ITTV960010A1 - PROCEDURE AND SYSTEM FOR THE MANUFACTURE OF CEMENTITIOUS PRODUCTS, SLABS AND RESULTING PRODUCTS - Google Patents

Abstract

From a mixture of a granulate of a stone material having a selected granulometry and of a mixture consisting of cement, water in an amount comprised between 0.25 and 0.36 parts by weight referred to the weight of cement and a fluidifier for cement mixes, called mixture being added in a quantity in slight excess with respect to the quantity corresponding to the void ratio of the granulate, single-layer tiles or slabs are prepared with a process and a system which provide that the forming mold containing a layer of predetermined thickness of said mixture is subjected to a first very short deaeration phase due to the action of a very strong vacuum and a subsequent vibration phase under vacuum, less forced, after which the mold passes to the setting and hardening phases.

Description

DESCRIPTION of the industrial invention

The present invention relates to artificial stone products useful for flooring and wall coverings.

The invention also concerns the process for their production and the related plant.

It is known that for many centuries natural stone materials, such as marble, granite, etc., have been used in the form of slabs and panels for both flooring and wall coverings.

The natural stone materials are extracted in the form of blocks from the quarries and the blocks are subjected to an operating cycle that involves numerous operations and processes, such as sawing, sanding, polishing and more.

Besides the undisputed aesthetic properties and the equally undeniable mechanical properties, natural stone materials nevertheless present some problems and drawbacks.

First of all, each block extracted from a quarry has sometimes slight but sometimes also significant differences compared to the blocks extracted from the same quarry, so it is not possible to obtain flooring or coatings of large surfaces that do not present significant aesthetic and / or chromatic differences. Secondly, already during the extraction of the blocks from the quarries, a significant part of the material excavated or extracted, for example by blasting mines, remains unused or becomes so during the workings.

By way of example, it can be mentioned that the percentage of material used by the excavation of stone quarries, i.e. sent to subsequent processing in the form of blocks, does not exceed 20-30% with evident waste that is not only disadvantageous from the industrial point of view but it is also a factor of environmental pollution and disfigurement of the landscape in the areas surrounding the quarries.

In the past and still today, attempts are made to use this waste stone material (ie the aforementioned 70% not used directly) in the manufacture of artificial stone artefacts.

An important solution consisted in the manufacture of cementitious products or tiles called “terrazzo”, substantially constituted by granulate of natural stone material dispersed in a cementitious matrix.

With the particular procedure adopted for this product, tiles are obtained having a high thickness (especially if referred to the unitary dimensions of the tile) and therefore also a high weight, obviously disadvantageous in view of the subsequent handling, especially when laying the tiles.

In general, a “terrazzo” tile has dimensions of 40x40 cm (with a thickness of not less than 3.5 cm) or 30x30 cm (with a thickness of 2.7 cm) or other less commonly used dimensions.

Furthermore, the mechanical properties are relatively poor.

In fact, the flexural strength (9.5-10 N / mmq.) And that to abrasion (560-580 mmc) have values that are certainly not of a high level, while the water absorption reaches 9-10% in weight.

A further disadvantage of this cementitious artifact lies in its aspect which denounces the presence of the cementitious binder in which the granulate is embedded, so from an aesthetic point of view the "terrazzo" tiles have never been taken into great consideration and therefore their large diffusion was mainly due to their cheapness.

Each tile is produced individually with a process that includes the following stages:

(1) spreads on the bottom of a mold and is subjected to slight vibration for a few seconds a layer of starting mixture or slurry, consisting of (a) the inert granulate previously reduced to the desired granulometry and (b) a cementitious binder formed by cement and water in which the percentage of water is clearly in excess of the quantity normally necessary to obtain the binding action;

(2) above this first layer (intended to form the so-called face of the tile) there is a second layer of very thin cementitious binder, just moistened with water;

(3) a pressing is applied above this second layer in order to force the excess water present in the first layer to be transferred to the overlying layer in order to integrate the percentage of water and port to values suitable for carrying out the subsequent phases setting and hardening; (4) the product is extracted from the mold and kept at rest for the time necessary for the setting to take place, on shelves or shelves where it is also left for the time necessary for the complete hardening phase.

In more recent weapons, industrial processes have been studied and industrially developed in which a granular charge of stone material, usually the scraps of the excavation of natural stone materials, previously brought to a suitable grain size, is mixed in appropriate proportions with a binder, which it can be either cementitious or made up of a hardenable synthetic resin.

The resulting mixture is subjected to a first stage of forming, for example by filling special molds or similar forming devices in order to form a layer of the desired thickness.

The mold or the forming device is then subjected to a mechanical compaction action (preferably by the action of a plate press), with the simultaneous application of a vibratory motion and keeping the mold under vacuum.

At the end of this operation, lasting a few minutes, a hardening phase takes place, the modalities of which depend on the nature of the binder.

More specifically, in the case of the cementitious binder, it is a traditional type of setting and subsequent hardening phase, whereby the product is left to rest for the necessary time.

In the case of a binder consisting of synthetic resin, hardening occurs in a short time in the presence of a catalyst with the application of heat or cold by the joint action of a catalyst and a promoter.

This process is not only advantageous as it is compatible with the standards of modern industrial production, but also and above all leads to certainly more advantageous products.

Among the advantages it should be noted in the first place the fact that it is possible to feverish slabs of really large dimensions, much larger than those of the “terrazzo” tiles and also of the tiles or artefacts of natural stone materials.

Secondly, the resulting artifact has a complete aesthetic homogeneity, so it is possible to create external floors or claddings of buildings of considerable extension.

Thirdly, the mechanical characteristics of the resulting slabs are much better than those of the "terrazzo" tiles.

In summary, therefore, before the present invention, the realization of artifacts consisting of granulates of natural stone materials, in particular granulates obtained from the grinding of excavation waste of natural stone materials, provided only the two alternatives briefly mentioned above, of which the first carried to mediocre or poor quality artifacts.

The second alternative, on the other hand, while giving rise to qualitatively satisfactory products, involves a higher unit cost of the resulting product, being on the one hand the investment and operating cost of the production plant is higher and on the other hand the cost is higher. of raw materials when the binder consists of a hardenable synthetic resin. The problem of the production of artifacts of the aforementioned type therefore remained unsolved when these artifacts were intended for economic building applications and in those in which the unit cost of the coating materials becomes a determining factor in the choice of materials if not even in the realization of the Opera.

The main purpose of the present invention is that of the realization of products in which natural stone materials are used in the form of granulates and a cementitious binder that are not subject to the problems of excessive unit weight, too thick and drawbacks, also of an aesthetic nature, briefly described above in relation to the solutions already known.

In the realization of manufactured articles constituting the aim set out above, the main problem that up to now has not found a satisfactory solution is that of filling the porosities or empty spaces that are created or remain between the particles of a granulate when it occupies a certain closed space or volume.

In fact, the greater the degree of filling, the more the resulting cementitious product will approach a natural stone material in terms of properties and also in terms of appearance.

If we now take the aforementioned volume or closed space containing a certain amount of granulate, the nature, above all as dimensions of the porosities or interstitial cavities between the particles, obviously depends on the particle size, so the degree of vacuum and therefore the volume of interstitial cavities to be filled with the cementitious binder depends on the particle size.

The cementitious binder, in turn, basically consists of powdered cement and water.

There is a known quantity of water in itself that is necessary for the reactions that characterize the setting and hardening phases of a cement to take place.

However, this quantity of water is not sufficient to give the mix of cement and water even minimal smoothness or fluidity, so that in the normal manufacturing technology of concrete products the amount of water added in the preparation phase of the mix is in excess of that necessary for the hydration of the cement.

In turn, this excess must be as small as possible compatibly with the manageability of the mixture, because the excess water ultimately affects the compactness and therefore the mechanical properties of the final concrete product.

Returning now to the preparation of the artifact of stone material in granular form and cementitious binder to which the present invention is directed, if a mixture of water and cement containing water in the quantity sufficient for hydration of the cement were used for filling the porosities, this mixture it would be very dense and would have insufficient smoothness or fluidity to fill by sliding the interstices between the granules of inert stone material.

If on the other hand you want to obtain the optimum filling degree, the initial mixing of water and cement should contain a percentage of excess water, as mentioned above, to the detriment of the mechanical properties of the cement matrix of the final product and therefore of the product itself. To get a more precise idea of the values involved, it is sufficient to consider that an almost ideal mixture for obtaining a concrete product with satisfactory characteristics and properties should have a water content of less than 0.315 parts by weight referred to the weight of cement. , while the percentage of water to obtain a satisfactory fluidity of the mixture such as to guarantee a satisfactory degree of filling of the interstitial cavities of a granulate should generally be greater than 0.55 parts by weight always referred to the weight of the cement and in this case the mechanical properties of the final product are decidedly poor.

It is precisely the contradictory nature of these two situations that has meant that in the solutions previously studied and implemented, in the case of the "terrazzo" type tiles, a mixture with a high excess of water in the cement mixture filling the porosity of the granulate was used. , then resorting to the expedient of the second layer of low-water mixture in order to balance the water content of the cementitious binder as a whole. it is possible to avoid that the final product has a very high thickness and weight in relation to the dimensions and moreover it has mediocre if not poor mechanical properties.

Therefore up to the present invention no industrially satisfactory solution to the problem has been found.

In recent years, moreover, fluidifying additives for cement mixtures have come into use with the aim of giving greater smoothness to mixtures containing cement and water in the optimal ratio, since otherwise they are pasty and therefore non-flowing.

With the present invention, on the other hand, the optimal solution has been found for the production of cementitious products comprising a granulate of natural stone material and a cementitious matrix for filling the porosity and interstitial cavities of the said granulate, artefacts having:

(i) thicknesses much lower than those according to the known art directly comparable as having the same composition,

(ii) physical and mechanical properties, in particular porosity and flexural strength, excellent and of the same order as those obtainable with the most recent processes, based on the vacuum vibro-compaction of mixtures of granulate and cementitious binder,

(iii) aesthetic appearance very similar to that of the natural stone material from which the starting granulate is formed, e

(iv) dimensions even significantly higher than those of traditional tiles, for example of the “terrazzo” type.

For the realization of the manufactured article having the aforementioned characteristics, the present invention consists of a process which provides for the following operations:

a) preparation of a granulate having a predetermined and controlled granulometry and calculation of the relative degree or ratio of voids;

b) preparation of a mixture of water and cement having a water content comprised between 0.25 and 0.36 parts by weight referred to the weight of cement, preferably comprised between 0.28 and 0.32 parts by weight, said mixture being with the addition of a well-known fluidifying additive for cement mixtures in such quantities that when "to carry out the minislump test" it is poured onto a surface it has such fluidity as to arrange itself in the rounded shape of a very thin layer with a diameter of about 20 cm. and apparently does not present a phenomenon of separation between the water and the concrete with deposition of this on the bottom of the form and outcrop of the water on the surface;

c) intimate mixing of the granulate and of a quantity of cement mixture such as to be in slight excess with respect to the degree of voids of the granulate itself;

d) distributing the resulting mixture in a mold or similar forming device to form a layer of the desired thickness;

e) application to the mixture contained in the mold of a very high vacuum, of the order of at least 720 mmHg, for a very short time but sufficient to carry out a substantially complete deaeration of the interstitial cavities and to remove all the air that may have remained incorporated in the starting mixture;

f) application to the deaerated layer of a vibratory motion with a frequency between 2000 and 4800, under a less severe vacuum than that of stage (e) but not less than 680 mmHg and for a time of at least 60 seconds, g) transfer of the mold to a gripping and initial hardening station e

h) demoulding of the product and maintenance on final hardening shelves. In the above definition, the expression "minislump test" means the simplified form of the fluidity test according to the method defined by the UNI 9418 standards.

By way of illustration, it can be noted that if equal volumes of water and cement are mixed, a mixture or slurry is obtained containing 0.32 parts by weight of water referred to the weight of cement. If you take a granulate coming for example from the grinding of marble with a grain size between 0, 1 and 6 mm. it has a void ratio of 26% by volume, so this is the theoretical quantity of cement mixture to add. In reality, the amount of dough that must be added in this case is increased to about 29% by volume.

Wanting to increase the quantity of cement paste for filling the interstitial cavities, for example when the void ratio increases, so that the amount of mix would increase correspondingly, it is possible and foreseen the use of inert materials in finely ground form (for example carbonate of calcium), so that the quantity of cement is kept low enough by replacing a part of it with an inert material.

Finally, it should be noted that other additives can also be added to the cement and water mixture, such as the usual dyes for cement, when, for example, particular chromatic or decorative effects are sought.

As for the fluidifying additive that improves the smoothness and therefore the fluidity of the cement mixture to be mixed with the granulate, these are well known additives in the art. Examples of such additives are the so-called superplasticizers based on naphthalenesulfonic compounds, based on melamine or based on acrylic polymers.

Taking into consideration more specifically the individual stages of the process of the invention as defined above, the first aspect worthy of more specific comments is that of the choice of the starting granulate.

As already mentioned, one of the advantageous aspects of the present invention lies in the fact that there is an integral reuse of waste stone material such as that resulting in the excavation of blocks of natural stone material.

If the starting granulate is homogeneous and therefore resulting from the same starting stone material, the optimal condition is to crush and grind this stone material up to a maximum particle size not exceeding 6 mm, (although in some cases this maximum size can reach 8 mm), and therefore use the granulate resulting from the grinding as it is (tout venant).

On the other hand, when the starting granulate is not homogeneous or it is desired, for example in order to obtain particular chromatic or aesthetic effects, to mix stone materials of different origins and provenance, in this case the composition of the starting granulate can be prepared by applying one of the usual formulas for calculating the composition and particle size distribution used in the field of cementitious products with reference to the inert component.

Examples of these formulas are the formulas of Fuller and Thompson or the Bolomey formula discussed for example in M. Collepardi, Science and technology of concrete, p. 292-303, Hoepli publisher.

Once the starting granulate and its composition and particle size distribution have been identified, it is possible to calculate the relative void ratio, for example from formula 7.12 of the same text indicated above.

On the basis of this void ratio, it is possible to identify the quantity of cement mixture which is theoretically sufficient to determine the filling of the porosities and interstitial cavities.

As already mentioned when defining the process of the present invention, the quantity of mixture actually used will be in a slight excess with respect to this theoretical quantity, an excess which, however, must not be such as to lead to the formation of an autonomous layer at the end of the process. alone cement on one of the two faces of the artifact. In practice, this excess is normally of the order of 10.% of the initial volume of cement mixture referred to the total volume of the mixture of granulate and cement mixture.

Turning now to consider the other stages of the process, they provide first of all to pour and / or spread a layer of the mixture of granulate and cement mixture on the bottom of a mold which can for example consist of a tray of the desired dimensions of the final slab. This layer is spread in a thickness substantially corresponding to that of the slab or final product: in the preferred embodiment this thickness will be of the order of 15-20 mm., More preferably of 17 rum. However, it is understood that greater thicknesses are also foreseeable, for example for particular needs.

Once the mixture is poured into the mold, it is subjected to a phase of forced deaeration, introducing the mold into a vacuum environment in which a high vacuum is practiced which must not be less than 720 mm Hg.

This deaeration phase must be very short and in experimental tests it has been found that it preferably does not last more than 20 seconds. This short duration is imposed by the need to prevent the water from boiling, with the formation of steam bubbles causing imperfect compaction, to the detriment of the final compactness and mechanical properties of the product.

When the deaeration phase under high vacuum has been completed, the mold containing the layer of mixture now deaerated is subjected to a vibration of a predetermined frequency, continuing to maintain the mold under a vacuum that is not as high as that of the deaeration phase and is preferably overflow of 680-690 mm Hg, in order to avoid boiling of the mixing water.

The duration of the vacuum vibration treatment is of the order of a few tens of minutes, preferably about two minutes.

Without this consideration having to be understood in a limiting sense, it seems plausible to believe that the application of vibration under vacuum to the deaerated mixture leads to a mutual settling of the granulate particles and to their better interpenetration or surface "closure" (for "closure" it means that the surface of the product or slab has very small areas of visible cementitious binder), since the particles can make microscopic displacements without being hindered by the friction that would hinder the identical settlement in the absence of the cementitious mixture that in this mode also acts in such a way as to substantially reduce friction, as well as obviously filling the interstitial cavities of the granulate.

As regards the procedure defined above, another aspect is noteworthy, namely the fact that the initial setting and hardening phase takes place approximately 8 hours after the start of the same phase and the completion of hardening, in the degree sufficient for mechanical demoulding. of the artifact, usually takes place within 24 hours.

Turning now to consider the plant for carrying out the process of the present invention, it comprises, as essential components: A) a mixer, in which the mixture of water, cement, fluidifying additive and any other additives (such as for example dyes for cement) and the charge of granulate of stone material; Β) a metering unit comprising a seat for at least one forming mold or more seats for several forming molds arranged in a battery;

C) a combined deaeration and settling station of the dough layer present in the forming mold, comprising a vacuum bell capable of engaging the entire surface of the mold or molds so that the entire upper surface of said layer is subjected to the action of the vacuum, means for controlling and regulating the vacuum existing in said bell, vibratory motion generating means adapted to apply a vibratory motion to said mold or said forming molds and

D) a gripping and initial hardening station in which said forming molds are sorted when the treatment phase in said combined deaeration and settling station is completed.

With the process and regret according to the present invention it is possible to fever single-layer tiles (ie without substrate) of marble-cement, granite-cement and other natural stone materials. The use of granulates resulting from the grinding of artificial products such as ceramic material is also foreseeable.

The resulting tiles have a reduced thickness of the order of 13-20 mm, although it is possible for special needs to obtain thicknesses up to 40 mm., And dimensions that can reach 600x600 mm. it's more.

The finishing degree of the resulting artefacts is comparable to that of natural stone slabs and tiles, as it is possible to carry out the usual calibration, grinding, chamfering and polishing treatments on the finished slabs. Furthermore, by suitably selecting the granulometry of the starting granulate it is possible to vary the resulting aesthetic effects. Furthermore, by examining a section of the sheets obtained with the process of the present invention, it is observed that the granulate is homogeneously distributed throughout the thickness, so the sheet is also characterized by a total isotropic property in the entire thickness as well as in the entire extension.

As regards the mechanical properties, the values reported in the following table were experimentally measured:

The following examples illustrate, by way of non-limitative, the realization of the cementitious products according to the present invention. As regards the additives added to the mixtures, these are the usual additives for cement mixtures for the functions indicated and the relative concentration ranges are shown below:

dye: 0-4% of the weight of the cement;

fluidifying agent (active substance): 1.5-2.0% on the weight of the cement;

deaerant (active substance): 0.4-0.6% on the weight of the cement;

retardant (active substance): 0.4-0.6% of the weight of the cement.

Example 1

The marble was ground to obtain a "tout venant" granulate having the following granulometric composition:

0 - 0.6 min 8.2% by volume

0.6 - 1.2 mm 9.6% by volume

1, 2 - 2, 5 mm 17.5% by volume

2.5 - 4.0 mm 21.7% by volume

4.0 - 6.0 mm 15.5% by volume

Water and white Portland cement were loaded into a cement mixer so that the cement was 13.7% by volume referring to the total volume of the final mix and the total water was 13.8% by volume. .

After mixing the water and the cement intimately, the charge of marble granules was added, also adding the additives mentioned above. We then proceed with the forming operations of sample slabs with dimensions of 40x40 cm and a thickness of 1.7 cm., Setting and hardening under the conditions indicated above.

Example 2

The procedure of Example 1 is repeated, using a marble granulate having the following particle size composition, calculated by applying the Bolomey formula:

0 - 0.045 mm (marble dust) 2.0% by volume

0.1 - 0.3 mm 8.0% by volume

1.2 - 2.5 28.8% by volume

2.5 - 4.5 mm 32.50% by volume

The mixture was prepared by mixing the granulate of the aforementioned composition with a mixture of water and cement comprising 14.3% by volume of white or gray Portland cement and 14.4% by volume of total water, in addition of course to the additives already cited.

Example 3

The procedure of Example 1 was repeated using a marble granulate having the following particle size composition:

0 - 0.045 mm (marble dust) 2.0% by volume

0.1 - 0.3 mm 6.3% by volume

1.2 - 2.5 mm 8.6% by volume

4.0 - 6.0 mm 57.0% by volume The mix of cement and water consisted of 13.0% by volume of white or gray Portland cement and 13.1% by volume of water (total). In this case the chosen particle size clearly implies a particle size “jump”.

Example 4

The procedure of example 1 was repeated with a granite granulate of the "tout venant" type obtained by grinding natural granite and having the following particle size composition:

0.2 - 0.6 mm 8.6% by volume

0.6 - 1.2 mm 12.5% by volume

1.2 - 2.5 mm 22.3% by volume

2.5 - 4.5 mm 25.9% by volume.

2.0% by volume of marble dust from 0 - 0.045 mm of granulometry was added to this granulate.

The cement mixture which was added with the granite granulate comprised 14.3% by volume of white or gray Portland cement and 14.4% by volume of total water.

Example 5

Example 1 was repeated with a granite granulate presenting a particle size jump and having the following particle size distribution:

0.1 - 0.3 mm 6.0% by volume

1.2 - 2.5 mm 8.0% by volume

4.0 - 6.0 mm 56% by volume

Also in this case the granulate was added with 2.0% by volume of marble powders with granulometry up to 0.045 mm.

In turn, the mixture of water and cement comprised 14.0% by volume of white or gray Portland cement and 14.0% by volume of total water. The physical and mechanical properties and characteristics of the slabs manufactured in the same way as the previous examples were determined, obtaining the data shown in table 1 below, data referring to slabs subjected to the ritual 28 days of curing.

The manufactured article according to the present invention is therefore distinguished from the known types of cementitious manufactured articles in terms of composition, mechanical properties and aesthetic properties.

Claims (11)

CLAIMS 1. Process for the manufacture of cementitious products in the form of slabs which involves the following operations: a) preparation of a granulate having a predetermined and controlled granulometry and calculation of the relative degree or ratio of voids; b) preparation of a mix of water and cement having a water content between 0.25 and 0.36 parts by weight referred to the weight of cement, said mix being added with a known fluidifying additive for cement mixes in such quantities that dough subjected to the “minislump” test has such a fluidity that it is arranged in the rounded shape of a very thin layer with a diameter of about 20 cm; c) intimate mixing of the granulate and of a quantity of cement mixture such as to be in slight excess with respect to the degree of voids of the granulate itself; d) distributing the resulting mixture in a mold or similar forming device to form a layer of the desired thickness; e) application to the mixture contained in the mold of a very high vacuum, of the order of at least 720 ramHg, for a very short time but sufficient to carry out a substantially complete deaeration of the interstitial cavities and to remove all the air that may have remained incorporated in the starting mixture; f) application to the deaerated layer of a vibratory motion with a frequency between 2000 and 4800, under a less severe vacuum than that of stage (e) but not less than 680 mmHg and for a time of at least 60 seconds, g) transfer of the mold to a gripping and initial hardening station e h) demoulding of the product and maintenance on final hardening shelves. 2. Process according to claim 1, characterized in that the starting granulate is the product directly resulting from the grinding and granulation of natural stone material. 3. Process according to claim 1, characterized in that said starting granulate has a granulometric composition calculated according to the Fuller-Thompson or Bolomey formula. 4. Process according to any one of claims 1-4, characterized in that said starting granulate has a particle size of between 0.1 and µm. 5. Process according to claim 1, characterized in that said mixture of water and cement has a water content comprised between 0.25 and 0.36 parts by weight. 6. Process according to claim 1, characterized in that said excess of cement mixture added to the granulate in said step (c) is 10% 7. Process according to claim 1, characterized in that said deaeration by applying a high vacuum is carried out at a vacuum of 720 mm Hg. and for a time of 30 minutes seconds. 8. Process according to claim 1, characterized in that said vibration stage is carried out by applying a vibration at a frequency comprised between 2000 and 4800 revolutions per minute and for a time of 60 minutes seconds. 9) Process according to claim 1, characterized by the fry that said starting granulate is selected from marble, granite and ceramic material ground to the desired granulometry. 10). Plant for the manufacture of cementitious products in slabs starting from a mixture of a granulate of stone material and a mixture of cement, water and a fluidifying agent for cement mixtures, characterized by including: A) a mixer, in which the mixture of water, cement and fluidifying additive as well as any other additives (such as dyes for cement) and the charge of granulate of stone material are intimately mixed; B) a metering unit comprising a seat for at least one forming mold or more seats for several forming molds arranged in a battery; C) a combined deaeration and settling station of the layer of cement mixture and slurry present in the molding mold comprising a vacuum bell adapted to engage the entire surface of the mold or molds so that the entire upper surface of said layer is subjected to the action of the vacuum, means for controlling and regulating the vacuum existing in said bell, vibratory motion generating means adapted to apply a vibratory motion to said mold or said forming molds and D) an initial gripping and hardening station in which said forming molds are sorted when the treatment phase in said combined deaeration and settling station is completed. 11. Slab product consisting of a granulate of stone material and a cementitious binder phase in the form of a single-layer tile and / or slab with a thickness of between 13 and 40 mm. and having homogeneous distribution of the granulate and of the binder phase, when obtained with the process according to each of claims 1-10.