Bentonite applications

Owing to its unique valuable properties, bentonite is employed in a great number of different applications, as illustrated below:

FoundryBentonite is used as a bonding material in the preparation of moulding sand for the production of cast iron, steel, and non-ferrous casting. The unique properties of bentonite yield green sand moulds with good flowability, compactability, and thermal stability for the production of high quality castings. DrillingOwing to its rheological properties and thixotropy of aqueous suspensions, bentonite is used as a mud constituent for oil and water well drilling. Its functions are mainly to stabilise the borehole, seal the borehole walls, and remove drill cuttings. Bentonite muds are thus employed for oil and water well drilling, tunnel, and microtunnel drilling. Civil engineeringBentonite slurries are used in the construction of special foundations for digging diaphragm walls and bored piles. In geothecnical engineering, bentonite is used for self-hardening mixtures employed to build cut off walls, grouting mortars, and grouting. Finally, bentonite waterproofing properties are best exploited in environmental engineering, to seal off soil infiltrations, and line the base of landfills. FeedstuffBentonite is used as an animal feed supplement. Under European regulations, it is classified as a food additive, with E number E558. Bentonite is used as a pelletizing aid in the production of animal feed pellets. Due to its high adsorption power, it is particularly effective against micotoxins. Water treatmentDue to its ion exchange, flocculation, and sedimentation properties, bentonite is used in environmental protection for water clarification, and as an aid to polyelectrolites and inorganic flocculants. AgricultureBentonite is used as an ion exchanger for soil improvement and conditioning. It is also used for gardening in soil compounds and mixtures to absorb humidity, and as a carrier for various herbicides and pesticides. CeramicsBentonite is used to enhance ceramic paste plasticity and as an anti-settling agent in ceramic enamels. PaperBentonite is used to improve the efficiency of conversion of pulp into paper, as well as for paper quality improvement by preventing rubber particle agglomeration. Due to its absorbing property, bentonite also offers useful de-inking properties for paper recycling. Wine makingIn winemaking, bentonite is used to enhance clarification and protein stabilization. Cat litterOwing to its swelling property, bentonite is used for cat litter, due to its advantage of absorbing refuse by forming clumps. Pelletizing of iron oreDue to its water absorption capacity and colloidal property, bentonite is used as a binding additive to convert iron ore fines into pellets. Pharmaceuticals, cosmetics, and spa mud therapyBentonite is used as a filler in pharmaceuticals, and for its absorption/adsorption functions. It is also employed in creams, face-powders, and spa mud preparations. Detergent additiveBentonite is used in detergents to soften the fabrics. Liquid cleansers/soaps rely on the inclusion of bentonite as a suspension agent and viscosity enhancer. Food industry (wine, edible oils and fats)Bentonite is utilized in the removal of impurities in oils where its absorptive properties are crucial in the processing of edible oils and fats. In drinks, bentonite is used as a clarification agent. Paints and varnishesBentonite functions as a thickening and/or suspension agent.