CN119654191A - Filter aid composite materials - Google Patents

Abstract

A composition comprising a cross-linking binder and mineral particles selected from the group consisting of: i) expanded ground perlite particles having a _D50 of about 5 to about 40 microns; ii) diatomaceous earth particles having a _D50 of about 10 to about 50 microns; and combinations thereof; wherein the mineral particles are bonded together by the cross-linking binder to form composite particles, wherein the composite particles have a _D50 of about 20 to 100 microns.

Description

Filtering-aid composite material

Technical Field

The present disclosure relates to compositions comprising composite particles and a cross-linked binder and methods of making the compositions. The disclosure also relates to filter aid materials comprising the composition and methods of filtering liquids using the composition.

Background

Filtration devices typically include filter aids containing solid particulates that enhance filtration efficiency. The filter aid is added to the suspension to be filtered or placed on the filter as a layer through which the liquid must pass.

Filter aids typically comprise materials derived from volcanic glass, such as perlite or pumice. The perlite filter aid is advantageously light, inert, does not impart a taste or odor to the filtered liquid and is practically insoluble in mineral and organic acids at all temperatures.

Diatomaceous Earth (DE) is another useful type of drainage aid material and is a naturally occurring sand made from fossil remains of diatoms, a ubiquitous material. Diatomaceous earth-based filter aids are typically used for primary clarification of beer and wine.

Due to health and regulatory concerns typically also existing with respect to crystalline silica, customers of the beer and wine industry are increasingly seeking DE-based filter aids that are free of standards. Perlite based filter aids may also suffer from problems with achieving a target clarity. Cross-flow wine and beer filtration devices normally operate at high cost. It is therefore desirable to provide a filter aid that is free of crystalline silica, low cost, and achieves the clarity of standard DE-containing filter aids.

Disclosure of Invention

Certain aspects and embodiments will become apparent in the following description. It is contemplated that aspects and embodiments in their broadest sense may be practiced without having one or more features of the aspects and embodiments. It is also contemplated that these aspects and embodiments are merely exemplary.

According to a first aspect, there is provided a composition comprising composite particles comprising a cross-linked binder and mineral particles selected from i) expanded abrasive perlite particles having a D ₅₀ of from about 5 to about 40 microns, ii) diatomaceous earth particles having a D ₅₀ of from about 5 to about 40 microns, and combinations thereof, wherein the mineral particles are bound together by the cross-linked binder to form composite particles, wherein the composite particles have a D ₅₀ of from about 20 to 100 microns, and wherein the binder is present in an amount of from 0.01 to 20wt% based on the total weight of the composition, wherein the cross-linked binder is the reaction product of a polymer and a cross-linking agent, wherein the polymer is selected from the group consisting of water soluble synthetic polymers and natural water soluble polymers.

According to a second aspect, there is provided a filter aid material comprising a composition according to the first aspect.

According to a third aspect, there is provided a method of filtering a liquid comprising contacting the liquid with a filter aid material according to the second aspect.

According to a fourth aspect, there is provided a method of preparing a composition according to the first aspect.

The skilled person will appreciate that features described in relation to any one of the above aspects may be applied mutatis mutandis to any other aspect, except where mutually exclusive. Furthermore, any feature described herein may be applicable to any aspect and/or combination with any other feature described herein, except where mutually exclusive.

Drawings

Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 depicts an X-ray diffraction (XRD) spectrum showing the crystallinity level (peak) of a comparative diatomaceous earth sample, a comparative perlite sample, and a novel composite sample of diatomaceous earth and expanded ground perlite.

FIG. 2 depicts a Walton filtration plot of turbidity versus pressure rise showing turbidity of a comparative diatomaceous earth sample, a comparative perlite sample, and two novel composite samples of diatomaceous earth and expanded ground perlite.

Figure 3 depicts mercury porosimetry plots comparing intrusion volumes versus pore size for two new composite samples of diatomaceous earth, comparative perlite samples, and expanded ground perlite.

Detailed Description

Reference will now be made in detail to exemplary embodiments that are illustrated in the accompanying drawings.

It has surprisingly been found that a composition comprising composite particles comprising a cross-linked binder and mineral particles selected from the group consisting of expanded ground perlite, diatomaceous earth particles, and combinations thereof achieves excellent filtration performance results.

Expanded and ground perlite particles

Perlite typically contains silica, alumina, sodium oxide, potassium oxide, iron oxide, magnesium oxide, calcium oxide, water and small amounts of other metallic elements.

The perlite particles of the invention are in the form of expanded perlite. Typically, expanded perlite comprises one or more cells or portions of cells, where a cell is a void space surrounded, either partially or completely, by glass walls, typically formed by the expansion of a gas when the glass is in a softened state. The method for expanding perlite may include heating the perlite in air in an expansion furnace to a temperature of at least about 700 ℃, typically between 800 ℃ and 1100 ℃. An exemplary method for producing expanded perlite is described in US2006/0075930, the entire contents of which are incorporated herein by reference. The total volume of expanded perlite is typically up to 20 times the total volume of unexpanded material.

According to the invention, the perlite is ground after it has been expanded in an expansion furnace.

Unless otherwise specified, the particle size characteristics of the perlite particles referred to herein are measured by methods employed in the field of laser scattering (or by other methods that give substantially the same results) using a CILAS1064L particle size analyzer as supplied by CILAS. In laser scattering techniques, the size of particles in powders, suspensions and emulsions can be measured using the diffraction base Yu Fulang of a laser beam and the application of the fischer-tropsch theory (Fraunhofer and Mie theory). Such machines provide a measurement and plot of the cumulative percentage of volume of particles having a size (referred to in the art as the "equivalent sphere diameter" (e.s.d)) that is less than a given e.s.d. value. The average particle size D ₅₀ is the value of the particle e.s.d determined in this way, at which 50% by volume of the particles have an equivalent sphere diameter smaller than the value D ₅₀.

In accordance with the present invention, the expanded abrasive perlite particles have a D ₅₀ of from about 10 to about 50 microns, such as a D ₅₀ of from about 15 to about 45 microns or from about 20 to about 40 microns or from about 25 to about 35 microns. In certain embodiments, the expanded abrasive perlite particles have a D ₅₀ of about 15 microns.

In certain embodiments, the expanded abrasive perlite particles have a bulk density of from about 0.05g/cm ³ to about 0.20g/cm ³, such as from about 0.06g/cm ³ to about 0.19g/cm ³, such as from about 0.07g/cm ³ to about 0.18g/cm ³, such as from about 0.08g/cm ³ to about 0.17g/cm ³, such as from about 0.09g/cm ³ to about 0.16g/cm ³, such as from about 0.10g/cm ³ to about 0.15g/cm ³, such as from about 0.11g/cm ³ to about 0.14g/cm ³, such as from about 0.12g/cm ³ to about 0.13g/cm ³.

In one embodiment, the perlite product is obtained from a commercially available perlite product. In another embodiment, at least one perlite product is available from Imerys Performance MaterialsA material.

Diatomite (DE) particles

Diatomaceous Earth (DE) is derived from remains of microscopic petrochemical marine or freshwater algae. DE is typically used as a filter aid. DE is known to have a complex and porous structure that is effective for trapping particulates during filtration.

The DE starting material may be DE in its crude form or may be subjected to one or more processing steps, such as physical or chemical modification. Physical modification methods include, but are not limited to, milling, drying, and air classification. Chemical modification methods include, but are not limited to, silylation. Such modification methods are used to render the surface of the DE more hydrophobic or hydrophilic using methods such as those described in US 3,915,735 and US 4,260,498, the contents of US 3,915,735 and US 4,260,498 being incorporated herein by reference.

DE typically comprises about 80 to 90% silica and 2 to 4% alumina (mainly due to clay minerals) and 0.5-2% iron oxide. The types of DE that can be obtained are well known to those skilled in the art.

The particle size characteristics of the DE particles referred to herein are measured by the method discussed above for expanded ground perlite particles, unless otherwise specified.

According to the invention, the DE particles have a D ₅₀ of about 10 to about 50 microns, for example about 15 to about 45 microns or about 20 to about 40 microns or about 25 to about 35 microns. In certain embodiments, the DE particles have a D ₅₀ of about 35 microns.

In certain embodiments, the DE microparticles have a bulk density of from about 0.05g/cm ³ to about 0.46g/cm ³, such as from about 0.06g/cm ³ to about 0.44g/cm ³, such as from about 0.07g/cm ³ to about 0.42g/cm ³, such as from about 0.08g/cm ³ to about 0.4g/cm ³, such as from about 0.09g/cm ³ to about 0.38g/cm ³, such as from about 0.10g/cm ³ to about 0.36g/cm ³, such as from about 0.11g/cm ³ to about 0.34g/cm ³, such as from about 0.12g/cm ³ to about 0.32g/cm ³.

In one embodiment, the DE particles are commercially available diatomaceous earth products. In another embodiment, at least one of the natural diatomaceous earth particles is obtainable from Imerys Performance MaterialsA material.

Adhesive agent

In accordance with the present invention, expanded abrasive perlite particles and/or DE are bonded together using a cross-linking binder to form composite particles. The crosslinked adhesive is the reaction product of a polymer and a crosslinking agent, wherein the polymer is selected from the group consisting of water-soluble synthetic polymers and natural water-soluble polymers.

The adhesive of the present invention is a permanent adhesive. By this we mean that the binder is intended to remain in the composite particle product and to provide structural strength to the composite particles, but is insoluble in the liquid to be filtered, for example when filtering beer.

In certain embodiments, the adhesive is comprised of a single type of polymer, or in certain embodiments, the adhesive comprises one or more polymers.

In certain embodiments, the polymer is selected from one or more of a water-soluble synthetic polymer and a natural water-soluble polymer. In certain embodiments, the polymer is a combination of these types of polymers.

In certain embodiments, the binder comprises a water-soluble synthetic polymer selected from, for example, polyvinyl alcohol (PVA), polyethylene glycol, urea formaldehyde, polyacrylamide, microcrystalline cellulose, polyacrylate, acrylic acid/maleic acid copolymer, and polyvinylpyrrolidone.

In certain embodiments, the binder comprises a natural water-soluble polymer, such as xanthan gum, sodium alginate, potassium alginate, lignosulfonate, locust bean gum, pectin, dextran, carrageenan, agar, xanthan gum, guar gum, acacia (gum arabic), cellulose ethers such as methylcellulose and ethylcellulose, starch, or starch-based derivatives.

According to the invention, the binder is a crosslinked binder, which is the reaction product of a polymer and a crosslinking agent. Crosslinking is the formation of chemical linkages between polymer chains to form a three-dimensional network of linked molecules. The polymers may be selected from the list of polymers described above. Crosslinking agents are well known in the art and may be selected depending on the type of polymer. The cross-linking agent is not a self-crosslinking polymer.

In certain embodiments, the crosslinker is an acid selected from one or more of the following:

(i) Dicarboxylic acids, including oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, malic acid, tartaric acid, tartronic acid, aspartic acid, glutamic acid, fumaric acid, itaconic acid, maleic acid, callic acid, camphoric acid, phthalic acid and derivatives thereof containing at least one boron or chlorine atom, tetrahydrophthalic acid and derivatives thereof containing at least one chlorine atom, isophthalic acid, terephthalic acid, mesaconic acid and citraconic acid,

(Ii) Tricarboxylic acids including citric acid, tricarballylic acid, 1,2, 4-butanetricarboxylic acid, aconitic acid, trimellitic acid, and trimesic acid;

(iii) Tetracarboxylic acids including 1,2,3, 4-butanetetracarboxylic acid and pyromellitic acid;

(iv) Polycarboxylic acids such as EDTA;

(v) Unsaturated carboxylic acids including monoesters of (ethyl) acrylic acid, crotonic acid, isocrotonic acid, maleic acid, cinnamic acid, 2-methyl maleic acid, fumaric acid, itaconic acid, 2-methyl itaconic acid, alpha, beta-methyleneglutaric acid and unsaturated dicarboxylic acids, and vinyl monomers are styrene optionally substituted with alkyl, hydroxy or sulfonyl groups or styrene optionally substituted with halogen atoms, (meth) acrylonitrile, (meth) acrylamides optionally substituted with C1-C10 alkyl groups, alkyl (meth) acrylates, glycidyl (meth) acrylate, butadiene and vinyl esters

(Vi) Inorganic acids such as boric acid and phosphoric acid.

In certain embodiments, the crosslinking agent is a carboxylic acid selected from the group consisting of dicarboxylic acids, tricarboxylic acids, tetracarboxylic acids, polycarboxylic acids, and unsaturated carboxylic acids. In certain embodiments, the carboxylic acid is a polycarboxylic acid such as citric acid or succinic acid. In certain embodiments, the carboxylic acid is an unsaturated carboxylic acid such as acrylic acid, methacrylic acid, and maleic acid.

In certain embodiments, the binder is the reaction product of polyvinyl alcohol and citric acid. Carboxylic acids are the preferred type of cross-linking agent because of their low toxicity and cost. Polyvinyl alcohol is also known to be non-toxic and biodegradable. The resulting crosslinked adhesive is insoluble in water and inexpensive to produce.

In certain embodiments, the binder is present in an amount of about 0.1wt% to about 40 wt%, or about 1wt% to about 35 wt%, or about 5wt% to about 30 wt%, or about 10wt% to about 25 wt%, or about 15 wt% to about 20wt%, or about 1wt% to about 5wt% of the total wt% of the granule.

In certain embodiments, the adhesive comprises a crosslinker in an amount of about 1 wt% to about 30 wt%, or, for example, about 2wt% to about 25 wt%, or, for example, about 3 wt% to about 20 wt%, or, for example, about 4 wt% to about 15 wt%, or, for example, about 5 wt% to about 10 wt%, based on the total weight of the adhesive.

Composite particles

According to the present invention, mineral particles having the particle sizes described above selected from the group consisting of expanded ground perlite particles, diatomaceous earth particles, and combinations thereof are bonded together using a binder to form composite particles. The primary powder particles agglomerate to form larger multiparticulate entities called composite particles.

In certain embodiments, the composite particles comprise or consist of expanded abrasive perlite particles and a binder. In certain embodiments, the composite particles comprise or consist of DE particles and a binder. In certain embodiments, the composite particles comprise or consist of a blend of expanded abrasive perlite particles and DE particles and binder.

The expanded abrasive perlite and/or DE particles are bonded/agglomerated together by a binder to form voids or otherwise referred to as interstitial void spaces between the particles. In some embodiments, the pores have a measurable intrusion volume, which can be measured by the methods explained in the measurement methods section below. In certain embodiments, the cumulative intrusion volume is from about 2.5mL/g to about 4.5mL/g, or about 2.6mL/g, or about 2.7mL/g, or about 2.8mL/g, or about 2.9mL/g, or about 3.0mL/g, or about 3.1mL/g, or about 3.2mL/g, or about 3.3mL/g, or about 3.4mL/g, or about 3.5mL/g, or about 3.6mL/g, or about 3.7mL/g, or about 3.8mL/g, or about 3.9mL/g, or about 4.0mL/g, or about 4.1mL/g, or about 4.2mL/g, or about 4.3mL/g, or about 4.4mL/g, or about 4.5mL/g. In certain embodiments, the median intrusion volume is preferably about 3.5mL/g.

It is advantageously found that the measured pore volume is more than 25% greater than that of the perlite or DE products typically used. For example, a higher pore volume means more volume per mass can pass through the filter. This allows for a larger solids holding capacity at equivalent filter aid doses.

In certain embodiments, the composite particles comprise expanded ground perlite particles and diatomaceous earth particles, and wherein at least one pore of the porous structure is filled with at least one unbound diatomaceous earth particle.

In certain embodiments, the ratio of expanded ground perlite to DE may be from about 5:1 to about 1:4 or from about 5:1 to about 1:3, or from about 5:1 to about 1:2, or from about 5:1 to about 1:1, or from about 5:1 to about 2:1, or from about 5:1 to about 1:3, or from about 4:1 to about 1:4, or from about 4:1 to about 1:3, or from about 4:1 to about 1:2, or from about 4:1 to about 1:1, or from about 4:1 to about 2:1, or from about 4:1 to about 1:3.

According to the present invention, the composite particles have a D ₅₀ of about 150 to about 2000 microns, such as about 200 microns to about 1900 microns, or about 300 microns to about 1800 microns, or about 400 microns to about 1700 microns, or about 500 microns to about 1600 microns, or about 600 microns to about 1500 microns, or about 700 microns to about 1400 microns, or about 800 microns to about 1300 microns, or about 900 microns to about 1200 microns, or about 1000 microns to about 1100 microns, or about 200 microns to about 600 microns, such as about 350 microns to about 550 microns, or about 400 microns to about 500 microns, or about 600 microns to about 1900 microns, such as about 700 microns to about 1800 microns, or about 800 microns to about 1600 microns, or about 900 microns to about 1500 microns, or about 1000 microns to about 1400 microns, or about 1100 microns to about 1300 microns, by laser diffraction method. By laser, the composite particles may have a D ₅₀ of about 200 microns to about 1000 microns, or about 300 microns to about 900 microns, or about 400 microns to about 800 microns, or about 500 microns to about 700 microns.

In certain embodiments, the composite particles have a bulk density of about 0.1g/cm ³ to about 0.50g/cm ³, such as about 0.15g/cm ³ to about 0.45g/cm ³, such as about 0.20g/cm ³ to about 0.40g/cm ³, such as about 0.20g/cm ³ to about 0.35g/cm ³, such as about 0.25g/cm ³ to about 0.30g/cm ³.

The composite particles of the present application may have a measurable BET surface area. The BET specific surface area refers to the surface area of the microparticles of the composite particle in terms of unit mass, as determined according to the BET method by the amount of nitrogen adsorbed on the surface of said microparticles so as to form a monolayer completely covering said surface (according to the BET method, AFNOR standards X11-621 and 622 or ISO 9277 measurements). Details of the BET specific surface area measurement method used in the preparation of the present application are set forth in the examples.

The composite particles may have a BET specific surface area of not less than about 1.5m ²/g, such as not less than about 1.6m ²/g, or not less than about 1.7m ²/g, or not less than about 1.8m ²/g, Or not less than about 1.9m ²/g, or not less than about 2.0m ²/g, or not less than about 2.5m ²/g, or not less than about 3.0m ²/g, Or not less than about 5.0m ²/g, or not less than about 10m ²/g (e.g., 10.0m ²/g), or not less than about 20m ²/g (e.g., 11.0m ²/g). The composite particles may have a BET specific surface area of no greater than about 50m ²/g (e.g., 50.0m ²/g), such as no greater than about 40m ²/g (e.g., 40.0m ²/g), Or not greater than about 30m ²/g (e.g., 30.0m ²/g), or not greater than about 20m ²/g (e.g., 20.0m ²/g), Or not greater than about 15m ²/g (e.g., 15.0m ²/g), or not greater than about 12m ²/g (e.g., 12.0m ²/g), Or not greater than about 11m ²/g (e.g., 11.0m ²/g), or not greater than about 10m ²/g (e.g., 10.0m ²/g), Or not greater than about 8.0m ²/g, or not greater than about 7.0m ²/g, or not greater than about 6.0m ²/g. The composite particles may have a BET specific surface area that may be from about 1.5m ²/g to about 50m ²/g (e.g., 50.0m ²/g), such as from about 2m ²/g to about 40m ²/g (e.g., 40.0m ²/g), Or about 5m ²/g to about 30m ²/g (e.g., 30.0m ²/g), or about 10m ²/g to about 20m ²/g (e.g., 20.0m ²/g).

In certain embodiments, the composite particles have an angle of repose of about 5 ° to about 35 °, as measured by the angle of repose (funnel method) using an EFT-01 powder flow tester, the composite particles have an absorption capacity of at least 150%, as measured using the Westinghouse method described herein in the experimental section and utilizing dioctyl adipate as the adsorbate, and a dust content of less than 10, as measured by the dust analyzer DustmonRD 100.

The angle of repose of the material is the steepest descent angle (angle of decent) or inclination with respect to the horizontal, to which the material can be deposited without slumping. The morphology of the material affects the angle of repose. When bulk particulate material is poured onto a horizontal surface, a cone-shaped pile will be formed. The internal angle between the surface of the stack and the horizontal surface is called the angle of repose and is related to the density, surface area and shape of the particles and the coefficient of friction of the material. Materials with low angles of repose form a flatter stack than materials with high angles of repose. Thus, smooth round sand grains do not accumulate as steeply as coarse interlocking sand. The method for calculating the angle of repose is described in more detail in the experimental section below.

In certain embodiments, the angle of repose (of the dried product) is from about 5 ° to about 35 °, such as from about 10 ° to about 30 °, such as from about 15 ° to about 25 °.

In certain embodiments, the composite particles have a low dust content of advantageously less than 10, such as less than 9 or 8 (using a dust analyzer Dustmon RD 100 (available fromObtained) measurement). The method of calculating the dust content value is explained in more detail in the experimental section.

Composition and method for producing the same

According to the present invention, there is provided a composition comprising composite particles. The composite particles are bonded together using a cross-linking adhesive.

In certain embodiments, the composition comprises an additional inorganic mineral component. Examples of additional inorganic mineral components include natural or synthetic silicate or aluminosilicate materials, pumice, natural glass, cellulose, activated carbon, feldspar, nepheline syenite, sepiolite, zeolite, and clay. Examples of clay minerals include halloysite, kaolinite, and bentonite. The additional inorganic mineral component may be added in an amount of from about 0.01 parts to about 10 parts, for example from about 0.5 parts to about 5 parts, per part of expanded ground perlite and/or DE.

The composition is prepared by dry blending one or more mineral particles (dry powders of expanded ground perlite and/or DE and any other desired additional inorganic materials) and then spray drying the one or more mineral particles with a binder such that agglomerates are formed. The adhesive is first prepared by dissolving the adhesive components in water.

When spray-dried, the aqueous binder mixture is fed to the inlet of a spray dryer and sprayed onto the dry-mixed mineral particles. One example of a suitable spray drying apparatus is a Niro Minor spray dryer unit. The machine has a drying chamber of 800mm diameter, 600mm height based on conical cylinders and is equipped with an air-driven disc atomizer. The atomizer may be operated at a speed of 30,000 rpm.

The curing step (crosslinking step) is then carried out in a kiln at a temperature of about 80-120 ℃. The curing step is typically performed for a period of time such that the granules dry and the binder cures. After the curing step, the moisture content of the granules is less than about 5% by weight of the granules, such as less than about 3% by weight or less than about 2% by weight. The curing step is performed for a period of time that brings the moisture content to the desired level as described above and may take 12 hours or 8 hours or 4 hours.

This is a much lower temperature than the temperature of standard production of DE in which kiln temperatures can exceed 1400 ℃. By avoiding the use of such high temperatures, and by keeping the temperature low, it is possible to prevent the formation of undesirable crystalline silica, such as quartz or cristobalite. The presence of cristobalite in the filter aid is generally undesirable because of its potentially unhealthy nature at higher concentrations.

In certain embodiments, the crystalline silica is present in the composition in a total amount of less than or equal to about 0.2 wt% of the total weight% of the composition. In certain embodiments, the composition comprises from about 0 wt% to about 0.2 wt% crystalline silica present in the composition, such as from about 0.01 wt% to about 0.1 wt% crystalline silica. In certain embodiments, the composition is free of crystalline silica, meaning that no crystalline silica is detected.

Methods of measuring cristobalite content may be measured using techniques known to those skilled in the art, including the specific methods described in WO 2010/042614.

Filter aid material

According to the present invention there is provided a filter aid material comprising the composition described herein. The filter aid composition may be formed into a sheet, pad, cartridge or other product for performing a filtration function.

The filter aids of the present invention may be used in a variety of processes and compositions as well as in a variety of filtration processes. In certain embodiments, a filter aid material is applied to the filter membrane to protect it and/or to enhance the clarity of the liquid to be filtered during filtration. In another embodiment, the filter-aid composition is added directly to the beverage to be filtered to increase the flow rate and/or extend the filtration period. In another embodiment, a method is provided for precoating at least one filter element with a filter aid material and contacting at least one liquid to be filtered with the at least one coated filter element, or the liquid is to be used for body feeding or a combination of precoating and body feeding.

The filter aid material of the present invention can also be used in various filtration methods. In one embodiment, the filtration process comprises pre-coating at least one filter element with the composition of the present invention and contacting at least one liquid to be filtered with at least one coated filter element. In such embodiments, contacting may include passing the liquid through the filter element. In another embodiment, the filtration method comprises suspending a filter aid material in at least one liquid containing particulates to be removed from the liquid, and then separating the filter aid material from the filtered liquid.

Filter-aid materials comprising the compositions of the present invention may also be used to filter various types of liquids. The skilled artisan will readily appreciate that liquids may be desirably filtered using methods that include a filter aid comprising at least one diatomaceous earth product disclosed herein. In one embodiment, the liquid is a beverage. Exemplary beverages include, but are not limited to, vegetable-based juices, fruit juices, distilled wines, and malt-based liquids. Exemplary malt-based liquids include, but are not limited to, beer and wine. In another embodiment, the liquid is a liquid that tends to form haze upon cooling. In further embodiments, the liquid is a beverage that tends to form cloudiness upon cooling. In yet another embodiment, the liquid is beer. In yet another embodiment, the liquid is an oil. In yet another embodiment, the liquid is an edible oil. In yet another embodiment, the liquid is a fuel oil. In another embodiment, the liquid is water, including but not limited to wastewater. In further embodiments, the liquid is blood. In yet another embodiment, the liquid is sake. In yet another embodiment, the liquid is a sweetener, such as corn syrup or molasses.

Examples

Details of the comparative DE samples, comparative perlite samples, and novel composite materials of DE and expanded mill perlite used in the examples below are shown in Table 1 below.

TABLE 1

Example 1

80G of expanded and ground perlite is used500, From Imerrys-sample C) novel composite 1 (sample F) was prepared by mixing 80g of the expanded ground perlite with 20g of natural diatomaceous earth [ (]615-Sample E) were placed together in a mixer (KITCHEN AID mixer) and the powders were dry blended for 5 minutes at the lowest setting. 1.5g of polyvinyl alcohol (PVA) and 4.5g of citric acid are dissolved in 50g of water. The final% by weight of binder was 6% by weight of the total composite particles. The binder composition was then sprayed onto the dry blended powder and the composite particles formed by agglomeration, taking 3 minutes to transfer all of the solution into KITCHEN AID mixer. The composite particles were then cured by heating in an oven at a temperature of 120 ℃ for 85 minutes. The novel composite 1 was subjected to X-ray diffraction, walton solid-liquid filtration and mercury porosimetry by the methods described below, and the results are shown in fig. 1,2 and 3, respectively.

Example 2

Using 66g of expanded grinding perlite500, From Imerrys-sample C) to prepare novel composite material 2 (sample G), mixing the 66G of expanded ground perlite with 33G of natural diatomaceous earth [ (]615-Sample E) were placed together in a mixer (KITCHEN AID mixer) and the powders were dry blended for 5 minutes at the lowest setting. 1.5g of polyvinyl alcohol (PVA) and 4.5g of citric acid are dissolved in 50g of water. The final% by weight of binder was 6% by weight of the total composite particles. The binder composition was then sprayed onto the dry blended powder and the composite particles formed by agglomeration, taking 3 minutes to transfer all of the solution into KITCHEN AID mixer. The composite particles were then cured by heating in an oven at a temperature of 120 ℃ for 85 minutes. The novel composite material 2 was subjected to Walton solid-liquid filtration and mercury porosimetry by the methods described below, and the results are shown in fig. 2 and 3, respectively.

The filtration properties of the novel composites 1 and 2 demonstrate their competitiveness with standard grade DE from Lompoc facilities when tested in Walton filters (vertical tank, single horizontal blade, positive pressure, alfield (Ovaltine) as suspended solids). The novel composites 1 and 2 representing the inventive compositions described herein demonstrate that the inventive compositions described herein present the clarity of Hyflo (sample a) with a reduced pressure rise over time. The inventive composition described herein is significantly better than H500 (sample C) at comparable pressures and is better than H200 (sample D) at significantly reduced pressures in terms of clarity compared to perlite, as shown in fig. 2.

In addition to filtration performance, it is important to note the increase in pore volume over Hyflo (sample a-3.1 mL/g) and Standard Supercel (sample B-2.8 mL/g) for the novel composites 1 and 2, as shown in fig. 3, hyflo and Standard Supercel were each rated as standard Lompoc DE. Typical calcined and flux calcined DE grades have a pore volume of about 2.8mL/g when measured in a mercury porosimeter. The novel composite 1 has a pore volume measured at 3.7mL/g, which is 25% increased compared to the typical DE. This allows for a greater solids holding capacity at equivalent filter aid doses.

Measurement method

PSD laser

Particle Size Distribution (PSD) was determined using Mastersizer 3500S from Malvern instruments.

D ₅₀ is the value of the average particle size (D50) measured by laser diffraction (Standard NFX-11-666 or ISO 13320-1), as described above and in the examples. Reference may be made to the articles of G.Baudet and J.P.Rona, ind.Min.Mines et Carr.les tehn.1990, month 6, 7, pages 55-61, which show that the lamellarity (lamellarity) index is related to the average ratio of the largest dimension of the microparticles to its smallest dimension.

Density of

The bulk density of the sample is estimated by measuring the volume of the sample into the tube and comparing the volume of the sample to the mass of the sample.

Specific surface area (SSA-B.E.Tm ²/g)

The BET specific surface area was determined using a method based on standard NF X11-621, titled "Détermination de l'aire massique(Surface Spécifique)des poudres par adsorption de gaz-Méthode B.E.T.-Mesure Volumétrique par adsorption d'azoteàbasse température"(, determination of the mass area of the powder by gas adsorption-BET method-volume measurement by nitrogen adsorption at low temperatures.

The method uses Micromeritics measuring equipment (available from Micromeritics Instrument corp., USA) comprising a vacuum pump, vacPrep 061 degas section, tristar 3000S measuring section and sample holder, METTLER AG balance with an accuracy of 0.1mg, dewar, nitrogen adsorption gas and helium carrier gas.

The sample was weighed (to a precision of 0.1 mg) near the empty sample holder and its mass M ₀ was recorded in g. The previously homogenized powder sample was then introduced into the sample holder using a funnel. Sufficient space (dead volume) is left between the sample and the top of the sample holder to allow free circulation of gas. The sample holder was placed in one of the degassing stations and degassed at 250 ℃ under a primary vacuum of 10Pa for about 20 minutes. After degassing, a sufficient volume of nitrogen is added to the sample holder to avoid introducing air during transfer of the sample holder from the degassing station to the measurement station.

The sample holder is then attached to the measurement station and a dewar containing liquid nitrogen is placed around the sample holder. BET measurement was started using device control software. The device then automatically performs the following operations:

vacuum removal of nitrogen introduced into the holder for transferring the sample;

leakage test;

helium carrier gas is added;

Measuring dead volume at ambient temperature;

measuring cold dead volume using liquid nitrogen;

Helium vacuum removal;

leakage test;

nitrogen was added at 950mm Hg and the saturation pressure was measured, and

Obtain an analysis value.

The instrument data acquisition and processing software plots the converted BET lines from the 5 measured adsorption points. The dewar is removed and then the sample holder is removed. The apparatus was allowed to return to ambient temperature and then the sample was again weighed (to an accuracy of 0.1 mg) near the sample holder and the weight was recorded as M ₂ in g. The mass M (in g) of the sample of the test part is calculated according to the following:

M=M₂-M₀

The value M is then introduced into a software calculation program which automatically calculates the BET specific surface area of the sample in M ²/g.

Porosity of the porous material

Porosity is the percentage of interstitial void space in the particles. It is calculated using the following formula:

Φ=V_v/V_T

where Φ is the porosity, V _v is the void volume, and V _T is the total volume.

The porosity is measured using mercury porosimetry that characterizes the porosity by forcing mercury into the pores. The method of measuring porosity used herein is a standard test for mercury porosimetry as set forth in ASTM D4404-18.

Angle of repose

The angle of repose was measured according to ISO 8398:1989 using a manual powder flow tester (EFT-01). The angle of repose is calculated as follows:

θ=tan^-1h/r

Where θ is the angle of repose, h is the height of the conical stack in cm, and r is the radius in cm.

The complementary measurement of the angle of repose is the dynamic angle of repose (or flow angle) measured using Granudrum. GranuDrum apparatus (available from GRANUTOOLS ^TM) is an automatic powder flow measurement technique based on the principle of a rotating drum. The drum was a horizontal cylinder with transparent side walls and half of it was filled with powder sample.

The drum rotates about its axis at an angular speed ranging from 2 to 70 rpm. In this case, the angular velocity is measured at 10rpm, and many snapshots are captured by the CCD camera. For the measured rotational speed, the dynamic cohesion index is measured from the interface fluctuations and the flow angle is calculated from the average interface position, also referred to in the literature as the "dynamic angle of repose". A low value of the flow angle corresponds to excellent flowability.

XRD

X-ray diffraction is used to identify and quantify mineral species, such as crystalline and inorganic species. The sample holder was filled with about 1 gram of the powder sample and placed in an XRD machine, i.e. using a Ge monochromator to generate CuK _α irradiated Rigaku Empyrean. The scanning range in terms of 2 theta angles is 2 deg. to 70 deg..

Crystalline silica ("CS") has a primary main peak at or near 21.5 °. Hyflo shows a distinctive primary peak of CS and characteristic secondary and tertiary peak signals at low count intensities. Perlite (H500) and the new composite materials 1 and 3 have very weak signals in this range even at very high count strengths.

Walton

A4L solid suspension was prepared as a model solid solution using Alternaria (consisting of 5g/L Alternaria in deionized water). It was hydrated for 45 minutes. The pressure vessel was filled with deionized water and a Hyflo precoat (2.0 g in 50 mL) was prepared on a20 cm ² stainless steel netherlands woven screen. This precoat was added at a flow rate of 150 mL/min. Once applied, turbidity was monitored by measuring NTU using a nephelometer, target NTU <1. After 45 minutes of alfield hydration, the respective sample filter aid was added to the 4L solid suspension at a concentration of 2 g/L. The suspension of the alfield and filter aid is referred to as the bulk feed (body feed). The subject charge was injected into the pressure vessel at 60mL/min for 30 minutes. Pressure and turbidity were monitored every minute. For the Walton plot in fig. 2, the pressure rise from 10 minutes to 20 minutes was collected and turbidity was reported at 20 minutes.

Perlite grades (H500 and H200) show higher turbidity relative to diatomaceous earth (Hyflo and Standard Supercel) and relative to the new composites 1 and 2. The perlite scale showed a higher pressure rise relative to the new composites 1 and 2. The diatomaceous earth grades show a higher pressure rise relative to the new composites 1 and 2. Furthermore, hyflo turbidity was higher compared to the novel composites 1 and 2, all as shown in fig. 2.

Claims (18)

1. A composition comprising composite particles comprising a cross-linked binder and mineral particles selected from the group consisting of: i) expanded ground perlite particles having a _D50 of about 5 to about 40 microns; ii) diatomaceous earth particles having a _D50 of about 10 to about 50 microns; and combinations thereof; wherein the mineral particles are bound together by the cross-linking binder to form composite particles, wherein the composite particles have a _D50 of about 20 to 100 microns, and wherein the binder is present in an amount of 0.1 wt % to about 40 wt % based on the total weight of the composition, wherein the cross-linking binder is a reaction product of a polymer and a cross-linking agent, wherein the polymer is selected from the group consisting of water-soluble synthetic polymers and natural water-soluble polymers. 2. The composition according to claim 1, wherein the crosslinking agent is an acid selected from one or more of the following: (i) dicarboxylic acids, including oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, malic acid, tartaric acid, tartronic acid, aspartic acid, glutamic acid, fumaric acid, itaconic acid, maleic acid, callic acid, camphoric acid, phthalic acid and its derivatives containing at least one boron or chlorine atom, tetrahydrophthalic acid and its derivatives containing at least one chlorine atom, isophthalic acid, terephthalic acid, mesaconic acid and citraconic acid, (ii) tricarboxylic acids including citric acid, tricarballylic acid, 1,2,4-butanetricarboxylic acid, aconitic acid, trimellitic acid, trimellitic acid and trimesic acid; (iii) tetracarboxylic acids including 1,2,3,4-butanetetracarboxylic acid and pyromellitic acid; (iv) polycarboxylic acids such as EDTA; (v) unsaturated carboxylic acids including (ethyl) acrylic acid, crotonic acid, isocrotonic acid, maleic acid, cinnamic acid, 2-methylmaleic acid, fumaric acid, itaconic acid, 2-methylitaconic acid, α,β-methyleneglutaric acid and monoesters of unsaturated dicarboxylic acids, and the vinyl monomer is styrene optionally substituted by an alkyl group, a hydroxyl group or a sulfonyl group or styrene optionally substituted by a halogen atom, (meth)acrylonitrile, (meth)acrylamide optionally substituted by a C1-C10 alkyl group, alkyl (meth)acrylate, glycidyl (meth)acrylate, butadiene and vinyl ester (i) Inorganic acids such as boric acid and phosphoric acid. 3. The composition of claim 2, wherein the binder is a reaction product of polyvinyl alcohol and an acid. 4. The composition of claim 3, wherein the acid is citric acid. 5 . The composition of claim 1 , wherein the composite particles are bonded by the cross-linking binder and form a porous structure comprising pores having a pore volume of 2.5 to 4.5 mL/g. 6. The composition of claim 5, wherein the composite particles comprise expanded ground perlite particles and diatomaceous earth particles. 7. The composition of claim 6, wherein at least one pore of the porous structure is filled with at least one unbound diatomaceous earth particle. 8. The composition according to claim 1, comprising: An angle of repose of about 5° to about 30° as measured by Angle of Repose (Funnel Method) using an EFT-01 Powder Flow Tester; An absorbent capacity of at least 150% as measured using the Westinghouse method described herein and utilizing dioctyl adipate as the absorbate; and Dust content of less than 10, as measured by the dust analyzer Dustmon RD 100. 9. The composition of claim 1 wherein the expanded ground perlite particles have a _D50 of about 15 microns. 10. The composition of claim 1, wherein the diatomaceous earth microparticles have a _D50 of about 35 microns. 11. The composition of claim 1 wherein the composite microparticles have a _D50 of about 30 to about 40 microns. 12. The composition of claim 1, wherein the composite particles comprise expanded ground perlite microparticles and diatomaceous earth microparticles in a ratio of 5:1 to 1:4. 13. The composition of claim 1, wherein the crystalline silica present in the composition is less than or equal to about 0.2 weight percent of the total weight percent of the composition. 14. A filter-aid material comprising the composition according to claim 1. 15. A method of filtering a liquid, the method comprising contacting the liquid with the filter-aid material according to claim 12. 16. A method of preparing a composition comprising composite particles, the method comprising: (a) spray drying mineral microparticles selected from the group consisting of: i) expanded ground perlite microparticles having a _D50 of about 5 to about 40 microns; ii) diatomaceous earth microparticles having a _D50 of about 10 to about 50 microns; and combinations thereof, wherein the composite particles have a _D50 of about 20 to 100 microns, and wherein the binder is present in an amount of 0.01 wt % to 20 wt % based on the total weight of the composition, wherein the cross-linked binder is the reaction product of a polymer and a cross-linking agent, wherein the polymer is selected from the group consisting of a water-soluble synthetic polymer and a natural water-soluble polymer; and (b) Curing the composition in a kiln. 17. The method of claim 14, wherein the curing step is performed in a kiln at a temperature of 80-300°C. 18. The method of claim 15, wherein the curing step is performed for 4 to 12 hours.