A process for water removal and/or recycling of sodium sulfate and/or sodium dithionate containing liquors derived from processing cobalt resource material essentially free of lithium comprising the steps of precipitation of cobalt as cobaltous carbonate or cobaltous hydroxide followed by removal thereof from the liquor, crystallization of sodium sulfate and sodium dithionate and removal of the crystals, followed by heating of the crystals to anhydrous sodium sulfate, sulphur dioxide and water and then separating the anhydrous sodium sulfate.