Adjuvant for improving the particle size distribution of a mineral composition having a reduced clinker content

Abstract

The present invention relates to a grinding method comprising grinding a mineral composition to be ground in the presence of an adjuvant composition comprising at least one polymer (P) of formula (1), wherein: - M represents, independently of one another, H+ or a cation of valency v selected from among an alkali metal cation, an alkaline earth metal cation, a bi- or trivalent metal cation, an ammonium cation or an organic ammonium cation, - if M = H, then v = 1, and if "M" represents a cation, v is the valency of the cation M, - R2, R3, R4 and R5 independently represent H, CH3 or –COO(M)1 / v, - m = 0, 1 or 2; p = 0 or 1; X is O or N, and - R1 represents -[Alkyl-O]z-R6, in which each "Alkyl" group is independently a C2 to C4 branched or linear alkylene, R6 represents H, a C1 to C20 alkyl, a cyclohexyl or an alkylaryl, and z ≥ 40, wherein the number of units (I) and (II) in the polymer (P) is defined by a repeating unit (A) comprising a unit (II) and "a" units (I), where a > 0, n being between 1.5 and 50, and the molecular weight of the repeating unit (A) Mw(A) ≤ 6500 g / mol, and wherein the mineral composition to be ground comprises 0% to 80% by weight of clinker, relative to the total weight of the mineral composition to be ground.

Description

[0001] Adjuvant for improving the particle size distribution of a mineral composition with reduced clinker content

[0002] The present invention relates to a method for grinding a mineral composition in the presence of a specific adjuvant.

[0003] The present invention also relates to a mineral composition and a hydraulic composition comprising such an adjuvant.

[0004] The present invention also relates to the use of this adjuvant for improving the grindability, in particular the particle size distribution of said mineral compositions.

[0005] Common cement compositions, even those containing mineral additions, contain a significant proportion of clinker. For example, most common cements defined in the EN 197-1:2011 standard “Composition, specifications and conformity criteria for common cements” contain at least 65% clinker by mass.

[0006] There is a need to lower the clinker content of cementitious compositions and hydraulic binder compositions in order to reduce their carbon impact while maintaining their mechanical and rheological properties. New cementitious compositions and hydraulic binders in which part of the clinker is replaced by mineral additions, including natural or artificial pozzolans, silica fume, calcined clays, fly ash and limestones, have emerged, such as in the OEM ll / CM described in EN 197-5: 2021 “Cement - Part 5: Portland-composite cement CEM ll / CM and composite cement CEM VI” which contain between 50% and 64% clinker by mass.

[0007] Furthermore, grinding is a central step in the production of cementitious compositions because it is energy-consuming, complex to carry out and the fineness and size distribution of the particles of the resulting cementitious composition will condition the performance of the hydraulic compositions that contain it (such as mortars and concretes), in particular the water demand and the mechanical compressive strengths. For example, the particle size fraction less than 32 pm and more particularly the particle size fraction between 2 and 32 pm is an important parameter in the acquisition of strengths. Indeed, particles that are too fine (< 2 pm) lead to too rapid setting with a risk of associated cracks. In addition, they can reduce the workability of hydraulic compositions including the mineral composition.Conversely, particles that are too coarse (> 32 pm) do not hydrate quickly enough to contribute significantly to the acquisition of the resistances expected in routine uses.

[0008] Furthermore, from an environmental perspective, it is also desirable to increase the production of grinding plants with the lowest possible energy consumption.

[0009] It is well known to use glycols or alkanolamines in particular to facilitate the comminution of materials and reduce grinding times. However, these grinding agents are not particularly satisfactory when grinding mineral compositions with reduced clinker content. In addition, grinding control is all the more complex when several mineral compounds are co-ground under the same composition and their hardnesses are different, which is the case for the compositions with reduced clinker content mentioned above. Indeed, co-grinding materials of different hardnesses can lead to over-grinding the softer ones and not grinding the harder ones sufficiently. These conditions can lead to a degradation of the compressive strengths of the hydraulic compositions comprising the mineral composition, in particular when the mineral composition includes clinker or blast furnace slag.When the mineral composition reaches a fine particle size, it is also necessary to control its water demand, which impacts the workability of the hydraulic compositions comprising the mineral composition. This is particularly the case when large proportions of calcined clays, limestones or pozzolans are used. It is also very difficult to properly grind a friable mineral material because the ground particles tend to agglomerate among themselves and on the surfaces of the mill, such as the balls of a ball mill, making grinding inefficient.

[0010] There is therefore a need for a new process to improve the grinding and grindability of reduced clinker mineral compositions, particularly when the grinding involves co-grinding several different mineral compounds or grinding a friable mineral material.

[0011] In particular, there is a need for a new process for increasing the proportion of the 2-32 pm fraction in the particle size distribution of mineral compositions with reduced clinker content.

[0012] There is also a need for new mineral compositions with reduced clinker content having high fineness and a high 2-32 pm fraction.

[0013] Another objective of the present invention is to provide a hydraulic composition based on a mineral composition with a reduced clinker content, having good mechanical properties, in particular good mechanical resistance in compression, in particular in the short term, for example at 1 and 2 days, and improved workability, particularly when the mineral composition comprises large proportions of calcined clays, fly ash, limestone and / or pozzolans.

[0014] For this purpose, the subject of the invention is a grinding process comprising the grinding of a mineral composition to be ground, in the presence of an adjuvant composition comprising at least one polymer (P) of the following formula: in which:

[0015] - “M” represents independently of each other H + or a cation of valence v chosen from an alkali metal cation, an alkaline earth metal cation, a bi- or trivalent metal cation, an ammonium cation or an organic ammonium cation,

[0016] - when “M” represents H, “v” represents 1, and when “M” represents a cation, “v” is the valence of the cation M,

[0017] - “R2” and “R3” independently represent hydrogen, methyl or a group of formula -COO(M)i / v with M and v as defined above, preferably hydrogen or methyl,

[0018] - “R4” and “R5” independently represent hydrogen, methyl or a group of formula -COO(M)i / v with M and v as defined above,

[0019] - “m” represents 0, 1 or 2,

[0020] - “p” represents 0 or 1,

[0021] - “X” is Y or N, and

[0022] - “R1” represents -[Alkyl-O] z -R6, wherein the “Alkyl” of each [Alkyl-O] unit independently represents a linear or branched alkylene comprising from 2 to 4 carbon atoms, “R6” represents H, a C1 to C20 alkyl group, a cyclohexyl group or an alkylaryl group, and “z” is greater than or equal to 40, the number of units (I) and (II) in the polymer (P) being defined by a repeating unit (A) comprising a unit (II) and “a” units (I), the repeating unit (A) being present “n” times in the polymer (P), - “a” being a non-zero positive number,

[0023] - “n” being between 1.5 and 50, and

[0024] - the molecular mass of the repeating unit (A) being less than or equal to 6500 g / mol, the mineral composition to be ground comprising from 0 to 80% by mass of clinker, relative to the total mass of the mineral composition to be ground.

[0025] Otherwise formulated, the polymer (P) comprises, or even consists of, n repeating units of the following formula (A): , units (I) and (II) being as defined above.

[0026] It is understood that the repeating units (A) of the polymer (P) may be different from each other, and preferably are all identical.

[0027] Indeed, the inventors have surprisingly discovered that the use of a specific polymer (P) as described above, during the grinding of a mineral composition with a reduced clinker content, makes it possible to improve the grindability of this composition, and in particular to increase the 2-32 pm fraction in the particle size distribution of the ground mineral composition. It is the combination of the length of the side chains (parameter “z”), the number of repeating units (A) (parameter “n”) and the size of the repeating unit (molecular mass of the repeating unit (A)), possibly in combination with the number of units (I) (parameter “a”) which makes it possible to solve the technical problems mentioned in this text.

[0028] The invention also relates to an adjuvanted ground mineral composition, comprising a mineral composition comprising from 0% to 80% by mass of clinker relative to the total dry mass of the mineral composition and a polymer (P) as defined above.The invention also relates to the use of a polymer (P) as defined above, for improving the grindability of a mineral composition to be ground comprising from 0% to 80% by mass of clinker relative to the total mass of the mineral composition to be ground, preferably for increasing the proportion of fraction 2-32 pm in the particle size distribution of a ground mineral composition, advantageously for increasing by at least 6% the proportion 2-32 pm in the particle size distribution of a ground mineral composition comprising from 0% to 80% by mass of clinker relative to the total mass of the mineral composition, relative to the proportion 2-32 pm in the particle size distribution of the ground mineral composition in the absence of polymer (P).

[0029] Grinding process

[0030] The present invention relates to a grinding method comprising grinding a mineral composition to be ground in the presence of an adjuvant composition comprising at least one polymer (P).

[0031] According to one embodiment, the method comprises a step of preparing a mixture to be ground comprising the mixing of the mineral composition to be ground and the adjuvant composition, followed by a step of grinding said mixture to be ground.

[0032] According to another embodiment, the method comprises a step of introducing the mineral composition to be ground into a grinder, followed by a step of adding the adjuvant composition into a grinder during the grinding of the mineral composition to be ground.

[0033] Continuously, the different constituents are introduced into the crusher by means of a belt conveyor or an airslide which takes care of the different materials before the main feed of the crusher, in the desired proportions by means of specific dosers relating to each of the constituents.

[0034] The additive composition is added to the materials at the conveyor belts before entering the crusher by means of nozzles and in the crusher by injection nozzles in the first or second chamber.

[0035] Preferably, the grinding process is carried out in grinding plants, the most common of which are:

[0036] - Ball mills, with or without a first, second or third generation separator. The circulating load level in the latter case is the determining parameter for improving grinding efficiency and yield. Filters and / or cyclones collect fine particles from the gas streams at the separator and mill, which are reintroduced into the finished product at the separator outlet.

[0037] - Vertical mills, which are increasingly popular due to their lower energy consumption. Since grinding temperatures are lower, this grinding process places greater demands on the permissible moisture levels of the raw materials. A bag filter separates the gas stream from the crushed solid particle bed.

[0038] - Series grinders, which can be used to increase productivity, for example by using roller presses to reduce the clinker particle size at the mill entrance.

[0039] - Other mills that are particularly effective in reducing grinding energy, comprising a cage fitted with grinding agents such as silica microbeads, can be used in series with other more conventional mills. These latter processes make it possible to achieve very high levels of fineness.

[0040] According to a first alternative, the grinding method is a method of co-grinding at least one first mineral material to be ground and at least one second mineral material to be ground. According to this alternative, the grinding method comprises a step of preparing a mineral composition to be ground, said step comprising mixing at least one first mineral material to be ground and at least one second mineral material to be ground to obtain the mineral composition to be ground.

[0041] The first mineral material to be ground and the second mineral material to be ground are as defined below in the description of the mineral composition to be ground.

[0042] According to a second alternative, the grinding method is a separate grinding of the materials of the mineral composition. Thus, preferably, the grinding method comprises a step of grinding a first mineral material to be ground in the presence of an adjuvant composition comprising at least one polymer (P) to obtain a first ground mineral material, a step of grinding a second mineral material to be ground, optionally in the presence of an adjuvant composition comprising at least one polymer (P), to obtain a second ground mineral material, and a step of mixing the first ground mineral material and the second ground mineral material, to obtain a ground mineral composition.

[0043] The first mineral material to be ground and the second mineral material to be ground are as defined below in the description of the mineral composition to be ground. The admixture composition may be mixed with the first mineral material to be ground and the second mineral material to be ground before introduction into the mill, or during their grinding.

[0044] Polymer (P)

[0045] The adjuvant composition used in the grinding process comprises at least one polymer (P) comprising units of formula (I) and (II): in which:

[0046] - “M” represents independently of each other H + or a cation of valence v chosen from an alkali metal cation, an alkaline earth metal cation, a bi- or trivalent metal cation, an ammonium cation or an organic ammonium cation,

[0047] - when “M” represents H, “v” represents 1, and when “M” represents a cation, “v” is the valence of the cation M,

[0048] - “R2” and “R3” independently represent hydrogen, methyl or a group of formula -COO(M)i / v with M and v as defined above, preferably hydrogen or methyl,

[0049] - “R4” and “R5” independently represent hydrogen, methyl or a group of formula -COO(M)i / v with M and v as defined above,

[0050] - “m” represents 0, 1 or 2,

[0051] - “p” represents 0 or 1,

[0052] - “X” is Y or N, and

[0053] - “R1” represents -[Alkyl-O] z-R6, wherein the “Alkyl” of each [Alkyl-O] unit independently represents a linear or branched alkylene comprising from 2 to 4 carbon atoms, “R6” represents H, a C1 to C20 alkyl group, a cyclohexyl group or an alkylaryl group, and “z” is greater than or equal to 40, the number of units (I) and (II) in the polymer (P) being modeled by a repeating unit (A) comprising a unit (II) and “a” units (I), the repeating unit (A) being present “n” times in the polymer (P), wherein: - “a” is a non-zero positive number,

[0054] - “n” is between 1.5 and 50, and

[0055] - the molecular mass of the repeating unit (A) is less than or equal to 6500 g / mol.

[0056] The polymer (P) can therefore be represented by the following formula:

[0057] “R2”, “R3”, “M”, “v”, “R4”, “R5”, “m”, “p”, “X”, “R1”, “a”, and “n” being as defined above, or according to any of the embodiments defined below.

[0058] It is understood that the repeating unit (A) is random and does not prejudge the sequence of units (I) and (II) in the polymer (P). Units (I) and (II) are preferably randomly distributed in the polymer (P).

[0059] Preferably, the molecular mass of the repeating unit (A) is between 1500 and 6500 g / mol, preferably between 2000 and 6500 g / mol, preferably between 2500 and 6500 g / mol, preferably between 3500 and 6000 g / mol, preferably between 4500 and 6000 g / mol, preferably between 5000 and 6000 g / mol, preferably between 5200 and 5600 g / mol.

[0060] “z” represents the number of [Alkyl-O] units in the R1 group.

[0061] Preferably, “z” is greater than or equal to 50, preferably greater than or equal to 70, preferably greater than or equal to 80, preferably greater than or equal to 85, preferably greater than or equal to 90, preferably greater than or equal to 100, preferably, z is between 40 and 230, preferably between 50 and 200, preferably between 70 and 150, preferably between 80 and 120, preferably between 90 and 120, preferably between 100 and 120.

[0062] “n” represents the number of repeating units (A) in the polymer (P).

[0063] Preferably, “n” is between 4 and 40, preferably between 5 and 25, preferably between 6 and 20, preferably between 7 and 18. Preferably, “a” is between 0.2 and 100, preferably between 0.5 and 50, preferably between 0.8 and 25, preferably between 1.0 and 20, preferably between 2.0 and 15, preferably between 3.0 and 10, preferably between 3.9 and 7, preferably between 4.0 and 6.

[0064] Preferably, the polymer (P) has a grafting rate strictly greater than 5%, preferably greater than or equal to 6%, preferably greater than or equal to 8%, preferably greater than or equal to 10%, preferably greater than or equal to 12%, preferably greater than or equal to 15%, preferably less than or equal to 50%, preferably less than or equal to 30%, preferably less than or equal to 25%, preferably less than or equal to 21%.

[0065] The grafting rate corresponds to the ratio between the number of units (II) and the total number of units (I) and (II) in the polymer (P). The grafting rate is determined by the molar quantities of monomers introduced for the synthesis of the polymer (P) considering a total conversion of said monomers.

[0066] “a” is related to the grafting rate by the following relationship: a = (1 - grafting rate) / (grafting rate)

[0067] The molecular mass of the repeating unit (A) MW can be expressed by the following relation:

[0068] MW(A) = MW(unit (II)) + a * MW(unit (I)),

[0069] Mw(unit (i)) representing the molecular mass of unit (I) of the polymer (P) and Mw( Un ity (H» represents the molecular mass of the unit (II) of the polymer (P). MWis a calculated molecular mass and in fact, the molecular mass by weight of the repeating unit (A) is equal to the molecular mass by number of the repeating unit (A). n corresponds to the following ratio: n = Mw(P) / MW(A)

[0070] MW(A) representing the molecular mass of the repeating unit (A), as defined above, and MW <P) représentant la masse moléculaire en nombre du polymère (P), Mwæ) étant déterminé par chromatographie d’exclusion stérique, par exemple dans les conditions suivantes :

[0071] Columns: Aquagel gard column, PL aquagel-OH 40, PL aquagel-OH 30, PL aquagel-OH 20

[0072] Mobile phase: Saline eluent (8.5 g NaNCh, 1.4 g NahLPCL, 2 H2O, 1.9 g Na2HPO4, 2 H2O, 0.7 g Na1Xh in 1 L pure water), Flow rate: 1 ml / min

[0073] Detectors: Refractive index + Light scattering + Viscometer Column compartment temperature: 30°C

[0074] Injection volume: 150 pl

[0075] Concentration: Approximately 10 mg / ml

[0076] Standard: PEO 45kDa.

[0077] Preferably, in the polymer (P), m = 0, p = 1 and X = 0.

[0078] The following embodiments may be considered independently or combined with each other, and combined with any of the above preferred embodiments:

[0079] - v = 1 and M = H + , and / or

[0080] - R2 = H, and / or

[0081] - R3 = CH3, and / or

[0082] - R4 = H, and / or

[0083] - R5 = CH3, and / or

[0084] - m = 0, and / or

[0085] - p = 1, and / or

[0086] - X = O, and / or

[0087] - R1 = [Alkyl-O]z-R6, with Alkyl = CH2-CH2 and / or R6 is a C1 to C20 alkyl group, preferably is CH3.

[0088] The polymer (P) is preferably used in a proportion ranging from 0.01% to 1% by mass, in particular from 0.05% to 0.5% by mass, preferably from 0.05% to 0.3%, preferably from 0.10% to 0.30% by mass, relative to the dry mass of the mineral composition to be ground.

[0089] Therefore, the adjuvant composition is preferably used in an amount that provides the above-mentioned polymer (P) proportions.

[0090] Adjuvant composition

[0091] The adjuvant composition may contain other ingredients. Examples of such compounds include, but are not limited to, alkanolamines, glycols, glycerols, accelerator compounds (including chlorinated salts, thiocyanates, formates, nitrates and / or nitrites and mixtures thereof), carboxylic acids or their salts (including acetic, adipic, gluconic, formic, oxalic, citric, maleic, lactic, tartaric, malonic acids and mixtures thereof), water-reducing and high-water-reducing compounds (including lignosulfonates, hydroxylated carboxylic acids, comb-type polycarboxylates and mixtures thereof), packset-reducing compounds, which is a relative numerical index, the measurement of which is described in ASTM C1565-19, representing the tendency of a cement to compact when stored or transported in bulk, (including polyacrylic acids), surfactants, anti-foam additives (including tributyl phosphate,tri-iso-butyl phosphate, dibutyl phthalate, octyl alcohol, alkyl amines, water-insoluble carbonic and boric acid esters and mixtures thereof), air-entraining additives (including wood resin salts, sulfonated lignin salts and mixtures thereof), setting retarders (including sugars, corn syrup and molasses and mixtures thereof) and mixtures thereof.,

[0092] Preferably, the adjuvant composition further comprises an ingredient selected from alkanolamines, glycols, glycerols, accelerator compounds (comprising chlorinated salts, thiocyanates, formates, nitrates and / or nitrites and mixtures thereof), carboxylic acids or their salts (comprising acetic, adipic, gluconic, formic, oxalic, citric, maleic, lactic, tartaric, malonic acids and mixtures thereof).

[0093] The adjuvant composition is preferably in the form of a solution, a suspension or a powder, preferably in the form of a solution.

[0094] Preferably, the polymer (P) content in the adjuvant composition ranges from 0.10% to 60% by mass, preferably from 0.10% to 40% by mass, preferably from 0.10% to 20% by mass, preferably from 1% to 10% by mass relative to the total mass of the composition.

[0095] The polymer (P), and more generally the adjuvant composition, in the proportions used, advantageously makes it possible to obtain a larger 2-32 pm fraction in the particle size distribution of the ground mineral composition.

[0096] This distribution is particularly advantageous in that it promotes good compressive strength, especially in the short term. Short-term compressive strength refers to compressive strength at 16 hours, 1 day and 2 days, preferably 2 days. These compressive strengths are measured according to standard NF EN 196-1 (September 2016) "Test methods for cement - Part 1: Determination of strengths - Test methods for cement" or standard ASTM C109 / C109M-21.

[0097] Mineral composition to be ground

[0098] The mineral composition to be ground comprises from 0% to 80% by mass of clinker, relative to the total dry mass of the mineral composition to be ground. The mineral composition to be ground therefore preferably comprises at least one mineral material to be ground other than clinker, and optionally clinker.

[0099] With regard to the nature of the mineral composition to be ground, the method according to the invention and the choice of the specific polymer (P) are particularly advantageous when grinding a friable mineral material, or when co-grinding a hard mineral material such as clinker with a friable mineral material.

[0100] For the purposes of the invention, the hardness or friability of a mineral material is related to its grindability (its ease of grinding). The grindability of a mineral material can be determined by grinding said material without additives in a closed laboratory ball mill. Indeed, grindability is related to the grinding energy, itself being directly related to the grinding time required to obtain a target Blaine fineness, if the other grinding and mill conditions are otherwise identical. Blaine fineness is determined according to standard NF EN 196-6. In particular, the particle size of the mineral materials before grinding must correspond to 100% passing through a 2.15 mm sieve.

[0101] For the purposes of the invention, a mineral material is friable if the grinding time of said mineral material to obtain a Blaine fineness between 1500 and 2500 cm 2 / g is at least two times lower (preferably two to twenty times lower, preferably two to ten times lower) than the grinding time of a clinker meeting the requirements of standard NF EN 197-1 to obtain the same Blaine fineness. It is understood that the mineral material tested and the clinker must be ground under the same conditions (apart from the grinding time) to implement this test.

[0102] Examples of friable materials are: calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, fly ashes, calcined shales, ground shales, diatomaceous earths, and any mixture thereof; more particularly calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, fly ashes, and any mixture thereof; more particularly calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, and any mixture thereof.

[0103] Conversely, a mineral material is hard if the grinding time of said mineral material to obtain a Blaine fineness between 1500 and 2500 cm 2 / g corresponds to 0.8 to 10 times the grinding time of a clinker meeting the requirements of standard NF EN 197-1 to obtain the same Blaine fineness.

[0104] Examples of hard materials are: clinker, silica fumes, granulated blast furnace slag, crystallized, expanded, vitrified (granulated or pelletized) blast furnace slag, conversion steel slag, slag from the production of carbon steels in the electrical sector, ladle slag, quartz, aluminous cements, sulfo-aluminous clinkers, ye'elimite, belitic clinkers, recycled glass, zeolites, recycled concrete fines from deconstruction, and any of their mixtures.

[0105] Preferably, the mineral composition to be ground comprises, relative to the total dry mass of the mineral composition to be ground, from 20% to 100% by mass of mineral material different from the clinker, preferably from 20% to 99.99% by mass, preferably from 30% to 99% by mass, preferably from 40% to 99% by mass, preferably from 45% to 95% by mass, preferably from 50% to 95% by mass, preferably from 60% to 90% by mass. If the mineral composition to be ground comprises several mineral materials different from the clinker, these contents correspond to the total content of mineral materials different from the clinker.

[0106] When the mineral composition to be ground comprises clinker, the clinker is present in a content preferably ranging from 0.01% to 80% by mass, preferably from 1% to 70% by mass, preferably from 1% to 60% by mass, preferably from 5% to 55% by mass, preferably from 5% to 50% by mass, preferably from 10% to 40% by mass, relative to the total dry mass of the mineral composition to be ground.

[0107] The clinker is in particular Portland or sulfoaluminous clinker, preferably Portland clinker as defined in the work "Cement Chemistry". Harry FW Taylor. Edition, 2., Academie Press, 1990).

[0108] The mineral material other than clinker can be any mineral material capable of entering into the composition of a hydraulic binder.

[0109] Mineral materials other than clinker suitable for the present invention are, for example, calcium sulfates, mineral additions (such as calcined clays, limestones, natural or artificial pozzolans, silica fumes, fly ash, granulated blast furnace slag, calcined shale), crystallized, expanded, vitrified (granulated or pelletized) blast furnace slag, conversion steelworks slag, slag from the production of carbon steels in the electrical sector, ladle slag, ground shale, quartz, aluminous cements, sulfoaluminous clinkers, ye'elimite, belitic clinkers, recycled glasses, zeolites, diatomaceous earths, recycled concrete fines from deconstruction, and any of their mixtures.

[0110] In particular, mineral materials other than clinker suitable for the present invention are, for example, calcium sulfates, mineral additions (such as calcined clays, limestones, natural or artificial pozzolans, silica fumes, fly ash, granulated blast furnace slag, calcined shale), crystallized, expanded, vitrified (granulated or pelletized) blast furnace slag, conversion steelworks slag, slag from the production of carbon steels in the electrical sector, ladle slag, crushed shale, quartz, aluminous cements, sulfoaluminous cements, recycled glasses, zeolites, diatomaceous earths, recycled concrete fines from deconstruction, and any of their mixtures.

[0111] In particular, the mineral material different from the clinker is chosen from calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, fly ash, calcined shale, ground shale, diatomaceous earth, and any of their mixtures; preferably from calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, fly ash, and any of their mixtures.

[0112] In particular, the mineral material other than clinker is chosen from calcium sulfates and mineral additions, more particularly from calcium sulfate, calcined clays, limestones, natural or artificial pozzolans, fly ash and blast furnace slags, even more particularly from calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, and any of their mixtures.

[0113] The term "mineral additions" refers to granulated blast furnace slags as defined in standard NF EN 197-1 (April 2012) "Composition, specifications and conformity criteria for common cements" paragraph 5.2.2), pozzolanic materials such as calcined clays (as defined in standard NF EN 197-1 (April 2012) "Composition, specifications and conformity criteria for common cements" paragraph 5.2.3), fly ash (as defined in standard NF EN 197-1 (April 2012) "Composition, specifications and conformity criteria for common cements" paragraph 5.2.4), calcined shales (as defined in standard NF EN 197-1 (April 2012) "Composition, specifications and conformity criteria for common cements" paragraph 5.2.5), limestones (as defined in standard NF EN 197-1 (April 2012) “Composition, specifications and conformity criteria of common cements” paragraph 5.2.6) or silica fumes (as defined in standard NF EN 197-1 (April 2012) “Composition, specifications and conformity criteria for common cements” paragraph 5.2.7) or their mixtures.

[0114] In particular, the mineral material other than the clinker is chosen from friable mineral materials. Preferably, the mineral composition to be ground comprises a mixture of at least one first mineral material to be ground and at least one second mineral material to be ground.

[0115] The first mineral material to be ground and the second mineral material to be ground are preferably independently selected from one of the above lists concerning “the mineral material other than the clinker suitable for the invention”, preferably from clinker, calcium sulfates, mineral additions (such as calcined clays, limestones, natural or artificial pozzolans, silica fumes, fly ash, granulated blast furnace slag, calcined shales), crystallized, expanded, vitrified (granulated or pelletized) blast furnace slags, conversion steelworks slags, slags from the production of carbon steels in the electric sector, ladle slags, ground shales, quartz, aluminous cements, sulfo-aluminous clinkers, ye'elimite, belitic clinkers, recycled glasses, zeolites, diatomaceous earths and recycled concrete fines from deconstruction,preferably chosen from clinker, calcium sulfate, calcined clays, limestones, natural or artificial pozzolans, and any of their mixtures.,

[0116] According to a particular embodiment, the first mineral material to be ground is a hard mineral material and the second mineral material to be ground is a friable mineral material. Thus, the mineral composition to be ground may comprise at least one hard mineral material and at least one friable mineral material. The hard and friable mineral materials are as defined above.

[0117] Preferably according to this embodiment, the mineral composition to be ground comprises, relative to the total dry mass of the mineral composition to be ground, from 1% to 99% by mass of friable mineral material, preferably from 10% to 90% by mass, preferably from 20% to 80% by mass, preferably from 30% to 70% by mass, preferably from 40% to 60% by mass. If the mineral composition to be ground comprises several friable mineral materials, these contents correspond to the total content of friable mineral materials.

[0118] Preferably according to this embodiment, the mineral composition to be ground comprises, relative to the total dry mass of the mineral composition to be ground, from 1% to 99% by mass of hard mineral material, preferably from 10% to 90% by mass, preferably from 20% to 80% by mass, preferably from 30% to 70% by mass, preferably from 40% to 60% by mass. If the mineral composition to be ground comprises several hard mineral materials, these contents correspond to the total content of hard mineral materials. According to a more specific embodiment, the first mineral material to be ground is clinker, and the second mineral material to be ground is a mineral material other than clinker, preferably chosen from one of the lists above concerning “the mineral material other than clinker suitable for the invention”, preferably from calcium sulfates, mineral additions (such as calcined clays, limestones, natural or artificial pozzolans,silica fumes, fly ash, granulated blast furnace slag, calcined shale), crystallized, expanded, vitrified (granulated or pelletized) blast furnace slag, conversion steelworks slag, slag from the production of carbon steels in the electrical sector, ladle slag, crushed shale, quartz, aluminous cements, sulfo-aluminous clinkers, ye'elimite, belitic clinkers, recycled glasses, zeolites, diatomaceous earths, recycled concrete fines from deconstruction, and any of their mixtures, preferably chosen from calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, fly ash, calcined shale, crushed shale, diatomaceous earths, and any of their mixtures mixtures; more preferably among calcium sulfates, calcined clays, limestones,natural or artificial pozzolans, fly ash, and any of their mixtures, even more preferably chosen from calcium sulfate, calcined clays, limestones, natural or artificial pozzolans, and any of their mixtures, and the clinker content ranges from 0.01% to 80% by mass, preferably from 1% to 70% by mass, preferably from 1% to 60% by mass, preferably from 5% to 55% by mass, preferably from 5% to 50% by mass, preferably from 10% to 40% by mass relative to the total dry mass of the mineral composition to be ground, and preferably the content of second mineral material to be ground ranges from 20% to 99.99% by mass, preferably from 30% to 99% by mass, preferably from 40% to 99% by mass, preferably from 55% to 95% by mass, preferably from 50% to 95% by mass, preferably from 60% to 90% by mass, relative to the total dry mass of the mineral composition to be ground.,

[0119] Preferably according to this embodiment, the second mineral material to be ground is a friable mineral material.

[0120] According to another more specific embodiment, the first mineral material to be ground and the second mineral material to be ground are each a mineral material to be ground different from the clinker, preferably independently chosen from one of the lists above concerning “the mineral material different from the clinker suitable for the invention”, preferably from calcium sulfates, mineral additions (such as calcined clays, limestones, natural or artificial pozzolans, silica fumes, fly ash, granulated blast furnace slag, calcined shales), crystallized, expanded, vitrified (granulated or pelletized) blast furnace slags, conversion steelworks slags, slags from the production of carbon steels in the electrical sector, ladle slags, crushed shales, quartz, aluminous cements, sulfo-aluminous clinkers, ye'elimite, belitic clinkers, recycled glasses, zeolites,diatomaceous earths, recycled concrete fines from deconstruction, and any of their mixtures, preferably chosen from calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, fly ash, calcined shale, crushed shale, diatomaceous earths, and any of their mixtures; more preferably from calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, fly ash, and any of their mixtures, even more preferably chosen from calcium sulfate, calcined clays, limestones, natural or artificial pozzolans, and any of their mixtures.,

[0121] Preferably, the mineral composition to be ground comprises a mixture of clinker and calcium sulfate; or clinker and calcined clay; or clinker and limestone; or clinker and pozzolana (of natural or artificial origin); or calcium sulfate and calcined clay; or calcium sulfate and limestone; or calcium sulfate and pozzolana (of natural or artificial origin); or limestone and calcined clay; or limestone and pozzolana (of natural or artificial origin); or calcined clay and pozzolana (of natural or artificial origin); or clinker, calcium sulfate and calcined clay; or clinker, calcium sulfate and limestone; or clinker, calcium sulfate and pozzolana (of natural or artificial origin); or clinker, calcium sulfate, calcined clay and limestone; or clinker, calcium sulfate, pozzolan (of natural or artificial origin) and limestone;or calcined clay, limestone and pozzolan (of natural or artificial origin), it being understood that when clinker is present, its content ranges from 0.01% to 80% by mass, preferably from 1% to 70% by mass, preferably from 1% to 60% by mass, preferably from 5% to 55% by mass, preferably from 5% to 50% by mass, preferably from 10% to 40% by mass relative to the total dry mass of the mineral composition to be ground.;

[0122] According to one embodiment, the mineral composition to be ground comprises calcium sulfate as an additional element, preferably in a content ranging from 0.1% to 10% by mass, preferably from 1% to 5% by mass relative to the dry mass of the mineral composition to be ground free of calcium sulfate. Indeed, according to this embodiment, the calcium sulfate content is then expressed relative to the total dry mass of all the constituents of the mineral composition to be ground except the calcium sulfate. Thus, according to this embodiment, all the contents of clinker and material(s) other than the clinker described above are also expressed relative to the dry mass of the mineral composition to be ground free of calcium sulfate.

[0123] According to this embodiment, calcium sulfate is present in the mineral composition to be ground in addition to the mineral material to be ground other than clinker, and the possible clinker, or in addition to the first mineral material to be ground and the second mineral material to be ground. In this embodiment, the mineral material to be ground other than clinker, or the first mineral material to be ground and the second mineral material to be ground are as defined above, but are different from calcium sulfate (all the embodiments defined above therefore apply, but without calcium sulfate in the lists of compounds).

[0124] Expressing the contents relative to the total dry mass of the mineral composition to be ground (and not relative to the dry mass of the mineral composition to be ground free of calcium sulfate), according to this embodiment, the mineral composition to be ground preferably comprises:

[0125] - from 0 to 80% by mass of clinker, preferably from 0.01% to 80% by mass, preferably from 1% to 70% by mass, preferably from 1% to 60% by mass, preferably from 5% to 55% by mass, preferably from 5% to 50% by mass, preferably from 10% to 40% by mass,

[0126] - from 19% to 95% by mass of mineral material other than clinker, preferably from 19% to 94.99% by mass, preferably from 19.9% ​​to 90% by mass, preferably from 19.9% ​​to 89.99% by mass, preferably from 29% to 94% by mass, preferably from 29.9% to 89% by mass, preferably from 39% to 94% by mass, preferably from 39.9% to 89% by mass, preferably from 44.9% to 85% by mass, preferably from 44% to 90% by mass, preferably from 49% to 90% by mass, preferably from 49.9% to 85% by mass, preferably from 59% to 85% by mass, preferably from 59.9% to 80% by mass, and

[0127] - from 0.1% to 10% by mass of calcium sulfate, preferably from 1% to 5% by mass.

[0128] Adjuvanted mineral composition The present invention also relates to an adjuvanted mineral composition.

[0129] For the purposes of the application, the term "adjuvanted mineral composition" means the mineral composition as defined above, further comprising the adjuvant composition, and the term "mineral composition" means the mineral composition free of adjuvant.

[0130] The adjuvanted mineral composition is preferably ground.

[0131] Preferably, the adjuvanted mineral composition has a fineness characterized by a median diameter (dso) less than or equal to 20 pm, preferably less than or equal to 15 pm, preferably less than or equal to 10 pm, preferably between 1 and 20 pm. This fineness parameter corresponds to the diameter for which half of the particle population is coarser and the other half finer.

[0132] Preferably, the adjuvanted mineral composition has, for a median diameter dso between 9 and 11 pm, preferably approximately 10 pm, at least 70% by volume of 2-32 pm particles, preferably at least 72% by volume, preferably at least 74% by volume, preferably between 70% and 95% by volume, relative to the total volume of the adjuvanted mineral composition.

[0133] The median diameter (dso) and the particle content 2-32 pm are extracted from the particle size distribution measured in laser particle size sizing for example with MALVERN Mastersizer 3000 equipment in dry process with a Mie model of 1.68 + 0.1 i (i being the imaginary index).

[0134] Preferably, in the adjuvanted mineral composition, the polymer (P) content is between 0.01% and 1% by mass, preferably between 0.05% and 0.5% by mass, preferably between 0.05% and 0.3% by mass, preferably between 0.10% and 0.30% by mass, relative to the total dry mass of the mineral composition.

[0135] Preferably, the adjuvanted mineral composition comprises from 0% to 80% by mass of clinker relative to the total dry mass of the mineral composition.

[0136] The mineral composition therefore preferably comprises at least one mineral material to be ground other than clinker, and possibly clinker.

[0137] Preferably, the adjuvanted mineral composition comprises, relative to the total dry mass of the mineral composition, from 20% to 100% by weight of mineral material other than clinker, preferably from 20% to 99.99% by mass, preferably from 30% to 99% by mass, preferably from 40% to 99% by mass, preferably from 45% to 95% by mass, preferably from 50% to 95% by mass, preferably from 60% to 90% by mass. When the adjuvanted mineral composition comprises clinker, the clinker is present in a content preferably ranging from 0.01% to 80% by mass, preferably from 1% to 70% by mass, preferably from 1% to 60% by mass, preferably from 5% to 55%, preferably from 5% to 50% by mass, preferably from 10% to 40% by mass relative to the total dry mass of the mineral composition.

[0138] The mineral material different from the clinker is as defined above for the mineral composition to be ground. According to one embodiment, the mineral material different from the clinker is a friable mineral material.

[0139] Preferably, the adjuvanted mineral composition comprises a mixture of at least one first mineral material and at least one second mineral material.

[0140] The first mineral material and the second mineral material are preferably independently selected from clinker, calcium sulfates, mineral additions (such as calcined clays, limestones, natural or artificial pozzolans, silica fumes, fly ash, granulated blast furnace slag, calcined shales), crystallized, expanded, vitrified (granulated or pelletized) blast furnace slags, conversion steelworks slags, slags from the production of carbon steels in the electrical sector, ladle slags, ground shales, quartz, aluminous cements, sulfoaluminous clinkers, ye'elimite, belitic clinkers, recycled glasses, zeolites, diatomaceous earths, recycled concrete fines from deconstruction, and any of their mixtures, preferably selected from clinker, calcium sulfates, calcined clays, limestones,natural or artificial pozzolans, and any of their mixtures. According to a specific embodiment, the first mineral material is a hard mineral material and the second mineral material is a friable mineral material, preferably according to the contents defined above for the mineral composition to be ground.,

[0141] According to a more specific embodiment, the first mineral material is clinker, and the second mineral material is chosen from calcium sulfates, mineral additions (such as calcined clays, limestones, natural or artificial pozzolans, silica fumes, fly ash, granulated blast furnace slag, calcined shales), crystallized, expanded, vitrified (granulated or pelletized) blast furnace slags, conversion steelworks slags, slags from the production of carbon steels in the electrical sector, ladle slags, crushed shales, quartz, aluminous cements, sulfo-aluminous clinkers, ye'elimite, belitic clinkers, recycled glasses, zeolites, diatomaceous earths, recycled concrete fines from deconstruction, and any of their mixtures, preferably chosen from calcium sulfates, calcined clays, limestones,natural or artificial pozzolans, fly ash, calcined shale, ground shale, diatomaceous earth, and any of their mixtures; more preferably from calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, fly ash, and any of their mixtures, even more preferably chosen from calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, and any of their mixtures, and the clinker content ranges from 0.01% to 80% by mass, preferably from 1% to 70% by mass, preferably from 1% to 60% by mass, preferably from 5% to 55% by mass, preferably from 5% to 50% by mass, preferably from 10% to 40% by mass relative to the total dry mass of the mineral composition. Preferably according to this embodiment, the second mineral material is a friable mineral material.,

[0142] According to another more specific embodiment, the first mineral material and the second mineral material are different from the clinker, and are preferably independently chosen from calcium sulfates, mineral additions (such as calcined clays, limestones, natural or artificial pozzolans, silica fumes, fly ash, granulated blast furnace slag, calcined shales), crystallized, expanded, vitrified (granulated or pelletized) blast furnace slags, conversion steelworks slags, slags from the production of carbon steels in the electrical sector, ladle slags, ground shales, quartz, aluminous cements, sulfoaluminous clinkers, ye'elimite, belitic clinkers, recycled glasses, zeolites, diatomaceous earths, recycled concrete fines from deconstruction, and any of their mixtures, preferably chosen from calcium sulfates,calcined clays, limestones, natural or artificial pozzolans, fly ash, calcined shale, ground shale, diatomaceous earth, and any of their mixtures; more preferably from calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, fly ash, and any of their mixtures, even more preferably chosen from calcium sulfate, calcined clays, limestones, natural or artificial pozzolans, and any of their mixtures.,

[0143] In particular, the admixed mineral composition comprises a mixture of clinker and calcium sulfate; or clinker and calcined clay; or clinker and limestone; or clinker and pozzolan (of natural or artificial origin); or calcium sulfate and calcined clay; or calcium sulfate and limestone; or calcium sulfate and pozzolan (of natural or artificial origin); or limestone and calcined clay; or limestone and pozzolan (of natural or artificial origin); or calcined clay and pozzolan (of natural or artificial origin);

[0144] Or clinker, calcium sulfate and calcined clay; or clinker, calcium sulfate and limestone; or clinker, calcium sulfate and pozzolans (of natural or artificial origin); or clinker, calcium sulfate, calcined clay and limestone; or clinker, calcium sulfate, pozzolana (of natural or artificial origin) and limestone; or calcined clay, limestone and pozzolana (of natural or artificial origin), it being understood that when clinker is present, its content ranges from 0.01% to 80% by mass, preferably from 1% to 60% by mass, preferably from 5% to 55% by mass, preferably from 5% to 50% by mass, preferably from 10% to 40% by mass relative to the total dry mass of the mineral composition.

[0145] According to one embodiment, the adjuvanted mineral composition comprises calcium sulfate as an additional element, preferably in a content ranging from 0.1% to 10% by mass, preferably from 1% to 5% by mass relative to the dry mass of the mineral composition free of calcium sulfate. Indeed, according to this embodiment, the calcium sulfate content is then expressed relative to the total dry mass of all the constituents of the mineral composition except the calcium sulfate. Thus, according to this embodiment, all the contents of clinker and material(s) other than the clinker described above are valid but are expressed relative to the dry mass of the mineral composition free of calcium sulfate.

[0146] According to this embodiment, the calcium sulfate is present in the admixed mineral composition in addition to the mineral material other than the clinker, and the possible clinker, or in addition to the first mineral material and the second mineral material. In this embodiment, the mineral material other than the clinker, or the first mineral material and the second mineral material are as defined above, but are different from calcium sulfate (all the embodiments defined above therefore apply, but without calcium sulfate in the lists of mineral compounds).

[0147] Expressing the contents relative to the total dry mass of the mineral composition (and not relative to the dry mass of the mineral composition free from calcium sulfate), according to this embodiment, the adjuvanted mineral composition preferably comprises:

[0148] - from 0% to 80% by mass of clinker, preferably from 0.01% to 80% by mass, preferably from 1% to 70% by mass, preferably from 1% to 60% by mass, preferably from 5% to 55% by mass, preferably from 5% to 50% by mass, preferably from 10% to 40% by mass,

[0149] - from 19% to 95% by mass of mineral material other than clinker, preferably from 19% to 94.99% by mass, preferably from 19.9% ​​to 90% by mass, preferably from 19.9% ​​to 89.99% by mass, preferably from 29% to 94% by mass, preferably from 29.9% to 89% by mass, preferably from 39% to 94% by mass, preferably from 39.9% to 89% by mass, preferably from 44.9% to 85% by mass, preferably from 44% to 90% by mass, preferably from 49% to 90% by mass, preferably from 49.9% to 85% by mass, preferably from 59% to 85% by mass, preferably from 59.9% to 80% by mass, and

[0150] - from 0.1% to 10% by mass of calcium sulfate, preferably from 1% to 5% by mass.

[0151] Preferably, the adjuvanted mineral composition is obtained by the grinding process according to the invention.

[0152] The adjuvanted mineral composition may contain other ingredients, which may be added before grinding, possibly via the addition of the adjuvant composition of the present application, or after grinding. Examples of such compounds include, but are not limited to, alkanolamines, glycols, glycerols, accelerator compounds (including chlorinated salts, thiocyanates, formates, nitrates and / or nitrites and mixtures thereof), carboxylic acids or their salts (including acetic, adipic, gluconic, formic, oxalic, citric, maleic, lactic, tartaric, malonic acids and mixtures thereof), water-reducing and high-water-reducing compounds (including lignosulfonates, hydroxylated carboxylic acids, comb-type polycarboxylates and mixtures thereof), packset-reducing compounds, which is a relative numerical index, the measurement of which is described in ASTM C1565-19,representing the tendency of a cement to compact when stored or transported in bulk, (including polyacrylic acids), surfactants, antifoam additives (including tributyl phosphate, tri-iso-butyl phosphate, dibutyl phthalate, octyl alcohol, alkyl amines, water-insoluble esters of carbonic and boric acids and mixtures thereof), air-entraining additives (including wood resin salts, sulfonated lignin salts and mixtures thereof), setting retarders (including sugars, corn syrup and molasses and mixtures thereof) and mixtures thereof.,

[0153] Hydraulic composition The present invention also relates to a hydraulic composition comprising:

[0154] - an adjuvanted mineral composition as defined above,

[0155] - water,

[0156] - possibly an aggregate, and

[0157] - possibly a mineral addition.

[0158] The hydraulic composition according to the invention is preferably a concrete, mortar or screed composition.

[0159] Hydraulic compositions are prepared in a conventional manner by mixing the above-mentioned constituents.

[0160] By "aggregates" we mean a set of mineral grains with an average diameter between 0 and 125 mm. Depending on their diameter, aggregates are classified into one of the following six families: fillers, sands, gravel, gravel and ballast (in standard NF P 18-545 (September 2011) "Aggregates - Elements of definition, conformity and codification".The most commonly used aggregates are: fillers, which have a diameter of less than 2 mm and for which at least 85% of the aggregates have a diameter of less than 1.25 mm and at least 70% of the aggregates have a diameter of less than 0.063 mm, sands with a diameter of between 0 and 4 mm (in standard NF EN 13242+A1 (March 2008) “Aggregates for materials treated with hydraulic binders and untreated materials used for civil engineering works and for road construction”, the diameter can be up to 6 mm), gravel with a diameter of more than 6.3 mm, gravel with a diameter of between 2 and 63 mm.

[0161] Sands are therefore included in the definition of aggregate according to the invention.

[0162] Fillers can be of limestone or dolomitic origin.

[0163] The hydraulic composition may also comprise other additives known to those skilled in the art, for example a mineral addition and / or additives, for example an anti-air entrainment additive, an anti-foaming agent, a setting accelerator or retarder, a rheology modifying agent, another fluidizer (plasticizer or superplasticizer), in particular a superplasticizer, for example a CHRYSOOFluid Premia 180 or CHRYSOOFluid Premia 196 superplasticizer.

[0164] In the context of the present invention, among the setting retarders, mention may in particular be made of setting retarders based on sugar, molasses or vinasse. Preferably, the water-reducing and high-water-reducing adjuvants are chosen from:

[0165] - Sulfonated salts of naphthalene and formaldehyde polycondensates, commonly called polynaphthalene sulfonates or naphthalene-based superplasticizers;

[0166] - Sulfonated salts of melamine and formaldehyde polycondensates, commonly called melamine-based superplasticizers;

[0167] - Lignin derivatives such as lignosulfonates;

[0168] - Sodium gluconate and sodium glucoheptonate;

[0169] - Polyacrylates;

[0170] - Polyaryl ethers (PAE);

[0171] - Products based on polycarboxylic acids, in particular polycarboxylate comb copolymers, which are branched polymers whose main chain carries carboxylic groups and whose side chains are composed of polyether-type sequences, in particular polyethylene oxide, such as poly [(meth)acrylic acid - grafted - polyethylene oxide]. Superplasticizers from the CHRYSO®Fluid Optima, CHRYSO®Fluid Premia and CHRYSO®Plast Omega ranges marketed by CHRYSO and ADVA®, MIRA®, ZYLA® and CONCERA® marketed by GCP may in particular be used;

[0172] - Products based on polyalkoxylated polyphosphonates, notably described in patent EP 0 663 892 (for example CHRYSO®Fluid Optima 100).

[0173] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example.

[0174] In all examples, unless otherwise stated, the contents of adjuvant(s) are expressed in mass relative to the total dry mass of the non-adjuvanted mineral composition.

[0175] EXAMPLES

[0176] The different polymers used are detailed in the following table:

[0177] [Table 1]

[0178]

[0179] *: comparative

[0180] Example 1: Effect of the nature of the polymer present during the grinding of a mineral composition on the particle distribution of the ground mineral composition A mineral composition comprising 55% by mass of clinker, 5% by mass of gypsum and 40% by mass of natural pozzolan relative to the mass of the dry mineral composition is ground alone or in the presence of polymers A, B, C, D, E and F dosed at 0.1% by mass of active material relative to the dry mass of the mineral composition in a laboratory ball mill, in a closed system and with a capacity of 5 kg.

[0181] When present, the polymer is introduced into the mill with the various materials before grinding begins.

[0182] For each test, the grinding of the mineral composition was carried out until the lowest possible median diameter (dso) was obtained. This fineness parameter, corresponding to the diameter for which half of the particle population is coarser and the other half finer, is extracted from the particle size distribution measured by laser particle size analysis with a MALVERN Mastersizer 3000 equipment in the dry process with a Mie model of 1.68 + 0.1 i. The proportion of particles with a diameter between 2 pm and 32 pm is also extracted from the particle size distribution. This proportion is expressed as a percentage.

[0183] The results obtained are collected in the following table 2:

[0184] [Table 2]

[0185] : comparison

[0186] These results show that the presence of a polymer during grinding makes it possible to increase the proportion of 2-32 pm particles for a dso of 10 pm compared to the reference system ground without adjuvant and to achieve a median diameter smaller than the reference. However, polymers B, C, D and E according to the invention make it possible to obtain a higher increase in the 2-32 pm proportion for a dso of 10 pm, i.e. greater than + 6%. The maximization of the proportion of 2-32 pm particles obtained with these specific polymers is linked to the combination of the length of the grafted chain (the z index of the units II), and the molecular mass of the repeating unit (A) on the one hand.

[0187] Example 2: Effect of the nature of the polymer present during the grinding of a mineral composition on the short-term resistance of hydraulic compositions comprising the ground mineral compositions of Example 1

[0188] Different hydraulic compositions including the ground mineral compositions of example 1 were prepared according to the protocol of standard NF EN 196-1 (September 2016) “Cement testing methods - Part 1: determination of strengths - Cement testing methods” with a water to cement composition ratio of 0.5.

[0189] The mechanical compressive strengths at 24 and 48 hours of the final compositions were evaluated according to standard NF EN 196-1 (September 2016) “Cement testing methods - Part 1: Determination of strengths - Cement testing methods”.

[0190] The results obtained are presented in the following Table 3:

[0191] [Table 3]

[0192] : comparison

[0193] These results show that polymers B, C, D and E, which allow a high rate of 2-32 pm particles to be obtained, also allow the 24-hour and 48-hour resistance of hydraulic compositions based on mineral compositions ground in the presence of said polymers to be further improved. Example 3: Effect of the nature of the mineral composition (calcined clay)

[0194] In this example, a mineral composition comprising 55% by mass of clinker, 5% by mass of gypsum and 40% by mass of calcined clay relative to the mass of the dry mineral composition is ground alone or in the presence of polymers A, B or G defined in Table 1, dosed at 0.1% in active matter relative to the dry mass of the mineral composition, in a laboratory ball mill, in a closed system with a grinding capacity of 5 kg. For each test, the grinding of the mineral composition was carried out until the smallest possible median diameter (dso) was obtained.

[0195] The results obtained are collected in the following table 4

[0196] [Table 4]

[0197] The compressive mechanical strengths at 24 hours and 48 hours of hydraulic compositions similar to those of Example 2 but including the ground mineral compositions 3-1*, 3-2* and 3-3 of Example 3 were also determined following the same protocol as in Example 2.

[0198] The results obtained are collected in the following table 5:

[0199] [Table 5] These results are similar to those obtained in Example 1, namely that the polymers meeting the definition according to the invention make it possible to obtain a higher proportion of 2-32 pm particles than the comparative polymer.

[0200] This shows that the specific choice of these polymers makes it possible to maximize this population of particles for different mineral compositions and therefore, the short-term mechanical compressive strengths, these mineral compositions being ground alone or mixed with clinker.

[0201] Example 4: Effect of the proportion of particles 2-32 um

[0202] The short-term (24 hours) compressive mechanical strengths were compared between a hydraulic composition comprising the mineral composition 3-5 of example 3, and a hydraulic composition comprising a similar mineral composition but not having been ground in the presence of polymer G, the latter having been added in the same proportions at the time of mixing, namely 0.1% active matter relative to the dry mass of the mineral composition.

[0203] The results are presented in the following Table 6:

[0204] [Table 6] comparison

[0205] These results illustrate the importance of the proportion of 2-32 pm particles for obtaining high short-term compressive strengths. In this example, the early-age hydration delay of the hydraulic composition induced by the acidity of the polymer is compensated by the increase in the fineness of the mineral composition.

[0206] Example 5: Comparison with a grinding agent of the prior art The efficiency of grinding the mineral composition of Example 3 was compared depending on whether it was carried out in the presence of polymer B at 0.1%, or in the presence of triethanolamine at 0.01%, the dosages being expressed as a percentage of active material relative to the mass of the mineral composition. For each test, the grinding of the mineral composition was carried out until a median diameter (dso) of 7.5 μm was obtained.

[0207] The results obtained are presented in the following table 7: [Table 7]

[0208] In agreement with the results of examples 1 and 3, polymer B made it possible to achieve a proportion of particles with a diameter of 2-32 pm higher than the reference system for a given dso (10 pm) but also in the final state unlike triethanolamine which did not make it possible to improve this property.

[0209] Example 6: Effect of the nature of the mineral composition

[0210] In this example, different mineral compositions were ground in the presence or absence of polymer G defined in Table 1, dosed at 0.1% active matter relative to the dry mass of the mineral composition, in a laboratory ball mill, in a closed system with a grinding capacity of 5 kg. For each test, the grinding of the mineral composition was carried out until a given median diameter (dso) was obtained (indicated as "dso considered").

[0211] The results obtained are collected in the following table 8:

[0212] [Table 8]

[0213] Example 7: Grinding of mineral additionsCalcined clay and limestone were ground either in the presence of polymer G (tests 7-2 and 7-4), or with a prior art grinding agent formulated with triethanolamine acetate (case of calcined clay, test 7-1*) or without any additive (case of limestone, test 7-3**).

[0214] The results obtained are collected in the following table 9:

[0215] [Table 9] comparative, grinding in the presence of a grinding agent based on triethanolamine acetate

[0216] **: comparison, grinding without any additives

[0217] The result with calcined clay shows that the use of polymers (P) makes it possible to obtain a particle content of 2-32 pm even higher than with a grinding agent of the prior art, which illustrates the interest of these polymers as an aid in the grinding of friable mineral materials such as calcined clays.

[0218] The result with limestone also shows the interest of polymers (P) as an aid in the grinding of friable mineral materials, since a very significant gain in particle content 2-32 pm is obtained in the presence of polymer G compared to limestone ground without grinding agent.

Claims

CLAIMS 1. Grinding method comprising grinding a mineral composition to be ground in the presence of an adjuvant composition comprising at least one polymer (P) comprising n repeating units (A) of the following formula: in which: - “M” represents independently of each other H + or a cation of valence v chosen from an alkali metal cation, an alkaline earth metal cation, a bi- or trivalent metal cation, an ammonium cation or an organic ammonium cation, - when “M” represents H, “v” represents 1, and when “M” represents a cation chosen from an alkali metal cation, an alkaline earth metal cation, a bi- or trivalent metal cation, an ammonium cation or an organic ammonium cation, “v” is the valence of the cation M, - “R2” and “R3” independently represent a hydrogen, a methyl or a group of formula -COO(M)i / vwith M and v as defined above, preferably hydrogen or methyl, - “R4” and “R5” independently represent a hydrogen, a methyl or a group of formula -COO(M)i / v with M and v as defined above, - “m” represents 0, 1 or 2, - “p” represents 0 or 1, - “X” is Y or N, and - “R1” represents -[Alkyl-O] z -R6, wherein the “Alkyl” of each [Alkyl-O] unit independently represents a linear or branched alkylene comprising from 2 to 4 carbon atoms, “R6” represents H, a C1 to C20 alkyl group, a cyclohexyl group or an alkylaryl group, and “z” is greater than or equal to 40, the number of units (I) and (II) in the polymer (P) being defined by the repeating unit (A) which comprises a unit (II) and “a” units (I), - “a” being a non-zero positive number, - “n” being between 1.5 and 50, and - the molecular mass of the repeating unit (A) being less than or equal to 6500 g / mol, the mineral composition to be ground comprising from 0% to 80% by mass of clinker and from 20% to 100% by mass of a mineral material other than clinker, relative to the total mass of the mineral composition to be ground.

2. Grinding method according to claim 1, wherein the molecular mass of the repeating unit (A) of the polymer (P) is between 1500 and 6500 g / mol, preferably between 2000 and 6500 g / mol, preferably between 2500 and 6500 g / mol, preferably between 4500 and 6000 g / mol, preferentially between 5200 and 5600 g / mol.

3. Grinding method according to claim 1 or 2, wherein the polymer (P) is such that “z” is greater than or equal to 50, preferably greater than or equal to 70, preferably greater than or equal to 80, preferably greater than or equal to 85, preferably greater than or equal to 90, preferably greater than or equal to 100.

4. Grinding method according to any one of the preceding claims, wherein the polymer (P) is such that “a” is between 0.2 and 100, preferably between 0.5 and 50, preferably between 1.0 and 20, preferably between 3.0 and 10, preferably between 3.9 and 7, preferably between 4.0 and 6.

5. Grinding method according to any one of the preceding claims, in which the polymer (P) has a grafting rate strictly greater than 5%, preferably greater than or equal to 6%, preferably greater than or equal to 10%, preferably greater than or equal to 12%.

6. Grinding method according to any one of the preceding claims, in which the mineral composition to be ground comprises at least one mineral material to be ground other than clinker, and optionally clinker in a content ranging from 0.01% to 80% by mass relative to the total dry mass of the mineral composition to be ground, the material other than clinker being chosen from calcium sulfates, mineral additions, crystallized, expanded, vitrified blast furnace slags, conversion steelworks slags, slags from the production of carbon steels in the electric sector, ladle slags, ground shales, quartz, aluminous cements, sulfoaluminous clinkers, ye'elimite, belitic clinkers, recycled glasses, zeolites, earths of diatoms, recycled concrete fines from deconstruction, and any of their mixtures, preferably chosen from calcium sulfates, calcined clays, limestones, natural or artificial pozzolans, fly ash, calcined shale, crushed shale, diatomaceous earth, and any of their mixtures.

7. Grinding method according to any one of the preceding claims, in which the mineral composition to be ground comprises at least one mineral material to be ground other than clinker, and optionally clinker in a content ranging from 0.01% to 80% by mass relative to the total dry mass of the mineral composition to be ground, the material other than clinker being chosen from friable mineral materials requiring a grinding time to obtain a Blaine fineness between 1500 and 2500 cm 2 / g at least twice less than the grinding time of a clinker meeting the requirements of standard NF EN 197-1 to obtain the same Blaine fineness.

8. Grinding method according to any one of the preceding claims, in which the content of polymer (P) introduced is between 0.01% and 1% by mass, preferably between 0.05% and 0.5% by mass, relative to the total dry mass of the mineral composition to be ground.

9. Grinding method according to any one of the preceding claims, being a method of co-grinding at least one first mineral material to be ground and at least one second mineral material to be ground, and further comprising a step of preparing a mineral composition to be ground, said step comprising mixing said at least first mineral material to be ground and said at least second mineral material to be ground to obtain the mineral composition to be ground.

10. Crushed mineral composition with admixture, comprising a mineral composition comprising, relative to the total dry mass of the mineral composition, from 0% to 80% by mass of clinker and from 20% to 100% by mass of a mineral material other than clinker, and a polymer (P) as defined according to any one of claims 1 to 5.

11. Crushed mineral composition with additive according to claim 10, having a fineness characterized by a median diameter (dso) less than or equal to 20 pm, preferably less than or equal to 15 pm, preferably less than or equal to 10 pm.

12. Crushed mineral composition with additive according to claim 10 or 11, in which the polymer (P) content is between 0.01% and 1% by mass, preferably between 0.05% and 0.5% by mass, relative to the total dry mass of the mineral composition.

13. Crushed mineral composition with admixture according to any one of claims 10 to 12, in which the clinker content is between 0.01% and 80% by mass, preferably between 1% and 60% by mass, preferably between 5% and 55% by mass, preferably between 5% and 50% by mass, preferably between 10% and 40% by mass relative to the total dry mass of the mineral composition.

14. Crushed mineral composition with additive according to any one of claims 10 to 13, obtained by the crushing process according to claims 1 to 9.

15. Hydraulic composition, comprising: - a ground mineral composition with an additive according to any one of claims 10 to 14, - water, - possibly an aggregate, and - possibly a mineral addition.

16. Use of a polymer (P) as defined according to any one of claims 1 to 5, for improving the grindability of a mineral composition to be ground comprising, relative to the total mass of the mineral composition to be ground, from 0% to 80% by mass of clinker and from 20% to 100% by mass of a mineral material other than clinker, preferably for increasing the proportion in fraction 2-32 pm in the particle size distribution of a ground mineral composition comprising from 0% to 80% by mass of clinker and from 20% to 100% by mass of a mineral material other than clinker relative to the total mass of the mineral composition.

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