Mud, gel or drilling clay: We have all used one of these terms to describe bentonite, the most common additive used to make up our drilling fluids. Bentonite is an absorbent aluminum phyllosilicate, typically a montmorillonite clay mined primarily in Wyoming. Most of the bentonite used for drilling fluids is the sodium montmorillonite variety because of its ability to attract and bind to water molecules. The chemical, physical and molecular properties of the bentonite, and how it provides viscosity and gel strength in a water-based drilling fluid, have been discussed in this and other water well publications many times. But did you know that bentonite has many other uses? Let’s look at how this clay is utilized outside of the drilling industry.
Cosmetics: Bentonite clay is utilized in the cosmetics industry in a variety of ways, including an absorbent, bulking agent, suspending agent and as an emulsion stabilizer. If you see the ingredient “Tixoton” on the packaging, you know that bentonite is in the mix. The clay is also used as a thickening agent in lipstick, shampoo and calamine lotion.