Some regularities of calcium oxide hydration activity

Authors

DOI:

https://doi.org/10.15587/1729-4061.2014.26239

Keywords:

lime, hydration activity, lime stone, hydration, crystallization, self-dispersion, expansion, shrinkage, heat emission

Abstract

Physicochemical factors that affect chemical and hydration activity of alkaline earth metal oxides are considered in the paper. It is shown that an important factor of monoxide binders, particularly based on calcium oxide is its rate of interaction with water. Unlike the hydration mechanism of clinker minerals, CaO hydration process flows very fast with the change in the crystal lattice structure and emission of the large amount of energy, which causes an increase in the volume of system and self-dispersion of hydration products. The main process that leads to high heat emission is the protonation of O2­- ions by water molecules and the appearance of OH- ions. The studies of hydration parameters of CaO, SrO and BaO oxides have revealed that high activity is caused by crystal-chemical features of their structure, in particular the coordination instability of cations. Due to electron-microscopic studies using the thin-film technique, it is found that CaO hydration kinetics is affected by the rate of water diffusion in the inner layers of grains and their subsequent destruction, and hydration rate deceleration is achieved by limiting the expansion of hardening system, removal of hydration heat and use of substances. CaO hydration kinetics in solutions, containing additives H3BO3, Na2CO3 and CaSO42H2O is investigated. It is shown that, under these conditions, the reaction between CaO and water takes place in the diffusion region. These data allow to regulate hydration activity of CaO and obtain special binding compositions on its basis. The practical value of the work is confirmed by the results of industrial tests and mastering the production of efficient building materials.

Author Biography

Ярослав Богданович Якимечко, Lviv Polytechnic University

Professor

Department of Chemical technology of silicates

References

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Published

2014-08-08

How to Cite

Якимечко, Я. Б. (2014). Some regularities of calcium oxide hydration activity. Eastern-European Journal of Enterprise Technologies, 4(6(70), 30–35. https://doi.org/10.15587/1729-4061.2014.26239

Issue

Section

Technology organic and inorganic substances