J.m. Huber Corporation

Kurt H Moller

Gary M Freeman

Richard Douglas Carter

Thad T Broome

Paris W Chen

Weiming Zhu

William J Jones

Randal A Moritz

Processes for making high quality PCC compositions, and the resulting PCC products thereof. A precipitated calcium carbonate (PCC) composition is prepared by a process comprising the step of wet media mill grinding an aqueous slurry of PCC made by carbonation of lime milk, with the grinding being done at a low solids content in a plurality of separate grinding stages, which can done while essentially free of the presence of organic dispersant. After the multi-stage wet grinding step, the ground PCC slurry is partially dewatered in the presence of an organic dispersant in a solid bowl centrifuge. Then, the partially dewatered PCC slurry is subjected, in the presence of an organic dispersant, to fluid shearing forces created in a rotor/stator type mixer. While these three steps are advantageously used together within a single PCC process flow for optimal effect, the individual steps also can be incorporated singly or in lesser combinations thereof into different PCC manufacturing schemes to beneficial effect. The resulting PCC compositions are endowed with reduced high-shear viscosity in aqueous slurry form at high solids content and contain PCC particles of narrower particle size distribution. PCC slurries are provided that are particularly well-suited for paper coatings applications including medium and low coating weight, woodfree paper coatings, although it has wider applicability and is by no means limited thereto. As another aspect, the additional cost otherwise associated with the use of evaporative-based dehydration procedures to increase the PCC solids content in a PCC slurry or associated with the adding of dry CaCO pigment to build slurry solids can be reduced or even eliminated by a facile made in a decanting operation within the inventive process flow.

Processes for preparing precipitated calcium carbonate compositions and the products thereof

A method of making an aluminum hydroxide and melamine blend. The method comprises jet milling a quantity of coarse particle size melamine until a line particle size melamine is obtain which has a median particle size of from about 0.5 .mu.m to about 45 .mu.m, passing the fine particle size melamine through an air classifier and a cyclone separator, and admixing the fine particle size melamine with a quantity of surface treated aluminum hydroxide in a high speed mixer.

Melamine and aluminum hydroxide blend and method for making and using

Sodium alumino-silicates are produced by silicate/clay reactions under hydrothermal conditions with increased solids during processing while still producing structural materials characterized by low oil absorption values, high total pore volume and increased differential pore volumes. The products are useful as coating pigments for paper and paperboard, paper fillers, paint pigments and as reinforcing pigments for rubber.

High performance synthetic alkali metal alumino-silicate, methods and

Pigments for use in paper are comprised of structured aggregate clays which are reaction products of kaolin clays and colloidal silicas. Silica modified clays of low treatment level can under certain high-shear mixing conditions be attritioned back to their starting clay particle size consequently yielding silica coated clay particles that provide unique properties. Also provided are structured aggregate clay products produced by the reaction of kaolin clay, colloidal silicas and spacer particles such as titanium dioxide, which products have improved porosity and light scattering characteristics. Also provided are clay slurry products which comprise mixtures of the reaction product of kaolin clay and colloidal silica, and optionally titanium dioxide, blended with other clay products.

Growing community of inventors

Warner Robins, GA, United States of America

Kurt H Moller