Abstract: This invention relates to a process for the production of an aqueous calcium chloride solution, which process comprises: locating a charge of calcium carbonate within a reaction vessel; and contacting an aqueous solution containing hydrochloric acid with the calcium carbonate charge to produce carbon dioxide and the aqueous calcium chloride solution. The carbon dioxide produces a foam at the top of the aqueous calcium chloride solution and entrains therewithin at least a portion of any fines contained in such solution. In one embodiment, the fines are removed from the reaction system by allowing the foam and its entrained fines to overflow the reaction vessel. In another embodiment, removal of the fines is achieved by providing a foam reservoir into which the foam and its entrained fines continuously enter and a defoaming mechanism for breaking down the entering foam.