently corrosion-resistant material like Corzan CPVC can convey this material (piping) and line tanks to deliver longer-lasting, maintenance-free performance.
4. How does hydrometallurgy differ from pyrometallurgy for lithium-ion battery recycling?
As their names suggest, hydrometallurgy relies on aqueous chemistry to recover valuable material from lithium-ion batteries, often at ambient or only slightly raised temperatures, while pyrometallurgy uses high-temperature methods like smelting.
Scientific studies on each method’s impact are being produced as both methods continue to be used. Many studies, like this one, have found that hydrometallurgy is a more environmentally and resource-conscious lithium-ion battery recycling method than pyrometallurgy. It uses less energy, produces far fewer greenhouse gasses and emissions and ultimately results in higher element recovery.
The strong acids needed for successful hydrometallurgy include sulfuric, hydrochloric, nitric and phosphoric acids. Corzan CPVC’s molecular chain is protected by a high level of chlorine, giving it increased resistance to strong acids like these. This makes Corzan CPVC suitable for use in many places in a hydrometallurgy-based lithium-ion battery recycling facility, including chemical transport process piping, chemical storage, chemical and process water waste piping and chemical exhaust ducting.