Is Lithium Sulfate Soluble in Water?

The chemical compound lithium sulfate is commonly used in medicine as an antidepressant. It is also used in ultrasound-type non-destructive testing as a very efficient sound generator. The metal is found naturally in several minerals, including petalite, spodumene and lepidolite. It has a low affinity to water, and it is not known to bioaccumulate. Lithium is considered a critical element for human life, taking part in the function of several organs.

The most common method for obtaining lithium is to process natural spodumene with sulfuric acid, which yields the lithium sulfate salt (Li 2 SO 4 2H 2 O). This salt, however, contains two water molecules. It is therefore not suitable for industrial production as it cannot be concentrated to a high degree.

Another option for producing lithium sulfate is to leach spodumene with sulfuric acid, and then concentrate the resulting solution. This produces a dihydrate of the salt, which can be purified to a pure product by using sodium hydroxide and carbon dioxide. This method, however, requires a significant amount of water to be evaporated and crystallised, which increases the cost of production.

Alternatively, a high-purity product can be obtained by dissolving lithium in a lacustrine brine. This process is currently the main technology for obtaining lithium from salt-lake brines. The concentration of lithium in the brines ranges from a few g/L up to 56 mg/L, depending on the location of the lake and the pretreatment of the brines.