Lithium hydroxide

Lithium hydroxide is an inorganic compound with the formula LiOH. It is a white hygroscopic crystalline material. It is soluble in water and slightly soluble in ethanol. Lithium hydroxide is produced mainly from lithium carbonate through a metathesis reaction with calcium hydroxide. It is a strong base and, as such, is used in the production of various lithium compounds and in applications requiring the absorption of carbon dioxide.

Production

Lithium hydroxide is produced by reacting lithium carbonate (Li2CO3) with calcium hydroxide (Ca(OH)2) in a metathesis reaction to produce lithium hydroxide and calcium carbonate (CaCO3). The reaction is as follows:

Li2CO3 + Ca(OH)2 → 2 LiOH + CaCO3

Another method involves the direct reaction of lithium with water, but this is less common due to the higher reactivity of lithium with water, which can be hazardous.

Uses

Lithium hydroxide is used in a variety of applications, including:

• As a catalyst in the production of biodiesel.
• In the production of lithium greases, which are used as lubricants in various industrial applications.
• In carbon dioxide scrubbers for breathing gas purification systems in spacecraft, submarines, and rebreathers to remove carbon dioxide from exhaled gas and replace it with oxygen.
• In the production of other lithium compounds, such as lithium stearate, which is used as a thickener in greases.
• In the nuclear power industry, lithium hydroxide is used to control the acidity of the coolant in pressurized water reactors.

Safety

Lithium hydroxide, like other strong bases, is corrosive and can cause severe burns upon contact with skin or eyes. It requires careful handling, with appropriate safety gear such as gloves and eye protection. In case of contact, the affected area should be rinsed immediately with plenty of water.

Environmental Impact

While lithium hydroxide itself is not considered highly toxic, its production and use must be managed carefully to minimize environmental impact. The extraction of lithium for lithium carbonate, a precursor to lithium hydroxide, can have significant environmental consequences, including water depletion and pollution.