Can magnesite ore be used to burn lime
Magnesite ore can theoretically be used to produce lime, but there are differences in actual production compared to common limestone.
The main component of magnesite ore is magnesium carbonate (MgCO3), and impurities usually include Si, Ca, Fe, Al and other components, accompanied by quartz, dolomite, chlorite and other forms. When the temperature rises to 620K, its carbonate begins to decompose and release carbon dioxide. At 970K, the decomposition reaction is fully carried out, and the product is magnesium oxide with loose texture and high chemical activity. Continuing to heat up to 1920K, lattice defects will be restored, and grain growth will form dense crystals. Finally, impurities will be separated at 3200K, and high-purity magnesium oxide crystals can be obtained after cooling.
However, there are significant differences in the calcination characteristics of magnesite compared to traditional limestone (mainly composed of calcium carbonate CaCO3). Calcium carbonate needs to be completely decomposed at around 900 ℃, while magnesium carbonate begins to decompose at around 550 ℃, and the activity control of magnesium oxide produced by magnesite calcination requires more precise temperature management. If the temperature control is improper, it may lead to a decrease in the activity of the product due to excessive calcination.
In actual production, the calcination of magnesite requires specialized equipment, such as a new type of small particle ore calcination vertical kiln, which uses a thermal storage heating process to allow small particle ores to receive thermal and radiation heat transfer, thereby increasing the decomposition temperature, ensuring heating time, and achieving complete decomposition results. The calcined product magnesium oxide can be used in refractory materials, metallurgy and other fields, but if it is used in traditional lime application scenarios, further research is needed on its hydration reaction characteristics and compatibility with other materials.
