During the production of lithium carbonate, the recovery rate in the lithium precipitation stage has long remained at around 80%, with approximately 20% of lithium resources retained in the precipitation mother liquor. This industry-wide challenge has become the “last untapped opportunity” for lithium salt producers seeking cost reduction and efficiency improvement.

When selecting equipment and processes for lithium recovery from precipitation mother liquor—whether from hard-rock lithium extraction or salt lake brine extraction—the mainstream approach involves adding excess sodium carbonate to carry out the precipitation reaction. While lithium carbonate is produced, a large volume of lithium-containing mother liquor is inevitably generated.
Taking the hard-rock process as an example: after conversion roasting, sulfuric acid digestion, leaching and impurity removal, and evaporation concentration, spodumene processing yields a lithium-rich lithium sulfate solution. This solution reacts with excess sodium carbonate to precipitate lithium carbonate. However, the lithium concentration in the mother liquor still reaches 2.0–3.0 g/L, accounting for 15%–30% of the total lithium prior to precipitation.
The salt lake process faces a similar situation. After adsorption, membrane separation, and evaporation concentration of brine, the lithium-rich solution undergoes sodium carbonate precipitation. The resulting mother liquor still contains about 1.5–2.5 g/L lithium, representing 15%–25% of the total lithium content.

The traditional recovery process of “neutralization–evaporation–crystallization” is characterized by a lengthy process flow and extremely high energy consumption, often placing companies in the dilemma where “recovery leads to losses.”

Breakthrough Solution: High-Efficiency Extraction System for Lithium Precipitation Mother Liquor

Zhengzhou Tiei Extraction Technology Co., Ltd. has developed an innovative high-efficiency extraction system for lithium precipitation mother liquor to address this long-standing industry bottleneck. By deeply integrating a novel extraction system with advanced liquid–liquid extraction equipment, the solution fundamentally reshapes the economic feasibility of lithium recovery from precipitation mother liquor.

The key technical breakthrough lies in the nature of the mother liquor itself: it is essentially a saturated saline solution dominated by sodium chloride, where lithium and sodium coexist, while other impurity elements have already been reduced to ppm levels through upstream purification. Conventional processes struggle to economically separate lithium from sodium. Tiei Extraction’s process combines targeted new-generation extractants with a multistage countercurrent centrifugal extraction process, enabling highly selective and high-recovery lithium extraction.

Five Technological Innovations: From Laboratory Validation to Industrial Value

1.Lithium Extraction Recovery Increased to 96%
By adopting a self-developed composite extractant system and using the CWL-M series centrifugal extractor as the core process equipment, stable single-pass lithium extraction efficiencies of 90%–96% are achieved under a four-stage countercurrent configuration. The lithium concentration in the raffinate mother liquor can be reduced to below 0.1 g/L, representing a substantial improvement in resource utilization.

2.Green Process with Zero Emissions
No third phase formation occurs in the extraction system. The entire process operates in sealed centrifugal extraction equipment, with no discharge of wastewater, exhaust gas, or solid waste. The stripping stage uses a pure-water system, allowing regeneration and recycling of the organic phase, eliminating the high energy consumption and carbon emissions associated with traditional evaporation processes.

3.Simplified Flowsheet and Rapid Deployment
Compared with the traditional “neutralization–evaporation–crystallization” route, which often spans hundreds of meters of process layout, the liquid–liquid extraction method requires only three unit operations: extraction, washing, and stripping. The modular design of the CWL-M centrifugal extractor integrates mixing, mass transfer, and phase separation into a single unit, reducing footprint to approximately one-fifth of conventional processes and shortening project construction time by more than 60%.

4.Disruptive Cost Advantage
The direct production cost of this process is approximately RMB 6,000–8,000 per ton of lithium carbonate (depending on lithium concentration in the mother liquor). For a plant with an annual capacity of 10,000 tons of lithium carbonate, increasing the precipitation-stage recovery by about 20 percentage points can reduce total production cost by more than 10%, with a typical investment payback period of less than 18 months.

5.Universal Platform Technology
The system does not require modification of existing upstream process routes and can be directly integrated into current lithium carbonate production lines. After deep purification, the recovered lithium product can reach battery-grade purity (Li₂CO₃ ≥ 99.5%) or even high-purity standards, significantly enhancing the value of by-product streams.

Industrial Validation: Three Years of Stable Operation at a Major Lithium Producer in Qinghai

The high-efficiency extraction system for lithium precipitation mother liquor developed by Zhengzhou Tiei Extraction has been successfully industrialized at a large publicly listed lithium company in Qinghai. The system has operated continuously and stably for more than 36 months.
The project processes precipitation mother liquor with a lithium concentration of 2.0–2.5 g/L. Lithium recovery in the extraction stage remains consistently above 93%. After deep impurity removal and concentration, followed by lithium re-precipitation, the final lithium carbonate product stably meets battery-grade purity standards. According to customer feedback, the comprehensive operating cost per ton of lithium has been reduced by 42% compared with the conventional evaporation process. The system also features a high level of automation, enabling unmanned operation of the extraction stage.

Strategic Value: From “Tail-Liquid Treatment” to a “New Profit Engine”

As global competition for lithium resources intensifies, recovery of lithium from precipitation mother liquor has evolved from an environmental compliance issue into a core profit driver for lithium producers. Leveraging the CWL-M series centrifugal extractor as its core liquid–liquid extraction equipment, together with full-process capabilities covering process package development, equipment integration, and intelligent control systems, Zhengzhou Tiei Extraction Technology Co., Ltd. is enabling an increasing number of lithium salt producers to transform “waste mother liquor” into a “second mine.”

For feasibility assessment, pilot-scale validation, or equipment selection proposals for lithium precipitation mother liquor treatment, welcome contact the Zhengzhou Tiei Extraction Technology Co., Ltd.
Email: sales@tieiextraction.com
Whatsapp: +86 19069612820