Calcium Carbonate
Calcium Carbonate is the main chemical substance of a white mineral called limestone.
The deposits of limestone can be found in three forms: chalk, calcite and marble.
The raw material Microfill K. Zafranas S.A. uses has the advantage exceptional chemical purity as it contains at least 99,7% of Calcium Carbonate. It is also superior in whiteness and has a low yellowness index due to the very white deposits of Calcium Carbonate in Greece.
Below one can read more about the advantages and disadvantages of the three forms of deposits
a. Microcrystalline CaCO3 (Chalk)
Originated from the shells of nanofossils. The deposits are on flat shelves
Advantages
• Easily processed
• Low mean size
Disadvantages
• Off White Brightness
• Increased Yellowness
• Increased absorption
• Poor rheology.
• Absorbs humidity during storage.
b. Calcite
It is of biogenic origin, but more compact than chalk
Advantages
• High Brightness.
• Low Yellowness.
• Low absorption.
• Easy dispersion.
• Good Rheological Properties.
• Increased hiding power.
Disadvantages
• Increased Cost of Production.
• Expensive Processing Installations.
c. Marble
It is formed when chalk or calcite crystallize under great pressure
Advantages
• High Brightness.
• Low Yellowness.
• Low absorption.
• Easy dispersion.
• Good Rheological Properties.
• Increased hiding power.
Disadvantages
• Unstable Brightness
• Increased abrasion.
• Increased Cost of Production.
• Expensive Processing Installations.
Talc
The mineral talc is a hydrous magnesium silicate. Its main characteristic is the shape of its crystals, which are macrocrystaline. The aspect ratio of these crystals is 11:1. It is this shape that gives unique mechanical properties to the materials it is applied, since it renders them with extreme elasticity. Talc has also the advantages of fragrance retention, luster, purity, softness and whiteness. Other important properties of talc -when used in the industry- are chemical inertness, high thermal and low electrical conductivity, high dielectric strength and oil and grease adsorption.
