Method and system for the production of potassium sulfate from potassium chloride

A system for the production of potassium sulfate, comprising:

• 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 from 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.