Precipitated Calcium Carbonate
Precipitated calcium carbonate (PCC) is an innovative product, derived from lime, which has many industrial applications. PCC is made by hydrating high-calcium quicklime, and then reacting the resulting slurry, or “milk-of-lime”, with carbon dioxide. The resulting product is extremely white and typically has a uniform narrow particle size distribution. PCC is available in numerous crystal morphologies and sizes, which can be tailored to optimize performance in a specific application.
With the alkaline conversion of the uncoated freesheet market and the continuing trend toward alkaline vs. acid process papermaking in the coated, ground wood and paperboard markets, PCC is well established as a filler and coating pigment for premium quality paper products. PCC is typically produced in slurry form at satellite plants located near paper mills. PCC enhances optical properties and print characteristics of paper products, improves paper machine productivity, and can reduce papermaking costs through the replacement of more expensive pulp fiber and optical brightening agents. Constantly improving quality targets make the brightness of paper, and thus PCC, an increasingly important factor.
PCC also finds many industrial uses due to its ability to achieve small particle sizes and special crystal shapes. In rigid polyvinyl chloride (PVC), such as vinyl siding and fencing, PCC increases impact strength, with some of the smaller particles able to replace expensive impact modifiers. Nano PCCs (less than 0.1 micron in size) control viscosity and sag in automotive and construction sealants, such as PVC plastisols, polysulfides, urethanes and silicones. In paint, PCC's unique particle shapes improve hiding and allow reductions in titanium dioxide levels.
An effective acid neutralizer, PCC is often used in calcium-based antacid tablets and liquids. Being high in calcium content, PCC enables the formulation of high dosage calcium supplements and multi-vitamin/mineral tablets. The small particle sizes and special particle shapes contribute to the development of good tasting calcium fortified foods and beverages.