A dipotassium hydrogen phosphate composition and the production process thereof

Abstract

The present invention concerns a dipotassium hydrogen phosphate composition and the process of preparation thereof. Said DKP composition comprising based on the total weight of said DKP composition at least 50.00 wt.% of DKP; said DKP composition having: a D10 of at least 10 µm, and a D50 of at least 50 µm and of at most 200 µm, said D10 and D50 being measured by laser granulometry in methanol after 3 minutes of ultrasonic sonication. The DKP composition has good flowability.

Description

[0001] ogen phosphate compositions, preferably dipotassium hydrogen phosphate compositions for use in food.

[0002] STATE OF THE ART

[0003] Dipotassium hydrogen phosphate (DKP) is also known as E340ii, a food additive often used as a stabilizer, emulsifier or texturizer in food preparations.

[0004] However, the DKP obtained by the processes of the prior art is often composed of coarse particles. Thus, it might be beneficial to be able to produce DKP with a lower median particle size (D50) because some applications might demand it for specific reasons such for example a homogenous blending, increased speed of dissolution.

[0005] However, DKP with low particle size sometimes exhibits low flowability which might create problems in processes requiring a good flowability.

[0006] Therefore the problem underlying the present invention relates to the improvement of the dynamic flowability of DKP composition having a low median particle size.

[0007] INVENTION SUMMARY

[0008] The inventors have surprisingly found that the present invention solves the above identified problems.

[0009] The present invention concerns a dipotassium hydrogen phosphate composition [hereafter “DKP composition”], comprising based on the total weight of said DKP composition at least 50.00 wt.% of DKP; said DKP composition having:

[0010] • a D50 of at least 50 pm and of at most 200 pm, said D10 and D50 being measured by laser granulometry in methanol.

[0011] The present invention also concerns a process for preparing a dipotassium hydrogen phosphate composition [hereafter, DKP composition] comprising at least the following steps of:

[0012] (i). providing at least one solution [hereafter, solution (A)] comprising based on the total weight of said solution (A) at least 45 wt.% of H3PO4;

[0013] (ii). contacting at least one alkaline composition comprising at least one potassic compound with said at least one solution (A) provided in step (i), thereby forming at least one composition [hereafter, composition (C)]; said composition (C) having a molar ratio K2O / P2O5 of at least 1 .90 and at most 2.10;

[0014] (iii). optionally adding an additive to said composition (C) or to said solution (A) or to said at least one alkaline composition;

[0015] (iv). drying said composition (C), thereby forming a DKP composition; said DKP composition having a particle size distribution [hereafter, PSD] and comprising, based on the total weight of said DKP composition at least 50.0 wt.% of DKP;

[0016] (v). adjusting the PSD of said DKP composition to a PSD having D10 of at least 10 pm and a D50 of at least 50 pm and at most 200 pm; said D10 and D50 being measured by laser granulometry in methanol after 3 minutes of ultrasonication.

[0017] The present invention also concerns a DKP composition obtained by the above process.

[0018] DETAILED DESCRIPTION

[0019] In the context of the present invention, the term “comprising” should not be interpreted as excluding features or elements other than those explicitly mentioned. It should be construed as specifying the presence of the features or elements indicated, but does not exclude the presence or addition of one or more other features or elements. Thus, the scope of the expression "a method comprising steps A and B" should not be limited to methods consisting only of steps A and B. Similarly, a composition comprising components A and B should not be limited to compositions consisting only of components A and B. Accordingly, the terms "comprising" and "including" encompass the terms more restrictive “consisting essentially of” and “consisting of”.

[0020] In the context of the present invention, if an element or component is said to be selected from a list of recited elements or components, it should be understood that the element or component can also be any one of the individual recited elements or components in said list, or can also be selected from a group consisting of any two or more of the explicitly listed elements or components.

[0021] Unless stated otherwise, all the percentages and ppm concentrations are respectively percentages by weight (= wt.%) and ppm in weight (= ppm).

[0022] The use of roman numerals such as (i), (ii), (iii) for designating steps in a process does not necessarily impart an order to said steps, unless specified otherwise. Thus, for example, a step (iii) can be carried out before a step (ii). If one of the step is optional that means that it can sometimes be omitted. For example if step (iii) is optional, the skilled in the art understands that step (iv) can be carried out after step (ii).

[0023] In the context of the present invention, the terms “DKP”, and “dipotassium hydrogen phosphate” are intended to refer to a compound having the formula K2HPO4.

[0024] The DKP composition

[0025] The present invention concerns a dipotassium hydrogen phosphate composition [hereafter “DKP composition”]. Preferably, said DKP composition is a DKP composition for use in food, more preferably for use in baby food.

[0026] According to the present invention, said DKP composition comprises, based on the total weight of said DKP composition, at least 50.00 wt.%, preferably at least 60.00 wt.%, more preferably at least 70.00 wt.%, even more preferably at least 80.00 wt.%, even more preferably at least 90.00 wt.%, even more preferably at least 90.00 wt.%, even more preferably at least 95.00 wt.%, even more preferably at least 98.00 wt.%, even more preferably at least 99.00 wt.% of DKP.

[0027] The DKP composition may comprise based on the total weight of said DKP composition at most 100.00 wt.%.

[0028] Preferably, the DKP composition essentially consists of DKP. The expression “essentially consisting of” is intended to denote that any additional ingredient in said DKP composition, different from DKP such as impurities, including for example pyrophosphate, sulfates and / or fluorides are only present in a minor amount, typically, less than 1 wt.%; being understood that said additional ingredients do not substantially modify the properties of said DKP composition, i.e. do not materially affect the essential characteristics of said DKP composition.

[0029] Within the context of the present invention, the “wt.% of H3PO4” represents the total amount of phosphorus atoms expressed as wt.% of H3PO4 equivalent, and may also be expressed in weight percentages of P2O5 equivalents, denoted wt.% of P2O5. The correspondence between the two concentration units is defined by the relation: 1 wt.% of P2O5 = 0.7245 wt.% of H3PO4.

[0030] According to the present invention, the DKP composition has preferably a D10 of at least 10 pm. Preferably, said DKP composition has a D10 of at least 15 pm, more preferably at least 18 pm, preferably at least 20 pm, more preferably at least 25 pm, even more preferably at least 30 pm, even more preferably at least 35 pm, even more preferably at least 40 pm. The DKP composition according to the present invention has preferably a D10 of at most 70, preferably at most 65 pm, more preferably at most 60 pm, more preferably at most 55 pm, even more preferably at most 50 pm, more preferably at most 45 pm, even more preferably at most 40 pm.

[0031] Preferably, said DKP composition has a D10 of at least 10 pm and at most 70 pm, more preferably, at least 15 pm and at most 65 pm, even more preferably at least 20 pm and at most 65 pm, even more preferably at least 25 pm and at most 65 pm, even more preferably at least 30 pm and at most 65 pm, even more preferably at least 35 pm and at most 65 pm, even more preferably at least 40 pm and at most 65 pm.

[0032] Within the context of the present invention, a D10 is defined as a diameter expressed in pm for which 10 % by volume with regards to the total volume of particles, have smaller diameter than the D10 value. Thus, for example, a DKP composition having a D10 of 30 pm means that 10 vol.% of the total volume of DKP composition has a particle diameter smaller than 30 pm.

[0033] Given the definitions of D10, D50 and D90, for a given composition the D10 is intrinsically always lower than the D50 and the D50 is always lower than D90.

[0034] In a preferred embodiment, said DKP composition has preferably a D10 of at least 10 pm and at most 50 pm, more preferably at least 15 pm and at most 45 pm, even more preferably at least 18 pm and at most 40 pm.

[0035] The DKP composition has preferably a D50 of at least 70 pm, more preferably at least 75 pm, even more preferably at least 80 pm. The DKP composition has preferably a D50 of at most 150 pm, more preferably at most 140 pm, even more preferably at most 130 pm.

[0036] Within the context of the present invention, a D50 is defined as a diameter expressed in pm for which 50 % by volume with regards to the total volume of particles, have smaller diameter than said D50 value. Thus, for example, a DKP composition having a D50 of 130 pm means that 50 vol.% of the total volume of DKP composition has a particle diameter smaller than 130 pm.

[0037] In a preferred embodiment, said DKP composition has preferably a D50 of at least 70 pm and at most 150 pm, more preferably at least 75 pm and at most 140 pm, even more preferably at least 80 pm and at most 130 pm.

[0038] The DKP composition has preferably a D90 of at least 155 pm, more preferably at least 180 pm, even more preferably at least 200 pm. The DKP composition according to the present invention has preferably a D90 of at most 700 pm, more preferably at most 650 pm, even more preferably at most 600 pm.

[0039] Within the context of the present invention, a D90 is defined as a diameter expressed in pm for which 90 % by volume with regards to the total volume of particles, have smaller diameter than said D90 value. Thus, for example, a DKP composition having a D90 of 400 pm means that 90 vol.% of the total volume of said DKP composition has a particle diameter smaller than 400 pm.

[0040] In a preferred embodiment, said DKP composition has preferably a D90 of at least 155 pm and at most 700 pm, more preferably at least 180 pm and at most 650 pm, even more preferably at least 200 pm and at most 600 pm.

[0041] In a more preferred embodiment, said DKP composition has preferably a D50 of at least 80 pm and at most 130 pm and a D10 of at least 19 pm and at most 40 pm and has preferably a D90 of at least 155 pm and at most 700 pm, more preferably at least 180 pm and at most 650 pm, even more preferably at least 200 pm and at most 600 pm.

[0042] Said DKP composition may have a D10 of at most 30 pm, preferably at most 27 pm, more preferably at most 25 pm, even more preferably at most 20 pm. In a preferred embodiment, said DKP composition has a D10 of at least 17 pm and at most 30 pm, more preferably at least 18 pm and at most 27 pm, more preferably at least 19 pm and at most 25 pm, even more preferably at least 19 pm and at most 25 pm.

[0043] Preferably, said DKP composition has a D50 of at least 17 pm, more preferably at least 18 pm, more preferably at least 19 pm. It is understood that said DKP composition may have a D50 of at most 30 pm, preferably at most 27 pm, more preferably at most 25 pm, even more preferably at most 20 pm.

[0044] In a preferred embodiment, said DKP composition has a D50 of at least 17 pm and at most 30 pm, more preferably at least 18 pm and at most 27 pm, more preferably at least 19 pm and at most 25 pm, even more preferably at least 19 pm and at most 25 pm.

[0045] The D10 and / or D50 and / or D90 may be obtained by successive sieving or granulation or atomization or milling or griding or, dynamic granulometry selection or static granulometry selection and combinations thereof or any other means known by the skilled in the art.

[0046] For example the D10 and / or D50 and / or D90 may be for example obtained by milling DKP in an impact mill or hammer mill.

[0047] The inventors have surprisingly found that the D50 of the DKP composition according to the present invention advantageously affects the bulk density to the DKP composition. Some applications require the use of defined bulk densities as this parameter is important to achieve homogeneous powder blends and as high bulk densities are generally more suitable for transportation and storage. Thus, said DKP composition preferably has a bulk density of at least 0.90, preferably at least 0.92, more preferably at least 0.94. If desired, said DKP composition has a bulk density of at most 1 .4, or at most 1 .3, or at most 1 .2. In a preferred embodiment, said DKP composition preferably has a bulk density of at least 0.90 and at most 1 .4, preferably at least 0.92 and at most 1 .3, more preferably at least 0.94 and at most 1 .2.

[0048] The inventors have also surprisingly found that the D10 and D50 of the DKP composition according to the present invention improves the flowability of said DKP composition. Thus, said DKP composition may have a dynamic flowability of at least 219 g / s, preferably at least 250 g / s, more preferably at least 300 g / s, even more preferably at least 350 g / s, even more preferably at least 380 g / s.

[0049] The inventors have also surprisingly found that D10 and D50 of the DKP composition according to the present invention lowers the caking behavior after 21 days in a closed cell. Thus, said DKP composition may have a caking value after 21 days in a closed cell of at most 139 N, preferably at most 120 N, more preferably at most 1 10 N, even more preferably at most 100 N, even more preferably at most 80 N, even more preferably at most 50 N.

[0050] The DKP composition may additionally comprise based on the total weight of said DKP composition, at most 20 ppm, at most 10 ppm at most than 4.00 ppm , preferably at most 2.00 ppm, more preferably at most 1 ppm, even more preferably at most 0.50 ppm, even more preferably at most 0.10 ppm of chlorate, even more preferably at most 0.05 ppm, even more preferably at most 0.03 ppm, even more preferably at most 0.02 ppm, even more preferably at most 0.01 ppm.

[0051] The DKP composition preferably comprises at most 0.060 wt.%, preferably at most 0.050 wt.%, more preferably at most 0.040 wt.%, even more preferably at most 0.030 wt.% of sulfate, even more preferably at most 0.020 wt.%, even more preferably at most 0.016 wt.% of SC .

[0052] The DKP composition preferably comprises at least 10 wt.%, even more preferably at least 15 wt.%, more preferably at least 20 wt.%, even more preferably at least 30 wt.%, even more preferably at least 40.5 wt.%, of P2O5 based on the total weight of said DKP composition. The DKP composition according to the present invention preferably comprises at most 42 wt.%, more preferably at most 41 .5 wt.%, even more preferably 41 wt.%, of P2O5 based on the total weight of said DKP composition.

[0053] Each feature described above for any given embodiment may be combined with any other feature of any other embodiments of the present invention.

[0054] Method for producing a DKP composition

[0055] The present invention also concerns a process for preparing a dipotassium hydrogen phosphate composition [hereafter, DKP composition] comprising at least the following steps of:

[0056] (i). providing at least one solution [hereafter, solution (A)] comprising based on the total weight of said solution (A) at least 45 wt.% of H3PO4;

[0057] (ii). contacting at least one alkaline composition comprising at least one potassic compound with said at least one solution (A), thereby forming at least one composition [hereafter, composition (C)]; said composition (C) having a molar ratio K2O / P2O5 of at least 1 .90 and at most 2.10;

[0058] (iii). optionally adding an additive to said composition (C) or to solution

[0059] (A) or said at least one alkaline composition;

[0060] (iv). drying said composition (C), thereby forming a DKP composition; said DKP composition having a particle size distribution [hereafter, PSD] and comprising, based on the total weight of said DKP composition at least 50.0 wt.% of DKP;

[0061] (v). adjusting the PSD of said DKP composition to a PSD having D10 of at least 10 pm and a D50 of at least 50 pm and at most 200 pm; said D10 and D50 being measured by laser granulometry in methanol after 3 minutes of ultrasonication. Step (i) and solution (A)

[0062] The process according to the present invention comprises a step (i) of providing at least one solution (A) comprising based on the total weight of said solution (A), at least 45 wt.%, preferably at least 60 wt.%, more preferably at least 70 wt.% of H3PO4.

[0063] It is understood that said solution (A) preferably comprises based on the total weight of said solution (A), at most 90 wt.%, more preferably at most 85 wt.% of H3PO4.

[0064] Preferably, said solution (A) comprises based on the total weight of said solution (A), at least 60 wt.% and at most 90 wt.%, more preferably at least 70 wt.% and at most 85 wt.%, even more preferably 75 wt.%, of H3PO4.

[0065] Preferably, said solution (A) has a weight ratio WSO4 / WP2OS below 0.030, preferably below 0.010; more preferably below 0.0050, even more preferably below 0.0010, wherein Wso4 represents the wt.% of SO4 in said solution (A) and WP205 represents the wt.% P2O5 in said solution (A). Both Wso4 and WP205 are based on the total weight of said solution (A).

[0066] In the context of the present invention, the “wt.% of SO4” represents the total amount of sulfur atoms in said solution (A) expressed as wt.% SO4 equivalent. Within the context of the present invention, all the wt.% of SO4 or Wso4 may be measured by any suitable method known in the art. For example, it can be measured by Inductively Coupled Plasma (ICP) spectrometry, more particularly by Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES).

[0067] Preferably, said solution (A) has a weight ratio WF / WP2OS below 0.01 , preferably below 0.005; wherein WF represents the percentage by weight of fluor in said solution (A). WF and WP205 are based on the total weight of said solution (A). Thus, it means that said solution (A) may comprise fluor based compounds such as for example but not limited to fluorides. In the context of the present invention, all the percentages by weight of fluor may be determined by any suitable method known in the art such as direct potentiometry.

[0068] In particular, said solution (A) may originally come from a phosphoric acid solution which is itself the result of a sulfuric acid attack of a phosphate source (ore or equivalent). The phosphoric acid solutions which are directly obtained after a sulfuric acid attack of a phosphate ore usually contain high amounts of impurities such as sulfates which need to be lowered, especially if the phosphoric acid is to be used in the production of food grade DKP.

[0069] The weight ratio WS04 / WP205 as defined above for solution (A) indicates that the solution (A) comprises a relatively low amount of sulfur in comparison to the amount of P2O5. This characteristic of solution (A) may for example be the result of various purification processes known by the skilled in the art which has reduced the amounts of sulfates in solution (A) such as desulfatation by adding a calcium source or by specific process such as the one described in for example described in WO 2012163425 A1 which is hereby incorporated by reference.

[0070] If desired, said solution (A) may be a phosphoric acid solution obtained by the process disclosed in WO 2021 / 254944 A1 which is hereby incorporated by reference. In particular, said solution (A) may be the result of a purification process which includes ion exchange and desulfatation. In other words, said solution (A) may be obtained from a sulfuric acid attack of a phosphate ore followed by purification by ion exchange and / or desulfatation.

[0071] Alternatively, said solution (A) may also come from polyphosphoric acid which is hydrolyzed or not. The obtained polyphosphoric acid may be the result of processes known by the skilled in the art such as dissolution of polyphosphate salt or such as production processes as described in WO 2010 / 108991 A1 which is hereby incorporated by reference. If desired, the process according to the present invention may comprise at least one addition of phosphoric acid salts such as potassium salts, into said solution (A). This enables the recycling of the phosphoric acid salts.

[0072] In particular, said solution (A) may also come from the dissolution of phosphoric or polyphosphoric acid salts in water or in phosphoric acid. Non limiting examples of salts include but are not limited to: monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, potassium pyrophosphate, tetrapotassium pyrophosphate or mixtures thereof.

[0073] Said solution (A) may comprise at least 0.50 ppm of chlorate, based on the total weight of said solution (A). Preferably, said solution (A) can comprise based on the total weight of said solution (A) at least 1 ppm or at least 2 ppm or at least 3 ppm, or at least 4 ppm of chlorate. It is understood that said solution (A) can comprise, based on the total weight of said solution (A) at most 15 ppm or at most 10 ppm or at most 5 ppm of chlorate.

[0074] In certain embodiments, said solution (A) can comprise based on the total weight of said solution (A) at least 1 ppm and at most 15 ppm or at least 2 ppm and at most 10 ppm or at least 4 ppm and at most 5 ppm of chlorate.

[0075] Said solution (A) of step (i) may be provided in any suitable container known by the skilled in the art such as a reactor or a tank. In certain cases, depending on the set-up and / or the origin of said solution (A), agitation may be needed, for example for the step(s) and / or (i) (ii). In this case, the reactor or the tank will be equipped with an devices enabling agitation to occur during the step(s) and / or (i) (ii).lf desired, said step (i) may be carried out in batch or continuously. Step (ii) and composition (C)

[0076] The process according to the present invention further comprises a step (ii) of contacting said solution (A) with at least one alkaline composition comprising at least one potassic compound thereby forming at least one composition (C) having a molar ratio K2O / P2O5 of at least 1 .90 and at most 2.10.

[0077] Within the context of the present invention, an alkaline composition is given its normal meaning in the art. Particularly, an alkaline composition can be defined as a composition which when added into an aqueous solution, will increase the pH of said aqueous solution.

[0078] Within the context of the present invention, a potassic compound is intended to denote a compound comprising at least one potassium cation.

[0079] The skilled in the art may use any suitable alkaline composition comprising at least one potassic compound. Examples of suitable potassic compounds suitable for all the embodiments of the present invention include but are not limited to: KOH (in a solid form such as prills or flakes or as a solution), K2CO3, KHCO3, KH2PO4, K2HPO4, K3PO4, K4P2O7, K2H2P2O7, KPO3, K5P3O10, HKP and mixtures thereof. Preferably, said potassic compound is KOH.

[0080] Within the context of the present invention said at least one alkaline composition comprising at least one potassic compound is sometimes may sometimes be referred to said / the at least one alkaline composition or said / the alkaline composition.

[0081] Within the context of the present invention, the molar ratio K2O / P2O5 refers to the ratio of mol.% of K2O comprised in said composition (C) over the mol.% of P2O5 comprised in said composition (C).

[0082] Within the context of the present invention the mol.% of K2O in said composition (C) refers to the total mol.% of potassium (K) comprised in said composition (C) expressed as K2O equivalent. In the context of the present invention, all the molar ratio K2O / P2O5 may be directly determined by titration.

[0083] It was advantageously found that the specific molar ratio K2O / P2O5 of at least 1 .90 and at most 2.10 enables to obtain DKP, in particular in the drying step (iv). Thus, said composition (C) preferably comprises DKP. Preferably, said DKP comprised in said composition (C) may be at least partially or totally dissolved in said composition (C). Preferably, said DKP comprised in said composition (C) may be at least partially or totally dissociated or undissociated form.

[0084] Preferably, said molar ratio K20 / P20s of said composition (C) is of at least 1.95, more preferably at least 1.98, even more preferably at least 1 .99. It is understood that said molar ratio K2O / P2O5 of said composition (C) is of at most 2.05, more preferably at most 2.02, even more preferably at most 2.01.

[0085] In a preferred embodiment, said molar ratio K2O / P2O5 of said composition (C) is of at least 1 .95 and at most 2.05, more preferably at least 1 .98 and at most 2.02, even more preferably at least 1 .99 and at most 2.01.

[0086] The contacting in step (ii) may be done in any suitable manner known by the skilled in the art with the proviso that said composition (C) has a molar ratio K2O / P2O5 as specified above. For example, the alkaline composition comprising at least one potassic compound may be added to said solution (A) which is already contained in a tank or a reactor. Alternatively, said solution (A) and said alkaline composition comprising at least one potassic compound may be added simultaneously into a tank or a reactor. In another alternative embodiment, said solution (A) is added to said alkaline composition comprising at least one potassic compound which is already contained in a tank or a reactor.

[0087] The contacting step (ii) preferably comprises a step (iia) of adding said alkaline composition comprising at least one potassic compound to said solution (A). More preferably, said alkaline composition comprising at least one potassic compound is added to said solution (A) in step (iia) until said solution (A) reaches a molar ratio K2O / P2O5 of at least 1.90 and at most 2.10.

[0088] If desired, said step (ii) may be carried out in batch or continuously.

[0089] The process according to the present invention preferably comprises a step (iib) of mixing said solution (A) and said alkaline composition comprising at least one potassic compound together. Said mixing step (iib) may be carried out simultaneously or after said step (iia), preferably said mixing step (iib) is an agitation step.

[0090] In step (ii), the alkaline composition comprising at least one potassic compound may be in any suitable form such as in solid form or in solution or as a slurry.

[0091] Preferably, said alkaline composition is in solid form and comprises based on the total weight of said alkaline composition at least 10 wt.%, preferably at least 20 wt.% of K2O.

[0092] It is understood that said alkaline composition in solid form may comprise preferably at most 80 wt.%, more preferably at most 75 wt.%, even more preferably at most 70 wt.% of K2O.

[0093] In a preferred embodiment, said alkaline composition is in solid form and comprises based on the total weight of said alkaline composition at least 10 wt.% and at most 80 wt.%, preferably at least 15 wt.% and at most 75 wt.%, even more preferably at least 20 wt.% and at most 70 wt.% of K2O.

[0094] Within the context of the present invention the wt.% of K2O in said composition (C) refers to the total wt.% of potassium (K) comprised in said composition (C) expressed as K2O equivalent.

[0095] Within the context of the present invention, all the wt.% of K2O can be measured by any suitable method known in the art. All the wt.% of K2O may be measured by potentiometric titration or by Inductively Coupled Plasma (ICP) spectrometry more particularly by Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES).

[0096] Preferably, said alkaline composition is in solid form and comprises based on the total weight of said alkaline composition at least 10 wt.%, preferably at least 20 wt.%, more preferably at least 30 wt., even more preferably at most 40 wt.%, even more preferably at most 50 wt.%, even more preferably at most 60 wt.%, even more preferably at most 80 wt.%, even more preferably at most 90 wt.%, even more preferably at most 99 wt.% of potassic compound.

[0097] Preferably, the alkaline composition is a solution [hereafter, solution (B)]. Said potassic compound may be at least partially or totally dissolved in said solution (B).

[0098] Preferably, said solution (B) comprises based on the total weight of said solution (B), at last 20 wt.%, more preferably at least 30 wt.%, more even preferably at least 40 wt.%, even more preferably at least 45 wt.% of K2O and / or of potassic compound.

[0099] It is understood that said solution (B) preferably comprises based on the total weight of said solution (B), at most 60 wt.%, more preferably at most 55 wt.% of K2O and / or of potassic compound.

[0100] In a preferred embodiment, said solution (B) preferably comprises based on the total weight of said solution (B), at least 30 wt.% and at most 60 wt.%, preferably at least 40 wt.% and at most 60 wt.% more preferably at least 45 wt.% and at most 55 wt.% of K2O and / or of potassic compound.

[0101] In a more preferred embodiment, the alkaline composition comprises at least one potassic compound selected from the group consisting of KOH, K2CO3, KHCO3, KH2PO4, K2HPO4, K3PO4, K4P2O7, K2H2P2O7, KPO3, K5P3O10 , HKP and mixtures thereof; wherein said alkaline composition is a solution (B) comprising based on the total weight of said solution (B), at least 40 wt.% and at most 55 wt.% of said potassic compound. It is understood that at least part or the totality of the potassic compound comprised in the alkaline composition may advantageously react with at least part or the totality of the phosphoric acid comprised in solution (A).

[0102] Preferably, said composition (C) has a pH of at least 8.5 and at most 9.5, more preferably a pH of at least 8.7 and at most 9.2.

[0103] Within the context of the present invention, the term “chlorate” is intended to denote a CIOs’ anion. Thus, the concentration of chlorate is calculated with regards to the CIOs’ anion. Of course, the chlorate may be present in the composition (C) in associated form with cations such as for example potassium or sodium in order to form KCIOs or NaCIOs. When in solution, chlorates such as KCIOs and NaCIOs may be at least partially or totally dissociated. Therefore, said chlorate may be KCIOs or NaCIOs or other chlorates.

[0104] The chlorate comprised in said composition (C) may come from different sources. For example, the chlorate may be comprised in said solution (A) and / or it may be comprised in said alkaline composition comprising at least one potassic compound. The skilled in the art knows that alkaline compositions comprising at least one potassic compound such as KOH may comprise significant amounts of chlorate because KOH is generally synthetized through electrolysis of an aqueous solution of potassium chloride (KCI) in diaphragm-type cell. The chlorate may also come from other additives which were added to said composition (C) or from the solution (A) provided in step (i).

[0105] Therefore, preferably, said alkaline composition or said solution (B), comprises based on the total weight of said alkaline composition or said solution (B), at least 1 ppm of chlorate, more preferably at least 2 ppm of chlorate, even more preferably at least 3 ppm of chlorate. It is understood that said alkaline composition or said solution (B) preferably comprises at most 15 ppm of chlorate, more preferably at most 10 ppm of chlorate, of chlorate based on the total weight of said alkaline composition or said solution (B).

[0106] In a preferred embodiment, said alkaline composition or said solution (B), comprises based on the total weight of said alkaline composition or said solution (B), at least 1 ppm and at most 15 ppm of chlorate, more preferably at least 2 ppm and at most 10 ppm of chlorate, even more preferably at least 3 ppm and at most 10 ppm of chlorate.

[0107] In a preferred embodiment, the alkaline composition comprises at least one potassic compound selected from the group consisting of KOH, K2CO3, KHCO3, KH2PO4, K2HPO4, K3PO4, K4P2O7, K2H2P2O7, KPO3, K5P3O10, HKP and mixtures thereof; and said alkaline composition is a solution (B) comprising based on the total weight of said solution (B), at least 40 wt.% and at most 55 wt.% of said potassic compound and at least 45 wt.% and at most 55 wt.%, preferably 50 wt.% of KOH and at least 2 ppm and at most 15 ppm of chlorate preferably 5 ppm of chlorate.

[0108] Said contacting step (ii) may be carried out in batch or continuously, preferably under agitation.

[0109] Said contacting step (ii) may preferably be carried out for at least 30 minutes, more preferably at least 1 hour, even more preferably at least 2 hours. It is understood that said contacting step (ii) may preferably be carried out for at most 8 hours, more preferably at least 6 hours. In a preferred embodiment, said contacting step (ii) may preferably be carried out for at least 1 hour and at most 8 hours, more preferably at least 2 hours and at most 6 hours.

[0110] Optional step (iii) and additives

[0111] According to step (iii) of process according to the present invention, an additive is optionally added to said composition (C) formed in step (ii) or to solution (A) or to said alkaline composition. The additive may be any suitable additive including for example processing aids or any food additive listed in the Codex Alimentarius CAC / GL 10 - 1979 which summarizes all the mineral supplements sources recommended for use in infant and baby food or raw materials.

[0112] Examples of suitable additives include but are not limited to potassium salts such as monopotassium or dipotassium phosphates, potassium hydroxide, potassium chloride, potassium acetate, potassium citrate; calcium or magnesium sources such as magnesium or calcium phosphates, magnesium or calcium carbonates, magnesium or calcium chloride, magnesium or calcium citrate, magnesium or calcium sulphate; iron sources such as iron phosphate, iron sulfate, zinc phosphate, zinc sulphate and mixtures thereof.

[0113] The said additive may preferably be added in an amount of at least 0.3mg, more preferably 0.5 mg, more preferably at least 1 mg, more preferably at least 5 mg, more preferably at least 7 mg, even more preferably at least 10 mg of metal element per kg of said DKP composition formed in step (iv). The said additive may preferably be added in an amount of at most 60 mg, more preferably at most 50 mg, even more preferably at most 40 mg, even more preferably at most 35 mg. even more preferably at most 30 mg. even more preferably at most 25 mg of metal element per kg of said DKP composition formed in step (iv).

[0114] Thus, the said additive may preferably be added in an amount between 0.5 and 60 mg, preferably between 5 and 50 mg, more preferably between 10 and 40 mg of metal element per kg of said DKP composition formed in step (iv).

[0115] If desired, said step (iii) may be carried out in batches or continuously, preferably under agitation.

[0116] Drying step (iv) The process according to the present invention further comprises a drying step (iv) of said composition (C) obtained in step (iii), thereby forming said DKP composition.

[0117] The drying step (iv) may be performed by any suitable means known by the skilled in the art. Preferably, said drying step (iv) may comprise drying said composition (C) using a direct or indirect contact with a fluid (preferably hot fluid, preferably hot gases). The drying step (iv) may be carried out with a drying device such as (but not limited to) a fluidized bed, an atomizer, a flash dryer, a drum dryer, a spray dryer or by a combination thereof.

[0118] Preferably said drying step (iv) is carried out until said DKP composition obtained in step (iv) comprises at most 10 wt.%, preferably at most 5 wt.%, more preferably at most 2 wt.%, even more preferably at most 1 wt.% of water, based on the total weight of said DKP composition.

[0119] Preferably, said drying step (iv) is carried out by heating said composition (C) until a temperature of at least 150 °C, more preferably at least 180°C, even more preferably at least 200°C, even more preferably at least 220°C is reached. It is understood that in said drying step said composition (C) may be dried in step (iv) until a temperature of at most 250°C is reached.

[0120] In a preferred embodiment, said drying step (iv) is carried out by heating said composition (C) until a temperature of at least 150 °C and at most 250°C, more preferably at least 180°C and at most 250°C, even more preferably at least 220°C and at most 250°C is reached.

[0121] Said composition (C) is preferably dried in step (iv) for an overall time of at least 2 hours, more preferably at least 3 hours, even more preferably at least 4 hours. Said composition (C) is preferably dried in step (iv) for at most 8 hours, more preferably at most 7 hours, even more preferably at most 6 hours. Alternatively, said composition (C) may be dried in step (iv) substantially instantaneously, preferably for at least 15 seconds, more preferably at least 1 minute, even more preferably at least 3 minutes, even more preferably at least 5 minutes, even more preferably at least 10 minutes, even more preferably at least 15 minutes, even more preferably at least 30 minutes, even more preferably at least 1 hour. Said composition (C) may be dried in step (iv) for at most 2 hours, more preferably at most 1 hour, even more preferably at most 45 minutes, even more preferably at most 20 minutes, even more preferably at most 10 minutes, even more preferably at most 5 minutes, even more preferably at most 1 minute.

[0122] In a preferred embodiment, said composition (C) may be dried in step (iv) during at least 10 seconds and at most 15 seconds, or at least 45 seconds and at most 90 seconds, or at least 4 minutes and at most 6 minutes or at least 10 minutes and at most 20 minutes, or at least 20 minutes and at most 40 minutes, or at least 1 hour and at most 2 hours.

[0123] Each feature described above for any given embodiment may be combined with any other feature of any other embodiments of the present invention.

[0124] Steps (v) - adjusting the particles size distribution (PSD)

[0125] The process according to the present invention comprises a step (v) of adjusting the PSD of said DKP composition, particularly, obtained in step (iv), to a PSD having D10 of at least 10 pm and a D50 of at least 50 pm and at most 200 pm, and optionally a D90 of at least 155 pm, more preferably at least 180 pm, even more preferably at least 200 pm; said D10 and D50 and optionally the D90 being measured by laser granulometry in methanol after 3 minutes of ultrasonication.

[0126] Preferably, the drying step (iv) and the step (v) may be carried out simultaneously or not or step (v) may be carried out after said step (iv).

[0127] If desired, the D10 and the D50 and optionally the D90 of the PSD of said DKP composition may be adjusted in different subsequent steps or simultaneously. In one embodiment, said step (v) may comprise:

[0128] • a step (va) of adjusting the PSD of said DKP composition, to a PSD having D10 of at least 10 pm; and

[0129] • a step (vb) of adjusting the D50 of said PSD of said DKP composition to a D50 of at least 50 pm and at most 200 pm; and

[0130] • optionally a step (vc) of adjusting the D90 of said PSD of said DKP composition to a D90 of at least 155 pm, more preferably at least 180 pm, even more preferably at least 200 pm.

[0131] Said steps (va), (vb) and optionally (vc) may be carried out by any known means enabling the adjustment of the D10, D50 and D90 to the above values. Said steps (va), (vb) and optionally (vc) may be carried out simultaneously in a single step or not.

[0132] The order of the steps (va), (vb) and (vc) may vary. For example, said step (vb) may be carried out before or after the step (va) or after the step (vc). The step (vc) may be carried out before or after the steps (va) and (vb).

[0133] In an alternative embodiment, said step (va) and (vb) may be carried out simultaneously and said step (vc) may be carried out after said steps (va) and (vb).

[0134] In an alternative embodiment, said step (va) and (vc) may be carried out simultaneously and said step (vb) may be carried out after said steps (va) and (vc).

[0135] In an alternative embodiment, said step (vc) and (vb) may be carried out simultaneously and said step (va) may be carried out after said steps (vc) and (vb).

[0136] Said step (v) or steps (va), (vb), (vc) may be carried out by a technique selected from the group consisting of milling, grinding, sieving and combinations thereof. Example of milling include but are not limited to bead milling, ball milling, impact milling, attrition milling and combination thereof.

[0137] Preferably, the milling may comprise the use of a static and dynamic selector.

[0138] Preferably, the milling is carried out by a milling apparatus comprising a stator-rotor system.

[0139] More preferably, said step (v) or steps (va), (vb) and optionally (vc) is carried out by impact milling, comprises the use of a static and dynamic selectors and is carried out by an apparatus comprising a stator-rotor system.

[0140] In particular, regarding said step (v) or steps (va), (vb) and optionally (vc) above, said milling or grinding may comprise cutting or compressing or impact milling or attrition milling or a combination thereof.

[0141] Preferably, in step (v) or step (va), the PSD of said DKP composition, particularly obtained in step (iv), is adjusted to a PSD having D10 of at least 15 pm, more preferably at least 18 pm. It is understood that in step (v) or step (va), the PSD of said DKP composition, particularly obtained in step (iv), may preferably be adjusted to a PSD having D10 of at most 50 pm, more preferably at most 45 pm, even more preferably at most 40 pm.

[0142] In a preferred embodiment, in step (v) or step (va), the PSD of said DKP composition, particularly obtained in step (iv), is adjusted to a PSD having D10 of at least 10 pm and at most 50 pm, more preferably at least 15 pm and at most 45 pm, even more preferably at least 18 pm and at most 40 pm.

[0143] Preferably, in step (v) or step (vb), the PSD of said DKP composition is adjusted, to a PSD having a D50 of at least 70 pm, more preferably at least 75 pm, even more preferably at least 80 pm. It is understood that in step (v) or in step (vb), the PSD of said DKP composition is adjusted to a PSD preferably having a D50 of at most 150 pm, more preferably at most 140 pm, even more preferably at most 130 pm.

[0144] In a preferred embodiment, in step (v) or step (vb), the PSD of said DKP composition is adjusted to PSD having a D50 of at least 70 pm and at most 150 pm, more preferably at least 75 pm and at most 140 pm, even more preferably at least 80 pm and at most 130 pm.

[0145] Preferably, in step (v) or step (vc), the PSD of said DKP composition is adjusted, to a PSD having a D90 of at least 155 pm, more preferably at least 180 pm, even more preferably at least 200 pm. It is understood that in step (v) or in step (vc), the PSD of said DKP composition is adjusted to a PSD preferably having a D90 of at most 700 pm, more preferably at most 650 pm, even more preferably at most 600 pm.

[0146] In a preferred embodiment, in step (v) or step (vc), the PSD of said DKP composition is adjusted to PSD having a D90 of at least 155 pm and at most 700 pm, more preferably at least 180 pm and at most 650 pm, even more preferably at least 200 pm and at most 600 pm.

[0147] In a preferred embodiment, in step (v), the PSD of said DKP composition, particularly, obtained in step (iv), is adjusted to a PSD having:

[0148] • a D10 of at least 18 pm and at most 40 pm and

[0149] • a D50 of at least 75 pm and at most 140 pm, even more preferably at least 80 pm and at most 130 pm; and

[0150] • a D90 of at least 155 pm and at most 700 pm, more preferably at least 180 pm and at most 650 pm, even more preferably at least 200 pm and at most 600 pm.

[0151] In another preferred embodiment, in step (v), the PSD of said DKP composition, particularly, obtained in step (iv), is adjusted to a PSD having:

[0152] • a D10 of at least 18 pm and at most 40 pm and

[0153] • a D50 of at least 80 pm and at most 130 pm; and • a D90 of at least 155 pm and at most 700 pm, more preferably at least 180 pm and at most 650 pm, even more preferably at least 200 pm and at most 600 pm.

[0154] The inventors have surprisingly found that the adjustment of the PSD of the DKP composition to a PSD having a D50 according to the present invention advantageously affects the bulk density to the DKP composition. Some applications require the use of defined bulk densities as this parameter is important to achieve homogeneous powder blends and as high bulk densities are generally more suitable for transportation and storage. Thus, said DKP composition obtained in step (v) preferably has a bulk density of at least 0.90, preferably at least 0.92, more preferably at least 0.94. Preferably, said DKP composition has a bulk density of at most 1 .4, preferably at most 1 .3, more preferably at most 1 .2.

[0155] In a preferred embodiment, said DKP composition obtained at step (v) preferably has a bulk density of at least 0.90 and at most 1 .4, preferably at least 0.92 and at most 1 .3, more preferably at least 0.94 and at most 1 .2.

[0156] The inventors have also surprisingly found that the values of the D10 and D50 of the DKP composition according to the present invention improves the flowability of said DKP composition. Thus, said DKP composition obtained in step (v) may have a dynamic flowability of at least 219 g / s, preferably at least 250 g / s, more preferably at least 300 g / s, even more preferably at least 350 g / s, even more preferably at least 380 g / s.

[0157] The inventors have also surprisingly found that D10 and D50 of the DKP composition according to the present invention advantageously impacts the caking value after 21 days in a closed cell. Thus, said DKP composition obtained at step (v) may have a caking value after 21 days in a closed cell of at most 139 N, preferably at most 120 N, more preferably at most 110 N, even more preferably at most 100 N, even more preferably at most 80 N, even more preferably at most 50 N. The DKP composition obtained at step (v) may comprise based on the total weight of said DKP composition, at most 20 ppm, at most 10 ppm at most than 4.00 ppm, preferably at most 2.00 ppm, more preferably at most 1 ppm, even more preferably at most 0.50 ppm, even more preferably at most 0.10 ppm of chlorate even more preferably at most 0.05 ppm, even more preferably at most 0.03 ppm, even more preferably at most 0.02 ppm, even more preferably at most 0.01 ppm.

[0158] The DKP composition preferably comprises at most 0.060 wt.%, preferably at most 0.050 wt.%, more preferably at most 0.040 wt.%, even more preferably at most 0.030 wt.% of sulfate, even more preferably at most 0.020 wt.%, even more preferably at most 0.016 wt.% of SC .

[0159] The DKP composition preferably comprises at least 10 wt.%, more preferably at least 20 wt.%, even more preferably at least 40.5 wt.%, of P2O5 based on the total weight of said DKP composition. The DKP composition according to the present invention preferably comprises at most 42 wt.%, more preferably at most 41 .5 wt.%, even more preferably 41 wt.%, of P2O5 based on the total weight of said DKP composition.

[0160] Method for measuring D10, D50 and D90

[0161] Within the context of the present invention, all the D10, D50 and D90 values are measured by laser granulometry (Mastersizer Hydro 200S of Malvern) after 3 minutes of ultrasonic sonication (maximum power), the dispersant is methanol.

[0162] Method for measuring P2O5 content

[0163] Within the context of the present invention, all the P2O5 wt.% may be measured by any suitable method known in the art. Preferably, all the P2O5 wt.% are measured by colorimetry of phosphor-vanado-molybdate at 436 nm (yellow) (Light absorption spectrophotometry). Protocol for measuring chlorate content

[0164] Within the context of the present invention, all the mentioned chlorate contents can be measured by any suitable method. Preferably, all the mentioned chlorate contents were measured according to the Quick Polar Pesticides Protocol (QuPPe). This protocol involves extraction with acidified methanol and LC-MS / MS measurement. Isotope labelled analogues of the compounds are used as internal standards (ILISs) to correct for volumetric variations, matrix effects and other biases. The separation of the species and the subsequent quantification is performed by a LC-MS / MS protocol. In particular, all the chlorate amounts measured in the context of the present patent application can be measured by application of the M2 protocol disclosed in the document : M. Anastassiades; A.-K. Wachtler; D. I. Kolberg; E. Eichhorn; H. Marks; A. Benkenstein; S. Zechmann; D. Mack; C. Wildgrube; A. Barth; I. Sigalov; S. Gbrlich; D. Dork; G. Cerchia, Quick Method for the Analysis of Highly Polar Pesticides in Food Involving Extraction with Acidified Methanol and LC- or IC-MS / MS Measurement, EU Reference Laboratory for pesticides requiring Single Residue Methods, European Commission, (EURL-SRM) Version 12 of the 22.07.2021 , page 52.

[0165] Method for measuring the bulk density

[0166] Within the context of the present invention, all the bulk density values can be determined according to the method defined in DIN ISO 697.

[0167] Method for measuring the caking value

[0168] The DKP caking test is carried out in two steps: a first step of consolidation of the powder into a solid mass followed by a quantitative evaluation. In the test, powders with a caking character are transformed into a cylindrical solidified mass whose hardness reflects the intensity of the caking behavior. The quantification of the caking is carried out by evaluating the force necessary to break the consolidated cylindrical mass.

[0169] Firstly, the powder is subject to a compressive force for a fixed time. Hence, a mass of DKP is homogeneously fed into a lined cylinder. The mass is first surmounted by a piston. In conditions that prevent exchanges with ambient air, the compression is maintained for 21 days at room temperature (22-25°C). The assembly is then placed on a mechanical bench equipped with dynamometer (Mecmesin Multitest-d fitted with a AFG 500N dynamometer). A tip moves at a speed of 60 mm / sec and compresses the cylinder of consolidated powder. The dynamometer records the force progressively applied up to the point of rupture of the consolidated mass. The greater the force at rupture, the higher the tendency to display a powder caking behavior in real storage conditions.

[0170] Method for measuring the dynamic flowability

[0171] The dynamic flowability behaviour of the DKP samples were assessed by measuring the time required by a defined quantity of DKP powder to empty a vessel. The outlet of the vessel is a has a 38 mm diameter. To break loose agglomerates to prior to testing, the DKP samples were sieved at 2 mm. The bottom of the cone was blocked. The sample was subsequently transferred to the cone in a reproducible manner. The closure of the outlet was released and the time necessary to empty the cone was measured. The experiment was repeated three times and averaged. The dynamic flowability was calculated and expressed in g / sec.

[0172] Examples

[0173] A solution of phosphoric acid (solution A) having the characteristics shown in table 1 was provided in a first step (i). Table 1

[0174] A solution of KOH in water was prepared. The solution comprised 50 wt.% based on the total weight of solution, of KOH and 2 ppm of chlorates.

[0175] In a step (ii), the solution of KOH and the phosphoric acid solution were added simultaneously into a 20L tank. The content of the tank was mixed during the whole addition. The amount of KOH solution added was such that the final pH of the resulting mixture (the composition (C)) had a pH of 8.5-9.5 and a K2O / P2O5 molar ratio comprised between 1 .98 and 2.02 (step (ii)). The obtained composition (C) comprised DKP which was at least partially or totally dissolved in said composition (C). During the whole step (ii), the solution of KOH (solution (B)) and the solution (A) of phosphoric acid were contacted for at least 1 hour and at most 6 hours.

[0176] There was no addition of other additives.

[0177] At a step (iv), the obtained mixture in the tank was dried until a maximum temperature of at least 210°C and at most 230°C is reached.

[0178] The drying was carried out until the DKP composition comprised over 99.00 wt.% of DKP, and less than 1 wt.% of water. Additionally, said DKP composition comprised at most 0.016 wt.% of SC . The wt.% are based on the total weight of said DKP composition.

[0179] The DKP composition obtained at step (iv) was milled in order to adjust the PSD of the DKP composition to a PSD having the D10, D50 and D90 values as summarized in table 2. The milling was achieved via an impact mill comprising a stator-rotor system with the rotor set at its lowest rotating speed. Additionally, the bulk density, the flowability and the caking values were measured and are also summarized in table 2. It was observed that the obtained DKP compositions had very good dynamic flowability.

[0180] Table 2

Claims

CLAIMS1. A dipotassium hydrogen phosphate composition [hereafter “DKP composition”], comprising based on the total weight of said DKP composition at least 50.00 wt.% of DKP; said DKP composition having:• a D10 of at least 10 pm, and• a D50 of at least 50 pm and of at most 200 pm, said D10 and D50 being measured by laser granulometry in methanol after 3 minutes of ultrasonic sonication.

2. The DKP composition according to claim 1 , wherein said DKP composition has a D10 of at least 15 pm, more preferably at least 18 pm.

3. The DKP composition according claim 1 or claim 2, wherein said DKP composition has a D10 of at most 50 pm, preferably at most 45 pm, more preferably at most 40 pm.

4. The DKP composition according to any one of the preceding claims, wherein said DKP composition has a D50 of at least 70 pm, more preferably at least 75 pm, even more preferably at least 80 pm.

5. The DKP composition according to any one of the preceding claims, wherein said DKP composition has preferably a D50 of at most 150 pm, more preferably at most 140 pm, even more preferably at most 130 pm.

6. The DKP composition according to any one of the preceding claims, wherein said DKP composition has a D90 of at least 155 pm, preferably at least 180 pm, more preferably at least 200 pm.

7. The DKP composition according to any one of the preceding claims, wherein said DKP composition has a D90 of at most 700 pm, preferably at most 650 pm, more preferably at most 600 pm.

8. A process for preparation a dipotassium hydrogen phosphate composition [hereafter, DKP composition] comprising at least the following steps of:(i). providing at least one solution [hereafter, solution (A)] comprising based on the total weight of said solution (A) at least 45 wt.% of H3PO4;(ii). contacting at least one alkaline composition comprising at least one potassic compound with said at least one solution (A) provided in step (i), thereby forming at least one composition [hereafter, composition (C)]; said composition (C) having a molar ratio K2O / P2O5 of at least 1.90 and at most 2.10;(iii). optionally adding an additive to said composition (C) or said at least one alkaline composition or to said solution (A);(iv). drying said composition (C), thereby forming a DKP composition; said DKP composition having a particle size distribution [hereafter, PSD] and comprising, based on the total weight of said DKP composition at least 50.0 wt.% of DKP;(v). adjusting the PSD of said DKP composition to a PSD having D10 of at least 10 pm and a D50 of at least 50 pm and at most 200 pm; said D10 and D50 being measured by laser granulometry in methanol after 3 minutes of ultrasonication.

9. The process according to claim 8, wherein said step (v) is carried out by a technique selected from the group consisting of milling, grinding, sieving and combinations thereof.

10. The process according to claim 9, wherein said milling is bead milling, ball milling, impact milling, attrition milling or combinations thereof; or is carried out by a milling apparatus comprising a stator-rotor system.

11. The process according to claim 9 or claim 10, wherein in step (v), the PSD of said DKP composition, particularly obtained in step (iv), is adjusted to a PSD having D10 of at least 15 pm, more preferably at least 18 pm.

12. The process according to any one of claims 9 to 11 , wherein in step (v), the PSD of said DKP composition, particularly obtained in step (iv), is adjusted to a PSD having D10 of at most 50 pm, more preferably at most 45 pm, even more preferably at most 40 pm.

13. The process according to any one of claims 9 to 12, wherein in step (v), the PSD of said DKP composition is adjusted to PSD having a D50 of at least 70 pm and at most 150 pm, more preferably at least 75 pm and at most 140 pm, even more preferably at least 80 pm and at most 130 pm.

14. The process according to any one of claims 9 to 13, wherein the PSD of said DKP composition is adjusted to PSD having a D90 of at least 155 pm and at most 700 pm, more preferably at least 180 pm and at most 650 pm, even more preferably at least 200 pm and at most 600 pm.

15. The process according to any one of the claims 9 to 14, wherein the PSD of said DKP composition, particularly obtained in step (iv), is adjusted to a PSD having:• a D10 of at least 18 pm and at most 40 pm; and• a D50 of at least 80 pm and at most 130 pm; and• a D90 of at least 155 pm and at most 700 pm, more preferably at least 180 pm and at most 650 pm, even more preferably at least 200 pm and at most 600 pm.

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