Dover Castle

Quicklime

RJ 1.03

White or creamy-white powders produced by the calcination of limestone or chalk in a kiln at a temperature of at least 900°C. Kiln temperatures are often significantly higher. When slaked, quicklime formed from pure limestone produces non-hydraulic lime that will not set underwater. Certain siliceous and argillaceous limestones when calcined at relatively low temperatures, c.1000°C, produce lime with weak hydraulic properties, containing silicates, aluminates and other trace elements. Unconverted limestone or chalk and small quantities of insoluble flint and/or quartz are also often present.

Usage/Purpose: 

Quicklime (Calcium oxide CaO) is hydrated or slaked to produce lime putty, lime-wash and hydrated lime, and there is renewed interest in the hot-mix mortar method where quicklime and sand or aggregate are mixed with water and either used immediately whilst hot or cooled and stored before use.

Colours: 

Mortar colour is determined by the sand or aggregate mixed with the lime.  

Shelf Life: 

Up to 3 months in original un-opened bags kept in DRY storage. Protect from air and rain as quicklime reacts with water.

Availability: 

Singleton Birch Microlime 90. Singleton Birch Fine Lime 2. Calbux 90

Health & Safety: 

EXTREME CAUTION.

FULL PPE ESSENTIAL.

Quicklime reacts violently and exothermically with water See Health and Safety Data Sheet RJ 5.01B.

CALCIUM OXIDE (CaO) Alkali (pH 13).

CAS No. 1305-78-8.

EINECS No. 215-138-9

Danger:

H318 Causes Serious Eye Damage.

H315 Causes skin burns and irritation.

Warning:

H335 May cause respiratory irritation.

Observations: 

The handling and use of quicklime is a potentially hazardous activity and great caution must be exercised and full PPE (personal protective equipment) worn. Operatives familiar with the mixing and use of quicklime and experience of the hot-mix method should be employed. Accurate volumetric site mixing is essential. Hot-mix method mortars set by reaction with atmospheric carbon dioxide in the presence of moisture. The control of the drying and curing process by ‘tending’ and protecting is crucial to success and long-term performance. Protections are essential. Do not use below a temperature of 5°C or above 25°C. Do not use if there is risk of frost. Seek technical advice.