Where potassium digested?

Potassium is essential for protein synthasis and for the conversion of blood sugar into glycogen. It activates a number of enzymes, particularly those concerned with energy production. Potassium is absorbed from the diet and does not need any specific mechanism and takes place in the small intestine as long as the concentration in the gut is higher that in the blood. Some potassium can be excreted in sweat. The kidneys are the main regulators

Potassium is not digested at all, because it is an element and therefore can not be decomposed into simpler substances by digestion or any other chemical process.