含金属离子的聚硅酸用作MMH－膨润土泥浆稀释剂的室内研究

LABORATORY INVESTIGATION OF POLYSILICIC ACID CONTAINING METAL ION AS THINNER FOR MMH-BENTONITE MUD

通过测定泥浆体系的电性能、流变性、抑制性和粒度分布，研究了含金属离子的聚硅酸（ＰＳＡＭ）对混合金属氢氧化物（ＭＭＩＩ）－膨润土泥浆的稀释作用。结果表明，ＰＳＡＭ对ＭＭＩＩ－膨润土泥浆的稀释能力强，能提高该泥浆体系的抑制性。ＰＳＡＭ的稀释机理为：ＰＳＡＭ产生的带正电二氧化硅颗粒通过静电作用吸附到ＭＭＩＩ－粘土网状结构的粘土颗粒表面，破坏网状结构，释放出大量自由水。

The thinning effect of a polysilicic acid containing mental ion (PSAM) on MMH-bentonite mud is investigated experimentally. PSAM is effctive for thinning MMH-bentonite mud only at low use levels. With increasing PSAM concentration in the mud up to 1000 mg/l,the zate potential of bentonite particles increases,the apparent viscosity and yield stress dramatically decrease, the filtration loss increases and the dilathion of Ca-bentonite samples in the mud decreases.With further increasing PSAM all these parameters level out.The thinning mechnizms by PSAM are discussed