Pore Structural Evolution and Properties of Active CaO Blocks Prepared from Carbide Slag
Abstract
The CaO block with high strength and high activity was prepared from waste carbide slags, which were by-product in the process of acetylene production using calcium carbide method, as raw materials. The results show that the CaO block prepared from the carbide slag at 1100 °C has the highest activity. With the increase of sintering temperature, the average pore diameter of CaO block increases gradually and the uniformity of pore structure increases as well, while the total pore area decreases. The pore structure of CaO block is controlled by both the decomposition of Ca(OH)2 and CaCO3 and sintering crystallization of CaO. The compressive strength of CaO decreases with increasing of porosity, showing a good semi logarithm linear relationship: \( \mathop y\limits^{..} \)s = 0e−bP. For the sintered CaO block, the higher the porosity is, the higher the activity is. Under the same porosity, the larger the pore diameter is, the higher CaO block activity is. With increasing average diameter of the pores, the sintering neck of CaO crystalline grains and the connection effect of the main and collateral channels between the holes becomes bigger and stronger, thus the thermal shock resistance of CaO block increases.
Graphical Abstract
Keywords
Carbide slag CaO blocks Structural evolution Compressive strength Activity Thermal shock resistanceNotes
Acknowledgements
The research of this paper was supported by Natural Science Foundation for Young Scholars of China (51604029) (51404225) and the National Science Fund for Outstanding Young Scholars of China (51422405).
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