The birth of calcium oxide (CaO) comes from a high-temperature "baptism". When limestone is calcined at high temperatures, the calcium carbonate molecules inside decompose — one calcium carbonate molecule (CaCO₃) breaks down into one calcium oxide molecule (CaO) and one carbon dioxide molecule (CO₂). In industrial production, this process is carried out in an orderly manner in large kilns, continuously supplying calcium oxide to various industries.

On the grand stage of industry, calcium oxide is an indispensable "leading role". In the metallurgical industry, it serves as a flux, which can lower the melting point of metals, facilitate better fusion and purification of metals during the smelting process, and improve the quality of metals. In industries such as plastics, rubber, papermaking, and coatings, calcium oxide is often used as a filler or additive. Adding calcium oxide to plastics can enhance the strength, hardness, and surface gloss of plastic products; in rubber, it acts as a reinforcing agent to improve the wear resistance and anti-aging performance of rubber products; in papermaking, as a filler and coating material, it can further enhance the whiteness, smoothness, and printing performance of paper; in coatings, it can improve the leveling property, hiding power, and durability of coatings.

In the field of agriculture, calcium oxide is also an excellent helper. The pH value of soil is crucial for the growth of crops. For acidic soil, spreading some calcium oxide is like giving the soil a "dose of good medicine" — it can neutralize the acidity of the soil and make the soil more "livable". At the same time, it can supplement calcium elements for crops, strengthen the "physique" of crops, and enhance their resistance to harsh environments and plant diseases and insect pests.

With its unique chemical properties, calcium oxide plays a vital role in many fields such as industry and agriculture, and has become an important force promoting social development.