申请人:AMCOL INTERNATIONAL CORPORATION
公开号:EP0645181A2
公开(公告)日:1995-03-29
There is disclosed a method of treating a water-swellable clay after the clay has been mined and dried to improve its properties when in contact with contaminated water. After the common initial drying of the clay to a moisture content of 12% by weight or less, the clay is impregnated with an aqueous solution containing a dissolved, water-soluble polymer, in an amount of at least about 0.5% by weight based on the dry weight of the clay, and the clay is 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, and then redried to a moisture content of 12% by weight or less, based on the dry weight of the clay. This rewetting step to hydrate and polymer-impregnate the clay, and then redrying the clay, unexpectedly improves the contaminated water absorbency, and viscosity properties when the clay is in contact with contaminated water; unexpectedly increases the rheology properties of the clays for oil well drilling fluids and lost circulation fields when contaminated water is encountered during drilling, enhances the clay properties when used as a suspending agent in the cosmetics and pharmaceutical industries when the composition contains a dissolved, inorganic salt and/or an organic liquid; and provides unexpectedly increased contaminated water-absorption in forming water-swellable clay-based water barriers.
本发明公开了一种在粘土开采和干燥后对其进行处理的方法,以改善粘土与受污染的水接触时的性能。在将粘土初步干燥至含水量不超过 12% (以重量计)之后,用含有溶解的水溶性聚合物的水溶液浸渍粘土,浸渍量至少为粘土干重的 0.5%(以重量计),然后将粘土润湿至含水量超过 12%(以重量计),最好至少为 15%(以重量计)或更高(以粘土干重为基础),然后再干燥至含水量不超过 12%(以重量计)(以粘土干重为基础)。这一重新润湿步骤使粘土水化并浸渍聚合物,然后重新干燥粘土,意外地改善了粘土与污染水接触时的污染水吸收性和粘度特性;当钻井过程中遇到受污染的水时,意外地提高了粘土在油井钻井液和失水循环油田中的流变特性;当组合物含有溶解的无机盐和/或有机液体时,提高了粘土在化妆品和制药业中用作悬浮剂的特性;以及在形成可吸水的粘土基水屏障时,意外地提高了受污染水的吸收性。