The importance of following a good production process

The production process starts at the quarry, where we get our raw material from, the limestone (calcium carbonate).


Limestone gets extracted through controlled blasts. Afterwards it is grinded and then classified by size. Whereas sizes between 20 and 80 millimetres are used for manufacturing lime, the smallest sizes are used for obtaining calcareous aggregates.


Once the stones are classified we move on to the calcination process hereof. The unslaked lime (quicklime) is obtained though the calcination of lime stones, with a content of calcium carbonate (CaCO3) higher than 95% and at a temperature of between 900-1.100°C.

Thanks to its calcination process the calcium oxide we manufacture has certain features, which differentiates it from the rest of limes in the market. With a high level of reactivity it is ideal for certain industrial processes.

Classification, grinding and micronization

Once calcium oxide is obtained, it is classified by sizes and qualities, depending on its later use. The product can be sent in bulk, in dump trucks, in pressurized tank trucks and in big bags and in bags.


To part of this calcium oxide, after grinding it, in a controlled way, water is added, converting it into calcium hydroxide (slaked lime).

This product is presented in bags as well as in bulk, in pressurized tanks and in big-bags. Its size is smaller than 200 microns.

In an intermediate phase, the calcium hydroxide is saturated with water, forming a ready to use lime milk delivered in 1.000 litres containers.

Quality Control

To be able to be present more than 50 years in the industry, it is necessary to offer quality products. With that purpose, CALES DE PACHS has highly technified installations and in the production process there is a rigorous quality control system, which guarantees the features of the different lime products we produce.

The product is controlled and analysed in our laboratory during the different stages of production. A systematic analysis of the drill hole debris at the different stages of the quarry is done. We constantly track the purity of calcium carbonate possessed by the extracted lime stone.

The Production Department does a basic follow-up of the richness in calcium oxide being produced by the calcination kilns, doing quick analysis which get reassessed on a daily basis in our Quality Control Laboratory, which also does daily controls on reactivity, fineness, useful lime and volume stability of our slaked lime.