Paper Industry

Lime in pulp production

The pulp industry uses lime in various stages of the production process:

- in chemical pulp production, sodium carbonate is treated with lime to regenerate the caustic soda;

- in the sulphate process, lime is used to produce a calcium bisulphate liquor capable of dissolving non-cellulose wood elements;

- lime is used as a bleaching agent for pulp, as well as a flocculating, neutralising and clarifying agent for residual water.

Lime to produce even whiter paper

Precipitated Calcium Carbonate, or PCC, is obtained by the carbonation of a milk-of-lime suspension. The papermaking sector uses large quantities of PCC as a filler or coating pigment to improve the optical properties of the paper.

A development in this field is the production of PCC on the premises of the papermaking plant, the so-called satellite-plant, by having the milk-of-lime reacting with CO₂ available on site.