Sodium Carbonate (Soda Ash) Pumping In Lithium Extraction From Brine
This article is from our Intrax partner, All Pumps. It has been translated into English and adapted for our UK and EMEA audience.
Soda ash, or sodium carbonate, is a white, odourless powder that is used in many industries, including chemicals, water treatment, and lithium extraction. In the process of extracting lithium from brines, soda ash is often used as a reagent in a specific step known as precipitation. This process involves dosing soda ash into lithium-rich brine, causing lithium carbonate to precipitate out of solution. Here, the lithium present in the brine reacts with sodium carbonate (Na₂CO₃) to form lithium carbonate (Li₂CO₃) and sodium chloride (NaCl). The lithium carbonate precipitate can be separated and further processed to obtain lithium compounds for use in batteries, ceramics, and other applications. This precipitation step is crucial to concentrate the lithium from the brine and make it more viable for further processing.
Selecting pumps for moving soda ash solution involves considering several aspects. On the one hand, materials used in the pump’s wet parts must be compatible with the corrosive, high pH nature of the fluid. Frequently, materials such as stainless steel, special alloys, or polymeric materials are used. On the other hand, the pump design must minimise the potential for crystals to form and accumulate, which could cause blockages and inaccurate dosing. In addition, attention must be paid to the shaft sealing system to prevent leaks, ensuring efficient and safe pumping for operators.
For pumping soda ash media, Toro progressive-cavity pumps, powered by Kronoa, have corrosion-resistant rotors and stators, and a special mechanical seal to prevent clogging due to crystallization. Being a positive displacement type of pump, with a geometry designed for high solids content, these pumps excel in the controlled application of high-content soda ash.
The SlurryPro pump range can be fitted with a semi-open propeller and mechanical seal, making it ideal for soda ash/lithium brine slurry since its design prevents crystallised buildup. Constructed with all wetted parts made of stainless steel or even more resistant materials, TORO ANSI pumps offer excellent chemical resistance to the fluid.
For applications where the use of metallic contact with the pumped media is not permitted, we recommend the use of LSM hose pumps or rubber-lined SlurryPro. Speak to Atlantic Pumps for application specific advice.
Once the pumps are installed, it is important to ensure regular maintenance to prevent excessive wear of their components, due to the abrasive properties of soda ash and mineral-rich brine fluids.
Read our lithium overview article and look out for our future feature on innovative lithium mining in the UK. We’ll be covering advanced DLE (direct lithium extraction) techniques and lithium production in the UK context.
