Pulping and bleaching are processes used in all pulp mills for the production of paper from wood. Pulping processes can be either chemical or mechanical. The purpose of the chemical pulping (CP) process is to break down/dissolve the lignin “glue” which binds the wood cells (often referred to as fibers, cellulose or carbohydrates) together by use of chemicals. The purpose of mechanical pulping (MP) is to mechanically separate the two without the use of chemicals (when heat is used the process is called thermo-mechanical or TMP). If mechanical pulping is reinforced by chemical means that soften the lignin, we have the so called chemi-mechanical pulping (CMP). In both MP and CMP the lignin remains in the pulp.
Go to the following link: http://www.grecianmagnesite.com/content/pulp-and-paper-application-mgo-r... and read the technical note of our R&D Department, describing the application of Magnesia in Pulp and Paper production.