With the rapid development of strategic emerging industries such as new energy, electronic information, and high-end manufacturing, the strategic importance of rare metals such as lithium, cobalt, nickel, rubidium, and cesium is becoming increasingly prominent. How to efficiently, cleanly, and economically extract these metals from complex ores or secondary resources has become a critical challenge affecting the independent control of industrial supply chains.
Among various separation technologies, centrifugal extractor has become core equipment in the solvent extraction section of rare metal hydrometallurgy due to their outstanding advantages, including high mass transfer efficiency, rapid phase separation, and continuous automated operation.
Working Principle of Tiei Extraction CWL-M Centrifugal Extractor
The Tiei Extraction CWL-M Centrifugal Extractor is a highly efficient separation and extraction equipment that utilizes the centrifugal force generated by high-speed rotation to achieve thorough mixing and rapid separation of two liquid phases. Its working process is as follows:
The aqueous phase solution containing target metals (such as lithium-bearing or cobalt-bearing leach solutions) and the organic extractant enter the high-speed rotating drum separately through two feed inlets located at the bottom of the equipment. Under the action of the centrifugal force field, the two liquid phases are sheared and dispersed into micron-sized droplets in the mixing zone, creating a large interfacial contact area. This allows mass transfer to be completed efficiently within seconds, enabling the target metal ions to transfer from the aqueous phase into the organic phase.
Subsequently, the mixed liquid enters the separation zone. Under centrifugal force hundreds or even thousands of times stronger than gravity, the two phases rapidly stratify along the radial direction of the drum. The denser heavy phase (usually the aqueous phase) is forced toward the outer edge of the drum, while the lighter phase (the organic phase) gathers toward the inner side. After separation, the two phases flow through their respective weirs into separate collection chambers and are discharged through independent pipelines, achieving continuous and stable extraction and separation.
A single equipment can complete the entire mixing–reaction–separation process. Multiple units connected in series can realize counter-current extraction, significantly improving separation efficiency and metal recovery rates.
Key Technologies in Rare Metal Extraction Process
1.Selection and Matching of Extractants
The key to rare metal extraction lies in the selection of suitable extractants. According to the coordination characteristics of different metal ions, various high-efficiency extractants have been developed for industrial applications:
Acidic extractants (such as P204 and P507): Widely used for the extraction and separation of nickel, cobalt, and rare earth elements.
Neutral extractants (such as TBP and the Cyanex series): Suitable for metals with high ionic potential, such as lithium, rubidium, and cesium.
Crown ether extractants: Possess unique selective separation capabilities for lithium isotopes.
2.Multi-Stage Counter-Current Extraction Process
To achieve the dual goals of high recovery rate and high purity, rare metal extraction usually adopts a multi-stage counter-current extraction process. The aqueous phase containing metal ions (feed solution) and the organic extractant are introduced separately from both ends of the process and flow in opposite directions, contacting stage by stage in each unit. The target metals in the feed solution are extracted step by step into the organic phase, while the feed solution is gradually depleted; the metal concentration in the organic phase is progressively enriched until saturation is reached. By adjusting parameters such as the number of stages, phase ratio, pH value, and mixing intensity, the metal extraction rate can reach more than 99%, while also achieving efficient separation from impurity ions.
3.Stripping and Extractant Regeneration
The loaded organic phase undergoes the stripping process, in which stripping agents such as high-acid solutions, high-salt solutions, or pure water are used to transfer the metal ions back into the aqueous phase, obtaining a high-concentration and high-purity stripping solution, which can be directly used for subsequent electrowinning, precipitation, or crystallization to prepare products. After stripping, the organic phase is recycled after washing and regeneration treatment, greatly reducing extractant consumption and significantly lowering production costs.
Core Advantages of CWL-M Centrifugal Extractor in Rare Metal Extraction
1.Ultra-High Mass Transfer Efficiency, Reducing Stage Investment
The CWL-M centrifugal extractor achieves micron-level mixing under a powerful centrifugal force field, with a mass transfer rate 5–8 times higher than that of traditional mixer-settlers. Under the same separation requirements, the number of extraction stages required can be reduced by 40%–50%, significantly reducing the number of equipment units, floor space, and supporting investment.
2.Rapid and Clear Separation, Completely Solving Emulsification Problems
Rare metal leaching solution systems are complex and often contain impurities such as iron, aluminum, and magnesium that can easily cause emulsification. The powerful centrifugal force of the CWL-M centrifugal extractor ensures phase separation within 1–2 seconds, with a clear interface between light and heavy phases. The extractant entrainment rate is lower than 0.1%, and organic phase loss is reduced by more than 30%.
3.Fully Enclosed Corrosion-Resistant Design, Adaptable to Harsh Media
The wetted parts of the centrifugal extractor can be made of various corrosion-resistant materials such as high-quality stainless steel, duplex steel, and fluorine materials, enabling resistance to high acid, high salt, high temperature, and chloride ion corrosion. The fully enclosed structure prevents solvent volatilization and odor leakage, improves the working environment, and meets increasingly stringent environmental protection regulations.
4.Automated Continuous Production, Ensuring Process Stability
The equipment is equipped with a PLC intelligent control system, which can monitor parameters such as flow rate, rotational speed, temperature, and current in real time, and supports seamless connection with the plant DCS system. It realizes one-button start and stop, automatic phase ratio adjustment, fault alarm, and interlock protection, greatly reducing manual intervention and ensuring long-term stable operation of the production line.
5.Flexible Adaptation to Multi-Stage Processes, Easy Scale-Up
The CWL-M centrifugal extractor is available in a complete range from laboratory models to large industrial units, with a single-unit processing capacity covering 0.05–50 m³/h. The modular design supports rapid series combination, and experimental data can be directly used for industrial scale-up, shortening the R&D cycle by more than 50%.
Centrifugal Extractor Application Cases
In a salt lake lithium extraction project in Qinghai, the CWL-M centrifugal extractor unit was used for lithium extraction and enrichment. Combined with a crown ether extractant system, after three-stage counter-current extraction, the lithium extraction rate reached 99.2%, while the removal rates of impurities such as sodium, potassium, and magnesium exceeded 98%. The lithium concentration in the stripping solution was enriched by more than 10 times, providing high-quality raw material for the subsequent lithium precipitation process.
In an overseas laterite nickel ore HPAL supporting MHP nickel extraction project, the CWL-M centrifugal extractor was used for nickel-cobalt separation in the P507 system. The cobalt content in the nickel solution was reduced from 2.5% to below 8 ppm, the nickel recovery rate increased from 94% to 98.6%, extractant consumption was reduced by 35%, and annual cost savings reached several million yuan.
If you have any requirements for extraction equipment, welcome contact Tiei Extraction.
Email: sales@tieiextraction.com
Whatsapp: +86 19069612820
