Refining lime into final products

When it comes out of the kilns, lime is sorted and stored according to grain size, residual CO2 and other physical or chemical characteristics, as determined by our laboratories. Separation is carried out using conveyor belts, augers, elevators, grinders and screens. There are three main size categories: lump lime, rice lime and fine lime.

Lime can be further processed to obtain new characteristics and to assure needs of emerging applications.



There are three lime refining processes:

Grinding and milling

Milled limes and ground limes are produced using mills fitted with classifiers: Hammer mills, rotary ball mills, vertical pendular and pan mills are all used for this purpose.


Hydrates are produced in hydrators that generate a dry powder; a hydroxide of calcium (Ca(OH)2). Hydrators are fitted with one, two or three hydration chambers and a premixer, where water starts reacting with the mother lime. Hydrated lime is graded by grain size and stored in silos. Hydrated dolime is also produced in Lhoist’s American plants, using pressurized vessels.

Lime slurry production

Milk of lime (lime slurry) is manufactured industrially in stirred reactor vessels, either from quicklime or from hydrated lime, in the presence of excess water. The final product is a suspension of hydrated lime.