Solution mining of sodium minerals with acids generated by electrodialytic water splitting

Abstract

A process employing two- and three-compartment electrodialytic water splitting for conversion of basic sodium material such as dry-mined or subterranean deposits of trona or nahcolite into a liquid comprising aqueous sodium base such as NaOH and/or Na.sub.2 CO.sub.3. The basic sodium material is contacted with a liquid comprising aqueous hydrogen ions for a time sufficient to produce a liquid comprising aqueous sodium ions. A liquid comprising water is introduced into each base compartment and the liquid comprising aqueous sodium ions is introduced into each remaining compartment of a two- or three-compartment water splitter. Direct current is passed through said water splitter to produce, a liquid comprising an aqueous sodium base in the base compartment and a liquid comprising aqueous hydrogen ions in an acid compartment of said water splitter. At least a portion of the liquid comprising aqueous hydrogen ions is used in the initial contacting step. In preferred embodiments, a subterranean deposit of trona is solution mined with a Na.sub.2 SO.sub.4 /H.sub.2 SO.sub.4 solution thereby converting the trona into CO.sub.2 and an aqueous solution (reaction liquid) of Na.sub.2 SO.sub.4, optionally containing NaHCO.sub.3, which is pumped to the surface and supplied to a water splitter to wherein a Na.sub.2 SO.sub.4 /H.sub.2 SO.sub.4 solution is regenerated and aqueous NaOH is produced. The regenerated Na.sub.2 SO.sub.4 /H.sub.2 SO.sub.4 may be reinjected into the trona deposit and the NaOH may be concentrated or optionally used to convert trona into soda ash.

Dependencies are inferred from the claim text.