WO2001012317A1

WO2001012317A1 - Binding hydrated aluminosilicates

Info

Publication number: WO2001012317A1
Application number: PCT/AU2000/000971
Authority: WO
Inventors: Raymond Peter Gannon
Original assignee: Currumbin Sand & Gravel Pty Ltd
Priority date: 1999-08-13
Filing date: 2000-08-14
Publication date: 2001-02-22
Also published as: AUPQ219399A0

Abstract

A method of treating an hydrated aluminosilicate which comprises the steps of: providing an aluminosilicate with a hydration level such that water will be expelled from the aluminosilicate upon heating, adding a binder to the aluminosilicate, to form a mixture the binder being hydrophobic, and able to be melted, and, heating the mixture sufficiently to at least partially expel water in the aluminosilicate, and to melt the binder.

Description

BINDING HYDRATED ALUMINOSILICATES

FIELD OF THE INVENTION

This invention relates to improvements to hydrated aluminosilicates, and relates particularly to a technique whereby aluminosilicate powders or granules can be bound together using a binder which does not fully encapsulate the aluminosilicate. In a broader form, the invention relates to a method for securing individual and/or groups of particles to form a substantially continuous matrix. This allows shaped articles to be moulded which have "active" or "exposed" aluminosilicate sites.

BACKGROUND ART It is often desirable to form shaped articles from powders, granulated materials, fibrous materials, and the like. It is well-known to form shaped articles from loose material simply by subjecting the loose material to fairly high pressure in a mould of a desired shape. Tablets, pellets, prills and the like are formed in this manner.

A disadvantage with forming shaped articles using pressure alone is that the formed articles are not particularly strong and are therefore unsuitable for many structural applications, or applications where the shaped product is subject to forces, wear and tear, and the like.

To make these shaped articles stronger, it is well-known to use a binder to bind the loose material together. Thousands of binders are well- known in the art and are used to bind loose material together. The binders can range from sugars and syrups to impart temporary self-supporting properties, for instance for pills and tablets, up to synthetic resins to provide structural shaped articles.

Typically, the binder and the loose material are mixed together (usually with other components as well) and the mixture is heated or otherwise treated to cause the mixture to set. The binder usually totally encapsulates the loose material.

The conventional binding technique creates a major problem if the surface properties of the loose material are required in a commercial application. As an example, hydrated aluminosilicates (of which zeolites are an example), have surface characteristics and pore structures which make them ideal for many commercial applications including water purification, ion exchange, absorption, and the like. However, if this material is totally encapsulated by a binder, the surface and the internal pores become isolated and not available for reaction.

It is not possible to simply press mould (without a binder) this type of material as the resultant shaped product is fragile and brittle and generally unsuitable for commercial applications.

For this reason, when aluminosilicates are required, the product is maintained in a loose flowing state as a bed of material through which water passes for purification, or for other uses. This of course requires the existence of a housing or container separate from the loose material and restricts the available commercial applications.

Other materials which have an active or reactive surface can include carbon-based structures, clays, natural silicates, metals, metal oxides, metal salts, and natural and synthetic hydrated aluminosilicates. Other materials are envisaged which have a desirable contact surface or pores or other structures in the material which would be rendered useless or of reduced reactivity should the material become substantially encapsulated by a binder.

Another known technique to provide structural articles is in powder metallurgical processes such as sintering. In this technique, there is no introduced binder material. The compressed powder is subjected to heat and pressure to cause sintering of the particles into a structural article which keeps a useful surface area. A disadvantage with sintering is that, at the sintering temperature, the porosity of the loose material can decrease which makes sintering unsuitable for materials where the porosity is a desirable feature (for instance ion exchange or water purification). Sintering generally also requires fairly high temperatures which makes the process unsuitable for materials which can decompose or which are otherwise sensitive to such temperatures.

OBJECT OF THE INVENTION The present invention is directed to a method that allows loose materials to be bound together using a binder but where the binder does not substantially encapsulate the material.

This allows shaped structural articles to be formed that still have a good unobstructed surface area and/or porosity.

The method may be applicable to a wide range of loose materials, but finds particular use with aluminosilicates and particularly hydrated aluminosilicates. The invention will be described with reference to hydrated aluminosilicates but it should be appreciated that no limitation is meant thereby.

A method has also now been developed which allows sintering or fusion of the loose material to occur with a binder (for instance glass powder) without a severe reduction in the porosity of the formed shaped product. This is in contrast to conventional sintering techniques that result in a loss of porosity.

In one form, the invention resides in a method of treating an hydrated aluminosilicate which comprises the steps of: 1. If necessary, adjusting the hydration level of the aluminosilicate such that water will be expelled from the aluminosilicate upon heating,

2. Adding a binder to the aluminosilicate, the binder being hydrophobic, and able to be melted, and

3. Heating the mixture of step 2 sufficiently to at least partially expel water in the aluminosilicate, and to melt the binder.

The invention is also directed to a hydrated aluminosilicate formed by the above method.

While not wishing to be bound by theory, it appears that the method allows a particular binder to be mixed with an aluminosilicate and heated which results in the binder acting as a binding bridge between the aluminosilicate particles but where the binder does not substantially encapsulate the particles. The reason for this appears to be ( but need not be limited to) as follows: The aluminosilicate particles are typically irregularly shaped (see Figure 1 ). Each particle is porous and has water in the pores. The binder is hydrophobic which means that it will naturally shy away from the water. The binder preferably has a fairly high surface tension which means that, when molten, it has a tendency to bead or ball instead of spreading over the particles. When the aluminosilicate particles and binder are mixed together, the binder particles will be substantially uniformly mixed between the aluminosilicate particles. When the mixture is heated, water vapour passes out of the pores which are substantially uniformly spaced over the aluminosilicate particles. The binder, being hydrophobic, will begin to melt but will move to a position between particles where the density of the pores (and therefore the amount of water vapour being emitted) is the least.

In Figure 1 , this is graphically illustrated, in an embodiment of the invention, as the areas where the irregularly shaped particles contact each other (that is the areas located within the circles). These areas can be called high-pressure particle contact points, and as these have the lowest number of pores per unit area, the binder will naturally favour these sites. Upon continued heating, the binder will melt and, at this preferred site, will key against or become anchored to the particles. When heating is discontinued and the mixture is cooled, the binder will set and hold the particles together into a structural product.

Said binder may also be itself modified before use, for instance, to add conductivity to the matrix it is binding. For example, a suitable binder such as a polyethylene or acetate, may be mixed with conductivity enhancing materials such as carbon, lithium salts, manganese, and other metals as powders and/or salts.

In a further example a combination of water retained in the aluminosilicate matrix and chemicals incorporated within the binder material provides a means whereby slow chemical release mechanisms can reasonably be predicted and controlled.

A combined matrix using nutrients and water has use as a sustainable environment for microbe action and containment.

In another preferred embodiment said binder may also be itself modified before use to provide additional cation exchange capacity to the matrix it is binding and/or as a stand-alone matrix. For example a suitable polyethylene or acetate may be mixed with anion and/or cation resin based media.

Figure 6 illustrates the binder positioned between the aluminosilicate particles and with a tendency to be positioned between the highest-pressure particle contact points. It is preferred that the ratio of the binder to the loose material

(for instance the hydrated aluminosilicate) is such that the aluminosilicate forms the major part of the mixture. A ratio of less than 50% binder and suitably 5 to 30% binder is preferred.

In the method, the aluminosilicate may be a natural product and will typically have a hydration level. If the hydration level is too low, water (or other liquid) can be added to ensure that water will be expelled from the aluminosilicate granules upon heating. Typically, the aluminosilicate has at least 8% weight/weight free surface water and at least 5 to 20% weight/weight of absorbed water. The aluminosilicate is preferably in the form of a granulated or powdered material and may have a particle size range of between 10 to 750 microns and with a multiple face topographical profile (irregular shape), to provide a high level of irregular contact points between the particles.

The binder should be hydrophobic in order to naturally shy away from the higher density pore areas of the aluminosilicate particles. The binder should be able to melt without appreciable decomposition or otherwise being unstable when melted. The binder should also have a surface tension to reduce spreading of the binder over the particle when molten. Various binders may fulfil the above properties. These binders may include polyalkylenes such as polyethylene and particularly linear low density polyethylene (LLDPE) having a specific gravity of 0.418. Other binders can include acetates, natural and synthetic polymers, polysaccharides and the like, and granulated and fibrous materials which can successfully attach and link the highest pressure contact points within the powder without substantially encapsulating the particle surface.

It is found that acceptable products can be formed with the binder being less than 50% of the mixture. The amount of binder may be from between 5 to 50% of the weight or volume of the mixture which will depend on the binder, the material to be bound, the desired structural parameters of the formed material, the particle size distribution, the water content, the binder particle size, and surface tension and viscosity of the binder, and if desired, the compacting pressure to shape the material into a desired article.

If the method includes a compacting pressure step, the pressure can be between 500kg p/cm² up to 20,000kg p/cm². If a pressure step is used to form a shaped article, the pressure is preferably applied prior to heating or with the heating step.

The material is heated sufficiently to at least partially expel the water in the aluminosilicate and to melt the binder. The temperature will of course depend upon the type of binder. For instance, if the binder is a polyethylene powder, a heat treatment regime of up to 220° is suitable. It is envisaged that pretreatment and/or post treatment of moulded sorption media such as aluminosilicates may be a feature of the method. In an embodiment, water, other solvents, metal and their salts, hydrocarbons, surfactants, enzymes, organic compounds (including microbes), metals and the like, can be introduced using a range of known and novel techniques.

While shaped products formed from the above method find suitability in a wide variety of applications (for instance water treatment), the binder is usually of the type which will decompose or volatise at elevated temperatures. Therefore, the invention also extends to a method for producing a higher temperature resistant aluminosilicate which has a sintering or fusion step but where the method includes steps which prevent or at least reduce the normally significant decrease in porosity which occurs with conventional sintering methods.

Therefore, in another form, the invention resides in a method of manufacturing a higher temperature resistant aluminosilicate which comprises the steps of:

1. Providing a hydrated aluminosilicate having sufficient hydration such that water will be expelled upon heating,

2. Adding a binder to the aluminosilicate, the binder being hydrophobic and able to be melted, 3. Adding a sintering agent to the aluminosilicate to act as a higher temperature binder, and

4. Heating the mixture to a temperature high enough to cause the sintering agent to fuse.

The sintering agent can be a glass such as a powdered soda/lime glass.

The above method steps 1 and 2 are similar to that in the earlier method and results in the binder linking the high pressure particle contact points in a manner similar to that described with reference to Figures 1 and 6.

A glass (for instance powdered glass) is added to the mixture and functions as a high temperature binder. The mixture can then be heated to much higher temperatures (typically above 500°) which causes the glass to fuse and act as a binder for the aluminosilicate particles.

While not wishing to be bound by theory, it appears that the binder in step 2 keeps the particles apart and in an open state for long enough such that the glass fusion does not substantially close the spacing between the aluminosilicate particles. As the binder (for instance polyethylene) is burnt out, it leaves behind residual carbon which acts as a spacer to hold the particles apart.

In this method, it is preferred that an additional carbon-based liquid or solvent is added and which will displace or combine with the absorbed water within the hydrated aluminosilicate. During the heating step, the carbon-based compounds can prevent general matrix collapse which is normally expected during sintering and fusing in a conventional manner.

In another form, the invention resides in a treated aluminosilicate formed from the above method.

The aluminosilicate is useable at higher temperatures, such as temperatures over 200°C.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described with reference to the following drawings in which:

Figure 1 illustrates diagrammatically six hydrated aluminosilicate particles having an irregular profile and therefore contacting each other at high pressure particle contact points identified by the circles in Figure 1.

Figure 2 illustrates a conventional sintering process which shows that a conventional high temperature sintering process causes collapse of the voids between the particles and results in a mass having a low porosity and therefore being unsuitable in many commercial applications.

Figure 3 illustrates a problem with the prior art which is when a conventional binder is used and illustrates that when the binder melts, it substantially encapsulates the loose particles.

Figure 4 illustrates what is considered to be the best prior art technique which still results in substantial encapsulation of the aluminosilicate particles.

Figure 5 illustrates an embodiment of the invention showing how it is possible to position the binder only around the high pressure particle contact points, leaving much of the surface area of the aluminosilicate particles free. Figure 6 illustrates the binder particles at the high pressure contact points while keeping a large part of each particle free.

Figures 7 and 8 illustrate section and perspective views of a press-moulded container formed from the method according to an embodiment of the invention.

Figure 9 illustrates a variation which is the container of Figures 7 and 8 but formed with additional openings.

Figure 10 illustrates a shaped cartridge formed from a method according to an embodiment of the invention.

Figure 11 illustrates a bonded/sintered electro device with an embedded metal rod.

Figure 12 illustrates in a 3-dimensional view compacted pre- sintered hydrated aluminosilicate particles.

Figure 13 illustrates the conventional sintering method and again illustrating the collapse of the pores.

Figure 14 illustrates a compacted pre-sintered hydrated aluminosilicate particles with carbon-based inclusions which reduce matrix and pore collapse during the firing regime.

Figure 15 illustrates the sintered and fused product of Figure 14 and showing a more open and porous structure relating to Figure 13.

Figure 16 illustrates an electrode assembly which has an outer cylindrical wall of conducted material, and an inner cylindrical wall (or barrier cylinder) of sintered or bonded aluminosilicate material. BEST MODE

Example 1 Manufacture of Shaped Article.

A binder consisting of a low density polyethylene powder having a particle size of less than 75 microns and having a specific gravity of 0.418 is added to a hydrated aluminosilicate i.e., natural zeolites (e.g., clintoptilolite, mordenite, analcine) and/or synthetic zeolites (Silicalite, Linde A, B, molecular sieves) which has at least 8% weight/weight free water and between 15 to 20% weight/weight absorbed water. The zeolite has a particle size range between 10 to 750 microns and has a multiple face topographical profile. The amount of binder is less than 50% of the zeolite and can be between 5 to 40%. Higher levels of binder can result in a stronger structural product but will also cause reduction in the free surface area of the clintoptilolite. The mixture may additionally contain an oligosaccharide (less than 15% by weight) which functions to modify the surface tension or wetting properties of the polyethylene powder once in fluid contact with the clintoptilolite. The resultant mixture is compacted at 500kg p/cm² into a mould of desired shape, or is shaped via known extrusion techniques. The shaped product is subjected to heating which are staged increases of 20° per minute up to 220°C and includes a dwell period of 5 minutes at this maximum temperature. The heated mixture is cooled to provide a shaped article which is fairly strong (or at least stronger than articles which do not contain a binder), and where an appreciable amount of the zeolite has not been totally encapsulated and therefore which is available for use (for instance in water purification).

Example 2 Manufacture of Shaped Article.

The polyethylene powder of Example 1 is mixed into as an aqueous polyvinyi acetate solution (1 :8 volume/volume acetate to water ratio). The aqueous solution is mixed with zeolite as described above in a ratio of 1 :4 weight/weight. The mixture is compacted and heated in the manner described in Example 1 , and when cooled provides a shaped articles having an acceptable strength.

Example 3 Manufacture of Shaped Article.

A polyethylene powder of the type described in Example 1 is mixed into a pulverised clintoptilolite material in a ratio of 10 to 20% by weight of polyethylene powder to the zeolite material. The zeolite material has a water content of between 5 to 15%. The resultant mixture is compacted at 15,000kg p/cm² into a suitable mould, or is shaped via known extrusion techniques. The mixture is subsequently heated and cooled in the manner described in Example 1 to form a shaped product.

General Example 4 Manufacture of Heat Stable Shaped Article using Fusion.

This general example is to the use of powdered glass as a binder. In this general example, powdered glass is used as the binder and is mixed with a zeolite. The mixture may be compacted at approximately

20,000kg p/cm² into suitable moulds, or shaped via known extrusion techniques. Heat treatment regimes may be applied during and/or after moulding and there may be further compression. The heat treatment regime can include staged temperature increases up to a threshold of, for example, 1 ,250°C including at least a 5 minute dwell period at the maximum temperature. Some preferred sintering/fusing regimes require that maximum furnace temperature be stabilised before the moulded article is introduced into the furnace, and the soak time is extended to greater than 10 minutes. Cooling regimes are appropriate to the thermal shock characteristics of the resultant sintered/fused article. Specific Example 4 Manufacture of Heat Stable Shaped Article using Fusion

A recycled soda/lime glass (Tg. 558°C) and having a particle size range from 75 microns to 300 microns is mixed with a zeolite material as described in Example 1 at a weight ratio of approximately 10 to 12% of the powdered glass. To a mixture is added a 1 :20 methanol - water solution at a ratio of 1 :10 weight/weight (alcohol: zeolite).

In the specific example a suitable glass based sintered aluminosilicate matrix comprises a lead/cadmium low Tg (320°C) glass containing 75%wt wt lead monosilicate and 25%wt wt cadmium oxide, to which 10%wt wt manganese dioxide has been added. This compound is added to a zeolite matrix that has been impregnated with lithium chloride solution using a vacuum technique, in the proportion previously described and sintered at 480°C. This sintered structure once cooled provides a matrix able to generate and/or store proton activity.

Other suitable carbon-based solvents may substitute the methanol including solvents into which oils or other carbon-based compounds have been dissolved and which will displace or combine with the absorbed water within the zeolite. The mixture can be moulded or extruded into a desired shape. The resultant mixture is heated to 1 ,250°C and is kept at the maximum temperature for at least 5 minutes. The powdered glass sinters at the temperature. The sintered mixture is cooled gradually in order to prevent or minimise cracking or thermal shock characteristics to form a shaped article having acceptable strength and which can tolerate much higher use temperatures. During the heating regime, the absorbed carbon-based compounds provide a beneficial reducing atmosphere and prevents interstitial and general matrix collapse which would be expected during conventional sintering/fusing techniques.

Other components may be added to the mixtures of the above examples. These components can be introduced before or after final shaping and can include metal powders, colloids, organic compounds, activated charcoal, metal salts, vitrifying initiators or enhancers, and metal strips, filings, mesh, plates, rods, wires and tubes. These additional components can modify the conductivity, porosity, catalytic and/or ion exchange properties, water retention and biosidal properties or a combination of the above, of the finished article. Said components can be encouraged to permeate into and onto the matrix of the sorption media by such means as low pressure fluid contact (vacuum chamber) where said fluid is for example a metal carbonyl within a solvent carrier such as an aqueous alcohol solution. Acetates and carbonyls of gallium, indium, selenium, lead, barium, copper, telluride, vanadium, platinum, silver, cadmium, lithium and combinations of these metals, can be impregnated into the sorption media by submerging said media within the selected metal compound solution under vacuum (<200 millibars).

The presence of hydrocarbons within the carrier solvent prevents interstitial and general matrix collapse and creates localized reducing atmospheres able to control oxidation effects during subsequent matrix heat treatment especially during the high temperature sintering steps previously described.

Other suitable solvents containing soluble metal salts can of course also be used in said low pressure sorption techniques, such as chlorides, nitrates, and the like.

In another preferred means of impregnating either a bonded or sintered aluminosilicate sorption matrix cartridge (Fig 10 or 11 ) can be loaded (impregnated) with previously mentioned metal salts using a suitable holding chamber in which a solution containing dissolved metal salts can be passed (pumped) preferentially through said cartridge. Such a chamber assembly may also incorporate a means whereby said solution passing through said cartridge may be electrically charged to encourage uptake of metal salts into the cartridge matrix. Said chamber assembly may also incorporate a means whereby gases can be introduced to control REDOX reactions and/or change feed solution solubility, and/or conductivity.

A cartridge so treated may then undergo further treatment to stabilize or bond permanently said loaded compounds within the aluminosilicate matrix. For example controlled REDOX heat treatment regimes to reduce metal salts to a uniform metal coating on all internal and external surfaces.

A cartridge so impregnated with said metal salts and/or heat treated may find commercial applications in ion exchange, or catalytic selective capacity), electromagnetic radiation conductive filter/barriers for biosidal applications, electrolytic cell construction, selectively permeable and semi-permeable barriers, metal and/or organic compound impregnated porous devices for insecticide, herbicide, fungicide, pesticides, fertilisers, high surface area electrodes for electroplating and electro-winning applications, plant propagation containers, microbe sustaining environments, and the like

The finished article can be used as a filter, ion exchange, slow release substrate, high surface area electrodes, ion-permeable barriers, selective absorption, desorption substrates, and the like. Referring specifically to the figures, Figure 1 is an illustration of aluminosilicate particles having an irregular shape. The particles contact each other at high pressure particle contact points which are between edges of the particles. In Figure 1 , these contact points are circled.

Figure 2 illustrates what happens with conventional high temperature sintering of particles of Figure 1 , and shows a general collapse of the voids and therefore a reduction in the porosity and the available surface area of the particles.

Figures 3 and 4 are prior art binder encapsulation techniques. Figure 3 illustrates what happens when a general binder is mixed in with the particles and heated. The binder melts and merely flows over, and more or less totally encapsulates the particles making the surfaces of the particles unavailable for reaction.

Figure 4 illustrates what can be considered the best prior art technique where by careful selection of the process parameters, the binder will not fully encapsulate the particles but leaves at least some of the particle surface area available for reaction. However, in Figure 4 the binder still covers too much of each particle. A disadvantage with the binder illustrated in Figures 3 and 4 is that should the particles be heated, water expelled from the pores of the particles can rupture and weaken the binder.

Figures 5 and 6 show the advantages of the method of an embodiment of the invention. In the method, the particularly selected binder and the particularly treated particles are such that, upon heating, the binder (being hydrophobic) will have a greater tendency to move to the parts of the particle which have the lowest expulsion of water vapour during the heating process. These parts are at the high pressure particle contact points. Figures 5 and 6 show the binder (in outline) and illustrate the tendency for the binder to bind particles at or adjacent the high pressure particle contact points. This results in a major part of each particle remaining free and available for reaction.

Figures 7 and 8 show a shaped article which can be made from the composition of any of the examples. The container is porous, robust, and has a considerable reactive surface area and therefore finds commercial use in water treatment, ion exchange, and the like.

Figure 9 illustrates the container of Figures 7 and 8 but this time formed with additional openings to improve the flow of water through the container. Figure 10 illustrates a pressed filter cartridge formed form the composition of Examples 1 to 3. The filter cartridge is suitable for water treatment at ambient temperatures or slightly elevated temperatures. The filter cartridge has sufficient strength to withstand reasonable water pressures without cracking or breaking. Figure 11 shows an electro device B which can replace for instance a car battery and which has an embedded metal rod A which can also be a mesh or plate. The electro device can be made using the sintering process of Example 4 and therefore suitable for high pressure use, or by the low temperature method of Examples 1 to 3 and therefore suitable for low temperature use.

Figure 12 illustrates aluminosilicate particles having pores arranged around the particle surface and where the particles are irregularly shaped.

Figure 13 shows a typical sintered/fused hydrated aluminosilicate particles made by conventional methods and which show the shrinkage of the general matrix and collapse of the pores which lowers the porosity.

Figure 14 illustrates graphically the mixture of Example 4 where the polyethylene and/or the methanol invade the pores in the particles and are also arranged about each particle such that high temperature fusion can be achieved with less pore reduction and general matrix collapse. The polyethylene and methanol functions to keep the pores and matrix open during the sintering process.

Figure 16 shows an electrode assembly which has an outer cylindrical wall of conducted material, an inner cylindrical wall (or barrier cylinder) of sintered or bonded aluminosilicate material manufactured by the examples given above, and a central electrode. The sintered or bonded aluminosilicate barrier cylinder separates the two electrodes and the two electrolytes.

One commercial use of this assembly allows ions to move through the porous barrier cylinder from one electrode to the other. In an example, a slurry of magnesium carbonate is placed in a central compartment with a titanium electrode introducing current to this electrolyte medium. The second electrolyte is a seawater solution. With an application or an alternating polarity electric charge, the salinity of the seawater is reduced and a deposition of magnesium metal occurs on the sintered or bonded aluminosilicate cylinder.

Another commercial use of the assembly is to establish an electrophoretic type gradient able to encourage the migration of microbes such as giardia, cryptosporidium, legionella, and other water borne organisms, through the porous matrix from one electrode to the other. Elimination of said microbes within the matrix and/or at one or other of the electrode areas can be achieved by the application of high voltage, electromagnetic radiation, and/or ultrasonic vibration. Another commercial use of the assembly is as a typical battery cell configuration whereby the cylindrical wall matrix is of an aluminosilicate/lead/cadmium conductive sintered glass material (described earlier). Said sintered matrix is in this case acting as an electrolyte allowing proton migration between a central and external, manganese rich, contact electrodes.

Commercial applications for novel devices manufactured using invention steps, may include: low temperature operation (<150°C) particulate filters (with or without ion exchange capacity), high temperature operation (>150°C->1 ,000°C) particulate filters (with or without, ion exchange capacity or catalytic selective capacity), electromagnetic radiation conductive filter/barriers for biosidal applications, electrolytic cell construction, selectively permeable and semi-permeable barriers, metal and/or organic compound impregnated porous devices for insecticide, herbicide, fungicide, pesticides, fertilisers, high surface area electrodes for electroplating and electro-winning applications, plant propagation containers, and the like.

It should be appreciated that various other changes and modifications may be made to the embodiments described without departing from the spirit and scope of the invention.

Claims

1. A method of treating an hydrated aluminosilicate which comprises the steps of: providing an aluminosilicate with a hydration level such that water will be expelled from the aluminosilicate upon heating, adding a binder to the aluminosilicate, to form a mixutre the binder being hydrophobic, and able to be melted, and, heating the mixture sufficiently to at least partially expel water in the aluminosilicate, and to melt the binder.

2. The method of claim 1 , wherein the ratio of the binder to the aluminosilicate is less than 50% binder .

3. The method of claim 2, wherein the ratio of the binder is between 5 to 30% .

4. The method of claim 2, wherein the aluminosilicate has at least 8% weight/weight free surface water and at least 5 to 20% weight/weight of absorbed water.

5. The method of claim 4, wherein the aluminosilicate is in the form of a granulated or powdered material which has a particle size range of between 10 to 750 microns and which has a multiple face topographical profile to provide a high level of irregular contact points between the particles.

6. The method of claim 5, wherein the binder is selected from the group consisting of polyalkylenes such as polyethylene, linear low density polyethylene (LLDPE) having a specific gravity of 0.418, acetates, natural and synthetic polymers, polysaccharides, granulated and fibrous materials which can successfully attach and link the highest pressure contact points within the powder without substantially encapsulating the particle surface.

7. The method of claim 6, wherein the binder has a surface tension which causes the binder to bead when molten.

8. The method of claim 7, wherein the binder, when at or slightly higher than the melting point, does not decompose.

9. The method of claim 8, wherein the binder is modified.

10. The method of claim 8, wherein the mixture is heated to above 100 ° C and below the decomposition point of the binder.

11. A product formed by the method of claim 9.

12. The method of claim 1 , incorporating a compacting pressure step.

13. The method of claim 12, wherein the pressure is between 500kg p/cm² up to 20,000kg p/cm².

14. The method of claim 13, wherein the pressure step is applied prior to heating or with the heating step.

15. A shaped product formed by the method of claim 14.

16. The method of claim 9 for manufacturing a higher temperature resistant aluminosilicate which comprises the additional steps of adding a sintering agent to the aluminosilicate to act as a higher temperature binder, and heating the mixture to a temperature high enough to cause the sintering agent to fuse.

17. The method of claim 16, wherein the sintering agent comprises a glass.

18. The method of claim 17, wherein the mixture is headed to above

500° to causes the glass to fuse and act as a binder for the aluminosilicate particles.

19. The method of claim 18, wherein an additional carbon-based liquid is added tol displace or combine with the absorbed water within the hydrated aluminosilicate

20. A treated aluminosilicate formed from the method of claim 19.

21. A method of treating an sorption product which comprises the steps of:

providing the sorption product with a hydration level such that water will be expelled from the product upon heating,

adding a binder to the product to form a mixture, the binder being hydrophobic, and able to be melted, and,

heating the mixture sufficiently to at least partially expel water in the product, and to melt the binder.