Method for the production of sulphate of potash granulates, sulphate of potash granulate obtained thereby, and use thereof

14:

• A process for producing potassium sulphate granulates, comprising:
• adding potassium chloride to the potassium sulphate in a granulation process in a quantity of 0.1 to 7.5% by weight, based on the potassium sulphate used.

15:

• The process according to claim 14, wherein the potassium chloride is added in the form of a dust with a maximum particle size of 200 μm or in the form of an aqueous solution.

16:

• The process according to claim 14, wherein part of the potassium chloride added is in the form of a dust with a maximum particle size of 200 μm, and a remaining quantity of the potassium chloride is in the form of an aqueous solution.

17:

• The process according to claim 14, wherein a volume of water added before or during the pressing process is between 0.1 and 2.5% by weight, and/or
• wherein a volume of water added after the pressing process is between 0.1 and 2.5% by weight,
• with the total volume of the added water amounting to 3.5% by weight as a maximum, the weight % being based on the water-free potassium sulphate.

18:

• The process according to claim 14, comprising:
• compacting of the potassium chloride, potassium sulphate and water mixture;
• wherein said compacting is performed as pressure agglomeration.

19:

• The process according to claim 18, wherein the pressure agglomeration comprises compacting of the mixture of potassium sulphate, potassium chloride and water with a roller press.

20:

• The process according to claim 19, wherein the pressure agglomeration comprises compacting of the mixture of potassium sulphate, potassium chloride and water with a roller press at a specific line force ranging between 30 and 100 kN/cm, based on a roller diameter of 1000 mm and an average slug thickness of 10 mm.

21:

• The process according to claim 18, wherein the compacting of the mixture of potassium sulphate, potassium chloride and water is performed with a roller press and followed by a subsequent milling and grading of slugs obtained from the compacting.

22:

• The process according to claim 21, wherein the slugs are moistened with water after the pressing process.

23:

• The process according to claim 14, wherein the granulation is performed at a temperature ranging between 20 and 100° C.

24:

• A potassium sulphate granulate obtainable by a process according to claim 14.

25:

• The potassium sulphate granulate according to claim 24, comprising a potassium chloride content ranging between 0.1 and 7.5% by weight, based on the amount of the potassium sulphate used.

26:

• A method for improving mechanical properties of potassium sulphate granulates, comprising:
• adding potassium chloride to the potassium sulphate during a granulation process.

27:

• The method according to claim 26, wherein the burst strength and/or abrasion resistance of said potassium sulphate granulates is increased compared to potassium sulphate granulates which do not comprise potassium chloride.