Potassium carbonate is widely used for the production of glass and soap. It is also used as a drying agent which is mild in nature. Many wine production processes involve the use of this compound as a buffering agent. Potassium carbonate is also used as a fire suppressant.

• It is use for soap, glass, and dishware production
• As a mild drying agent where other drying agents, such as calcium chloride and magnesium sulfate, may be incompatible. It is not suitable for acidic compounds, but can be useful for drying an organic phase if one has a small amount of acidic impurity. It may also be used to dry some ketones, alcohols, and amines prior to distillation.
• In the alkalization of cocoa powder to produce Dutch process chocolate by balancing the pH (i.e., reduce the acidity) of natural cocoa beans; it also enhances aroma.
• In antique documents, it is reported to have been used to soften hard water.
• As a fire suppressant in extinguishing deep-fat fryers and various other B class-related fires.
• as an ingredient in welding fluxes, and in the flux coating on arc-welding rods.