The present disclosure relates to a process for the production of potassium sulphate based mineral fertilizers, by means of an exchange reaction between potassium chloride and ammonium sulphate (2KCl+(NH.sub.4).sub.2SO.sub.4<.fwdarw.K.sub.2SO.sub.4+2NH.sub.4Cl) in controlled conditions. The process, subject of the invention, makes it possible to obtain, in a single reaction stage, a crystalline product classifiable as low-chlorine-content mineral fertilizer, containing potassium sulphate, with K.sub.2O in an amount of between 40% and 50% by dry weight, ammoniacal nitrogen in an amount of less than 5% by dry weight and chlorine in an amount of less than 3% by dry weight, with a high potassium-conversion efficiency (calculated as the ratio between what the amount found in the solid main product and the amount introduced as KCl to the reaction with ammonium sulphate) and a by-product, which can be used directly as NK fertilizer (containing nitrogen (N) and potassium oxide (K.sub.2O) both in an amount comprised between 15% and 20% by dry weight) or as raw material for the production of complex fertilizers.

There is provided herein a fertilizer granule comprising Urea, Polyhalite and Ammonium Sulphate.

There is provided herein a fertilizer granule comprising Urea, Polyhalite and Ammonium Sulphate.

There is provided herein a fertilizer granule comprising Urea, Polyhalite and Ammonium Sulphate.

A method for producing potassium chloride granulates from a crystalline potassium chloride raw material. The potassium chloride raw material is treated, prior to granulation, with at least one alkali metal carbonate and at least one phosphate additive selected from alkali metal monophosphates, alkali metal pyrophosphates, linear alkali metal polyphosphates and mixtures thereof, in the presence of water.

A method for producing potassium chloride granulates from a crystalline potassium chloride raw material. The potassium chloride raw material is treated, prior to granulation, with at least one alkali metal carbonate and at least one phosphate additive selected from alkali metal monophosphates, alkali metal pyrophosphates, linear alkali metal polyphosphates and mixtures thereof, in the presence of water.

Methods and system for increasing the water solubility and availability of zinc in granular fertilizers using acid treatments. The treatment of granular fertilizers with an acidic solution increases an amount of water-soluble zinc, which in turn, increases the efficiency of zinc uptake and reduces the costs and equipment otherwise needed to mitigate zinc deficiencies.

Methods and system for increasing the water solubility and availability of zinc in granular fertilizers using acid treatments. The treatment of granular fertilizers with an acidic solution increases an amount of water-soluble zinc, which in turn, increases the efficiency of zinc uptake and reduces the costs and equipment otherwise needed to mitigate zinc deficiencies.

A method for producing potassium chloride granular materials from a crystalline potassium chloride raw material, wherein, before the granulation process, the potassium chloride raw material is treated with at least one alkali metal carbonate and at least one metaphosphate additive in the presence of water.

A method for producing potassium chloride granular materials from a crystalline potassium chloride raw material, wherein, before the granulation process, the potassium chloride raw material is treated with at least one alkali metal carbonate and at least one metaphosphate additive in the presence of water.