Lithium carbonate extraction and purification technology is an important part of the lithium resource development process. The following is a detailed introduction to the extraction and purification technology of lithium carbonate:
First, the extraction of lithium carbonate
The extraction of lithium carbonate mainly adopts two methods: ore method and brine method.
1. Ore method: through crushing, grinding, flotation and other processes, the lithium element in the lithium ore is extracted. Among them, the flotation method is the most commonly used method, through specific flotation agent and process conditions, the lithium ore lithium minerals and other minerals are separated.
2. Brine method: lithium carbonate is extracted from the brine of salt lakes. The lithium content in the brine of the salt lake is high and can be extracted directly. Commonly used extraction methods include precipitation, solvent extraction and ion exchange.
Second, the purification of lithium carbonate
Extracted lithium carbonate often contains impurities and needs to be purified. Commonly used purification methods include heating decomposition method, solvent extraction method and ion exchange method.
1. Heating decomposition method: lithium carbonate is heated to a certain temperature, so that it decomposes into sodium carbonate and lithium salt. By controlling the heating temperature and time, higher purity lithium carbonate can be obtained.
2. Solvent extraction method: using different solvents for lithium carbonate and impurities of different selectivity, through the selection of extractant and control of operating conditions, the impurities from the lithium carbonate separation.
3. Ion exchange method: using ion exchange resin on lithium carbonate and impurity ions with different adsorption capacity, through the selection of suitable ion exchange resin and operating conditions, the impurity ions will be removed from lithium carbonate.