Abstract: This paper studied on the reaction between sulfuric acid and potassium carbonate in the bentonite layer to potassium sulfate for crystalline in the layer. The optimum experimental conditions were as follows:water bath temperature is 80 ℃,stirring speed is 1.5 m/s, stirring time is 30 min, concentration is 20 g bentonite slurry dissolved in distilled water whose volume is 100 mL; sub-water bath temperature is 70-70 ℃, sub-stirring speed is 0.5-2.0 m/s.The results of single factor experiments and orthogonal experimental are anastomosis. Order of its factors: stirring speed> pulp concentration > water temperature> stirring time. Its best crystallization of layers achieve is 4.2 g. The SEM, EDS picture shows the success of the crystallization of potassium sulfate in the bentonite layer space. The phenomenon of package isn' t appear,so it's a better understanding for releasing of fixed potassium.

Key words: potassium carbonate;potassium sulfate;bentonite;crystallization of layers