Solution mining of trona or nahcolite ore with electrodialytically- produced aqueous sodium hydroxide

摘要

A cyclic solution mining method that uses aqueous sodium hydroxide for recovering valuable alkali values, preferably as soda ash, from subterranean deposits of trona or nahcolite, even when such deposits are NaCl-contaminated. The aqueous sodium hydroxide mining solvent is generated via electrodialysis of a recirculating sodium chloride brine stream. Hydrogen chloride that is also generated in the cell's operation is neutralized with aqueous sodium carbonate, to regenerate sodium chloride brine that is recirculated to the electrodialysis cell as brine feed.