Novel aspects of Bentonite assessment

摘要

The behavior of bentonite slurries represents the determing factor in the attenuation of the negative effect of cake formation. We tested 12 different samples of bentonite powder, in suspensions of 6 percent, or, in 2 percent suspensions with additives of 0.2 percent polymers, prepared with tap or distilled water. The obtained cakes, on filter paper or rock samples, were tested for ease of removal with solutions of hexametafosfate, hydrogen peroxide and enzymes, respectively. The results lead to thefollowing recommendations: to include the consistency and power indexes into the technical specifications for bentonite assessment and to use support fluids with low solid contents, together with a polymer additive. Cleaning of the cakes was efficient with hexametafosfate + hydrogen peroxide solutions. For suspensions with low solid contents the use of enzymes in the cleaning operation was successful.