Lithium carbonate, an inorganic compound whose chemical formula is Li2CO3, is a colorless monoclinic crystal or white powder. The density of 2.11 g/cm3. Melting point 618 ℃ (1.013 * 10 ^ 5 pa). Dissolved in dilute acid. Slightly soluble in water, solubility in cold water is greater than under hot water. Insoluble in alcohol and acetone. Can be used to produce ceramics, drugs, catalysts, etc. Common lithium ion battery material.
There are several methods to extract lithium from salt lake — industrial lithium carbonate factory.
- Electrodialysis
The smallest ions are driven through the membrane by electricity, and the remaining ions are isolated on the other side of the membrane. The adsorption and adhesion of magnesium ions on the membrane, as well as the penetration rate of magnesium ions in the membrane will affect the entire production cost and production cycle. The core problem to be solved by electrodialysis is to isolate magnesium.
- The extraction method
Alkali metal ions belong to hard acid and can form stable complexes with hard alkali. According to this property, the extraction method can be used to extract lithium. At present, the core problem is the research and development of extractant, extractive base and corrosion-resistant materials to meet the requirements of the present extraction method. High-purity lithium chloride can be obtained through extraction and reverse extraction solution before extraction and extraction, and finally lithium carbonate can be obtained.
At present, there are two different salt lakes in China. Lithium chloride is extracted by extraction method for the same type of salt lake resources. The salt lake in xitai, using the technology of the Chinese academy of sciences, has completed the 9999 lithium chloride production line and initiated the project. The production line of battery level lithium carbonate was started in 2017 and completed in 2018. The first production line of battery level lithium carbonate was clearly proposed in China, and it was the first place to put forward the battery level lithium carbonate production line of 10,000 tons — lithium carbonate price
Another salt lake, where experts from the nonferrous extraction industry have stepped in, has built a 1,000-ton line of lithium chloride, with a purity of about 95%, to produce some conventional lithium carbonate.
- The precipitation
Precipitation is achieved through concentrated crystallization or carbonization, with relatively low purity. In the future, auxiliary manufacturers or secondary manufacturers are required to process, to meet the needs of battery materials.
China is a salt lake country, but much of it is relatively dispersed and difficult to exploit on a large scale, and magnesium and lithium are relatively high. The foreign countries can use the classical precipitation method to extract lithium from the bittern on a large scale, an important reason is that the magnesium lithium in the brine is relatively low or does not contain magnesium. The classic sedimentation method is not suitable (except for Tibetan zabuye salt lake and so on) to extract lithium from most of China’s salt lake brine, mainly because: 1) the law requires the concentration of Li+ mass in brine to be greater than 0.5g/L, while most of China’s salt lake brine is lower than this value; 2) the method requires that the content of Ca2+ and Mg2+ in brine should not be too high, especially Mg2+. 3) the method requires special geographical conditions of drought, little rainfall, long sunshine time and large annual evaporation, but the salt lakes in mainland China cannot meet this requirement.
- The adsorption
Inorganic ion adsorption is a method to select lithium from dilute solution by using the characteristics of high selectivity and specific memory effect of inorganic ion adsorbent on Li+. Now the technical difficulty of adsorption method has not been completely broken. At present, the adsorption method is mainly applied to some salt lakes with the lowest lithium content and concentration, such as qarhan salt lake. The magnesium lithium ratio is as high as 1800 times, and the lithium ion concentration in the original halogen is only about 30ppm. By the end of last year it had produced around 1,500 tonnes, and is now in effect the world’s largest adsorption capacity. Byd and the adsorption method of the manufacturer of the cyanli to carry out a new round of cooperation, on October 29, 2016, started production capacity of 30,000 tons of battery level carbonic acid lithium production line.
