MICROFIBROSA COMPOSITION COMPRISING SILICON SPONGIARIA SPICES, PROCESSES AND EQUIPMENT FOR OBTAINING THEM Field of the invention The present invention relates to a microfibrous texture composition comprising essentially siliceous spicules of spongiaria, as well as processes and equipment to obtain them. The microfibrous composition can be used, among other uses, for thermal insulation. The techniques involved in the manufacture of the same are related to the ceramic industry and the artifact manufacturing sector for civil architecture. BACKGROUND OF THE INVENTION The bodies composed of fibers, for example of animal hair, are mostly good thermal insulators. Thus, several products made of natural fibers are used. In the animal kingdom there is sheep wool, rabbit hair and other animals. In the plant kingdom, there are wood fibers, from which paper and cardboard are made, and others, such as cotton fibers to manufacture various fabrics. In the mineral kingdom, there are products such as chrysotile, commonly called asbestos. Several fibrous synthetic products have emerged and are good products for the isolation of heat and sound. Among them, polymer fibers such as nylon and polyesters are prominent. In a field of use Ref. 171642 for insulation designed for higher temperatures, glass fibers, "mineral wool or asbestos", calcium silicate fibers and also the so-called "ceramic fibers" have appeared. In addition to the fibrous form, there are also insulators that have a high porosity, such as corks of vegetable origin, expanded polystyrene and polyurethane, as well as insulations based on kaolin and / or based on diatomite. Focusing now on the field of fibrous insulators of high temperature, it can be seen that asbestos is a very interesting product, but in our days there are serious restrictions for the use of it, mainly due to health issues. Since this product is expected to leave the market, only the synthetic fibers mentioned above will be left. Glass fibers are relatively noble products and can be long, continuous or short filaments of great chemical and physical homogeneity. They resist up to 800 ° C and are sold in frames, which are relatively expensive. Calcium silicate fibers are less expensive fibers, but are proposed to be used at a temperature not higher than 600 ° C. They are also sold in frames or as semi-rigid aggregate products.
The "asbestos" are products derived from the fusion of basaltic rock. They bear temperatures of around 800 ° C and are cheaper than glass fibers. They are marketed in frames or in semi-rigid pieces. Such products are frequently used today in domestic and industrial furnaces such as bakeries and also in the isolation of solar heaters. The "ceramic fibers" are more refractive having types that withstand temperatures from 1250 ° C to 1400 ° C, some of which are able to withstand even higher temperatures. They generally have a silica-aluminous composition up to aluminous, and their refractive capacity is increased according to the amount of aluminum included in them. There is also pure silica fiber with good refractive properties. The manufacturing costs of these fibers depend on their resistance to deterioration under high temperatures. In general, all types of this fiber have good thermal insulation properties. However, these fibers, under high temperatures, deteriorate by melting or become brittle by the recrystallization mainly of the cristobalite in the vitreous mass. Ceramic fibers are commercialized in long fibers that constitute wefts, or later, in short fibers, generally, added by components of agglutination of the resin that constitute semi-rigid products. The ceramic fibers exhibit, as a restriction to their use, a low resistance to flexion or a low resistance to compression, even in so-called "rigid" products, and a high linear shrinkage of up to 8%, found in the first burned at continuous use temperatures. In addition, such products are very expensive with respect to the other high temperature insulators. The microfibrous composition of the present invention comprises siliceous spherules of spongiaria (explained in more detail below) and frequently its appearance is similar to the synthetic products constituted by short ceramic fibers. The siliceous spherules of spongiaria are cylindrical microneedles with a length of the order of 500 μm, a thickness of the order of 10 μm, composed essentially of silica. Such spicules can be classified as fibers or microfibers due to said dimensions. Such terminology will be used here later, in this context. The siliceous spicules of spongiaria are parts that remain from the skeletons of the colonies of certain organisms that are scientifically called sponges. Sponges are small aquatic life animals, which form colonies called spongiaries. Cyclically, the colonies die, releasing the spicules that are dispersed in the aquatic environment, sedimenting on the beds of the lakes or the sea, and then they are fossilized. This process, which occurs after dozens or hundreds of years in the same biological medium, makes possible the formation of significant deposits of these materials. The important concentrations of sponge spicules are found in the sedimentary extracts of specific geological environments, always mixed with clays, sands and other materials predominantly of aquatic organic origin. The rocks rich in these materials receive the geological name of "spongilitas", which are commonly known, in Brazil, as "mico's mud" or simply "mico", which corresponds to their appearance similar to fine hair. The ceramic products derived from the materials constituted by siliceous spicules of spongiaria are widely known. By way of clarification, the following is reported: a) since before Brazil was discovered, certain indigenous tribes had already used materials derived from sponges in ceramic crafts to make highly resistant vessels proposed for cooking food; b) in Brazil, there is a vessel manufacturing industry for several centuries, which is based specifically on these materials. At present, it is estimated that in this country approximately 50,000 families are living from this activity, dispersed in small communities, some of them with around 5,000 inhabitants, always located near or around natural deposits; c) the ceramic pieces, made of these materials, which are preferably bricks, are characterized by their high strength, their heat insulation properties and some refractory characteristics; by virtue of these properties, they are used in civil architecture, in the manufacture of ceramic ovens, ovens for the barbecue and charcoal industry, among other possibilities. They are commonly known as "tijólos de mico" or "tijólos de pó de mico"; d) the formulations used, for example, to make ceramic pieces, are very variable, depending on the availability of the minerals in the place or at the time. Thus, according to the site or the time, the production of pieces varies a lot from pieces very rich in microfibers with up to approximately 50% (by weight) to very poor pieces in microfibers with from 5% to 10%. The clays and sands, which are present close to the microfibers in the minerals, constitute the rest of the formulations, with few exceptions. These natural concentrations of sponge microfibres are not enough to provide pieces with excellent heat and sound insulation properties. Microfibers are considered the strong point of these materials. Thus, the products that have the useful properties, optimized from microfibers, were developed, thus obtaining levels of industrial compliance that meet the specific requirements present these days. To achieve the results known in our days, the following stages were necessary: a - development of technology to benefit minerals that lead to the separation of microfibers; b - multiple trials on formulations and development and optimization thereof; c - systematic studies involving the shaping of the pieces and the technical characterization of the microfibrous compositions obtained at the laboratory scale; and d - development of technology to form and manufacture artifacts at a scale of industrial production. With the study of these materials during the course of these years, it has been possible to obtain much purer concentrates thereof, that is, they exhibit high concentrations of spicules. With these concentrates, the high quality insulating parts with the help of industrial forming techniques can be elaborated, which are also the object of the present invention. OBJECTIVES OF THE INVENTION An object of the present invention is to provide a microfibrous composition comprising siliceous spongy spicules, the amount thereof varying from 70% to 99% by weight, based on the total weight of the composition. This amount is much higher than that already obtained in the prior art, and which leads to relevant improvements in the physical-chemical properties inherent in the pieces made with this composition. Another objective of the present invention is to provide the processes and the respective equipment to obtain the microfibrous composition that is intended. BRIEF DESCRIPTION OF THE INVENTION The objectives of the present invention are achieved by means of a microfibrous composition, used particularly for heat insulation and sound isolation, characterized in that it comprises a quantity of siliceous spicules of spongiaria ranging from 70% to 99%. % by weight, based on the total weight of the composition. The objectives of the present invention are also achieved by means of a process to obtain the microfibrous composition, which comprises the following steps: a-mixing the microfibers with water and at least one agglutination component in a friction tank; b - stir the mixture until a homogeneous pulp is achieved; c - shaping the pulp in a shaping equipment to remove excess water and agglutination components and to obtain a residual cake; d - to cure the residual cake by a hardening process, to obtain the microfibrous composition. In addition, the objects of the invention are achieved by means of a device for promoting the formation of the residual cake, comprising: a mold associated, in its upper part, with a container and, in its lower part, with a screen; the mold is also associated, in its lower part, to a liquid collector and to an outlet for the residual pulp. The presented microfibrous composition now has many advantages over products based on synthetic fibers and on products comprising a lower concentration of siliceous microfibers, primarily in heat insulation, strength and dimensional stability when used at elevated temperatures, some of which are listed later. Although some of the fibers of the prior art, such as glass fibers, "asbestos", calcium silicate fibers, among others, are resistant to temperatures up to 800 ° C, the microfibrous compositions of this invention exhibit resistance against the heat at higher temperatures, reaching temperatures of approximately 1,250 ° C. - It is possible to make larger and less dense pieces with the microfibrous composition of the present invention, in comparison with the pieces made of kaolin / diatomite line insulators. Compared with the ceramic / fiber compositions: The microfibrous composition of the present invention exhibits dimensional stability, configured by linear shrinkage in the reburn of the order of 1 mm / m, or 0.10%, while the pieces made of ceramic fibers exhibit values even higher than 4.5%. - The stiffer pieces of the ceramic fibers are mostly deformed under tension, unlike the pieces comprising the microfibrous composition of the present invention, which exhibit rigidity even until rupture. - Regarding the resistance, measuring pieces having a specific mass of 0.40 g / cm3, the composite bodies of the microfibrous composition of the present invention exhibit values of the order of 0.47 and 0.41 MPa of compressive strength and flexural strength , respectively, while composite bodies of ceramic fibers exhibit a compressive strength of the order of 0.25 MPa and a virtually zero value with respect to flexural strength, - The parts comprising the microfibrous composition of the present invention exhibit properties of heat insulation very similar to those inherent in the best fiber-ceramic pieces. For example, at a heat front temperature of the order of 1,000 ° C, the pieces made of the microfibrous composition exhibit a coefficient of thermal conductivity of 0.192 W / mK, while an optimum product constituted by ceramic fibers exhibited a coefficient of conduction heat of 0.190 W / mK Comparing the microfibrous composition of the present invention with compositions made of asbestos and calcium silicate wool: The microfibrous composition exhibits higher values of refractory properties with respect to the pieces made of asbestos and calcium silicate wool. - In addition, it exhibits a greater dimensional stability while being subjected to elevated temperatures.
With respect to the insulating products composed of kaolin / diatomite: The pieces (bricks) made of kaolin / diatomite usually exhibit dimensions corresponding to 224 x 112 x 76 mm. On the other hand, using the methods of manufacturing parts, explained in greater detail below, it is possible to manufacture larger pieces comprising the microfibrous composition of the present invention, with at least one of the dimensions still larger than 1.0 meter each. It is possible to manufacture parts comprising the microfibrous composition of the present invention which exhibits a much lower apparent specific weight compared to all known parts made with kaolin and diatomite. BRIEF DESCRIPTION OF THE FIGURES The present invention will now be described in greater detail with reference to the embodiments shown in the figures. The figures show: - Figure 1 illustrates a flow chart of industrial processing to obtain the microfibrous composition of the present invention; Figure 2 illustrates a first schematic embodiment of the equipment used in the process of obtaining the microfibrous composition of the present invention; Figure 3 illustrates a second schematic embodiment of the equipment used in the process of obtaining the microfibrous composition of the present invention; and Figure 4 illustrates a third schematic embodiment of the equipment used in the process of obtaining the microfibrous composition of the present invention. DETAILED DESCRIPTION OF THE INVENTION The microfibrous composition of the present invention is composed of microfibres of siliceous spicules of spongiaria and agglutination components such as various kinds of clays. It is proposed for applications that require refraction properties at elevated temperatures of up to 1,250 ° C or higher. 1 - Microfibers of spongiaries Microfibers must be cleaned, loosened and classified according to their size so that they are used in the microfibrous composition of the present invention. To obtain microfibers free of natural industrial impurities, the minerals are processed. The processes include hydration and grinding using chemical dispersants, thus obtaining a pulp in which the grains are subsequently classified. The sand and fine residues are removed by hydrocyclone treatment and sedimentation, respectively. The microfibers may have different shapes, that is, they may be constituted by whole or fragmented original spicules, whether mixed or not, provided that they exhibit the properties and characteristics listed below.
According to the properties and characteristics described above, the spicules of spongiaria are needles or needles, the maximum length of which is 0.5 millimeters, which are transparent, rigid, composed of amorphous silica and volatile components. A relation between the length and the thickness of the order of 10 to 20 times and a length smaller than 0.5 m makes it possible for them to be technically called fibers or microfibers.
2 - . 2 - Microfibrous composition As shown above, the microfibrous composition has a microfibrous texture and consists essentially of siliceous spongy spicules. It mainly has the characteristics described later:
Note: The mechanical properties of the microfibrous composition depend on the agglutination component chosen to be used in its composition. The function of the bonding component is to provide adhesion of the microfibers. The main agglutination components that may be used in the present composition are: aluminous clays, kaolinitic clays, smectite clays, mixed clays, colloidal silica and silicic acids. However, other agglutination components can be used, since they exhibit the characteristics necessary for the microfibrous formulation already described. The tests carried out have shown relative success with: aluminous clays, kaolinitic clays, smectite clays, mixed clays or mixtures thereof and colloidal silica, among others. The choice of the same will be conditioned to the final destination of the microfibrous composition. In the field of heat insulators for high temperatures, for example, kaolinitic clays or aluminous clays can be used and, for low temperatures, smectite clays. The process of harng the microfibrous composition also varies, depending on the agglutination component chosen. This process can be carried out: with exposure to air, in furnaces or in calcination furnaces. The apparent specific mass of the microfibrous composition is a function of the special arrangement of the microfibers, as well as the distribution of the average sizes thereof. The values of the order from 0.40 to 0.60 g / cm3 are obtained more commonly. For lower values, it is necessary to apply procedures that open the microfiber mesh, for example, by the introduction of fillers with volatile components and, for higher values, procedures similar to the application of vibrations that cause their approximation, making e to the aggregate. The values from 0.06 to 1.2 g / cm3 have already been obtained in this way. The porosity is inversely proportional to the apparent specific mass, in this case, with very high values, ranging from 45% to 95%. The melting temperature of the microfibrous composition will depend on the type of agglutination component used. The microfibers, which are essentially siliceous in nature, have a melting point close to the melting point of quartz, in the order from 1740 to 1760 ° C. Linked by the colloidal silica, for example, the microfibrous composition exhibits a melt strength close to this value. Joined by kaolinitic clays, for example, the melting point will be of order from 1550 to 1600 ° C. The aluminous clays allow higher melting temperatures, in the order from 1600 to 1650 ° C. Joined by smectite clays, there will be a reduction in the melting point to approximately 1350 ° C. The mechanical properties of the microfibrous composition will also depend on the type of agglutination component used. There are destinations for which there is no interest in high mechanical performance, as is the case of certain heating insulators for "standby" ovens, that is, those heat insulators do not receive heat directly from the hottest portion of the furnace. On the other hand, there are cases in which resistance is fundamental. Significant results can be achieved, for example, in pieces whose agglutination components are kaolinitic clays sterilized at elevated temperatures, reaching a pressure of up to 1.0 MPa of bending for pieces with an apparent specific mass of 0.50 g / cm3, which is a value surprising with regard to the heat insulators available in the market. In the following table, some results are shown, which were achieved after the calcinations at 1250 ° C, using several types of agglutination components.
It can be seen that the best agglutination component to be used in the constitution of the microfibrous composition is the smectite clay, when it is desired to obtain high values of resistance. In addition to the resistance variation configured by the various types of agglutination components, other variations naturally result from the final apparent specific masses of the obtained microfibrous composition. The table given below illustrates the values of the compressive strength obtained after burning, at a temperature of 1,250 ° C, the test bodies have kaolinitic clays as agglutination components:
It can thus be concluded that, when the microfibrous composition comprises kaolinitic clay as an agglutination component, the cold compressive strength increases proportionally with the increase in the apparent specific mass. The microfibrous composition generally comprises at least 70% microfibers and the rest of the agglutination components. In most products, the amount of microfibers is higher than 90%, reaching 99% of the composition, and the remaining amount is of agglutination components, which make up an extremely thin film that encloses the microfibers. With respect to the chemical composition, the amount of silicon dioxide varies from about 80% to about 99.0%, and the latter value can be obtained when the siliceous chemical agglutination components, similar to colloidal silica, are used. 2.1 Examples of the microfibrous composition The microfibrous composition is basically composed of microfibers and bonding components, the microfibers are the main components, the amount of which varies from 70 to 99%. Examples of the microfibrous composition are described below (values by weight, dry basis):
The most usual composition for the production of articles having excellent heat and sound insulation properties preferably contain about 90% by weight of microfibers. In the event that the agglutination component is colloidal silica, this amount then becomes 96%.
Some more interesting examples for the industry can be pointed out, especially:
The above examples are preferred embodiments of the microfibrous composition of the present invention and should not be taken as limitations thereof. Thus, many variations of the composition can be carried out within the scope of protection defined by the appended claims. 3 - Processes for obtaining the microfibrous composition The process for obtaining the microfibrous composition is illustrated in Figure 1 and comprises the following steps: a) a mixture of water and at least one agglutination component is prepared in the proportions from 80% to 90 % water and the rest of the agglutination components, obtaining the pulp called slip; b) a quantity of previously cleaned and cleaned microfibers 1 is added, together with the slurry pulp in a ratio ranging from 1: 3 to 1: 5 in a shredding tank 2, provided with rotating tabs driven by reducing mechanisms, for be mixed and homogenized so as to provide a homogeneous pulp 4; c) the pulp 4 is directed through tubes to a forming equipment 5, wherein the shape and consistency of the microfibre agglomerate are verified; the processes of sedimentation with or without vibrations, filtrations under pressure or vacuum can be used for this purpose, according to the type of equipment 5, as will be detailed later; d) in the shaping equipment 5, a wet residual cake 6 is formed with the arrangement of the fibers that exhibit a density on the order of 0.8 to 1.0 g / cm3, which varies according to the degree of aeration at which the cake residual 6 is submitted, which makes it possible to handle it on special trays; the mixture comprising water and the residual agglutination components 3 is removed or recovered for recirculation; e) the residual cake 6 obtained is subjected to a hardening process 7, which is preferably carried out by drying in ovens; the drying of the obtained residual cake 6 will stiffen the products, imparting resistance in them, leading to the microfibrous composition. Optionally, the microfibrous composition obtained with the hardening process 7 can then undergo a burning process 8 at temperatures of up to 800 ° C, carried out in ceramic ovens. This process is suitable for the microfibrous composition, the agglutination components which are clays that must be sintered at elevated temperatures. This burning process 8 can be of the continuous type, with the use of tunnel ovens or roller ovens or also intermittent, using various types of ovens, such as the traditional type, called "demijohn oven", or others. In addition, the hardened microfibrous composition, depending on the requirements of the field of use, can be mechanically rectified, whereby curvatures and imperfections beyond the standard dimension are eliminated. Such polishing 9 is carried out using polishing machines. 4 - Equipment to obtain the microfibrous composition The processes, presented in summary, are three: a) the sedimentation that includes the "simple" or "with vibrations" variants. b) filtration under pressure, and c) vacuum filtration. The sedimentation process consists of the physical action of this process on the pulps maintained in the containers, called molds, during a time interval of approximately 20 minutes per operation, leading to a relatively rigid body, configured by the entanglement of the microfibers. Vibrations can be applied in the course of sedimentation, promotion or reduction in the empty spaces between the microfibres, generating a microfibrous composition of greater relative density. Such obtained piece, depending on the agglutination component used and the proposed use, must be made rigid or hardened by drying in ion furnaces or with exposure to air; such drying may or may not be followed by burning at elevated temperatures. This process will be described in greater detail later. On the other hand, the pressure-filtration process consists of obtaining a filtered cake, by the forced passage of the pulps containing the agglutination components and the microfibers through a semipermeable wall, usually a thin weft, which contains the microfibers and part of the agglutination components. Such a filtered cake is moist, consistent to the extent to which it can be handled with the shapes that are provided by the molds coupled to the semipermeable wall. The pressure is provided by the compressed air that is going to be injected in jars in the form of bells superimposed on the weft, or also by the forced pumping of the pulp itself. This process will be described in greater detail later. Finally, the vacuum filtration process is similar to that described above, with the difference that the filtration acceleration agent is vacuum, which is applied in a hermetic chamber placed below the semipermeable wall. The obtained cake will also be subjected to drying and may also be burned at elevated temperatures, depending on the choice of the agglutination component and the destination thereof. All the residual pulps of the three processes defined above are reused after being re-conditioned, the consumed portions of the agglutination component are replaced. 4.1 First mode of the process and equipment - Sedimentation process The microfibrous composition can be obtained by means of a process called sedimentation process, which consists of the action of this process on pulps containing microfibres, where the water and the agglutination components are also mixed. The shaping can be done by means of a simple sedimentation process, where the particles settle according to the viscosity of the pulp at speeds ranging from 0.5 to 2.0 cm / minute, resting on the bottom of the mold, one on the top of the other, forming a cake sedimented. On the other hand, in the case of sedimentation under vibrations, unlike simple sedimentation, vibrations of frequencies varying from 0.02 Hz to 40 KHz are applied, provided by mechanical, electric and also ultrasonic vibrators. Such vibrations, applied to the molds, will be transferred to the sedimented cake, compacting it and generating a product different from that obtained by a simple sedimentation. At the end of the process, the superimposed pulp, now free of the microfibers, can be eliminated. In the case of the molds containing fine wefts in the lower part, the elimination of the pulp can be carried out by the pouring through the obtained cake, by gravity or by forced spillage, by means of vacuum chambers and cameras. of pressure coupled to the mold. In the case that the option of waterproof molds is taken, the residual pulp is removed by pumping or by external flow. The microfibers, which are sedimented on the bottom, are intricate arrangements in a permeable, unique cake, which exhibits a density of the order of 0.8 to 1.0 g / cm3, varying according to the degree of aeration to which the residual cake is submitted, which makes it possible to handle it on special trays. In figure 2, a schematic representation of the equipment designed to mold pieces by sedimentation is illustrated, with or without the application of vibrations, with the removal of the residual pulp by pouring through the sedimented cake. This equipment comprises a mold 10, in which the mixture of the microfibrous composition is maintained in its upper part, a container 11 is applied, proposed to contain a large amount of pulp 4. In the lower part of the mold there is a wall 12, constituted by a very thin weave, which provides a very slow external flow of permeable liquids in the sedimented material. Below the wall 12, there is a liquid collecting tray 13, which is welded to the mold 10; this tray 13 has a hole for letting the liquid out of the residual pump 14 and, in its lower part, it can have a vibrator coupled 15. The complete equipment is supported by a spring device 16, which can be composed of coil springs or high strength rubber pads, fixed to the bottom of the tray 13. The mold 10 can be of any shape, as long as it retains the volume of the pulp comprising the microfibers and the component (s) of agglutination. Particularly, the mold 10 is of a triangular shape with dimensions of the order of 1.40 m x 0.70 m. The container 11 can be in any way that can be useful for the equipment, that is, it can represent a space corresponding to the volume of the pulp to be processed. The weft 12 is preferably very thin, to provide better retention of liquid, including a product with less water, but the opening of the weft mesh may vary according to the final product. It will be obtained. Preferably, a weft made of stainless steel is still used in meshes of a Tyler sieve of 60-200 mesh. The collection tray 13 of the liquid has the function of collecting the liquid removed from the initial cake; thus, their shape or size are not relevant. In a molding operation, the pulp 4 containing known amounts of microfibers and agglutination components (obtained by the process outlined in Figure 1) is placed in the mold 10. The pulp 4 remains sedimented during a time interval varying from 20 to 30 minutes, to achieve the total sedimentation of the particles and the discharge of the residual liquids through the frame 12, which is collected by the tray 13 and eliminated by the outlet 14. At this time, vibrations can be applied by the actuation of the vibrator 15, which will vibrate the complete assembly, from the spring device 16, which is preferably composed of helical springs, whereby the sedimented cake becomes dense. For the removal of the intermediate product formed here, manual techniques or suitable mechanisms can be used. A manual technique indicated to remove the previous intermediate product consists of placing a preferably metallic or wooden tray, securing it to one side of the mold, rotating the complete equipment and supporting the tray on a lectern. Once this has been done, the tray is released and the equipment is raised, while the filtered piece remains, now released from the mold, on the lectern. This technique can be carried out mechanically; for this purpose, all that is needed is a rotating mechanism in the complete equipment by means of cranes and a mechanism to remove the tray by means of a platform proposed to collect the tray containing the piece on it, which moves vertically by the mechanical drive. The choice of the best technique to remove the intermediate product depends on the type and dimensions of the pieces that will be made. 4.2 Second variation of the process and equipment - Filtration process under pressure The filtration process under pressure consists of applying pressure on the pulps containing microfibers, forcing the passage of them through a wall that has small holes, generating a filtered cake , humid and consistent that can be handled (it exhibits a density of the order of 0.8 to 1.0 g / cm3, which varies according to the degree of aeration to which the residual cake is subjected), the form of which is provided by the molds attached to the wall. Filtration under pressure is an intermittent process, in which the pressure of the order of 0.5 kg / cm2 is applied, which will promote the acceleration of the process. This operation consists in the forced passage of the pulp through walls that have small holes, smaller than 0.30 mm. Such walls can be wefts made of steel, organic materials such as fabrics, shells or plastic wefts, or also papers suitable for filtration. Two mechanisms are used to apply pressure: the introduction of compressed air and hydrostatic pressurization by pumping the pulp; this last case is similar to the filtration in cap filters. The applied pressure will depend on the mechanism used, and it is a common matter to use pressure values of the order of 0.2 to 10.0 kg / cm2. At the end of the filtration under pressure, the microfibers become a wet cake with some consistency (density of the order from 0.8 to 1.0 g / cm3), which makes it possible to handle it on the special trays. On the other hand, the mixture comprising the water and the agglutination components, which results from the filtration, is removed or recovered for recirculation. In Figure 3, a schematic representation of a pressurized air driven filter is illustrated. A filter usually consists of two main parts: upper hoods 17 and the mold 18. The upper hood 17 is a container large enough to hold the amount of pulp 4 of a filtration operation; one inserted into a feeding tube 19, which has a coupled diaphragm 19a, which closes automatically when the upper bell 17 is pressurized. Also in this upper hood 17 there is an inlet 20 for compressed air and a safety gauge. The mold 18 is a reinforced piece having, in its lower part, a thin weft 22 and a lower container for collecting the residual pulps 23, in which a tube 24 is installed for the discharge of such pulps. Between the upper bell 17 and the mold 18 there are movable hooks 25 proposed to join or disengage the union of both pieces. In the filtering operations, the pulp 4, the volume of which is previously measured, is introduced into the machine through a feeding tube 19 until the desired quantity is reached. The compressed air under a controlled pressure is injected, which will activate the diaphragm 19a, closing it and pressurizing the upper bell 17. The pressure then forces the passage of the liquids through the single outlet, which is the frame 22 located below the mold 18, forming a filtered cake on the weft 22, and the residual pulp flows through the lower container 23, being discharged by the outlet pipe 24. The filtration process ends when only the compressed air leaves the outlet pipe 24 At this time, the compressed air inlet must be closed by disengaging the movable hooks 25, the upper bell 17 and the filtered piece must be removed. The mold 18 can have any shape as long as it can contain the volume of the pulp comprising the microfibers and the agglutination component (s). The containers 17 and 23 can have any shape that is useful for the equipment, that is, they can have a space corresponding to the volume of the pulp on which it is going to work. The weft 22 is preferably very thin to promote better retention of the liquid, producing a product with less water, but the opening of the weft mesh may vary according to the final product to be contained. Preferably, a weft made of stainless steel in meshes that vary in a Tyler sieve from 60 mesh to 200 mesh is used. The mold 18, as well as the bell 17, have a particularly rectangular shape, with dimensions of the order of 1.40 x 0.70 m, being hermetic to leakage of liquids or compressed air. They consist of sturdy, steel parts, at least 5 mm thick, made to withstand high pressures. The movable hooks 25 are very resistant pieces, which are built to withstand pressures higher than 15 tons. 4.3 Third variation of the equipment-Vacuum filtration process The vacuum filtration process is an intermediate process, where vacuum causes the acceleration of the filtration process. This operation consists of the forced passage of the pulp through walls that have small holes of less than 0.30 mm. Such walls can be made of steel, organic materials similar to fabrics, hoses or plastic frames, or also suitable papers for filtration. In a closed chamber, located below the wall, the vacuum is applied, to cause the pulp to suck through the wall. The microfibers are retained in the wall, and the other liquids are allowed to pass through the newly formed cake, sedimenting in the lower chamber. The processes end when the complete superimposed liquid has been sucked and only passes the air through the filtered cake. With these mechanisms, a vacuum is generated by a conventional vacuum pump. For reasons of dynamism and rapidity of the process, the industrial installation must have a deposit in which large volumes are accumulated with a difference in negative pressure. At the end of filtration, the microfibers become a wet cake with a consistency (density of about 0.8 to 1.0 g / cm3), which allows operation thereof in special trays. On the other hand, the mixture containing water and the agglutination component (s), which results from the filtration, is removed or recovered for circulation. In figure 4, a schematic figure of a vacuum-operated filter is illustrated. It is basically composed of three main parts: a reservoir for the pulp 26, a mold 27 and the vacuum chamber 29. The reservoir 26 is a container completely open on its upper part, large enough to contain the amount of pulp of a filtration operation, which is coupled to the mold 27 in its lower part. The mold 27 is closed in its lower part by means of a wall 28, which can be, for example, a very thin screen. Below the wall 28 there is a closed chamber called the vacuum chamber 29, which has a coupled diaphragm 30 which closes automatically when the vacuum is applied to the chamber. To cause the vacuum in the chamber 29, is necessary to introduce a vacuum line 31, which can establish communication between the chamber 29 and the vacuum tank 32. In the chamber 29, a vacuum gauge 33 may be installed for better operational control for filtering. In filtration operations, the pulp 4, the volume of which is previously measured, is introduced to the tank 25 until the preset amount is reached. The vacuum is applied through the conduit 31, which causes a difference in the negative pressure in the vacuum chamber 29, which in turn causes the diaphragm 30 to close thereby depressurizing the vacuum chamber 29. The vacuum then causes suction of the liquid, forcing them to pass through the wall 28, located downstream of mold 27, forming a filtered cake on the wall 28, through the mold 27. the residual liquid remains accumulated in the vacuum chamber 29. the Filtration operation ends when there are no more liquids superimposed on the filter cake. At this time, by turning off the vacuum by means of a meter placed in the vacuum conduit 31, the vacuum chamber 29 is now under atmospheric pressure, releasing the diaphragm 20 and allowing the accumulated liquids to flow outward. The filtered cake can then be removed from the mold. For this purpose it is necessary to use mechanisms to rotate the complete equipment with the gravity removal of the cake on special trays. The mold 27 can have any shape, as long as it contains the volume of the pulp comprising the microfibers and the agglutination component (s). Particularly, the mold 27 has a rectangular shape with dimensions of the order of 1.40 m x 0.70 m. The container 26 can have any shape that is useful for the equipment, that is, it can represent a space corresponding to the volume of the pulp on which it is going to work. The wall 28, preferably, is a stainless steel screen in meshes of a Tyker sieve of 60 to 200 mesh. The filtering operation does not involve sedimentation processes, which differ from the latter by their speed, and it is often possible to obtain pieces filtered at intervals shorter than 3 minutes, depending on the degree of automation and the adjustment of operations. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.