More precisely, the precipitation of calcium ions associated with the presence of hydrogen carbonates in water and under the effect of heat causes the formation of calcium carbonate deposits.
Calcium or limestone
Although these two elements are similar, they are not identical. In fact, calcium is an element of the periodic table of the alkaline earth metals family. Moreover, calcium is not found in its raw state in nature. Limestone, on the other hand, is a sedimentary rock composed mainly or entirely of calcium carbonate (CaCO3).
In comparison, limestone and calcium are very similar to silica and silicon dioxide in that the basic element (silicon & calcium) is not found in nature and both can cause problems in water treatment equipment.
- To learn more about silica and its derivatives, see this article: How to extract silica from water?
As mentioned above, the precipitation of calcium and hydrogen carbonate ions, which is better known as sodium bicarbonate, causes scale formation. Briefly, precipitation is a chemical reaction caused by changes in the pH or solubility of a solution.
- As an aside, water hardness is a good indicator of the scaling potential of water.
Reducing the risk of scaling
Several techniques can be used to reduce the risk of scaling. To begin with, we can think of water softening. Indeed, a water softener system will allow the extraction of calcium ions, which, as we said, are at the centre of scale formation.
In addition to these ion exchange systems, the addition of chemicals categorized as antiscalants or electrolytic scale removal (ESR).
In short, to learn more about scale removal technologies, we invite you to consult this article: