Abstract: A method for releasing impurities from a calcium-based mineral is described. The method comprises reacting a calcium-based mineral containing impurities with an aqueous solution of one or more ionic salts at a temperature of approximately 85° C. or above, wherein at least one of the calcium-based mineral and the one or more ionic salts comprises sulphate and at least one of the calcium-based mineral and the one or more ionic salts comprises ammonium, and wherein the concentration of the solution is approximately 25% or higher mass fraction, such that double salt crystals are formed and impurities are released. The method further comprises separating the double salt crystals from the impurities. Various products of the process are also described.

Abstract: A process for capturing a target gas from a flowing gas mixture by use of at least a pair of capture and release sections together with a discharge section is described. The at least one pair of capture and release sections includes a target gas capture section and a target gas release section in fluid communication with one another. The target gas discharge section is in fluid communication with the target gas capture section. The capture, release and discharge sections have a high surface area medium and a fluid contained therein, and include a fluid entry point at a first end and a collection tank at a second end.