Is lime poisonous?

The smell of lime is non-toxic, and dust or suspension droplets will irritate mucous membranes, which is not as heavy as sodium hydroxide and will cause sneezing and coughing. Like alkali, lime can emulsify fat, absorb water, dissolve protein, stimulate and corrode tissues.

Pay attention to protect respiratory organs when working, wear overalls, gloves and closed dustproof glasses made of dustproof fibers, and apply grease ointment to prevent inhalation of dust.

In the lime slurry formed by the digestion of quicklime, lime particles form the colloidal structure of calcium hydroxide, with extremely fine particles (particle size is about 1 micron) and large specific surface area (up to 10 ~ 30 m2/g). The surface of lime slurry can absorb a thick water film and a large amount of water, so it has strong water retention ability, that is, good water retention.

Extended data:

Lime hardens by drying, crystallization and carbonization. Because of the low content of carbon dioxide in the air, the hard shell of calcium carbonate formed after carbonization prevents carbon dioxide from infiltrating into the interior and moisture from evaporating outward, so the hardening is slow and the strength after hardening is not high. The compressive strength of 1: 3 lime mortar for 28 d is only 0.2~0.5 MPa.

When in a humid environment, the water in lime will not evaporate and carbon dioxide will not penetrate, so the hardening will stop. In addition, calcium hydroxide is slightly soluble in water, and hardened lime will dissolve and collapse when it meets water. Therefore, lime should not be used in long-term wet and soaking environment.

References:

Baidu encyclopedia-lime