Abstract: A process and system are disclosed for producing a lithium product from a solution comprising lithium nitrate. The solution comprising lithium nitrate can be obtained by reacting a lithium-containing metal silicate with nitric acid. The process and system comprise subjecting the solution comprising lithium nitrate to a first thermal treatment procedure (in one or more heated vessels) in which water and nitric acid (when present) are removed, and whereby a resultant lithium nitrate-rich crystal slurry is heated to produce a molten liquid. The process and system also comprise passing the molten liquid to a second thermal treatment procedure (in a further-heated vessel) in which the molten liquid is heated to substantially decompose lithium nitrate to lithium oxide.

Abstract: A process and system are disclosed for producing lithium oxide from lithium nitrate. In the process and system, the lithium nitrate is thermally decomposed in a manner such that a fraction of the lithium nitrate forms lithium oxide, and such that a remaining fraction of the lithium nitrate does not decompose to lithium oxide. The thermal decomposition may be terminated after a determined time period to ensure that there is a remaining fraction of lithium nitrate and to thereby produce a lithium oxide in lithium nitrate product. The lithium oxide in lithium nitrate product may have one or more transition-metal oxides, hydroxides, carbonates or nitrates added thereto to form a battery electrode. The lithium oxide in lithium nitrate product may alternatively be subjected to carbothermal reduction to produce lithium metal.

Abstract: A process and system are disclosed for recovering lithium from a lithium-containing silicate mineral. The process and system comprise mixing the silicate mineral with nitric acid. The process and system also comprise subjecting the mixture to a leaching process having conditions such that lithium values in the silicate mineral are leached from the silicate mineral as lithium nitrate. The nitric acid can be in aqueous, gaseous or precursor gaseous form.

Abstract: A process and system are disclosed for capturing carbon dioxide from a gas stream. The process and system comprise a first stage, in which a metal silicate is reacted with nitric acid to produce a metal nitrate. The metal silicate can be one or more of: an alkaline-earth metal silicate, in particular magnesium or calcium; or an alkali metal silicate, in particular lithium. The process and system also comprise a second stage, in which the metal nitrate from the first stage is heated to a temperature sufficient to decompose the metal nitrate to a metal oxide. The process and system further comprise a third stage, in which the metal oxide is mixed with water to convert the metal oxide to a metal hydroxide solution. The process and system additionally comprise a fourth stage, in which the gas stream is scrubbed with the solution from the third stage such that the metal hydroxide reacts with the carbon dioxide to form a metal carbonate/bicarbonate product.