METHOD OF OBTAINING BENTONITE CLAY POWDER Russian patent published in 2009 - IPC C09K8/05 

FIELD: construction.

SUBSTANCE: method of obtaining bentonite clay powder for drilling mud involves activation of humid bentonite clay by sodium carbonate, stirring, drying and milling. Activation of bentonite clay humidified to 23-27% or of its mix with subbentonite clay is performed by 1.8-2.0% of sodium carbonate, the mix is left to mature for 300 to 670 hours, and further stirring is followed by plastifying in granulating maschine, with further drying of obtained granules up to humidity of 4-5% and mixing them after milling with 3.5-4.5% of magnesium oxide. Magnesium oxide can be combined with 3-4% (of dry weight) of heat and salt resistant carboxymethyl cellulose reagent.

EFFECT: possible adjustment of rheological parametres.

2 cl, 3 tbl