The Method That Lithium Carbonate Is Produced From Lepidolite
2023-02-12
In China’s lithium industry, spodumene, lepidolite ore and salt lake brine are mainly used as raw materials for lithium extraction, but the methods for extracting lithium from ores have their shortcomings.
Lithium carbonate is the basic material for the production of secondary lithium salts and lithium metal products, so it has become the most used lithium product in the lithium industry, and other lithium products are basically downstream products of lithium carbonate. The production process of lithium carbonate can be divided into salt lake brine extraction and ore extraction according to the source of raw materials. At present, lithium carbonate is mainly produced by salt lake brine extraction process, while in China, solid ore extraction process is mainly used. Although China is also actively mining lithium resources in salt lakes, due to limitations in technology, resources and other factors, the development speed is relatively slow.
Extract Lithium From Ore
Lithium carbonate and other lithium products are mainly produced from solid lithium ores such as spodumene and lepidolite. Extracting lithium resources from ores has a long history and mature technology. The main production processes include lime sintering and sulfuric acid method, among which sulfuric acid method is the main method currently used.
1. Lime Sintering Method
The limestone method is to mix lepidolite with limestone, crush and grind the finished product, and roast it at 900-1100°C so that the alkali metals in it can be converted into water-soluble compounds, and then extracted by water immersion Lithium resources among them.
Advantages: The raw materials for lithium extraction are easy to obtain, the core crushing and grinding equipment of the front-end design is simple to configure, the overall process is simple, and the cost is controllable.
Disadvantages: high-temperature roasting, high energy consumption, low recovery rate of lithium, and a large amount of slag during the treatment process, which is difficult to reuse and easily causes serious secondary pollution.
2. Sulfuric Acid Method
The sulfuric acid method is currently the main method for extracting lithium from lepidolite in China, and can be subdivided into sulfuric acid roasting and impregnation method and sulfuric acid leaching method. The sulfuric acid roasting and impregnation method has been gradually replaced by the salt roasting method because the roasting temperature is too high, resulting in high energy consumption, and the extraction rate of lithium is also low. The sulfuric acid leaching method is widely used to extract lithium from lithium ores and has been developed.
Advantages: Avoid high-temperature roasting, low energy consumption, low reaction temperature, it is a relatively efficient lithium extraction process, and the amount of waste residue is small.
Disadvantages: There are requirements for the fineness of lepidolite. Lepidolite needs to be ground to a certain fineness to meet the requirements of the leaching rate, and the reaction time is relatively long; a large amount of aluminum is also dissolved during the leaching process, and a large amount of aluminum needs to be removed, which will cause Larger loss of lithium; more sulfuric acid remains after the reaction is completed, and a large amount of alkali needs to be consumed to neutralize the residual acid.
Lithium Ore Grinding Process
After the lithium ore has undergone overall blasting, the rough stone after blasting should be coarsely crushed by crushing equipment (jaw crusher, hammer crusher, mobile crusher), and the coarsely crushed finished product will enter the medium and fine crushing equipment (cone crusher, impact crusher). After the finely crushed lithium ore meets the grinding particle size, it enters the mill for grinding (vertical mill, European mill)
The ground material reaches a certain fineness and can enter the process of extracting lithium.
Lithium carbonate is widely used in batteries, ceramics, grease, etc. The added value of lithium carbonate is high, and there are resources to develop lithium carbonate.
