Lepidolite Flotation: Current Situation, Problems and Research Progress

As one of the important sources of lithium ore, lepidolite has attracted much attention in the development and utilization with the booming development of the new energy industry. Flotation, as a key method for lepidolite separation, plays a decisive role in the efficient utilization of lepidolite resources. This paper deeply analyzes the current situation, existing problems and related research progress of lepidolite flotation, aiming to provide a comprehensive reference for the further development of lepidolite flotation technology.

1. Introduction

With the increasing global demand for clean energy, the new energy industry has developed rapidly. As a key metal, lithium is more widely used in fields such as electric vehicles, electronic products and energy storage systems. Lepidolite is an important part of lithium ore. China is rich in lepidolite resources. Yichun, Jiangxi Province, has the world's largest associated lepidolite deposit, with relatively low mining costs. However, the raw lepidolite ore has a complex composition and a low lithium grade. It is necessary to carry out separation and enrichment before lithium extraction. The flotation method has become the most commonly used separation method at present because it is suitable for fine - grained disseminated lithium - bearing ores.

2. Current Situation of Lepidolite Flotation

Most lepidolites belong to the fine - grained disseminated type and are often symbiotically embedded with gangue minerals such as quartz and feldspar. This mineral characteristic determines that fine - grained lepidolites are mostly separated and enriched by the flotation method. In actual industrial production, the flotation method has been widely used, and with the continuous progress of technology, its separation effect is also gradually improving.
At present, there are many separation methods for lithium - bearing ores in industry, including hand - sorting, flotation, magnetic separation, thermal cracking, chemical treatment, gravity separation, etc. The hand - sorting method is suitable for lithium - bearing ores with good crystallization, but due to the large amount of labor required and low efficiency, it is rarely used in industrial applications. The magnetic separation method is mainly used for two weakly magnetic ores, spodumene and zinnwaldite, or for removing magnetic impurities in concentrate products. Thermal cracking realizes mineral separation by roasting to change the crystal structure of the target mineral, and is mostly used for spodumene with a good ore composition. The chemical treatment method is mostly used for extracting lithium from salt lakes, mainly including ion exchange, precipitation, extraction and salting - out. Gravity separation is based on the density difference between the target mineral and the gangue mineral for separation. However, the densities of most lithium - bearing ores are close to those of common gangue minerals, making it difficult to effectively separate. Gravity separation is mostly used for the separation of spodumene. In contrast, the flotation method has become the mainstream method for lepidolite separation due to its adaptability to fine - grained disseminated lithium - bearing ores.

3. Problems in Lepidolite Flotation

3.1 Poor Selectivity of Collectors

Traditional collectors for oxidized ores have obvious deficiencies in lepidolite flotation. With the gradual reduction of high - grade coarse - grained lepidolite ore resources, the separation of fine - grained low - grade lepidolite ores has become increasingly difficult. Traditional collectors are difficult to accurately separate fine - grained low - grade lepidolite ores, resulting in difficulties in obtaining qualified lepidolite concentrates and affecting the lepidolite recovery efficiency and concentrate quality.

3.2 Poor Practicality of Gangue Depressants

The commonly used depressants in lepidolite flotation at present are mainly sodium sulfide and water glass. Although sodium sulfide has a certain depressing effect, it is highly toxic and easy to oxidize. Its use will pollute the environment during the process, which does not conform to the concept of green and environmentally friendly production. Water glass has a large dosage in practical applications, which not only increases the production cost but also causes difficulties in subsequent filtration, affecting production efficiency and product quality.

3.3 Complex Flotation Process

The lepidolite flotation process is relatively complex, and the degree of interdependence between various links is high. This complex process greatly increases the operation difficulty of the flotation operation, and requires high technical levels and experience of operators. At the same time, the complexity of the process also increases the uncertainty in the production process. Once a problem occurs in a certain link, it may have a greater impact on the entire flotation process, resulting in a decline in separation effect.

4. Research Progress in Lepidolite Flotation

4.1 Development of New Collectors

In response to the problems of traditional collectors, researchers are committed to the development of new collectors. Huang Wanfu et al. used a new collector HT in combination with organic amines in a certain proportion. Through a large number of tests, it was verified that this reagent system could increase the grade of lepidolite concentrate by nearly 2% and the recovery rate by about 20%, effectively realizing the recovery of lepidolite. He Guichun et al. took the lepidolite in the gravity separation tailings of Yichun Tantalum - Niobium Mine as the research object and carried out experimental research on the flotation of lepidolite with a combined collector. The results showed that when the self - prepared reagent LZ - 00 was combined with coconut oil amine in a mass ratio of 2:1 for lepidolite flotation, the index was the best, and the optimal total reagent dosage was 360 g/t. Under this reagent system, a lepidolite concentrate with a grade of 4.12% and a recovery rate of 70.37% was obtained, which was significantly improved compared with the on - site index. Through infrared spectroscopy analysis, it was found that when LZ - 00 and coconut oil amine were combined for flotation, there were chemical adsorption, physical adsorption and hydrogen - bond interactions on the surface of lepidolite minerals, which further revealed the action mechanism of the new collector.

4.2 Optimization of Flotation Process

In addition to the development of new collectors, the optimization of the flotation process is also a key research direction. Researchers optimize the parameters of each link in the flotation process, such as adjusting the grinding fineness, controlling the flotation time and temperature, and optimizing the reagent addition sequence, to improve the flotation effect of lepidolite. At the same time, some new flotation technologies are constantly emerging, such as step - by - step flotation and asynchronous flotation. These technologies can better adapt to the characteristics of lepidolite ores and improve the separation efficiency and concentrate quality.

5. Conclusion

Lepidolite flotation plays a crucial role in the development and utilization of lepidolite resources. Although there are still many problems in practical applications, such as poor collector selectivity, poor gangue depressant practicality and complex flotation process, with the development of new collectors and the continuous optimization of the flotation process, significant research progress has been made in lepidolite flotation technology. In the future, it is necessary to further strengthen the research on the basic theory of lepidolite flotation, deeply explore the interaction mechanism between minerals and reagents, and develop more efficient and environmentally friendly flotation reagents and advanced flotation processes, so as to achieve the efficient and clean utilization of lepidolite resources, meet the demand for lithium resources in the new energy industry, and promote the sustainable development of related industries.