Properties and Applications of Attapulgite
Finding the best quality and most effective industrial ingredients is important to manufacturing competitive products for your business or operation. One of the most versatile materials widely used across a range of industries is attapulgite clay.
As a naturally occurring mineral, attapulgite clay is composed of magnesium-aluminum silicate. It needs to be mined and extracted from naturally occurring deposits in the environment. The largest source of natural attapulgite clay is found in southwestern Georgia and northern Florida. In fact, the name attapulgite comes from Attapulgus, Georgia 一 the town where the mineral is found in its highest abundance. Attapulgite is an in-demand material because of its natural properties that make it a highly desirable industrial additive.
What is attapulgite used for? Industrial applications of attapulgite range from drilling fluid additives and concrete admixtures to rheology modifiers and ceramic coatings. It is a preferred mineral ingredient in the manufacturing, automotive and agriculture industries.
What Is Attapulgite and Its Properties?
Attapulgite is a 2:1 magnesium aluminum silicate clay. It is found in the earth as a marginal marine sedimentary deposit, where it can be separated and extracted from surrounding areas. In its raw form, attapulgite clay is a blueish-gray or grayish-green color. It is a lightweight mineral material that is smooth yet soapy.
- Chemistry: The attapulgite molecular formula is (Mg,Al)2Si4O10(OH)•4(H2O). Attapulgite clay has a high surface area (150-320m2/g), which is what gives it its desirable absorbent properties.
- Structure: At the microscopic level, the attapulgite structure is crystalline, with each individual crystal being in the shape of a rod. This rod-like structure differentiates attapulgite from other similar types of clay, such as bentonite, which is flatter and flakier in structure. Attapulgite clay mined in the U.S. has particles that are approximately 2.5 microns long or less and 25 nanometers wide, which makes attapulgite the ideal shape and size for forming a three-dimensional lattice structure for trapping liquids and other substances. Its particles are tightly compressed, and the clay clumps in large bundles that get dried and separated in preparation for processing.
Attapulgite’s unique mineral composition and structure give it highly desirable properties as an industrial ingredient. Some attapulgite properties include:
- Stability in liquid formulations due to being naturally colloidal
- Highly absorbent of liquids and impurities
- Highly adsorbent by other liquids
- High thermal activation
- Plastic and adhesive qualities when wet
Attapulgite clay can be processed into different states, including pulverized into a powder or converted into a gel form. However, only certain deposits around the world produce attapulgite clay in high enough quality that makes it gel grade. This is why the majority of gellant attapulgite products have their clay minerals sourced from deposits in southwestern Georgia and northern Florida, where the deposits are high enough quality for formulating gellant products.
Attapulgite compared to in-kind components or additives:
Attapulgite clay is a naturally occurring thixotropic thickener that shares some performance properties with other minerals and additives such as bentonite and sepiolite. In many industries and applications attapulgite outperforms due to superior absorption capacity, exceptional thixotropic properties, and heightened heat resistance.
Attapulgite and bentonite clay share many of the same properties and uses. While both clay types are used as industrial absorbents, they differ in the type and quantity of substances they effectively absorb. When compared to bentonite, attapulgite is often found to be superior when being used for suspension and flow characteristics in paints and coatings and binder applications. In the drilling industry it is often referred to as “salt gel” because of the ability to perform in high salt environments where the chemical make-up of bentonite fails.
Partial thickener replacement:
Attapulgite offers an advantageous partial replacement for various thickeners such as cellulosic, urethane, acrylic associative thickeners, and gums, not only enhancing performance but also potentially yielding cost savings. Its unique structural properties and thixotropic behavior make it an ideal complement to these thickeners, allowing for improved viscosity, stability, and rheology control in formulations for paints, coatings, adhesives, and more. By incorporating attapulgite as a partial replacement, manufacturers can potentially reduce the overall dependence on expensive traditional thickeners while maintaining or even enhancing the desired product characteristics, thus contributing to significant cost efficiencies without compromising on quality or functionality in various industrial applications.
Synthetic rheology modifiers:
The natural origin and inherent characteristics of attapulgite provide a more sustainable and environmentally friendly option compared to synthetic rheology modifiers. Additionally, attapulgite’s cost-effectiveness and versatility in various applications, such as paints, coatings, adhesives, and drilling fluids, make it a preferred choice, delivering high-performance results without the drawbacks associated with some synthetic options such as limited compatibility, long term stability, and weak performance.
Like bentonite, attapulgite shares properties and uses with sepiolite. However, attapulgite typically exhibits superior performance and a broader adaptability across industries. It absorbs liquids and impurities more effectively, particularly in applications requiring robust absorbency, while offering better stability in diverse applications like paints, coatings, and drilling fluids. Additionally, attapulgite’s increased heat stability is crucial in industries exposed to higher temperatures.
Attapulgite in Building Products
Attapulgite clays and powders are found in a variety of building products. Building product manufacturers source attapulgite mixture products and use these additives to produce their final products. Attapulgite ingredients can be used to modify the state of an existing substance, a process known as rheology, or the deformation or flow of solids or liquids.
Attapulgite is also used to bind substances together to create a cohesive mixture. Below are some of the types of manufactured building products that require the properties of attapulgite clay to be produced:
- Concrete: Traditionally, concrete is a mixture of Portland cement, water, sand or silica and aggregates. The exact proportion and specific types of silica, sand, or aggregates differentiate concrete mixtures or concrete-formed products between manufacturers. In some cases, manufacturers use attapulgite clay or powder as an additive in addition to silica agents or as a replacement for silica agents. Attapulgite acts as a binding agent for the concrete mixture.
- Sealants and adhesives: Because of attapulgite clay’s natural thixotropic properties, it’s used to thicken up mixtures without reducing the particle sizes of any of its substances. This is a particularly useful property in the manufacturing of polymers, adhesives, sealants, or any manufactured building products that need to maintain a specific structure. Attapulgite gel is an especially helpful form of the substance for producing caulks, adhesives, and sealants.
Attapulgite in Livestock Feeds
Attapulgite industrial applications are incredibly diverse, even being used in the manufacturing of livestock feed. To produce high-quality livestock feed, manufacturers need a way to bind feed ingredients together in pelletized form. The binding agents should also be shelf-stable and able to extend the life of the feed during long-term storage, keeping the feed intact and safe. Attapulgite offers all these benefits and more in the production of livestock feed.
Attapulgite in Agriculture
Another innovative industrial application of attapulgite is in the manufacturing of agricultural products. Below are some of the ways that attapulgite is used in agricultural products:
- Seed coatings: Seed coatings are used in the agricultural industry to increase distribution efficiency, promote germination. Attapulgite is an active ingredient in many seed coating products as it is used as a binding agent to promote adhesion between the formula and the seed.
- Fertilizer: Manufacturers of liquid fertilizers need innovative ways to produce formulas that suspend nutrients in liquid. Attapulgite is an additive in liquid fertilizers that helps promote the suspension of nutrients and allows the formulation to remain stable for more effective fertilizing.
- Agricultural Formulations: Herbicide and pesticide manufacturers use inert ingredients in their formulations to stabilize the mixtures. Attapulgite-based substances are EPA-approved inert ingredients added to control rheology, syneresis, and act as carriers. Thixotropic thickening and suspension properties stabilize mixtures and enable easy spraying and pumping.
Attapulgite in Paints and Coatings
Attapulgite clay has numerous properties that make it ideal as an additive in paint and coatings products. Manufacturers use attapulgite to help preserve and reinforce paints and coatings. Primarily, attapulgite clay is used as an anti-settling agent added to paint products to help prevent or delay the solidification of paints during storage. Attapulgite gel acts as a shear thinning and thixotrope, which stabilize the paint and coating products and make them easier to apply.
Attapulgite gel’s absorbent and adsorbent properties also help improve paint and coating surface volume and ability to adhere to surfaces. This helps improve the quality of the products. Attapulgite also has rheological properties. This means that it can suspend and retain solids and flow properly under stress without altering the chemical and physical properties of the mixture. Attapulgite clay in paint is also used to help improve pigment tinting and prevent pigment flooding and settling.
One of the reasons why attapulgite is preferred over other thickening agents is that attapulgite is non-swelling and chemically inert. This means that it doesn’t impact the mixtures physically or chemically compared to other types of agents.
Discover how AMI’s Min-U-Gel® attapulgite thixotropic thickeners are used in paints and coatings for rheological modification and more.
Attapulgite in Oil and Gas Drilling
Gel-quality attapulgite has properties that make it a useful material in the oil and gas drilling sector. Whether it’s oil and gas well drilling, foundation and footing drilling in construction or digging trenches for environmental containment, attapulgite helps improve the ability for the fluid mud slurry to stay contained and prevent fluid loss.
Attapulgite gives the mud superior ability to suspend the cuttings and push them up to the surface for removal. Its thermal-resistance properties also help to cool the mud while remaining chemically and physically unaffected by the high temperatures. Because attapulgite gel is unaffected by the high ionic concentration in drilling, it’s referred to as “salt gel.” Many fracking fluids, in particular, require thickening and suspending additives to promote stabilization. Attapulgite is often used as one of these additives because of its thixotropic thickening and suspension properties.
Learn how AMI’s Florigel® HY gel-quality attapulgite product is benefiting the oil and gas drilling industry thanks to its unique mineral properties and advantages over other thickening agents.
Attapulgite as Bleaching Clay for Renewable Fuels
Specially activated attapulgite bleaching clay can be used to pre-treat feedstocks for renewable fuels such as biodiesel, renewable diesel, and sustainable aviation fuel. Once activated through a patent pending process the clay shows an enhanced affinity for contaminants such as metals and phosphorous that are detrimental to the refinery catalyst. Activated attapulgite clay can effectively removes these contaminants from a variety of feedstock sources including soybean oil, used cooking oil, and more.
Activated attapulgite may show improved performance compared to standard bleaching clays. High efficiency may allow a lower clay dosage to be achieved. This could result in reduced bleaching and disposal costs. Because of the rodlike porous structure of attapulgite, higher filtration rates could also be realized, improving refinery throughput.
Attapulgite in Molecular Sieves
To produce molecular sieves, catalysts and fluid separators, manufacturers need binding agents that effectively bind in the formation of molecular sieve granules. Gel-quality attapulgite aids in the finishing and drying processes of molecular science and catalyst manufacturing. It can also help extend the service during end-use applications.
Attapulgite’s adsorbent properties make it a useful ingredient in manufacturing catalysts and molecular sieves to its ability to remove certain chemicals during the manufacturing process. This helps to promote the purity of the end result due to its low silica and carbonate content. Because attapulgite gel is colloidal, it also helps to promote and preserve the porosity and the uniformity of pores in molecular sieves to increase their precision and effectiveness.
Discover more about attapulgite uses in molecular sieves, catalysts and fluid separators.
Surface Functionalized Attapulgite for Mercury and PFAS Adsorption
Natural attapulgite can be surface functionalized with mercury affinity group or PFAS affinity group for mercury and PFAS removal applications. In lab testing surface functionalized attapulgite mercury adsorbent has shown high mercury removal with low adsorbent usage. Surface functionalized attapulgite has also been shown to work quickly for a reduced mercury adsorption process time. In extensive lab testing the surface functionalized attapulgite PFAS adsorbent exhibited the ability to effectively remove the majority of PFAS substances in mixed PFAS solutions. High removal efficiency on the most common PFAS substances such as PFOA, PFOS, PFHxS, PFNA can be achieved with surface functionalized attapulgite PFAS adsorbent.
Contact Active Minerals About Our Attapulgite Products
Attapulgite is an extremely versatile and effective mineral product capable of maximizing the properties of manufactured products and extending their applications. Because of its extensive properties, attapulgite is a desirable mineral additive across a range of manufacturing and industrial applications. To find the highest quality attapulgite mineral, it must be sourced from a supplier with the right mining and proprietary processing qualifications.
Active Minerals International is a global leader in mining, processing, and producing the highest quality gel, powder and liquid grade attapulgite mineral products. Discover the various markets we serve and review our attapulgite product selection that meets rigorous performance standards. Contact us today to learn more about our production capabilities or to obtain a quote. Fill out an online form or call 410-825-2920 for assistance.