Potassium sulfate is a white crystalline powder, an inorganic salt with the chemical formula K2SO4. Agricultural potassium sulfate typically has a light yellow appearance and exhibits low hygroscopicity, preventing agglomeration and ensuring good physical properties. It serves as an excellent water-soluble potassium fertilizer, commonly utilized as a primary ingredient in chlorine-free nitrogen, phosphorus, and potassium compound fertilizers. This versatile compound can be directly applied as fertilizer to various soils and crops, enhancing their growth and yield. Additionally, it finds application as a food additive, providing dough conditioning properties, among other uses.
| Name | Potassium sulphate |
| CAS Number | 7778-80-5 |
| EINECS Number | 231-915-5 |
| Molecular weight | 174.259 |
| Chemical formula | K2SO4 |
| Melting point | 1067 ℃ |
| Boiling point | 1689 ℃ |
| Density | 2.66 g/cm³ |
| Appearance | White crystalline powder |
Application
The basic raw material for the manufacture of various potassium salts such as potassium carbonate and potassium persulphate. Used as a sinker in the glass industry. Used as an intermediate in the dye industry. In the spice industry it is used as an auxiliary, etc. In the pharmaceutical industry it is also used as a diarrhoeic agent and as a treatment for soluble barium salt poisoning. Potassium sulphate is commonly used in agriculture as a potash fertiliser, with a potassium oxide content of 50%.
Agricultural applications
Potassium sulphate is a good water-soluble potash fertiliser as it is colourless crystalline, has little hygroscopicity, is not easily caked, has good physical properties and is easy to apply. Potassium sulphate is also a chemically neutral and physiologically acidic fertiliser. Potassium sulphate is a non-chlorinated, high quality and efficient potash fertiliser, especially in the cultivation of chloride-sensitive crops such as tobacco, grapes, sugar beet, tea trees, potatoes, flax and various fruit trees; it is also the main raw material for high quality nitrogen, phosphorus and potassium ternary compound fertilisers.
The potassium sulphate compound fertiliser is produced by low temperature conversion of potassium chloride, chemical synthesis and slurry granulation process. It is stable and contains not only the three main nutrients necessary for plants, such as N, P and K, but also S, Ca, Mg, Zn, Fe, Cu and other trace elements. This type of fertiliser is suitable for all kinds of cash crops, especially those sensitive to chlorine. The main components of potassium sulphate fertilisers are MAP (monoammonium phosphate), DAP (diammonium phosphate) and ammonium sulphate (mainly derived from low temperature conversion of surplus sulphuric acid neutralised with gaseous ammonia). Potassium sulphate, urea and other impurities such as calcium sulphate, iron, aluminium, magnesium and other salts of phosphoric acid, as well as trace amounts of incomplete potassium chloride.