United States Gypsum Company

Usg Corporation

Kenneth R Watkins

Michael Lawrence Bolind

Donald A Randolph

Robert John Wenk

Mineral filler materials are provided with improved hydrophobic coatings by pressure coating of porous minerals using steam as a carrier for the coating material. Thereby more complete sealing of fissures and cracks in the porous filler materials' surface is provided, resulting in very water-resistant coated particles useful in filling polymeric substrates such as paints, plastics and joint compounds.

Pressure coating of mineral fillers

A homogeneous, free-flowing urea containing composition which has particular utility as an animal feed supplement or a fertilizer material and an improved process for preparing same are disclosed. In the process urea and particular forms of calcium sulphate are intimately mixed, optionally with calcium phosphate and one or more desired additives, and pelletized or granulated as by compression compaction. In one embodiment, micronutrients are blended into the urea-calcium sulphate mixture before compaction and the granules so produced may be subsequently utilized as a fertilizer supplement or in combination with primary nutrients as a complete fertilizer. In a second embodiment, the urea-calcium sulphate constitute an animal feed supplement to be blended with other, non-hygroscopic, nutrients such as calcium phosphate and the like in forming a silage or complete animal feed.

Free-flowing granular urea nutrient supplements

A sulfur fortified gypsum granule is provided, preferably adapted for agricultural uses so as to give a timed release of sulfate nutrients in soil comprising a combination of at least about 5 percent by weight of elemental sulfur and a major proportion of calcium sulfate which combination has been roll pressure compacted at a mixture temperature of about 110.degree.-230.degree. F to form hard granular shapes.

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Wheaton, IL, United States of America

Kenneth R Watkins