Lime in PCC Manufacturing
Traditionally, paper made in North America was made in an acidic manufacturing environment, and involved the use of a variety of chemicals, including alum, rosin sizing and clays. Beginning in the mid to late 1980s, a revolution took place as paper manufacturers began switching to an alkaline-based environment. One of the primary advantages to this adjustment was the introduction of precipitated calcium carbonate (PCC). The primary use of PCC is as a filler when constructing the paper, which provides a number of advantages. These advantages include brighter paper, better opacity, improved printability, increased thickness, and most importantly, a reduction in the amount of wood fiber required to make paper.
Another important advantage of PCC is that it is generally less expensive than the clay-fillers it has replaced. This is because the raw materials used to make PCC are lime (calcium oxide or CaO) and the carbon dioxide (CO2) emitted by mills.
Graymont has played a major role in the development of the PCC market and supplies a number of production facilities with the high quality of quicklime required for this exacting process.