Process for producing potassium carbonate

Abstract

A method for producing potassium carbonate using a continuous countercurrent exchange system. A continuous ion exchange system with resin in the ammonium form is flushed with a saturated potassium chloride solution which displaces the ammonium ion and replaces it with potassium. Ammonium carbonate is then passed through the ion exchanger to place the ammonium in the reserve form, by displacing the potassium, and produce a concentrated potassium carbonate solution. This process is done in a continuous countercurrent manner which allows maximum recovery of the potassium carbonate as a 15-18% by weight solution with minimum impurities, and at high throughput rates. The potassium carbonate solution is then removed, evaporated, dried, sized and stored for subsequent shipment. The ammonium chloride from the ion exchanger is treated with slaked lime to produce ammonium hydroxide, which in turn is reacted with carbon dioxide (from calcined limestone or an outside source) to regenerate ammonium carbonate for reuse in the ion exchanger. Calcium chloride is a co-product of the overall reaction.