Spodumene, lithium permeable feldspar and lepidolite can be used for many purposes after beneficiation and concentration. The cut-off grade and industrial grade of lithium deposit are divided into manual ore and machine ore, and the grade indexes are determined respectively. According to the production practice experience, if the particle size of spodumene in the ore body is greater than 3cm, the ore grade is more than 2% ~ 3%. If the particle size of beryl is greater than 0.5cm and the ore grade is more than 0.1% ~ 0.2%, it is suitable for manual separation. It is divided into manual separation ore, and the mineral reserves of manual separation are calculated. The tailings of hand beneficiation ore with machine beneficiation value and unsuitable for hand beneficiation belong to machine beneficiation ore.
Lithium ore dressing methods include manual separation, flotation, chemistry or chemistry_ Flotation combined method, thermal cracking method, radioactive method and particle flotation method, among which the first three methods are more commonly used. Next, Fodamon engineer will explain these three common sorting methods.
1、 Manual selection of lithium ore
Manual beneficiation was one of the main beneficiation methods in the production of lithium and beryllium concentrates at home and abroad in the 1950s and 1960s. In 1959, China’s Xinjiang, Hunan and other provinces and regions produced more than 2800 tons of beryl concentrate by hand. In 1962, the world output of beryl concentrate was 7400t, of which hand concentrate accounted for 91%. This is mainly due to the fact that most lithium and plated ores come from PEGMATITE DEPOSITS, and other main industrial minerals such as spodumene and beryl are large and easy to be selected by hand. However, it should be noted that manual beneficiation is gradually replaced by mechanical beneficiation because of its high labor intensity, low production efficiency, large waste of resources and low beneficiation index. However, in developing countries with cheap labor force, manual separation is still the main method to produce lithium beryllium concentrate.
2、 Flotation method of lithium ore
The research and application of flotation method were earlier. Flotation method has been used in the industrial production of spodumene concentrate abroad in the 1930s. Some spodumene flotation uses reverse flotation and some use positive flotation. Lepidolite is easy to float, which is commonly used in positive flotation; The industrial flotation of beryl is rarely reported. In the late 1950s, China began to study the flotation of spodumene and beryl, and then carried out the research on lithium mica flotation, lithium beryllium separation and other lithium plating ores. The flotation process of spodumene, beryl and lithium mica was determined and applied in the new lithium plating beneficiation.
3、 Chemistry or chemistry – combined flotation method of lithium ore
This method is suitable for extracting lithium salt from lithium ore in salt lake. The process is to evaporate the brine on the sun farm, precipitate the sodium salt and potassium salt, increase the concentration of lithium chloride to about 6%, and then put it into the factory to convert lithium chloride into lithium carbonate solid product by soda method.
Lithium extraction from lithium ore is one of the earliest methods, which has been developed more mature. The main process includes three steps: beneficiation, extraction and processing. At present, the main mature technologies include manual magnetic separation process, flotation magnetic separation process, flotation, gravity separation, combined magnetic separation process, combined beneficiation chemical treatment process, combined beneficiation metallurgical process, etc. Each process has its own characteristics, which can be selected according to the composition and properties of lithium deposit and main products.
Lithium extraction from lithium ore mainly includes spodumene, lime sintering method, lepidolite, lime sintering method, spodumene, sulfuric acid roasting method, lepidolite chlorination roasting method, spodumene soda autoclave method, etc. Recently, the main method of producing metal lithium is baking salt electrolysis, but this method consumes a lot of DC power, and the chlorine discharged from the anode must be collected and treated. Lithium salt (lithium chloride) as raw material is expensive and requires high purity.