Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.

Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.

Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.

A process for extracting lithium from lithium-bearing salt brines including: (i) subjecting a feed brine to a primary evaporation step using mechanical evaporators, to form a first concentrated brine and sodium chloride; (ii) separating the sodium chloride in a salt removal step; (iii) reacting lime with the first concentrated brine in a liming step to precipitate out and discard magnesium and sulphate ions and other contaminants and to form a limed brine; (iv) subjecting the limed brine to a secondary evaporation step, to form a second concentrated brine and precipitating calcium chloride; (v) separating the calcium chloride from the second concentrated brine; (vi) reacting sodium sulphate with the second concentrated brine to precipitate out and discard calcium sulphate, to form a lithium-rich brine; (vii) reacting soda ash with the lithium rich brine thereby forming a precipitate of lithium carbonate; and (viii) separating the lithium carbonate.

The present disclosure relates to methods for producing hydrogen and calcium- or magnesium-bearing carbonates by capturing, converting, and storing carbon dioxide. The methods may include providing one or more calcium- or magnesium-bearing compounds; providing one or more water-soluble oxygenates; providing a plurality of catalysts; and reacting one or more calcium- or magnesium-bearing compounds and one or more water-soluble oxygenates with plurality of catalysts under conditions to produce hydrogen and calcium- or magnesium-bearing carbonates. The methods may include providing one or more calcium- or magnesium-bearing silicates; providing carbon monoxide; providing water vapor; and reacting one or more calcium- or magnesium-bearing silicates, carbon monoxide, and water vapor. The methods may include providing one or more calcium- or magnesium-bearing compounds; providing one or more water-soluble oxygenates; providing a catalyst; and reacting one or more calcium- or magnesium-bearing compounds and one or more water-soluble oxygenates with said catalyst.

Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.

A produced water stream in a GOSP is pretreated to remove total suspended solids, emulsified oil, total organic carbon, chemical organics and inorganics, and biodegradable matter. The pretreated produced water stream is further processed to remove hydrogen sulfide gas, which is split in an electrolysis cell to produce hydrogen, sulfur, and water. Following this, bromine gas is removed. The pretreated produced water stream, after the removal of hydrogen sulfide and bromine gas, is further treated using CO.sub.2 to produce several minerals. The pretreated produced water stream, after mineral production, is desalinated to produce fresh water and a reject stream. Several valuable chemicals are produced from the reject stream. This process recovers valuable minerals and chemicals from a produced water stream in a GOSP.