Chemical composition analysis of lime kiln raw materials
The core raw material of a lime kiln is limestone, and its chemical composition directly determines the quality and industrial application value of the calcined product. The main component of limestone is calcium carbonate (CaCO3), and its content needs to be ≥ 90% to meet the requirements of efficient calcination. If the CaCO3 content is insufficient, it will lead to a decrease in the production of calcium oxide (CaO) after calcination, affecting the activity and purity of quicklime.
Impurities are a key factor affecting the quality of lime. The content of silicon dioxide (SiO ₂) should be ≤ 3%. If it exceeds the standard, it will react with CaO to form calcium silicate (CaSiO ∝), which reduces the activity of lime and can easily lead to slag thickening and poor fluidity in steel smelting; The content of magnesium oxide (MgO) should be ≤ 3%. If it is too high, it will increase the sintering temperature of lime and increase energy consumption; The total amount of impurities such as alumina (Al ₂ O3) and iron oxide (Fe ₂ O3) must be ≤ 1%, otherwise it will reduce the purity of lime and affect its application effect in environmental protection (flue gas desulfurization) and chemical (calcium carbide production) fields.
Modern lime kilns optimize the composition through raw material pretreatment technology, such as using double-layer vibrating screens to classify raw materials, ensuring a 60% proportion of 15-30mm particle size and improving calcination uniformity; Real time monitoring of CaCO3 content using X-ray fluorescence spectrometer (XRF) with an error of ≤± 0.2%, achieving precise batching. These measures stabilize the CaO content of active lime at over 90%, with an activity level of ≥ 300ml, meeting the demands of high-end industry.
