Open for Business!

Incoa Performance Minerals proudly reports that the first truckload of high-purity ground calcium carbonate (GCC) from our state-of-the art processing plant has been delivered. The time from the order’s receipt to its shipment was less than 48 hours and our first customer is in receipt of a truckload of InCal® 7. InCal® 7, our 6.5-micron … Read more

Exciting News!

You now have a distinctive, focused new source of North American ground calcium carbonate products – INCOA Performance Minerals. Construction is underway on our new, state-of-the-art ground calcium carbonate (GCC) processing facility on the gulf coast near Mobile, Alabama USA. Our facility, expected to be producing by mid-2021, will manufacture fine particle sized GCC under … Read more


A calculated value that describes the breadth of the particle size distribution by looking at the size of the particle below which 90% of all particles are found (d90), the median and the size of the particle below which 10% of all particles are found (d10).

The Span is calculated from the following equation:

d90 = particle size below which 90 % of the particles are described
d10 = particle size below which 10% of the particles are described
d50 = particle size below which 50% of the particles are described, also known as the median

Broader distributions have a larger span while narrower distributions have a smaller span.

Level of Ultrafines

The percentage of the total distribution that includes particles that are 0.5 microns or smaller.

Some demanding applications require careful control of the level of very small particles. These particles can make the powder difficult to disperse and can actually absorb important components of formulations ultimately altering end-use performance.


The size below which 100% of the particles can be found.

Unlike most ground calcium carbonate suppliers, INCOA specifies at the 100% passing rather than the industry standards of 95% or 98% passing. We recognize that even very low levels of oversize particles can interfere with the performance of our products in your applications


The size below which 50% of the particles can be found.

This is the most common means of describing the size of ground calcium carbonate powders. INCOA describes our medians on the final product as-received by our customers. This means that the specification testing is performed on samples of the shipment before shipment on the final product not on material still in-process.