WO2019077030A1

WO2019077030A1 - Carbonized minerals

Info

Publication number: WO2019077030A1
Application number: PCT/EP2018/078524
Authority: WO
Inventors: Andrew Mark Riley; Jie Lu; Jarrod Hart
Original assignee: Imertech Sas
Priority date: 2017-10-20
Filing date: 2018-10-18
Publication date: 2019-04-25

Abstract

An inorganic particulate material having a coating comprising carbon, methods of making said coated inorganic particulate material and uses of said coated inorganic particulate material.

Description

CARBONIZED MINERALS

TECHNICAL FIELD The present invention relates generally to inorganic particulate materials having a coating comprising carbon and methods of making said coated inorganic particulate materials. The present invention further relates to the various uses of the coated inorganic particulate materials, for example for filtration and/or removal of contaminants from a feed material.

BACKGROUND

Various inorganic particulate materials may be used to remove undesirable components from feed materials, for example by filtration and/or adsorption. Exemplary feed materials include food and beverage products such as sugar syrups, wine, beer, oils, milk, fruit juices, water and other soft drinks and materials in the oil and gas industry such as biodiesel. The appropriate type of inorganic particulate material that is used may vary depending on the feed material and the types of undesirable components that are intended to be removed. It is therefore desirable to provide improved and/or alternative materials for the removal of undesirable components from feed materials.

SUMMARY In accordance with a first aspect of the present invention there is provided an inorganic particulate material having a coating comprising carbon. The coated inorganic particulate material may have a BET surface area greater than about 15 m²/g. The coated inorganic particulate material may have a carbon content equal to or less than about 30 wt%.

In accordance with the second aspect of the present invention there is provided a method for making a coated inorganic particulate material, the method comprising coating an inorganic particulate material with a carbon precursor and converting the carbon precursor to carbon by pyrolysis to form the coated inorganic particulate material. The coated inorganic particulate material may be in accordance with the first aspect of the present invention, including any embodiment thereof. In accordance with a third aspect of the present invention there is provided the use of a coated inorganic particulate material having a coating comprising carbon for filtration of a feed material. The coated inorganic particulate material may be in accordance with the first aspect of the present invention, including any embodiment thereof.

In accordance with a fourth aspect of the present invention there is provided the use of a coated inorganic particulate material having a coating comprising carbon to remove one or more contaminant(s) from a gas or liquid. The coated inorganic particulate material may be in accordance with the first aspect of the present invention, including any embodiment thereof.

Certain embodiments of any aspect of the present invention may provide one or more of the following advantages:

• Removal (e.g. increased removal) of undesirable components from a feed material;

• Combination of the filtration capacity of an inorganic particulate material with the adsorption performance of carbon;

· Simplified processing performance, for example by reducing the number of steps to remove undesirable components from the feed material;

• Easy removal of the inorganic particulate material from the feed material after processing is complete;

• Desired safety in terms of amount and type of contaminants in filtered liquid; · Provision of safe filter aid to use in food and beverage industry.

The details, examples and preferences provided in relation to any particulate one or more of the stated aspects of the present invention will be further described herein and apply equally to all aspects of the present invention. Any combination of the embodiments, examples and preferences described herein in all possible variations thereof is encompassed by the present invention unless otherwise indicated herein, or otherwise clearly contradicted by context.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows SEM images of product 26 from example 2. DETAILED DESCRIPTION

Coated Inorganic Particulate Material There is provided herein an inorganic particulate material having a coating comprising carbon. The coated inorganic particulate material may have a BET surface area greater than about 15 m²/g. Additionally or alternatively, the coated inorganic particulate material may have a carbon content equal to or less than about 30 wt%. The coated inorganic particulate material may, for example, have a BET surface area greater than about 15 m²/g. For example, the coated inorganic particulate material may have a BET surface area equal to or greater than about 20 m²/g or equal to or greater than about 25 m²/g or equal to or greater than about 30 m²/g or equal to or greater than about 35 m²/g or equal to or greater than about 40 m²/g or equal to or greater than about 45 m²/g or equal to or greater than about 50 m²/g.

The coated inorganic particulate material may, for example, have a BET surface area equal to or less than about 200 m²/g. For example, the coated inorganic particulate material may have a BET surface area equal to or less than about 190 m²/g or equal to or less than about 180 m²/g or equal to or less than about 170 m²/g or equal to or less than about 160 m²/g or equal to or less than about 150 m²/g or equal to or less than about 140 m²/g or equal to or less than about 130 m²/g or equal to or less than about 120 m²/g or equal to or less than about 110 m²/g or equal to or less than about 100 m²/g or equal to or less than about 90 m²/g or equal to or less than about 80 m²/g or equal to or less than about 70 m²/g or equal to or less than about 60 m²/g.

The coated inorganic particulate material may, for example, have a BET surface area ranging from about 20 m /g to about 200 m²/g, for example from about 20 m²/g to about 150 m²/g, for example from about 20 m /g to about 100 m²/g, for example from about 20 m²/g to about 80 m /g, for example from about 20 m²/g to about 50 m²/g. For example, the coated inorganic particulate material may have a BET surface area ranging from about 30 m²/g to about 60 m /g, for example from about 35 m²/g to about 55 m²/g. As used herein, "BET surface area" refers to the area of the surface of the particles of the particulate material with respect to unit mass, determined according to the BET method by the quantity of nitrogen adsorbed on the surface of said particles so as to form a monomolecular layer completely covering said surface (measurement according to the BET method, AFNOR standard X1 1-621 and 622 or ISO 9277). In certain embodiments, BET surface area is determined in accordance with ISO 9277 or any method equivalent thereto.

The carbon in the coating of the coated inorganic particulate material may, for example, contribute at least about 30 % of the total surface area of the coated inorganic particulate material. For example, the carbon in the coating of the coated inorganic particulate material may provide at least about 35 % or at least about 40 % or at least about 45 % of the total surface area of the coated inorganic particulate material.

The carbon in the coating of the coated inorganic particulate material may, for example, contribute up to about 80 % of the total surface area of the coated inorganic particulate material. For example, the carbon in the coating of the coated inorganic particulate material may provide up to about 75 % or up to about 70 % or up to about 65 % or up to about 60 % or up to about 55 % of the total surface area of the coated inorganic particulate material. The % of the total surface area of the coated inorganic particulate material that is provided by the carbon may be determined by determining the BET surface area of the inorganic particulate material (prior to and after coating) and the total carbon content of the coated inorganic particulate material by thermogravimetric analysis (TGA) as described herein.

The coated inorganic particulate material may, for example, have a carbon content equal to or less than about 30 wt%. The coated inorganic particulate material may, for example, have a carbon content equal to or less than about 28 wt% or equal to or less than about 26 wt% or equal to or less than about 25 wt% or equal to or less than about 24 wt% or equal to or less than about 22 wt% or equal to or less than about 20 wt% or equal to or less than about 18 wt% or equal to or less than about 16 wt% or equal to or less than about 15 wt% or equal to or less than about 14 wt% or equal to or less than about 12 wt% or equal to or less than about 10 wt%. The coated inorganic particulate material may, for example, have a carbon content equal to or greater than about 2 wt%. For example, the coated inorganic particulate material may have a carbon content equal to or greater than about 3 wt% or equal to or greater than about 4 wt% or equal to or greater than about 5 wt% or equal to or greater than about 6 wt% or equal to or greater than about 7 wt% or equal to or greater than about 8 wt%.

The carbon content of the coated inorganic particulate material may be measured by thermogravimetric analysis (TGA). Each sample may be weighed and heated at 10K/minute in air flowing at 20 ml/minute to initially 200°C for 30 minutes to remove any moisture, then to 1000°C for 60 minutes to burn off the carbon content. The mass loss is then calculated between 200°C and 1000°C.

The coated inorganic particulate material may, for example, have a surface area ranging from about 30 m²/g to about 50 m²/g and a carbon content ranging from about 4 wt% to about 10 wt%. For example, the coated inorganic particulate material may have a surface area ranging from about 35 m²/g to about 45 m²/g and a carbon content ranging from about 5 wt% to about 10 wt%. For example, the coated inorganic particulate material may have a surface area ranging from about 40 m^z/g to about 45 m²/g and a carbon content ranging from about 6 wt% to about 10 wt%. The coated inorganic particulate material may, for example, have a surface area ranging from about 80 m²/g to about 160 m²/g and a carbon content ranging from about 15 wt% to about 25 wt%. For example, the coated inorganic particulate material may have a surface area ranging from about 100 m²/g to about 140 m²/g and a carbon content ranging from about 17 wt% to about 23 wt%. For example, the coated inorganic particulate material may have a surface area ranging from about 190 m²/g to about 1 10 m²/g and a carbon content ranging from about 18 wt% to about 22 wt%.

The coated inorganic particulate material may, for example, have an oleic acid adsorption capacity of at least about 0.01 M/g. For example, the coated inorganic particulate material may have an oleic acid adsorption capacity of at least about 0.015 M/g or at least about 0.02 M/g. The coated inorganic particulate material may, for example, have an oleic acid adsorption capacity equal to or less than about 0.05 M/g or equal to or less than about 0.04 M/g or equal to or less than about 0.03 M/g or equal to or less than about 0.02 M/g. Oleic acid adsorption capacity may be determined using a UV/vis spectrometer such as a UNICAM UV4-100. Dilutions of oleic acid in methanol are made as a calibration (e.g. 0.01 , 0.005 M, 0.0025 M and 0.001 M) and are analysed between 190 nm and 300 nm. 0.2 g of coated inorganic particulate material is added to 10 mi of the 0.01 oleic acid solution and removed and analysed on the UV spectrophotometer after 30 minutes of contact time. A blank run of uncoated inorganic particulate material is also run to determine if adsorption is due to the inorganic particulate material and/or the coating. These are compared to the oleic acid calibration curve. Values of absorption at the peak in the curve (e.g. 220 nm) are taken.

The inorganic particulate material used to make the coated inorganic particulate material may, for example, be a filter aid. A filter aid is any material that can be used in filtration to separate solids from fluids (liquids or gases) when the fluid flows through it. Typical filter aids include, for example, cellulose and mineral filter aids such as diatomaceous earth (DE) and perlite.

The inorganic particulate material used to make the coated inorganic particulate material may, for example, be an inorganic particulate mineral. For example, the inorganic particulate material may be selected from the group consisting of diatomaceous earth (DE), a diatomaceous earth-derived mineral, calcium silicate, magnesium silicate, perlite, kaolin, talc, mica, bentonite, smectite, wollastonite, calcium carbonate, zeolites and combinations thereof. Diatomaceous earth-derived minerals include any minerals that may be or are formed from diatomaceous earth, for example, magnesium silicate and calcium silicate. In certain embodiments, the inorganic particulate material is diatomaceous earth (DE) or perlite.

The inorganic particulate material may, for example, be a waste inorganic particulate material (an inorganic particulate material that has already been used for another purpose). For example, the inorganic particulate material may be a waste filter cake (an inorganic particulate material that has already been used for filtration), for example a diatomaceous earth filter cake or perlite filter cake. The term "filter cake" refers to the material through which a material has been filtered and thus comprises both the filter material and any debris that was prevented from passing through the filter material. The waste inorganic particulate material may, for example, be a recycled inorganic particulate material (a waste inorganic particulate material that has been used for one purpose and then processed to make it suitable for a further purpose (whether the same or different to the first purpose)). A waste inorganic particulate material is not an inorganic particulate material that has been obtained from its source and optionally processed to make it suitable for its first use. Diatomaceous earth (also called "DE" or "diatomite") is generally a sediment enriched in biogenic silica (i.e. silica produced or brought about by living organisms) in the form of siliceous skeletons (frustules) of diatoms. Diatoms are a diverse array of microscopic, single-celled, golden-brown algae generally of the class Bacillariophyceae that possess an ornate siliceous skeleton of varied and intricate structures comprising two valves that, in the living diatom, fit together much like a pill box.

DE may be obtained from a saltwater or freshwater source. Natural diatomaceous earth is, in general, a sedimentary biogenic silica deposit comprising the fossilized skeletons of diatoms, one-celled algae-like plants that accumulate in marine or fresh water environments. The DE generally has honeycomb silica structures, which may, for example, give DE a useful porous structure that makes it suitable for filtration applications. The DE may thus also have useful characteristics such as high absorptive capacity, high surface area, chemical stability and/or low bulk density. The DE may, for example, comprise about 80 wt% to about 90 wt% silica. For example, the DE may comprise about 90 wt% silica. The DE may, for example, further comprise various metal oxides, for example selected from one or more of Al, Fe, Ca and Mg oxides. For example, the DE may comprise about 1 wt% to about 5 wt%, for example from about 2 wt% to about 4 wt% alumina (Al₂0₃). For example, the DE may comprise from about 0.1 wt% to about 4 wt%, for example from about 0.5 wt% to about 2 wt% iron oxide.

The DE may, for example, comprise one or more natural impurities such as clay and organic matters. Prior to its first use, the DE may undergo one or more chemical and/or physical modification processes which may, for example, remove one or more natural impurities. Physical modification processes include, for example, milling, drying and classifying. Chemical modification processes include, for example, silanization and calcination. Alternatively, prior to its first use, the DE may be unprocessed following mining or extraction. Perlite is a natural glass, also known as volcanic glass, which is formed by the rapid cooling of siliceous magma or lava. Most natural glasses are chemically equivalent to rhyolite. Natural glasses which are chemically equivalent to trachyte, dacite, andesite, latite, and basalt are known but are less common. The term "obsidian" is generally applied to dark, most often black, massive natural glasses that are rich in silica (i.e.,Si0₂). Obsidian glasses may be classified into subcategories according to their silica content, with rhyolitic obsidians (containing typically about 73% Si0₂ by weight) as the most common (Berry et al., 1983). Perlite ore is a hydrated natural glass containing typically about 72-75% Si0₂, 12-1 % Al₂0₃, 0.5-2% Fe₂0₃, 3-5 % Na₂0, 4-5% K₂0, 0.4-1.5% CaO (by weight), and small concentrations of other metallic elements. Perlite ore is distinguished from other natural glasses by a higher content (2-10% by weight) of chemically bonded water, the presence of a vitreous, pearly luster, and characteristic concentric or arcuate onion skin-like (i.e., perlitic) fractures.

Perlite products may be prepared by methods disclosed herein which may include milling, screening, and thermal expansion. The perlite products can possess commercially valuable physical properties such as high porosity, low bulk density, and chemical inertness. Depending on the quality of the perlite ore and the method of processing, expanded perlite products can be used as filter aids, lightweight insulating materials, filler materials, horticultural and hydroponic media, and chemical carriers.

The processing of perlite can include comminution of the ore (crushing and grinding), screening, thermal expansion, milling, and air size separation of the expanded material to meet the specification of the finished product and other methods known in the art. For example, perlite ore is crushed, ground, and separated to a predetermined particle size range (e.g., passing 30 mesh), then the separated material is heated in air at a temperature of 870-1 100°C in an expansion furnace (cf. Neuschotz, 1947; Zoradi, 1952), where the simultaneous softening of the glass and vaporization of contained water leads to rapid expansion of glass particles to form a frothy glass material with a bulk volume up to 20 times that of the unexpanded ore. The expanded perlite is then separated to meet the size specification of the final product. Expanded perlite includes one or more cells, or parts of cells, in which a cell is essentially a void space partially or entirely surrounded by walls of glass, usually formed from expansion of gases when the glass is in a softened state. The presence of gas-filled or vacuous cells in a given volume of glass results in lower centrifuged wet density than for the same volume of solid glass. If cells are closed and air is entrapped, the particles of perlite may float on liquid. Fracturing of perlite, for example, by milling, can create an intricate cellular structure that retains the characteristic of low wet density and also provides useful features for filtration and functional filler applications. The expanded perlite products can be used in a variety of filtration applications. The term "filtration" is used herein in the conventional sense and refers to the removal of particulate matter from a fluid in which the particulate matter is suspended. An exemplary filtration process is one which comprises the step of passing the fluid through a filter aid material supported on a septum (e.g. mesh screen, membrane, or pad). The intricate cellular structure of expanded perlite is particularly effective for the physical entrapment of particles in filtration processes. The perlite products can be applied to a septum to improve clarity and increase flow rate in filtration processes, in a step sometimes referred to as "precoating." Perlite products are also can be added directly to a fluid as it is being filtered to reduce the loading of undesirable particulate at the septum while maintaining a designed liquid flow rate, in a step often referred to as "body feeding". Depending on particular separation involved, the perlite products may be used in precoating, body feeding, or both. The perlite products, especially those which are surface treated, also may provide pre-selected properties during filtration that can further enhance clarification or purification of a fluid.

The inorganic particulate material used to make the coated inorganic particulate material may be chosen depending on the intended end-use of the coated inorganic particulate material. For example, where the coated inorganic particulate material is intended to function as a filter aid, an inorganic particulate material with appropriate permeability will be selected. For example, where it is desirable for the coated inorganic particulate material to have a high surface area, an inorganic particulate starting material with a high surface area will be selected and the coating comprising carbon formed thereon.

The coated inorganic particulate material may, for example, be spray-dried. The process of spray-drying produces dry particles from a slurry by drying rapidly with hot gas using an atomizer or spray nozzle to disperse the liquid or slurry into a controlled drop size spray. This process generally imparts a specific form on the spray-dried particles wherein the particles are substantially spherical in shape. Therefore, the coated inorganic particulate material may be in the form of substantially spherical particles. Materials made by spray-drying mixtures of inorganic particulate materials and particulate carbon do not constitute coated inorganic particulate materials in accordance with the present disclosure.

The coated inorganic particulate material may, for example, have a d₅₀ equal to or greater than about 30 pm. For example, the coated inorganic particulate material may have a d₅₀ equal to or greater than about 35 pm or equal to or greater than about 40 μιη or equal to or greater than about 45 pm.

The coated inorganic particulate material may, for example, have a d₅₀ equal to or less than about 80 pm. For example, the coated inorganic particulate material may have a d_5C equal to or less than about 75 pm or equal to or less than about 70 pm or equal to or less than about 65 pm or equal to or less than about 60 pm or equal to or less than about 55 pm or equal to or less than about 50 pm.

The coated inorganic particulate material may, for example, have a d₅₀ ranging from about 30 pm to about 80 pm or from about 35 pm to about 60 pm or from about 40 pm to about 55 pm or from about 40 pm to about 50 pm.

The coated inorganic particulate material may, for example, have a d₁₀ equal to or greater than about 5 pm. For example, the coated inorganic particulate material may have a i₀ equal to or greater than about 6 pm or equal to or greater than about 7 pm or equal to or greater than about 8 pm or equal to or greater than about 9 pm or equal to or greater than about 10 pm or equal to or greater than about 11 pm or equal to or greater than about 12 pm or equal to or greater than about 13 pm or equal to or greater than about 14 pm. The coated inorganic particulate material may, for example, have a d₁₀ equal to or less than about 25 pm. For example, the coated inorganic particulate material may have a d ₀ equal to or less than about 24 pm or equal to or less than about 23 pm or equal to or less than about 22 pm or equal to or less than about 21 pm or equal to or less than about 20 pm or equal to or less than about 19 pm or equal to or less than about 18 pm or equal to or less than about 17 pm or equal to or less than about 16 pm. For example, the coated inorganic particulate material may have a d₁₀ ranging from about 5 pm to about 25 pm or from about 8 pm to about 22 pm or from about 10 pm to about 20 pm or from about 12 pm to about 18 pm or from about 13 pm to about 17 pm. The coated inorganic particulate material may, for example, have a d₉₀ equal to or greater than about 60 pm. For example, the coated inorganic particulate material may have a d₉₀ equal to or greater than about 62 pm or equal to or greater than about 64 pm or equal to or greater than about 65 pm or equal to or greater than about 66 pm or equal to or greater than about 68 pm or equal to or greater than about 70 pm or equal to or greater than about 72 pm or equal to or greater than about 74 pm or equal to or greater than about 75 pm or equal to or greater than about 76 pm or equal to or greater than about 77 pm or equal to or greater than about 78 pm. The coated inorganic particulate material may, for example, have a d₉₀ equal to or less than about 100 pm. For example, the coated inorganic particulate material may have a d₉₀ equal to or less than about 98 pm or equal to or less than about 96 pm or equal to or less than about 95 pm or equal to or less than about 94 pm or equal to or less than about 92 pm or equal to or less than about 90 pm or equal to or less than about 88 pm or equal to or less than about 86 pm or equal to or less than about 85 pm or equal to or less than about 84 pm or equal to or less than about 82 pm. For example, the coated inorganic particulate material may have a d₉₀ ranging from about 60 pm to about 100 pm or from about 65 pm to about 95 pm or from about 70 pm to about 90 pm or from about 75 pm to about 85 pm. Unless otherwise stated, particle size properties referred to herein for the inorganic particulate materials are as measured by the well-known conventional method employed in the art of laser light scattering, using a CI LAS 1064 instrument (or by other methods which give essentially the same result). In the laser light scattering technique, the size of particles in powders, suspensions and emulsions may be measured using the diffraction of a laser beam, based on an application of Fraunhofer theory. Such a machine provides measurements and a plot of the cumulative percentage by volume of particles having a size, referred to in the art as the 'equivalent spherical diameter' (e.s.d), less than given e.s.d values. The d_w is the value determined in this way of the particle e.s.d at which there are 50% by volume of the particles which have an equivalent spherical diameter less than that d₅₀ value. The term d₉₀ is the particle size value less than which there are 90% by volume of the particles.

The coating of the coated inorganic particulate material comprises carbon, for example carbon formed from the pyrolysis of the carbon precursor that is initially used to coat the inorganic particulate material. Thus, in certain embodiments, the carbon is pyrolytic carbon (carbon formed from the pyrolysis of a carbon precursor). In certain embodiments, the pyrolysis process does not convert all of the carbon precursor to carbon. Therefore, the coating of the coated inorganic particulate material may further comprise one or more carbon precursor(s), for example in an amount equal to or less than about 10 wt% or equal to or less than about 9 wt% or equal to or less than about 8 wt% or equal to or less than about 7 wt% or equal to or less than about 6 wt% or equal to or less than about 5 wt% or equal to or less than about 4 wt% or equal to or less than about 3 wt% or equal to or less than about 2 wt% or equal to or less than about 1 wt%. In certain embodiments, the carbon (e.g. pyroiytic carbon) is not atomically pure and some other functional groups (e.g. organic groups) may be present in combination with the carbon, for example on the surface of the carbon, after pyrolysis.

In certain embodiments, the coating consists essentially of or consists of carbon. In certain embodiments, the coating consists of carbon and optionally one or more carbon precursor(s). The term "consists essentially of may, for example, exclude any additional component not explicitly recited unless the additional component does not materially affect the basic and novel properties of the invention. For example, coatings consisting essentially of carbon may further comprise one or more carbon precursors. Where one or more additional component(s) are present in the coating, the total amount of additional component(s) may, for example, be limited to 10 wt%, for example 9 wt% or 8 wt% or 7 wt% or 6 wt% or 5 wt% or 4 wt% or 3 wt% or 2 wt% or 1 wt%.

In certain embodiments, the carbon is not bonded to the inorganic particulate material by means of an adhesive. In certain embodiments, the coating of the coated inorganic particulate material does not comprise an adhesive.

The carbon in the coating of the inorganic particulate material may, for example, be activated carbon. Activated carbon is a form of carbon that has been processed to have pores that increase its surface area. The pores of activated carbon can be visualized using a microscope.

Method of Making the Coated Inorganic Particulate Material

There is also provided herein a method of making a coated inorganic particulate material, the method comprising coating an inorganic particulate material with a carbon precursor and converting the carbon precursor to carbon by pyrolysis. The method may, for example, make a coated inorganic particulate material in accordance with any aspect or embodiment described herein.

Coating the inorganic particulate material may, for example, comprise mixing the inorganic particulate material with the carbon precursor. Any suitable mixing equipment may be used. This may, for example, form a suspension or slurry comprising the inorganic particulate material and the carbon precursor.

The mixture may, for example, have a solids content of at least about 10 wt%. For example, the mixture may have a solids content of at least about 15 wt% or at least about 20 wt%. The mixture may, for example, have a solids content up to about 90 wt%. For example, the mixture may have a solids content up to about 85 wt% or up to about 80 wt% or up to about 75 wt% or up to about 70 wt%. The mixture may, for example, have a solids content ranging from about 10 wt% to about 50 wt% or from about 10 wt% to about 40 wt% or from about 10 wt% to about 30 wt% or from about 15 wt% to about 30 wt% or from about 15 wt% to about 25 wt%.

The mixture may, for example, comprise at least about 5 wt% inorganic particulate material. For example, the mixture may comprise at least about 10 wt% or at least about 15 wt% or at least about 20 wt% or at ieast about 25 wt% or at least about 30 wt% or at Ieast about 35 wt% or at Ieast about 40 wt% or at Ieast about 45 wt% or at least about 50 wt% inorganic particulate material. The mixture may, for example, comprise up to about 90 wt% inorganic particulate material. For example, the mixture may comprise up to about 85 wt% or up to about 80 wt% or up to about 75 wt% or up to about 70 wt% or up to about 65 wt% or up to about 60 wt% inorganic particulate material. For example, the mixture may comprise from about 5 wt% to about 50 wt% or from about 10 wt% to about 45 wt% or from about 15 wt% to about 40 wt% or from about 15 wt% to about 30 wt% or from about 15 wt% to about 25 wt% inorganic particulate material. Where the mixture is to be spray-dried, the solids content of the mixture may be selected depending on the method of spray-drying that is to be used.

The mixture may, for example, comprise at Ieast about 20 wt% carbon precursor based on the total weight of the inorganic particulate material. For example, the mixture may comprise at Ieast about 25 wt% or at Ieast about 30 wt% or at Ieast about 35 wt% or at Ieast about 40 wt% or at Ieast about 45 wt% or at Ieast about 50 wt% carbon precursor based on the total weight of the inorganic particulate material. The mixture may, for example, comprise up to about 80 wt% carbon precursor based on the total weight of the inorganic particulate material. For example, the mixture may comprise up to about 75 wt% or up to about 70 wt% or up to about 65 wt% or up to about 60 wt% carbon precursor. For example, the mixture may comprise from about 20 wt% to about 60 wt% or from about 25 wt% to about 55 wt% or from about 30 wt% to about 50 wt% carbon precursor based on the total weight of the inorganic particulate material. The amount of carbon precursor may be selected depending on the desired carbon content and/or surface area of the coated inorganic particulate material having a coating comprising carbon.

The mixture of the inorganic particulate material and carbon precursor may, for example, be dried to form dry particles of inorganic particulate material coated with the carbon precursor. The mixture of the inorganic particulate material and carbon precursor may, for example, be spray-dried to form dry particles of inorganic particulate material coated with the carbon precursor.

The mixture may be spray-dried in a manner which is known per se. The mixture may be fed to the inlet of a spray-dryer and spray-dried material is discharged from the atomiser.

Spray-drying may also be carried out using a nozzle atomiser or fountain spray-drying technique, in which the mixture is sprayed upwards from the cone of the drying chamber. This allows drying to take place during the complete flight-arc of the droplets before they return to the bottom of the dryer, providing a coarser, more free-flowing powder.

Another type of spray-dryer which may be used is one which employs a "rotating wheel" or "spinning disc" atomiser. One example of a suitable spray-drying apparatus is a Niro® Minor spray dryer unit. This machine may have a drying chamber 800mm in diameter, 600mm cylindrical height being conical based and is fitted with an air driven disc type atomiser. The atomiser may be run at a speed of 30,000rpm. Drying may be carried out using an inlet-air temperature of about 250°C to about 450°C, for example from about 300°C to about 400°C, for example about 350°C. Slurry is fed via a peristaltic pump to the atomiser at a rate selected to maintain the required outlet temperature (typically 110 to 120°C).

The spray-dried product comprises substantially spherical granules, which may have an outer wall or shell which surround a hollow core. The outer wall comprises the particles of inorganic particulate material held together by non-covalent forces and a binder. The carbon precursor may act as the binder to hold together particles of inorganic particulate material. The mixture of inorganic particulate material and carbon precursor may, for example, not comprise any further binder. The spray-drying process may yield uniform, or substantially uniform, spray-dried granules. The steepness of the particle size distribution curve, as characterized by the d90/d10 ratio, is typically at least 5, preferably at least 8. In some embodiments, the spray-dried granulate may be essentially mono-disperse. The carbon precursor coating the inorganic particulate material is converted to carbon by pyrolysis. Pyrolysis is the thermal decomposition of a material by heat treatment in the absence of oxygen or halogen. Pyrolysis may, for example, be carried out in a nitrogen (N₂) atmosphere. Pyrolysis may, for example, take place at a temperature of at least about 200°C. For example, pyrolysis may take place at a temperature of at least about 250°C or at least about 300°C or at least about 350°C or at least about 400°C or at least about 450°C or at least about 500°C. Pyrolysis may, for example, take place at a temperature up to about 1000°C or up to about 950°C or up to about 900°C or up to about 850°C or up to about 800°C or up to about 750°C or up to about 700°C or up to about 650°C or up to about 600°C. For example, pyrolysis may take place at a temperature ranging from about 300°C to about 700°C or from about 350°C to about 650°C or from about 400°C to about 600°C or from about 450°C to about 550°C. For example, pyrolysis may take place at a temperature ranging from about 460°C to about 540°C or from about 470°C to about 530°C or from about 480°C to about 520°C or from about 490°C to about 510°C, for example at a temperature of about 500°C.

Pyrolysis may, for example, be carried out for at least about 10 minutes. For example, pyrolysis may be carried out for at least about 15 minutes or at least about 20 minutes or at least about 25 minutes or at least about 30 minutes. Pyrolysis may, for example, be carried out for up to about 120 minutes. For example, pyrolysis may be carried out for up to about 1 10 minutes or up to about 100 minutes or up to about 90 minutes or up to about 80 minutes or up to about 70 minutes or up to about 60 minutes or up to about 50 minutes or up to about 40 minutes. For example, pyroiysis may be carried out for a period of time ranging from about 10 minutes to about 120 minutes or from about 15 minutes to about 90 minutes or from about 20 minutes to about 60 minutes or from about 25 minutes to about 50 minutes or from about 25 minutes to about 40 minutes or from about 25 minutes to about 35 minutes. For example, pyroiysis may be carried out for about 30 minutes. The time is measured from the point at which the desired temperature is reached.

The temperature may be increased at a rate of at least about 5°C/minute, for example at least about 10°C/minute until the desired pyroiysis temperature is reached. For example, the temperature may be increased at a rate up to about 20°C/minute or up to about 15°C/minute until the desired pyroiysis temperature is reached.

The coated inorganic particulate material having a coating comprising carbon may, for example, be cooled in an inert or oxygen- and halogen-free atmosphere following pyroiysis. For example, the coated inorganic particulate material having a coating comprising carbon may be cooled in a nitrogen atmosphere following pyroiysis.

The carbon in the coating of the inorganic particulate material after pyroiysis may, for example, be further activated to form activated carbon. Activation of the carbon may, for example, be carried out by any suitable process known to those skilled in the art, for example chemical or physical activation processes. For example, activation of the carbon may be carried out by treatment with steam and/or carbon dioxide.

Activation may, for example, involve heating at a temperature ranging from about 400°C to about 1200°C. For example, activation may involve heating at a temperature ranging from about 450°C to about 100°C or from about 500°C to about 1000°C or from about 550°C to about 900°C or from about 600°C to about 800°C.

Activation may, for example, be carried out for at least about 10 minutes. For example, activation may be carried out for at least about 15 minutes or at least about 20 minutes or at least about 25 minutes or at least about 30 minutes. Activation may, for example, be carried out for up to about 120 minutes. For example, activation may be carried out for up to about 110 minutes or up to about 100 minutes or up to about 90 minutes or up to about 80 minutes or up to about 70 minutes or up to about 60 minutes or up to about 50 minutes or up to about 40 minutes. For example, activation may be carried out for a period of time ranging from about 10 minutes to about 120 minutes or from about 15 minutes to about 90 minutes or from about 20 minutes to about 60 minutes. Time is measured from the point at which the desired temperature is reached.

The inorganic particulate material having a coating comprising activated carbon may, for example, be cooled in an inert or oxygen- and halogen-free atmosphere following activation. For example, the coated inorganic particulate material having a coating comprising activated carbon may be cooled in a nitrogen atmosphere following activation.

The carbon precursor may, for example, be a liquid. For example, the carbon precursor may be an aqueous or non-aqueous liquid.

Any material that forms carbon upon pyrolysis may be suitable for use as a carbon precursor in the method described herein. The carbon precursor may, for example, be a compound comprising carbon. The carbon precursor may, for example, be a carbohydrate or may be derived from a carbohydrate. For example, the carbon precursor may be a monosaccharide, a disaccharide, an oligosaccharide (comprising 3 to 10 carbon atoms) or a polysaccharide (comprising more than 10 carbon atoms). The polysaccharide may, for example, be starch, amylose, amylopectin, cellulose (e.g. soluble cellulose), hemicellulose, pectins, ^■ hydrocolloids, carrageenans or any combination thereof. For example, the carbon precursor may be a monosaccharide or a disaccharide. The monosaccharide may, for example, be glucose, galactose, fructose, xylose or any combination thereof. The disaccharide may, for example, be sucrose, lactose, maltose, trehalose or any combination thereof. The carbohydrate- derived carbon precursor may, for example, be obtained by adding a hydroxyi group to a carbohydrate, for example mannitol or sorbitol. In certain embodiments, the carbon precursor is a disaccharide, for example sucrose.

Uses of the Coated Inorganic Particulate Material

There is further provided herein the various uses of the coated inorganic particulate material. The coated inorganic particulate material may, for example, be used for filtration of a feed material. The coated inorganic particulate material may, for example, be used to remove one or more contaminant(s) from a gas or liquid. The coated inorganic particulate material may, for example, be used in a wine production process, for example during fining and/or clarification of the wine. The feed material that is filtered may, for example, be a gas or liquid. For example, the feed material may be a food or beverage product or may be a material in the oil and gas industry.

Exemplary food and beverage products include, but are not limited to, liquids such as vegetable-based juices, fruit juices, sugar syrups, edible oils, milk, water, soft drinks, distilled spirits, liquors, and malt-based liquids. Exemplary malt-based liquids include, but are not limited to, beer and wine. Exemplary materials in the oil and gas industry include, for example, biodiesel, diesel and petroleum. The liquid may, for example, be one that tends to form haze upon chilling. The liquid may, for example, be a beverage that tends to form haze upon chilling. The liquid may, for example, be a beer. The liquid may, for example, be an oil. The liquid may, for example, be an edible oil such as olive oil, palm oil, peanut oil, coconut oil, cottonseed oil, corn oil, rapeseed oil, sesame oil, soybean oil or sunflower oil. The liquid may, for example, be a non-edible oil such as a biodiesel or a fuel oil. The liquid may, for example, be water, including but not limited to waste water. The liquid may, for example, be blood. The liquid may, for example, be a sake. The liquid may, for example, be a sweetener, such as for example corn syrup or molasses. The term "contaminants" refers to one or more substances to be removed from the feed material to be treated using the coated inorganic particulate materials. Contaminants are undesirable additions to the feed material.

The one or more contaminant(s) may, for example, be selected from the group consisting of volatile organic compounds (VOCs), pesticides, fungicides, herbicides, phenolics, purines, a by-product of the metabolism of yeasts, a by-product of food processing, micro-organisms, proteins such as enzymes, and trace metals.

Contaminants may be selected from fenhexamid, iprodione, 4-ethyl guaiacol, 4-ethyl phenol, azoxystrobine, boscalid, benalaxyl, carbendazime, cyprodinil, dimetomorphe, fludioxinil, fluopicolide, iprovalicarb, mandipropamid, metalaxyl- , metrafenone, myclobutanil, pyrimethanil, spiroxamine, tebuconazole, tebufenozide, triadimenol and combinations thereof.

The concentration of contaminants in the feed material to be treated may be between about 0.001 mg to about 7 mg per litre, preferably between about 0.01 mg and about 5 mg per litre, preferably between about 0.05 mg and about 3 mg per litre, preferably between about 0.1 mg and about 1 mg per litre, preferably between about 0.2 mg and about 0.5 mg per litre. The coated inorganic particulate material may also be effective in treating higher amounts of contaminants.

The amount of contaminants in the treated feed material is less than the amount of contaminants in the untreated feed material. The amount of contaminants is reduced from the weight of contaminants in a volume of material to be treated to the weight of contaminants in a volume of treated material and expressed as a percentage change of weight by volume; % (w/v). In certain embodiments, the percentage reduction of contaminants using the method of the invention may be at least 1 % (w/v), at least 5% (w/v), at least 10% (w/v), 20% (w/v), 30% (w/v), 40% (w/v), 50% (w/v), 60% (w/v), 70% (w/v), 80% (w/v), 90% (w/v), 95% (w/v), 98% (w/v), 99% (w/v). The coated inorganic particulate material may contact the feed material to be treated in various ways, such as "decanting", "pre-coating", "body feeding" or a combination of both "decanting", "pre-coating" and "body feeding".

In a "decanting" method, the coated inorganic particulate material is added to the feed material, optionally shaken, and allowed to sediment. The supernatant is then decanted from the sediment.

In a "pre-coating" method, the coated inorganic particulate material is initially applied to a filter element before the material to be filtered is applied to the filter element. For example, pre-coating may involve preparing a slurry containing water and a coated inorganic particulate material, and then introducing the slurry into a stream flowing through a filter element or septum. During the pre-coating process, a thin layer (e.g., 1.5-3.0 mm) is deposited onto the surface of the filtering element or septum. This will prevent or reduce gelatinous solids from plugging the filter element or septum during a subsequent filtration process, often providing a clearer filtrate. In a "body feeding" method, the coated inorganic particulate material is introduced into a material to be filtered before the material reaches the filter element or septum. During filtration the coated inorganic particulate material then follows the path of the unfiltered material and eventually reaches the filter element or septum. Upon reaching the filter element or septum, the added coated inorganic particulate material will bind to a filter cake covering the filter element or septum. This can increase the porosity of the filter cake and may cause the filter cake to swell and thicken thereby increasing the permeability of the filter cake during filtration and possibly increasing the capacity of the filter cake. The filter cake comprises the combined layers of coated inorganic particulate material and contaminants on the surface of the septum.

EXAMPL S

The following illustrates examples of the methods and other aspects described herein. Thus, these Examples should not be considered as limitations of the present disclosure, but are merely in place to teach how to make examples of the present disclosure.

Example 1

Various coated inorganic particulate materials were by preparing a slurry of diatomaceous earth in water at 20 wt% solids content with either 30 wt% or 50 wt% sucrose based on the total weight of the inorganic particulate material. The slurry was then spray-dried using Mobile Minor (manufactured by Niro Atomizer of Denmark) with an inlet air temperature of 350°C and outlet (product) temperature maintained at 110 - 120°C by variation of feed slurry flow rate. This formed a free flowing powder for use in pyrolysis experiments. The spray-dried products were then pyrolysed in a nitrogen atmosphere at different temperatures and for different times. The surface area of the diatomaceous earth starting material was 30 m²/g.

The total BET surface area and carbon content of the products obtained from the pyrolysis reaction were tested by the BET and TGA methods described herein. To determine BET surface area, a TRISTAR FlowPrep was used. The results are shown in Table 1. Table 1.

Products 13 to 22 were made using 30 wt% sucrose and product 27 was made using 50 wt% sucrose.

A significant increase in surface area compared to the surface area of untreated diatomaceous earth can be seen.

Using the results of overall surface area and carbon content of the products, the surface area of the carbon alone can be calculated. Results are shown for products 19 and 27 in Error! Reference source not found.2.

For example for product 19:

Surface Area = 52.5 m²g^"1

C content = 9.53%

90.47g DE at 30m ¹ in 100g composite at 52.5m²g^"1

9.53g C at unknown surface area

100 x 52.5 = 5250m² total

90.47 x 30 = 2714.1 m² from DE

5250 - 2714.1 = 2535.9m² due to C

2535.9/9.53 = 266.097 therefore 266.1 m²g^"1 surface area of C alone Table 2.

Example 2 Various coated inorganic particulate materials were made by preparing a slurry of diatomaceous earth in water at 20 wt% solids content with either 30 wt% or 50 wt% sucrose based on the total weight of the inorganic particulate material. The slurry was then spray-dried using Mobile Minor (manufactured by Niro Atomizer of Denmark) with an inlet air temperature of 350°C and outlet (product) temperature maintained at 110 - 120°C by variation of feed slurry flow rate. This formed a free flowing powder for use in pyrolysis experiments. The spray-dried products were then pyrolysed by heating in a nitrogen atmosphere at a ramp rate of 10°C/minute to a certain temperature. The temperature was held for 30 minutes to allow the pyrolysis reaction to complete. The pyrolysis temperature was the same as the "temperature of activation" listed in Table 3 below. The products of the pyrolysis reaction were then activated by treatment with carbon dioxide. Once the furnace reached the required temperature for activation it is held constant and the gas flow over the sample switched from nitrogen to C0₂ at 50 ml/min flow rate for the stated time. The gas was then switched back to a flow of nitrogen and the furnace cooled. The surface area of the diatomaceous earth starting material was 30 m²/g.

The total BET surface area and carbon content of the products obtained after the activation reaction were tested by the BET and TGA methods described herein. The results are shown in Table 3. SEM images of product 26 at various magnifications is shown in Figure 1 . The individual porous diatomaceous earth particles can be clearly seen indicated that the carbon has coated the surface but not blocked any pores. Table 3.

Products 20 to 25 were formed using 30 wt% sucrose and products 26 and 28 were formed using 50 wt% sucrose. All show an increase in surface area compared to diatomaceous earth alone.

As described for example 1 , the surface area of the carbon alone can be calculated. The results are shown in Table 4. Table 4.

Example 3

The oleic acid adsorption capacity of various products from examples 1 and 2 were determined by the method described herein using 0.01 M oleic acid. The results are shown in Table 5.

Table 5.

The coated inorganic particulate materials had a greater oleic acid adsorption capacity than the uncoated diatomaceous earth.

Example 4

A diatomaceous earth having a carbon coating was prepared using the Imerys filtration grade diatomaceous earth product "FilterCel® E". A slurry of 1.5kg sucrose and 1.5kg FilterCei E in 6L water was spray dried to give ,a precursor that was 50% sucrose. This precursor was pyrolysed by heating under nitrogen at a ramp rate of 10°C/min to a temperature of 500°C. The sample was held in an atmosphere of nitrogen at 50Q°C for 30 minutes then the nitrogen atmosphere was replaced by C0₂ and the temperature maintained at 500°C for a further 30 minutes. After this time the atmosphere was returned to nitrogen and the sample allowed to cool to room temperature.

Analysis of the final product indicated a surface area of 1 13.89 m²g^"1- The carbon content of the final product determined by thermogravimetric analysis was 19.88%. Surface area of the carbon coating deposited on the DE was calculated to be 539 m²g^"

1

The ability of the coated diatomaceous earth product to remove Fenhexamid from wine was determined by HPLC-UV Absorption. A 10 mg L^"1 solution of FEX in red wine was made up by dissolving 10 mg of FEX in 50 ml of methylated spirits and mixing this with 950 ml of red wine. This FEX-spiked red wine was then contacted with the materials (in triplicate) in the same manner as above before being filtered through a 0.45 pm PTFE membrane filter. In order to extract the pesticide from the wine 7 ml of the filtered wine was mixed with 7 ml of HPLC grade acetonitriie by shaking on oscillating flask shaker for 30 minutes at ambient temperature. Subsequently 1.5 g of potassium chloride was added, causing the mixture to separate into two layers, a clear upper (organic) layer with a lower (aqueous) layer which was dark red and opaque. The top layer was removed and analysed by HPLC. For HPLC, a 10 mg L^"1 FEX solution was prepared in model wine, exposed to the adsorbents in the same way but in triplicate, and filtered in the same manner. The residual pesticide concentration was measured using HPLC/UV (LaChrom Elite, Hitachi). A 20 μΙ filtered sample was injected into a Sphereclone octadecylsilane (ODS) column (4.6 x 250 mm, 5 pm 0; Phenomenex) at a flow rate of 2 ml min^"1. The mobile phase consisted of 50:50 (v:v) acetonitriie/ distilled water (with 1 g NaH₂P0 L^"1) and the UV absorption of the eluate monitored at 210 nm. Standard solutions of 10 -0.1 mg L^" of FEX in model wine were injected in triplicate in order to calibrate the assay. The R² value for this calibration was at least 0.9941 and the mean retention time for FEX was 5.6 minutes.

99.20 % of the fenhexamid was removed from the model wine, whereas the the diatomacoues earth alone (no coating) only adsorbed 4.0% of fenhexamid.

The amount of arsenic and lead in the coated diatomaceous earth product was also determined by X-ray fluorescence analysis using a fused cast bead method and Panalytical Magix Pro XRF. First materials were heated to 1000^°C and 1.3 g of the residue was mixed with 6.5 g spectroflux 100B (Lithium metaborate: Lithium tetraborate 80:20 w/w %). This mixture was melted using a Vulcan 6 A fusion instrument and the resulting bead cooled. The bead was then ready to be analysed using the XRF spectrometer. It was found that the product contained less than 2 ppm lead and less than 5 ppm arsenic.

The ability of the coated diatomaceous earth product to adsorb iprodione was also determined in the same manner as the fenhexamid tests described above using 10 mg/L solution of iprodione in model wine.

99.92 % of iprodione was removed from the model wine.

The foregoing broadly describes certain embodiments of the present invention without limitation. Variations and modifications as will be readily apparent to those skilled in the art are intended to be within the scope of the present invention as defined in and by the appended claims.

Claims

CLAMS

An inorganic particulate material having a coating comprising carbon, wherein the coated inorganic particulate material has a BET surface area greater than about 15 m²/g and/or wherein the coated inorganic particulate material has a carbon content equal to or less than about 30 wt%.

The coated inorganic particulate material of claim 1 , wherein the coated inorganic particulate material has a BET surface area equal to or greater than about 30 m²/g.

The coated inorganic particulate material of claim 1 or 2, wherein the coated inorganic particulate material has a carbon content equal to or less than about 20 wt%.

The coated inorganic particulate material of any preceding claim, wherein the carbon provides at least about 30 %, for example at least about 40 %, of the total surface area of the coated inorganic particulate material.

The coated inorganic particulate material of any preceding claim, wherein the inorganic particulate material is a filter aid.

The coated inorganic particulate material of any preceding claim, wherein the inorganic particulate material is an inorganic particulate mineral, for example selected from the group consisting of diatomaceous earth (DE), a diatomaceous earth-derived mineral, perlite, kaolin, talc, bentonite, zeolites and combinations thereof.

The coated inorganic particulate material of any preceding claim, wherein the inorganic particulate material is a waste inorganic particulate material, for example wherein the inorganic particulate material is a waste filter cake.

The coated inorganic particulate material of any preceding claim, wherein the coated inorganic particulate material is spray-dried.

The coated inorganic particulate material of any preceding claim, wherein the coated inorganic particulate material has a d₅₀ equal to or greater than about 30 μηι, for example equal to or greater than about 40 μητ

10. The coated inorganic particulate material of any preceding claim, wherein the carbon is pyrolytic carbon.

1 1 . The coated inorganic particulate material of any preceding claim, wherein the coating comprises activated carbon, for example activated pyrolytic carbon.

12. The coated inorganic particulate material of any preceding claim, wherein the carbon in the coating is not bonded to the inorganic particulate material by means of an adhesive.

13. The coated inorganic particulate material of any preceding claim, wherein the coated inorganic particulate material has an oleic acid adsorption capacity of at least about 0.01 M/g.

14. A method of making a coated inorganic particulate material of any preceding claim, wherein the method comprises:

coating an inorganic particulate material with a carbon precursor; and converting the carbon precursor to carbon by pyrolysis to form the coated inorganic particulate material of any preceding claim.

15. The method of claim 14, wherein the method comprises mixing the inorganic particulate material with the carbon precursor.

16. The method of claim 14 or 15, wherein the method comprises spray-drying a mixture of the inorganic particulate material and carbon precursor followed by subjecting the spray-dried material to pyrolysis.

17. The method of any one of claims 14 to 16, wherein the method further

comprises converting the carbon present in the coating of the inorganic particulate mineral to activated carbon.

18. The method of any one of claims 14 to 17, wherein the carbon precursor is a carbohydrate.

19. The method of any one of claims 14 to 18, wherein the carbon precursor is a monosaccharide or disaccharide. 20 The method of any one of claims 14 to 19, wherein the carbon precursor is sucrose.

21. The method of any one of claims 14 to 20, wherein the carbon precursor is used in an amount equal to or greater than about 5 wt%, for example equal to or greater than about 10 wt%, based on the total weight of the inorganic particulate material.

22. The method of any one of claims 14 to 21 , wherein the carbon precursor is used in an amount equal to or less than about 80 wt%, for example equal to or less than about 60 wt%, based on the total weight of the inorganic particulate material.

23. The method of any one of claims 14 to 22, wherein pyrolysis is carried out in a nitrogen (N₂) atmosphere.

24. The method of any one of claims 14 to 23, wherein pyrolysis is carried out at a temperature ranging from 400°C to about 600°C. 25. The method of any one of claims 14 to 24, wherein pyrolysis is carried out for a period of time ranging from about 20 minutes to about 60 minutes.

26. The method of any one of claims 14 to 15, wherein the coated inorganic

particulate material is cooied in a nitrogen (N₂) atmosphere after pyrolysis.

27. The method of any one of claims 7 to 26, wherein the carbon is converted to activated carbon by heating in an atmosphere of carbon dioxide (C0₂) and/or steam. 28. The method of any one of claims 17 to 27, wherein the carbon is converted to activated carbon by heating at a temperature ranging from about 600°C to about 1200°C.

29. The method of any one of claims 7 to 28, wherein the carbon is converted to activated carbon by heating for a period of time ranging from about 20 minutes to about 60 minutes.

30. Use of the coated inorganic particulate material of any one of claims 1 to 13 for filtration of a feed material.

31. The use of claim 30, wherein one or more contaminant(s) are removed from the feed material during filtration.

32. The use of claim 30 or 31 , wherein the one or more contaminant(s) is selected from the group consisting of volatile organic compounds (VOCs), pesticides, fungicides, herbicides, phenolics, purines, a by-product of the metabolism of yeasts, a by-product of food processing and trace metals.

33. The use of any one of claims 30 to 32, wherein the feed material is a material in the oil or gas industry or a food or beverage product.

34. The use of any one of claims 30 to 33, wherein the feed material is beer or wine.

35. Use of the coated inorganic particulate material of any one of claims 1 to 13 to remove one or more contaminant(s) from a gas or liquid.

36. The use of claim 35, wherein the one or more contaminant(s) is selected from the group consisting of volatile organic compounds (VOCs), pesticides, fungicides, herbicides, phenolics, purines, a by-product of the metabolism of yeasts, a by-product of food processing and trace metals.

37. The use of claim 35 or 36, wherein the liquid is a material in the oil or gas industry or a food or beverage product.

38. The use of any one of claims 35 to 37, wherein the liquid is beer or wine.