摘要 |
A method of treating a water-swellable clay after the clay has been mined and dried. After the common initial drying of the clay to a moisture content of 12% or less, the clay is re-wetted to a moisture content of more than 12% by weight, preferably at least about 15% or more, based on the dry weight of the clay, then redried to a moisture content of 12% by weight or less, based on the dry weight of the clay. This re-wetting and re-drying processing of a dried clay unexpectedly improves the water absorbency, and viscosity properties; increases the effectiveness of the clays as binders in sand molds and iron ore pelletizing; unexpectedly increases the rheology properties of the clays for oilwell drilling fluids, and lost circulation fluids, and as a suspending agent in the cosmetics and pharmaceutical industries; improves the binding characteristics of the clays to act as a binder for iron ores, such as taconite, and sand molding (foundry industry); and provides unexpectedly increased water absorption in forming water-swellable clay-based water barriers.
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