Abstract: An improved process for the production of potassium sulfate crystals by the reaction of saturated solution of potassium chloride with langbeinite in the solid phase at a temperature of from 45.degree.-55.degree. C., thereby forming potassium sulfate crystals and magnesium chloride solution comprising the step of conducting the reaction in the presence of a growth enhancer comprising monosulfonated or monosulfated surfactant and a neutralized disulfonated surfactant in a weight ratio of from about 0.14 to 0.69.

Abstract: A nutritional mineral supplement for animal feeds comprising amorphous sulfur, potassium chloride and langbeinite when prepared by mixing same, heating the mixture to above 107.degree. C., adding amorphous sulfur with agitation and allowing the mixture to cool.

Abstract: A process for the granulation of potash salts to produce granules in high yield by the steps of mixing the potash salt with an inorganic phosphate binder and water, granulating the mixture and drying it.

Abstract: An improved method of producing potassium sulfate from langbeinite. The improved method employs a "salting out" step to remove additional KCl from the mother liquor resulting from K.sub.2 SO.sub.4 crystallization. NaCl is added to the mother liquor to cause precipitation of KCl crystals. The amount of NaCl added is controlled to an amount below the saturation point for NaCl in the solution to avoid contaminating the KCl with solid NaCl. The KCl crystals are recycled back to the K.sub.2 SO.sub.4 reactors as a source of KCl. The "salting out" step eliminates an energy-intensive submerged combustion evaporation step from the K.sub.2 SO.sub.4 recovery process and consequently reduces atmospheric emissions.