Pulp industry

Lime in Pulp Production

Paper is made from pulp, cellulose, which can be obtained from the sulphate processes by cooking wood chips in a solution called white liquor. The chemicals used in the cooking process are circulated in the pulp mill's recycling line, where their chemical composition is altered through a causticising process, using quicklime, to suit the cooking process. The lime circulating in the pulp process is then slaked, whereupon the causticising process begins and the lime is carbonated. The resulting lime mud is then burned again in the mill's own kiln. Part of the lime mud must be replaced by new quicklime, which must be chemically pure.

If the lime mud kiln is out of order, large quantities of so-called replacement quicklime are needed from external sources in order to keep the pulp production going. This poses great demands on both quality and reliable deliveries from the lime supplier.

To achieve a causticising process with the best possible efficiency and smoothness one needs lime products with a high content of active CaO, low content of trace elements and a reactivity that suits the plant's own processes. All of these qualities are found in Nordkalk products.

Our factories in Norway, Sweden and Finland use various kinds of raw materials to make high-quality lime products for the pulp industry.

The pulp industry also uses lime products to neutralise wastewater and for flue gas cleaning. For these purposes Nordkalk produces quicklime, slaked lime and powdered lime.

Sales contacts

• Jernström, Sara
  Nordkalk Corporation, Sales Manager
• Nyström, Bror
  Nordkalk Corporation, Sales Manager