IT202100009602A1 - FORMULATIONS INCLUDING GEOPOLYMERS AND OLIVE POMACE FOR THE CREATION OF PRODUCTS PRINTED THROUGH 3D PRINTING - Google Patents

Description

FORMULATIONS INCLUDING GEOPOLYMERS AND OLIVE POMACE

FOR THE CREATION OF PRODUCTS PRINTED BY

3D PRINTING

TECHNICAL FIELD

The present invention relates to formulations comprising geopolymers and olive pomace for making manufactured articles printed using the 3D printing technique.

STATE OF ART

The pomace of olives? a by-product of the olive oil extraction process composed of skin films, pulp residues and stone fragments.

The production of olive oil ? for Mediterranean countries such as Spain, Greece, Italy, Turkey and Tunisia an important activity? agro-industrial. Only in Tunisia does the annual production of olive oil reach 200 x10<3 >T.

With the current production processes from 100kg of olives, about 30% of pomace is obtained. Due to the high content of phenols and lignin, the solid fraction is ? hardly degradable with natural processes and ? known as landfilling can become a very complex environmental problem to solve.

According to the European Directive 91/689/EEC solid waste deriving from the treatment of edible oil are not considered dangerous and can therefore be disposed of. be used in recycling and reuse processes. Furthermore, the Italian law (D.L. 05-02-1997 n.22) encourages the reuse of this type of materials in recycled products rather than their disposal in landfills.

? why? the need to find valid applications from an industrial and economic point of view for this by-product of one of the most important agricultural productions is particularly felt. important for the country.

Various uses of olive pomace have been proposed, for example as a filler in thermoplastic composites (Journal of Polymers and the Environment, Vol. 9, No. 4, October 2001 (q 2002) pag 157-161), composites with polyvinyl chloride (J Appl. Polym. Sci. 2014, DOI: 10.1002/APP.41083, and filler in ethylenepropylene Polymer Engineering and Science?2016 pp.27-35 matrix).

The Applicant has developed a process which reuses high percentages of olive pomace, in formulations comprising geopolymers for the production of manufactured articles printed using the 3D printing technique.

Geopolymers are organic materials created in 1976 by the French scientist Devidovits. ("Solid-Phase Synthesis of a Mineral Blockpolymer by Low Temperature Polycondensation of Alumino-Silicate Polymers: Napoly (sialate) or Na-PS and Characteristics" Joseph DAVIDOVITS, IUPAC Symposium on Long-Term Properties of Polymers and Polymeric Materials, Stockholm 1976, Topic III).

The geopolymer ? an inorganic material with a non-crystalline structure, formed by a source of silica and alumina (aluminosilicates) and an alkaline solution which activates the geopolymerization process at room temperature. Easy-to-use alkaline reagents, such as sodium or potassium silicates, are useful in geopolymerization.

In recent years, geopolymer has attracted considerable attention due to its high compressive strength, exceptional resistance to sulphate attack, and resistance to acids, as well as being, by its nature, an environmentally sound material. .

These materials are currently used as mixtures to replace cements as building materials and to make composite materials formed from a geopolymer matrix in which organic fibers are dispersed in an orderly manner and which have good mechanical and thermal insulation characteristics.

In recent years, yes? developed an advanced construction technology involving concrete, known as "3D concrete printing", or "Additive Manufacturing (AM) in concrete".

3D printing can be defined as "a process of assembling materials to prepare elements or objects from a 3D model, usually layer by layer".

An idea of using 3D concrete printing technique is applied to develop automated building structures in three dimensions. In this case, through dedicated software, a computer sends the necessary information to a ?3D printer?. The 3D printer adds consecutive thin layers to form a solid object.

3D printing turns out to be an industrial production method that gives a wide freedom formal and creative, allowing designers to indulge themselves in the creation of unconventional and different shapes each time, not possible with standard serial production methods. This ? possible especially through the use of parametric modeling software that allow you to formulate real algorithms, through which ? It is possible to vary the parameters arbitrarily to obtain always different shapes.

In the literature you can find several publications and patents concerning geopolymer formulations to be used for 3D printing, but the combination with olive pomace is not? never been described.

WO2017/077246 discloses a dry mortar composition comprising various types of binders and different types of bio-fillers including olive pomace. actually? in the cited patent there is no mention of pomace, but? of olive stone (commonly called nocciolino) and the dry mortar? used in sprayable mortars, not for 3D printing. Furthermore, traditional binders are disclosed which cannot be validly used in the present invention.

OBJECTS AND SUMMARY OF THE INVENTION

From a technical point of view, the main problem? that of finding a recipe that could use the pomace, without it having to undergo further processing after its production, i.e. after having only dried it to a humidity level of 100%. pre-established.

Another problem? the presence of a fine component, together with a residual oily patina which remains on the pomace after the production of the oil.

These elements do not allow a satisfactory grip by cement binders and also do not allow to obtain the properties? rheological and mechanical, the basis of a correct deposition with 3D printing, also considering a durability? in the time of the artifact. (there is no development of efflorescence thanks to the geopolymer, a very important aspect both aesthetically and in terms of the durability of the material).

A further problem? to obtain three-dimensional artifacts printed, products with a quantity? high in olive pomace.

In the context of these problems, an object of the present invention is that of obtaining a formulation comprising geopolymers and olive pomace such as to allow 3D printing of the composition.

Another object of the present invention relates to a method for obtaining the formulation comprising geopolymers and olive pomace.

A further object of the present invention ? that of having a process for 3D printing of three-dimensional solids such as panels that use the formulation of geopolymers and olive pomace.

For ?three-dimensional solids? according to the present invention solid geometric shapes are meant which can be of variable size, self-supporting and capable of adhering to solid elements formed from other materials.

Pi? in general, the formulations of the invention lend themselves to making products of any type, even of large dimensions, for example for the building industry, provided that 3D printers specially made in large dimensions or complex shapes of smaller dimensions are used, which if necessary they can also be printed on a substrate, for example consisting of a flat paneling, having ascertained the excellent adhesion between the 3D printed and the underlying substrate.

These and other objects of the present invention are achieved by means of a system incorporating the characteristics of the attached claims, which form an integral part of the present description.

According to a first aspect, the present invention ? directed to a formulation for 3d printing of solid products comprising a geopolymer and olive pomace where the olive pomace, after drying, has humidity? residual less than 15% m/m, preferably less than 10% m/m measured according to the UNI EN 14774-2: 2010 standard.

For ?olive pomace? (pomace) in the present invention is meant the solid residue (stones, peel films, parts of pulp) from the pressing of the olive paste. Usually the origin of the olives? of biological origin. It represents 30-50% of the processed olives.

Generally, the composition of pomace useful for the invention?:

- oil from 2 to 15%

-water from 20 to 40%

-solid fraction from 50 to 80%

where the % ? to be understood in weight with respect to the sum of the constituents.

In a preferred aspect of the invention, the pomace has the following composition:

- oil from 5 to 10%

-water from 25 to 30%

- solid fraction from 60 to 70%

The pomace is collected from the mills and taken to a covered place to be able to work it later. ? It is necessary that this undergoes a drying treatment to be depleted of the water present inside it, for the benefit of a more constant compositional consistency. easy to handle when mixing with the geopolymer binder. Drying can take place in any of the ways known in the art, both naturally, at room temperature, and artificially with flows of hot air in industrial plants.

Advantageously the? Humidity? residue of pomace after drying? less than 15%, preferably less than 10% measured according to the UNI EN 14774-2: 2010 standard. Generally the ash content ? less than 5%, preferably less than 3%. ? It has been verified, through quality control, that the pomace does not contain allergens, toxic substances or chemical additives. The pomace has a particle size of less than 8 mm, preferably 5 mm.

In a preferred aspect of the invention, the pomace is screened and divided into two dimensions with respect to its granulometric curve. The screening can be performed in any mode? and with any tool, as long as? dimensional separation is respected. The part below 1 mm is used together with the geopolymer binder for 3D printing.

The geopolymer ? the binder which is used in the formulation of the present invention.

The geopolymer ? the reaction product of an amorphous silico-aluminous source (powder) and an alkaline liquid which activates the geopolymerization process at a suitable temperature (liquid).

Generally in a preferred aspect of the invention the temperature ? the room temperature, but the technician can? easily increase or decrease the temperature in order to accelerate or reduce the time of the geopolymerization process.

In the formulation according to the present invention the amorphous silico-aluminous reactive powder comprises metakaolin, F-type coal fly ash and steel plant recycled materials.

The ?coal fly ash? according to the present invention belongs to class F according to the ASTM C618 standard and ? the residue from the burning of bituminous coals or anthracite. ? consisting essentially of SiO2 (silica) and reactive Al2O3 (alumina). It comes in the form of a very fine powder with activity? pozzolanic.

The ?metakaolin? according to the present invention, it has the formula (Al2O3?2SiO2), and is obtained with the thermal activation of kaolinite clay at about 750?C.

The ?recycled steel? according to the present invention they are powders deriving from the metal smelting process (blast furnace slag) or in ?nanopowders? (amorphous micro and nano silicas) generated in electric arc power plants. The powders deriving from the production of steel in an electric arc furnace (called ?black slag?) can also be used.

The alkaline liquid that is used for the polymerization reaction? an alkali silicate preferably of Na or K.

Generally the ratio between geopolymer and olive pomace after drying varies between 30/70 and 90/10 in weight with respect to the sum of the two constituents.

The part of the geopolymer ? to be understood as formed by the sum of the silicate (alkaline liquid) and the precursor (powder).

In a preferred aspect of the invention an air entraining additive is used.

A second object of the invention is a process for the preparation of a formulation comprising a geopolymer and olive pomace.

It includes the following stages:

a) Dry the olive pomace until it reaches a humidity value? residual less than 15% m/m measured according to the UNI EN 14774-2: 2010 standard;

b) Mix the reactive powders including metakaolin, type F fly ash, and steel mill recyclates in a suitable container;

c) Add the alkaline liquid and mix the amalgam for a suitable time;

d) Add the dried olive pomace in phase a) possibly mixed with the appropriate additives to the amalgam in phase c);

e) Mix the product obtained from phase d) for a suitable time.

The container mentioned in step b), how ? known by the technician of the branch, it will depend? the size of the batch; for small batches plastic containers can be used, while for industrial productions the container will be? of metal, preferably coated thanks to a surface treatment.

The mixing time? a feature that the technician of the branch pu? evaluate without problem.

Generally, the mixing time rises as the quantities increase. of the dough in play. As for an industrial plant it pu? vary from 5 to 20 minutes, preferably 15 minutes. Naturally the type of composition of the geopolymer? an important factor in evaluating the mixing time. The branch technician? able without problems to evaluate the time necessary for a correct mixing.

The mixing with the alkaline liquid preferably takes place continuously using a whip drill (for small batches) or with coated steel augers (at an industrial level).

To the pomace mixture and possibly the air-entraining additive, you can add a water content of up to 15% by weight, preferably 8% by weight in order to increase the homogeneity? of the final formulation.

After a few minutes of further mixing, the formulation? ready for your application.

A third object of the present invention is a process for making three-dimensional solids printed by 3D printing.

This method involves the following stages:

a) preparing a formulation for 3D printing as described above;

b) move the formulation of phase a) through a hopper, in a screw pump (MAI international), which, through a delivery pipe, pumps the material up to the end? opposite where? present the? extruder that ? hooked to the flange (print head) of a robotic arm (Universal Robots) that pu? vary the movement of the extruded product on the three axes X, Y, Z;

c) extruding the layer of mortar through a nozzle while moving said nozzle relative to the support so as to create one or more? layers of mortar arranged according to a predetermined geometry.

A further object of the present invention is a ?three-dimensional solid? printed with the method described above.

Pi? in general, the formulations of the invention lend themselves to making products of any type, both of large dimensions for example for the building industry (provided you use 3D printers purposely made in large dimensions) or complex shapes of smaller dimensions, which all If necessary, they can also be printed on a substrate, for example consisting of a flat paneling, having ascertained the excellent adhesion between the 3D printed and the underlying substrate.

The formulations of the invention can also possess, in the geopolymerized solid state, particular mechanical and/or insulating characteristics, for example by adding suitable fillers or additives such as rubber, organic resins, air-entrainers, glass, mineral fillers, short polymeric or inorganic fibers.

The deposition of the 3D mortar takes place through the extrusion of the same through a nozzle that moves in the X, Y, Z directions relative to the printing substrate as described above.

This technique is used according to the invention to print unusual geometric shapes on a base material (substrate) (such as, for example, a panel made of geopolymeric mortar or geopolymeric "composite") which, thanks to the composition comprising a geopolymer, allows a ?excellent adhesion between the 3D printed and said substrate.

? particularly surprising that 3D printed three-dimensional solids with so? high percentages of olive pomace are particularly suitable thanks to an excellent adhesion, to be printed on composite materials containing geopolymers. The word ?composite? in this context it concerns any type of formulation or product containing geopolymers.

? For example, the adhesion of three-dimensional shapes printed using 3D mortar on geopolymeric mortar specimens after a few hours of curing (dry mortar) was verified.

This synergy between the two parts (3D printed and substrate)? possible due to the use of a geopolymer, which does not need to be wet or heated to higher temperatures? higher than ambient or coated with a primer before applying the 3D mortar. In fact, the latter? able to recognize the chemical structure of the geopolymer on which it is placed, establishing a strong attraction with it.

In a preferred aspect of the invention the 3D printed three-dimensional solid of the invention is adhered to a panel containing a geopolymer.

For example plasterboard products containing geopolymers.

In particular, bending tests on specimens of geopolymeric composite materials demonstrate that the usual failure of the specimen occurs transversally to it, without particular signs of yielding in the joint between the two materials.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will become clearer from the following detailed description of some of its preferred embodiments, made with reference to the accompanying drawings.

The different features in the individual configurations can be combined with each other as desired according to the previous description, if one has to make use of the advantages specifically resulting from a particular combination.

In such drawings, figure 1 is a representation of the 3D printing process used with the formulation of the invention.

Figure 2 ? a representation of the molding of a three-dimensional solid onto a panel.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, for the illustration of the figures, identical reference numbers or symbols are used to indicate construction elements with the same function.

While the invention? susceptible to various modifications and alternative constructions, some preferred embodiments are shown in the drawings and will be described in detail below. It must be understood, however, that there is no no intention of limiting the invention to the specific embodiment illustrated, but, on the contrary, the invention intends to cover all modifications, alternative constructions and equivalents which fall within the scope of the invention as defined in the claims.

The use of ?for example?, ?etc?, ?or? indicates non-exclusive alternatives without limitation unless otherwise indicated. The use of ?includes? and ?include? means ?includes or includes, but not limited to? unless otherwise indicated.

As described above the present invention ? directed to a formulation for 3d printing of solid products comprising a geopolymer and olive pomace where the olive pomace, after drying, has humidity? residual less than 15% m/m, preferably less than 10% m/m measured according to the UNI EN 14774-2: 2010 standard.

Before the drying process, the pomace looks like a pulverulent material with a density of apparent of about 800-850 grams/litre in a mixed curve of about 0-5 mm obtained by crushing the stones and olives.

The drying of pomace can also effectively take place under the sun in the most? warmest of the year, with a mixing system to ensure its homogeneity? until reaching the humidity? expected residual.

It is stored in a closed shed at room temperature with a humidity more low as possible.

Although it is possible to use the pomace as such, after drying, it is it is preferable to carry out a screening of the pomace.

In a preferred aspect of the invention ? a MATEST electronic vibro-sieve with vibration timer was used.

After the vibro-sieving of the virgin pomace it appears as a pulverulent material of density apparent of about 900 grams/litre in curve 0-1mm approximately.

The reduction of the granulometric curve? however due to the compatibility? with the 3D printer used. After some tests carried out ? the need emerged? to reduce the granulometry of the extrudable material, due to obvious dimensional limitations of the nozzle and the lack of an adequate pumping system.

The use of an aggregate cos? end, required a further change of the GP binder to pomace ratio.

For this reason the relationship between geopolymer and pomace can to vary. between 30/70 and 90/10 by weight with respect to the sum of the two constituents.

The part of the geopolymer ? to be understood as formed by the sum of the silicate (alkaline liquid) and the precursor (powder).

The geopolymer ? the binder that is used in the formulation of the present invention, as other cement-type binders cannot be used, even the fast-acting ones containing sulfoalumina cement that are often described in 3D printing applications.

The geopolymer ? the reaction product of an amorphous silico-aluminous source (powder) and an alkaline liquid which activates the geopolymerization process at room temperature (liquid).

The geopolymerized material ? stable, not d? place to phenomena of efflorescence or leaching, does not emit odors or gases and pu? be recycled as demolition aggregate at the end of its life, in other geopolymeric or even cementitious materials. In case of disposal, it does not require post-treatments as it does not release polluting substances, does not contain heavy metals or hexavalent chromium (typical in Portland greys). Not being soluble, pu? be disposed of in open landfills. ? an eco-sustainable binder and the production process of the raw materials used to produce it? low energy consumption (there are no carbonates in the quarry raw materials calcined at a low temperature around 750-1150?C) with a saving of CO2 emissions of up to 80%. ? a binder ?carbon negative, then pu? capture a certain amount? of environmental CO2 and give rise to a subtle superficial potassium carbonation, without giving rise to spots or halos.

The characteristics of the geopolymer used in the present invention are as follows:

LEG GP CREAM produced from precursor in micronized powder with D(50) about 8 microns. The liquid reagent? a potassium silicate in aqueous solution, non-commercial grade, but designed to promote geopolymerization, has a pH of about 13.4 (lower than that of milk of lime) Has a viscosity? of about about 20 mPs. The density? mixed with the complete binder? about 1.5 g/cm3 (precursor powder is light, about 0.5-0.6 g/cm3, but silicate is heavier about 1.4 g/cm3). Workability time? or pot life, ? compliant with 3D printing and ? about an hour at 23?C. It does not contain organic or inorganic additives, therefore it does not contain volatile organic compounds (organic content 0%). Does not contain fibers. Features recycled content that can? ranging from 20 to 60% by weight.

As for Figure 1, it describes the 3D printing process the formulation of the invention? moved through a hopper (1), in a screw pump (2), which, through a delivery pipe (3), pumps the material up to the end? opposite where? present the extruder (4) that ? hooked to the flange (print head) (5) of a robotic arm (6) that pu? vary the movement of the extruded product on three axes X, Y, Z.

?The screw pump? in a preferred aspect of the invention, ? consisting of a rotor and a stator.

The layer of mortar is extruded through a nozzle (7) moving at the same time said nozzle relative to the support so as to create one or more? layers of mortar arranged according to a predetermined geometry.

As regards figure 2, it describes the deposition of a three-dimensional solid (8) on a panel (9), obtained with the method of the invention using the robotic arm (6) and the extruder (4).

The invention? illustrated below through experimental examples, which are not to be considered limiting for the scope of the invention.

EXAMPLE 1

? unscreened pomace was used having the following composition: oil from 5 to 10%, water from 25 to 30%, solid fraction from 60 to 70%. The pomace? been dried under the sun's rays outdoors, until reaching the humidity? desired residual. ? been verified by UNI EN 14774-2: 2010 a humidity? residual at 10%m/m.

Yes ? there is a total mass of the final compound of 1 kg of extra additives and water calculated on 100% (1 kg of geopolymer + pomace).

? LEG GP CREAM and potassium reagent were used, with a ratio (precursor + liquid): pomace 70: 30.

The powder binder (0.37 kg) ? was placed in a plastic container with a capacity of 14 l. ? been added the alkaline liquid (0.33 Kg) and ? started mixing with a whip drill. After about 5 minutes the amalgam was homogeneous with a fluid consistency.

Meanwhile, 0.3 kg of pomace after drying was added to the amalgam with about 11% water. ? continued mixing for a further 5 minutes. The resulting mortar was extrudable having the correct thixotropic consistency.

EXAMPLE 2

? Pomace was used with the composition: oil from 5 to 10%, water from 25 to 30% solid fraction from 60 to 70%.

The pomace? been dried under the sun's rays outdoors, until reaching the humidity? desired residual. ? been verified by UNI EN 14774-2: 2010 a humidity? residual at 10%m/m.

Yes ? there is a total mass of the final compound of 1 kg of extra additives and water calculated on 100% (1 kg of geopolymer + pomace).

? LEG GP CREAM and potassium reagent were used, with a ratio (precursor + alkaline liquid): pomace 80:20.

The powder binder (0.42 kg) ? was placed in a plastic container with a capacity of 14 l. ? been added the alkaline liquid (0.38 kg) and ? started mixing with a whip drill. After about 5 minutes the amalgam was homogeneous with a fluid consistency.

In the meantime, 0.2 kg of pomace after drying was added to the amalgam with about 4% water. AND? continued mixing for a further 5 minutes. The resulting mortar was extrudable having the correct thixotropic consistency.

EXAMPLE 3

? Pomace was used with the composition: oil from 5 to 10%, water from 25 to 30% solid fraction from 60 to 70%. The pomace? was screened by vibro sieving obtaining a granulometric curve of less than 1 mm.

The pomace? been dried under the sun's rays outdoors, until it reaches the humidity? desired residual. ? been verified by UNI EN 14774-2: 2010 a humidity? residual at 10%m/m.

Yes ? there is a total mass of the final compound of 1 kg of extra additives and water calculated on 100% (1 kg of geopolymer + pomace).

AND? LEG GP CREAM and potassium reagent were used, with a ratio (precursor + liquid): pomace 85:15.

The powder binder (0.45 kg) ? was placed in a plastic container with a capacity of 14 l. ? been added the alkaline liquid (0.40 kg) and ? started mixing with a whip drill. After about 5 minutes the amalgam was homogeneous with a fluid consistency.

In the meantime, 0.15 kg of screened and dried pomace were added to the amalgam together with 0.0015 kg of BEROPORE 30? with about 8% water. ? continued mixing for a further 5 minutes. The resulting mortar was extrudable having the correct thixotropic consistency.

EXAMPLE 4

Mechanical tests were carried out on the mortars of examples 1-3 to evaluate their properties.

All tests were carried out in the laboratory using the EN 1504-3 standard at a temperature of 23?C and humidity? of the air by 55%. The press what? been used? an automatic double-channel MATEST (for Bending maximum load 15 KN and for Compression maximum load 300 KN). Polyurethane formwork was used.

The results are summarized in table 1

Table 1

Example 5 (comparison)

? The olive pomace used in example 1 was used with a Portland-based cement mix. The ingredients of the mixture used are the following:

- Portland cement 52.5 R gray: 80%

- Polycarboxylic superplasticizer: MELFLUX 5581 F 1% (on 100% by weight) - Water, with w/c ratio = 0.55;

- low viscosity cellulose: Tylose MH 60010 P40.8% (on 100% by weight) - Anti-sediment agent: Starvis 30030.1% (on 100% by weight)

- Setting accelerator: Calcium formate 1.6% (on 100% by weight)

- Olive pomace: 12% (out of 100% by weight)

- acrylic resin powder; ELOTEX FX 23204% (on 100% by weight) - Thixotropic agent: bentonite 0.5%. (on 100% by weight) The result? a false grip, since? once the mix is mixed with the pomace as it is, the material does not harden, it soon loses workability, without developing mechanical resistance.

Claims (19)

1. Formulation for 3D printing of solid products comprising a geopolymer and olive pomace where the olive pomace, after drying, has humidity? residual less than 15% m/m, preferably less than 10% m/m measured according to the UNI EN 14774-2: 2010 standard. 2. Formulation according to claim 1 wherein the olive pomace has the following composition, before drying (% by weight with respect to the sum of the components): - oil from 2 to 15% -water from 20 to 40% -solid fraction from 50 to 80% 3. Formulation according to claim 1 wherein the olive pomace has the following composition, before drying, (% by weight with respect to the sum of the components): - oil from 5 to 10% -water from 25 to 30% - solid fraction from 60 to 70% 4. Formulation according to any one of the preceding claims wherein the olive pomace after drying has a granulometric curve between 0 and 5 mm. 5. Formulation according to any one of the preceding claims wherein the olive pomace after drying has a granulometric curve between 0 and 1 mm. 6. Formulation according to any of the preceding claims wherein the geopolymer is the reaction product at room temperature between an amorphous aluminous silico reactive powder and an alkaline liquid. The formulation according to claim 6 wherein the amorphous silico-aluminous reactive powder comprises metakaolin, F-type coal fly ash, steel mill recycleds, and mixtures thereof. 8. Formulation according to claim 6 wherein the alkaline liquid is an alkali silicate preferably of Na or K. 9. Formulation according to any one of the preceding claims wherein the ratio between geopolymer and olive pomace after drying varies between 30/70 and 90/10 by weight with respect to the sum of the two constituents. 10. Formulation according to any one of the preceding claims comprising a breather-entraining additive. 11. Process for the preparation of a formulation according to one of the preceding claims comprising the following steps: a) Dry the olive pomace until it reaches a residual humidity value of less than 15% m/m measured according to the UNI EN 14774-2: 2010 standard; b) Mixing the reactive powders including metakaolin, type F fly ash and steel mill recycled; c) Add the alkaline liquid and mix the amalgam for a suitable time; d) Add the dried olive pomace in phase a) possibly mixed with the appropriate additives to the amalgam in phase c); e) Mix the product obtained from phase d) for a suitable time. 12. Process for the preparation of a formulation according to claim 11 where the amalgam is mixed with a whip drill or with coated steel augers for a time between 5 and 15 minutes. 13. Process for the preparation of a formulation according to claim 11 wherein in step d) a quantity of water up to 15% by weight, preferably up to 8% by weight with respect to the sum of the constituents. 14. Process for the preparation of a formulation according to claim 11 wherein the olive pomace after step a) is sieved until a particle size ranging from 0 to 1 mm is obtained. 15. Method for the construction of a three-dimensional solid structure, characterized in that it comprises the following phases: a) preparing a formulation for 3D printing according to one of claims 1 to 11; b) move the formulation of phase a) through a hopper (1), in a screw pump (2), which, through a delivery pipe (3), pumps the material up to the end? opposite where? present the extruder (4) that ? hooked to the flange (print head) (5) of a robotic arm (6) that pu? vary the movement of the extruded product on three axes X, Y, Z; c) extruding the layer of mortar through a nozzle (7) moving at the same time said nozzle relative to the support so as to create one or more? layers of mortar arranged according to a predetermined geometry. 16. Three-dimensional solid printed with the formulation of any one of claims 1 to 10. The three-dimensional solid printed with the formulation of any one of claims 1 to 10 onto a substrate, such as a board, containing a primer. The three-dimensional solid printed with the formulation of any one of claims 1 to 10 on a substrate, such as a board, containing geopolymers. 19. Three-dimensional solid according to claim 18 where the substrate is plasterboard containing geopolymers.