Application of dispersants in bentonite
The application of dispersants in bentonite is mainly reflected in improving the performance of bentonite
and enhancing its application effect. The following is a detailed analysis of the application of dispersants
in bentonite:
1. Definition and function of dispersants
Dispersants are surfactants that have two opposite properties, lipophilicity and hydrophilicity, in the molecule.
It can evenly disperse the solid and liquid particles of inorganic and organic pigments that are difficult to
dissolve in liquids, and at the same time prevent the sedimentation and coagulation of particles to form
amphiphilic agents required for stable suspensions. In bentonite, dispersants can significantly reduce the
interaction between particles, making bentonite particles easier to disperse in water and forming a stable
suspension.
2. Types of dispersants
Dispersants are generally divided into two categories: inorganic dispersants and organic dispersants.
Commonly used inorganic dispersants are silicates (such as water glass) and alkali metal phosphates
(such as sodium tripolyphosphate, sodium hexametaphosphate and
sodium pyrophosphate). Organic dispersants include triethylhexyl phosphate, sodium dodecyl sulfate,
methyl amyl alcohol, cellulose derivatives, polyacrylamide, guar gum, fatty acid polyethylene glycol esters, etc.
3. Specific application of dispersants in bentonite
Improving dispersibility: Dispersants can significantly improve the dispersibility of bentonite particles in
water, making it less likely to precipitate and maintaining the stability and uniformity of the coating. This
helps bentonite to perform better in various applications.
Improving viscosity and cohesion: Some dispersants (such as carboxymethyl cellulose, etc.) can also increase
the viscosity and cohesion of bentonite, making it have stronger cohesion and impermeability in specific
applications (such as drilling mud, waterproof material production, etc.).
Adjusting pH value: By adding alkaline dispersants such as sodium carbonate, the pH value of bentonite mud
can be adjusted to keep it within an appropriate range (such as 8~10), thereby improving the colloidal rate and
stability of the mud and reducing water loss.
Preventing aggregation: Coagulants such as polyamide can be used to solve the aggregation problem caused by
the strong surface adsorption of bentonite, and improve its effect in applications such as paints, adhesives, and printing
and dyeing agents.
4. Practical application cases
In drilling mud, dispersants such as FIC (chromium iron lignin sulfonate sodium salt) or nitric acid humic sodium carbonate
(coal alkali agent) are often used to improve the performance of mud. These dispersants can improve the performance of
mud that has deteriorated due to the mixing of soil, sand, crushed pebbles and salt, etc., so that particles such as drill cuttings
aggregate and accelerate precipitation, thereby improving the performance indicators of the wall protection mud and allowing
it to continue to be recycled.
5. Precautions
Select a suitable dispersant: The appropriate type and amount of dispersant should be selected according to the specific
application needs and performance requirements of bentonite.
Avoid excessive addition: Excessive addition of dispersant may cause the performance of bentonite to deteriorate or produce
other adverse effects.
Pay attention to the compatibility of the dispersant: Make sure that the selected dispersant has good compatibility with bentonite
and other additives to avoid adverse reactions.
In summary
The application of dispersants in bentonite has significant effects and broad application prospects. By rationally selecting and using
dispersants, the performance of bentonite can be significantly improved to meet the needs of different industries and products.
