How long does it take for a stone to turn into lime when burned
Transforming ordinary stones into pure white lime is a millennium long process of fire tempering. The core secret of this seemingly simple process lies in high-temperature calcination, and time is the most critical link in it. So, how long does it take to burn a stone to complete this transformation?
The answer is not fixed, it depends on several core factors. Firstly, temperature, the true qualitative change requires a high temperature of approximately 900 ℃ to 1200 ℃. Under these conditions, the main component of the stone, calcium carbonate, will begin to decompose, releasing carbon dioxide and leaving behind calcium oxide, namely quicklime.
Next is the size and type of stone material. Limestone with uniform texture and moderate pores is an ideal raw material. Large stones take longer for heat to transfer to the core, while small pieces or crushed stones can complete the reaction faster. Therefore, the calcination time ranges from several hours to tens of hours. In traditional earthen kilns, the entire process may even take several days to ensure sufficient heat infiltration.
Finally, the technology of the kiln is also crucial. Modern and efficient rotary kilns can achieve uniform heating and continuous production, which may only take two to three hours to complete. Traditional earth kilns or shaft kilns, on the other hand, have much longer calcination cycles due to their lower thermal efficiency.
Burning stones is not simply a matter of timing, but a comprehensive test of temperature, raw materials, and craftsmanship. When encountering enough high temperature at the right time, hard stones will unload their heavy burden in the flames and transform into white lime with wide application value. This process can be called a wonderful mineral deformation record.
