摘要 |
A method and a system for the production of potassium sulfate. The method comprises reacting a source of water soluble potassium with a magnesium sulfate-containing substance in presence of an aqueous alcoholic solution. The system comprises a first reactor for dissolving a water soluble potassium in water into a first solution; a second reactor for dissolving magnesium sulfate hydrate in water and adding methanol into a second solution; a third reactor, adapted to receive the first and the second solutions, mixed then under stirring and cool them down into a slurry; a filter collecting and filtering the slurry from the third reactor; delivering, after rinsing of the solid part with methanol, chloride-free potassium sulfate, and a combined filtrate and rinsings; a column receiving and distilling the combined filtrate and rinsings, delivering methanol back to the second reactor and to the filter and a concentrated solution of magnesium chloride; a fourth reactor, adapted to receive the concentrated solution of magnesium chloride, which crystallizes upon cooling, and to treat the concentrate with sulfuric acid, delivering hydrochloric acid and a residual mass; a collector, adapted to absorb the hydrochloric acid delivered form the fourth reactor; and a fifth reactor, adapted to collect and crystallise the residual mass from the fourth reactor, for recycling to the second reactor as magnesium sulfate heptahydrate. |