Method for improving handleability of calcium carbonate containing materials

A process for preparing calcium carbonate containing composite particles comprising the following steps:

• a) providing at least one calcium carbonate containing mineral powder,
• b) preparing at least one solution or emulsion or dispersion of at least one binder selected from the group consisting of copolymers of acrylonitrile, butadiene, acrylate, butyl acrylate, styrene, styrene-butadiene, and acrylic ester, and any mixture thereof, wherein the amount of binder is less than 10 wt. %, based on the total weight of the calcium carbonate containing mineral material, and
• c) contacting the at least one calcium carbonate containing mineral powder of step a) with the at least one solution or emulsion or dispersion of the binder of step b) in an amount to form calcium carbonate containing composite particles having a solids content of at least 90 wt. % based on the total weight of the calcium carbonate composite particles,
• wherein the calcium carbonate containing composite particles, when dried to achieve a total surface moisture content of less than 0.5 wt.-%, based on the total weight of the composite particles, have increased bulk density at equal or improved flowability compared to the calcium carbonate containing mineral powder provided in step a) when dried to achieve a total surface moisture content of less than 0.5 wt.-%.