Essential Insights into the Mineral Processing Flow Sheet for New Energy Lithium Ore

Lithium resources are a core raw material for the new energy industry. Various types of lithium ores, such as spodumene and lithium mica, exhibit complex mineralisation patterns and are often accompanied by impurity minerals such as iron, tantalum and niobium. To efficiently separate lithium minerals and produce qualified lithium concentrate, it is necessary to follow a standardised four-stage mineral processing flow sheet, with each stage utilising dedicated equipment that balances liberation efficiency, overall recovery and the quality of the dewatered final product. The complete production line is divided into four core sections: crushing and screening, grinding and classification, combined multi-process beneficiation, and concentrate thickening and dewatering. The process logic and supporting equipment for each stage are as follows.

I. Crushing and Screening Section: Implementing the ‘More Crushing, Less Grinding’ Production Principle

The lithium ore crushing stage strictly adheres to the industry principle of ‘more crushing, less grinding’. Depending on variations in the feed size of the raw ore, either a two-stage closed-circuit or a three-stage closed-circuit process is flexibly selected. For mines with large chunks of raw ore and significant fluctuations in feed particle size, the three-stage closed-circuit process is prioritised to stabilise the overall processing capacity and optimise subsequent grinding and beneficiation indicators.

The equipment is configured into standardised combinations: jaw crushers are used in the primary crushing stage to process large chunks of raw ore; conical crushers are employed in the medium and fine crushing stages to progressively reduce the ore’s particle size; circular vibrating screens are uniformly adopted for screening, where post-crushing material is screened and graded. Non-compliant large lumps are returned to the crusher for re-crushing, forming a closed-circuit cycle that controls the feed size entering the grinding mill whilst reducing energy consumption and equipment wear during grinding.

II. Grinding and Classification Section: Achieving Full Individual Liberation of Minerals

The qualified crushed ore is fed into the grinding and classification system, the core objective of which is to achieve complete liberation of lithium minerals from gangue. The mainstream approach employs a single-stage closed-circuit grinding process, with the option to add a secondary regrinding stage depending on the coarseness of the ore’s mineral distribution.

For the single-stage grinding process, wet grid-type ball mills and rod mills are selected; the ground slurry is then fed into a hydrocyclone bank for classification; If the ore contains very fine particles, wet overflow ball mills are employed for secondary fine grinding. As some lithium ores are severely weathered and have a high clay content, a desliming unit must be added after grinding. This unit utilises thickening hydrocyclones and inclined-plate thickeners to separate the ore slime, thereby eliminating the interference of fine slime on subsequent flotation and ensuring separation efficiency.

III. Integrated Beneficiation Section: Comprehensive Recovery of Valuable Minerals via Multiple Processes

Lithium ores contain a wide variety of associated minerals; single-stage flotation alone cannot adequately recover both lithium and the associated tantalum and niobium metals. The industry generally adopts a combined beneficiation process centred on flotation, supplemented by gravity and magnetic separation.

Floating is the core method for extracting lithium minerals and is suitable for mainstream lithium ores such as spodumene, lithium mica and lithium feldspar. On-site operations commonly utilise air-agitated KYF and XCF flotation cells, paired with SF, JJF and BF mechanical agitation flotation units; the XCF and KYF models can be combined to enable a horizontal layout within the plant, significantly reducing capital expenditure on civil engineering works.

For lithium ores containing associated tantalum and niobium, a gravity separation stage is added, utilising shaking tables and centrifugal separators to recover high-density tantalum and niobium minerals, thereby enabling the simultaneous recovery of multiple metals; The magnetic separation process is used to remove ferrous magnetic impurities and improve the quality of the lithium concentrate. As the gangue consists mainly of weakly magnetic minerals, strong magnetic separators and high-gradient magnetic separation equipment are employed in production to effectively reduce the iron impurity content in the concentrate.

IV. Concentrate Thickening and Dewatering Section: Production of High-Quality Dry Lithium Concentrate

The lithium concentrate produced after separation has a relatively high moisture content and must undergo two processes—thickening and dewatering—to meet smelting and processing standards. The lithium concentrate produced by flotation is first conveyed to a high-efficiency hydraulic centre-driven thickener to undergo preliminary solid–liquid separation; the thickener underflow is then transported via slurry pumps to the dewatering section, where it undergoes deep dewatering using disc and vacuum disc filters, significantly reducing the moisture content of the concentrate to yield dry, high-grade lithium concentrate. The water recovered from the beneficiation process can be recycled back to earlier stages, thereby conserving production water.

The entire lithium ore beneficiation process features a clear logic, from crushing to control particle size and grinding to promote liberation, through to combined flotation, magnetic and gravity separation, and deep dewatering for shaping. The equipment configuration throughout the process is well-established and can be adapted to different types of lithium ore, balancing lithium metal recovery rates with the comprehensive utilisation of associated resources. It represents the mainstream process solution for standardised lithium mine construction at present.