PROCESS TO PREPARE SODIUM AND/OR POTASSIUM SALT PRODUCTS, SALT PRODUCT OBTAINABLE THEREBY AND THE USE THEREOF

Abstract

The present invention relates to a process to prepare a free-flowing salt product comprising sodium chloride (NaCl) and/or potassium chloride (KCl), wherein the salt product has a particle size of from 50 m to 1000 m, which process comprises the steps of (a) processing a source of pure NaCl, pure KCl, or mixture of salts, to form particles with an average size of less than 100 micrometer; (b) subsequently, compacting the particles from step a) using a pressure of from 40 to 400 MPa; and optionally, crushing the thus obtained particles; and (c) subsequently, absorbing one or more agents into the salt particles, characterized in that no agent is added in or during steps a) and b) or between steps a) and b).

Claims

1.-4. (canceled)

5. Process to prepare a free-flowing salt product comprising sodium chloride (NaCl) and/or potassium chloride (KCl), wherein the salt product has a particle size of from 50 m to 1000 m, which process comprises the steps of: a. processing a source of pure NaCl, pure KCl, or mixture of salts, to form particles with an average size of less than 100 micrometer; b. subsequently, compacting the particles from step a) using a pressure of from 40 to 400 MPa; and optionally, crushing the thus obtained particles; and c. subsequently, absorbing one or more agents into the salt particles, characterized in that no agent is added in or during steps a) and b) or between steps a) and b), and wherein the agent is in liquid form, not being water or any other liquid in which the salt dissolves for more than 5% by weight at 20 C. at 1 atm (1,013 bar).

6. Process according to claim 5 wherein the agent is selected from a flavouring agent, a colouring agent, and a fragrance.

7. Process according to claim 5 wherein the agent is selected from the group consisting of butterfat, depot fat, lard, lard oil, neat's-foot oil, tallow, cod-liver oil, herring oil, menhaden oil, sardine oil, sperm oil, whale oil; vegetable oils derived from allspice, almond, aloe-vera, angelica, aniseed, apricot kernel, arnica, avocado, baobab, basil, bay, benzoin, bergamot, birch, bitter almond, pepper, bell pepper, blackberry, blueberry, boldo, buchu, cajuput, calamus, capsicum, cardamom, chamomile, chicory root, calendula, camphor, caraway, carrot seed, cassia, cedar wood, chive, cineole, cinnamon, citronella, citrus, clary sage, clove, cocoa butter, coconut, coffee, coriander, corn, cotton seed, cumin, cypress, dill, elemi, eucalyptus, evening primrose, fennel, frankincense, garlic, geranium, ginger, grape seed, grapefruit, hazelnut, helichrysum, hop, hyssop, jasmine, jojoba, juniper, kola, lavandin, lavender, leek, lemon, lemongrass, lemon verbena, licorice root, lime, linseed, macadamia, mandarin, marigold, marjoram, marula, melissa, mugwort, mustard, myrrh, neem, neroli, niaouli, niger seed, nutmeg, oiticica, olive, onion, orange, oregano, palm, palm kernel, palma rosa, paprika, patchouli, peanut, pennyroyal, peppermint, perilla, petitgrain, pimento, pine, poppy seed, pumpkin seed, rapeseed, rice bran, rose, rose geranium, rose otto, rosehip, rosemary, rosewood, rue, safflower, sage, sandalwood, sarsaparilla root, sassafras bark, savin, sesame, soybean, spearmint, spikenard, sunflower, high oleic sunflower, tagetes, tamarind, tangerine, tansy, tarragon, thuja, thyme, tea tree, tuberose, tung, turmeric, vanilla, vernonia, vetiver, walnut, wheat germ, wintergreen, wormseed, wormwood, yarrow, ylang-ylang, babassu oil, castor oil, yeast extracts, celery extracts, mushroom extracts, benzaldehyde, diacetyl(2,2-butanedione), vanillin, ethyl vanillin, and citral (3,7-dimethyl-2,6-octadienal).

8. Process according to claim 5 wherein the mixture of salts used in step (a) comprises from 1 to 50% by weight of a salt which is selected from the group consisting of sodium lactate, trisodium citrate, sodium gluconate, monosodium phosphate, disodium phosphate, trisodium phosphate, tetrasodium acid pyrophosphate, sodium acid sulfate, sodium carbonate, sodium bicarbonate, potassium citrate, potassium gluconate, monopotassium phosphate, dipotassium phosphate, tripotassium phosphate, tetrapotassium pyrophosphate, potassium sulfate, potassium acetate, potassium bicarbonate, potassium bromide, potassium lactate, calcium chloride, calcium acetate, calcium chloride, calcium citrate, calcium-D-gluconate, calcium lactate, calcium levulinate, dibasic calcium phosphate, magnesium oxide, magnesium chloride, magnesium carbonate and magnesium sulfate, ammonium chloride, and combinations thereof.

9. Process according to claim 5, wherein the amount of the one or more agents which is absorbed into the salt grains is between 0.1 to 8% by weight, based on the total weight of the salt product.

Description

EXAMPLE 1

[0064] Another way to describe the flowability of a particulate solid than the Degussa test as mentioned above is via the Dynamic Angle of Repose. In this test a fixed amount of the particulate solid is charged into a flat disc (diameter 25.9 cm, width 3.5 cm) which is connected to a drive with variable speed. The inner circumferential wall of the disc is provided with P60 sand paper. When the disc is filled with the test sample, the drive is switched on and the disc starts rotating at the lowest speed. Subsequently, the speed is gradually increased, until the backsliding sample forms a smooth surface. The angle this smooth surface makes to the horizontal is called the dynamic angle of repose.

[0065] Commercially available NaCl (Suprasel Extra Fine, ex Akzo Nobel) and Suprasel OneGrain A30 Extra Fine, ex Akzo Nobel, were split into comparable portions of approx. 142 ml each. This is the required amount to perform the test.

[0066] The first test was done with blank Suprasel Extra Fine, no liquid was added. The rotation speed of the disc was 7 rpm. When the angle was determined, the sample was taken out of the disc into a plastic bag and 0.1 wt % Hozol (High Oleic Sunflower Oil, ex Contined) was added. The sample was manually homogenized for 2 minutes and then left for 15 minutes after which it was homogenized once more for 1 minute. Subsequently, the sample was put in the disc again and the test was repeated. It was repeated once more with the addition of 1 wt % Hozol. The results are shown in the table below.

TABLE-US-00003 TABLE 1 Suprasel Extra Fine Amount of Dynamic angle Test Hozol added of repose no. [wt %] [] 1 0.0 34.5 2 0.1 48.5 3 1.0

[0067] These results show that after the addition of only 0.1 wt % Hozol to the Suprasel Extra Fine the dynamic angle of repose increases significantly, which indicates a worsening of the flowability. The addition of 1 wt % Hozol to the salt makes it even stick to the wall of the disc and the dynamic angle of repose cannot be determined anymore.

[0068] Then the same test was performed with a salt composition according to the present invention. This composition was prepared as follows: A mix of 69% NaCl (Suprasel Fine ex Akzo Nobel), 26% KCl ex K+S Kali GmbH and 5% yeast extract ex DSM Food Specialties b.v. were fed to an air classifying mill and milled until the particle size met the requirement of max. 5% retention on a 212 m screen, 0-10% retention on a 150 m screen and 45-60% retention on a 45 m screen.

[0069] On a roll compactor the mix was compacted to cigar-like compacts and subsequently milled on a Fitzmill DKSO12 hammer mill. The resulting product was sieved on a gyratory screen supplied with a 140 m and a 250 m screen, whereby the fines and coarse are sieved off, providing a product which is denoted as Salt Extra Fine. Certain amounts of Hozol were added.

[0070] The results are shown in the following table. From these results, it is clear that significantly more Hozol could be added before the dynamic angle of repose was significantly impacted. When 2.0 wt % Hozol was added, a slight increase of the angle was noticed.

TABLE-US-00004 TABLE 2 Salt Extra Fine with different amounts of Hozol Amount of Dynamic angle Test Hozol added of repose no. [wt %] [] 1 0.0 38 2 0.1 36.5 3 1.0 38 4 2.0 41.5

[0071] This test shows that the addition of only 0.1 wt % of Hozol to regular extra fine NaCl is enough to impact the flowability of Suprasel Extra Fine, expressed as the dynamic angle of repose, significantly. However, the addition of 2.0 wt % of Hozol to Salt Extra Fine only results in a small increase of the dynamic angle of repose.

EXAMPLE 2

[0072] A good way to describe the flowability of a particulate solid is via the Degussa test, vide supra. In this test, a sample is transferred into various cups with different outlet sizes, starting with the widest one. In this example, glass funnels were used of 41.6 mm diameter and with a 90 mm height. As explained above, after deblocking the outlet, the sample should pour out spontaneously. If this is the case, the next smaller outlet is tried, until the sample does not flow out of the cup spontaneously. The number of the latest cup with spontaneous flow is recorded. The flowability is classified according the following table.

TABLE-US-00005 TABLE 3 Flowability qualification Flow from Outlet diameter cup no. [mm] Classification 1 2.5 Very good 2 5 Good 3 8 Satisfactory 4 12 just sufficient 5 18 Insufficient no flow Bad

[0073] Four different salt compositions were tested: [0074] (a) a salt composition which was prepared according to the present invention, denoted as A30 Fine (A30F), [0075] (b) another salt composition which was prepared according to the present invention denoted as TS-M100 Fine, [0076] (c) a salt composition which is not according to the present invention, viz. Morton Star Flake Dendritic Salt ex Morton Salt Inc, and [0077] (d) another salt composition which is not according to the present invention, viz. Suprasel Microzo ex AkzoNobel.

[0078] For the preparation of A30 Fine, a mix of 69% NaCl (Suprasel Fine ex Akzo Nobel), 26% KCl ex K+S Kali GmbH and 5% yeast extract ex DSM Food Specialties b.v. were fed to an air classifying mill and milled until the particle size met the requirement of max. 5% retention on a 212 m screen, 0-10% retention on a 150 m screen and 45-60% retention on a 45 m screen.

[0079] On a roll compactor the mix was compacted to cigar-like compacts and subsequently milled on a Fitzmill DKSO12 hammer mill. The resulting product was sieved on a gyratory screen supplied with a 250 m and a 710 m screen, whereby the fines and coarse are sieved off.

[0080] For the preparation of TS-M100 Fine, the same process was followed, but the mix consisted of 56.9% NaCl (Suprasel Fine ex Akzo Nobel), 37.6% KCl ex K+S Kali GmbH and 5.5% flavor ex Givaudan.

[0081] From each test 100 g was charged into a small plastic bag. The test was started with the blank salts, no Hozol was added, and the cup no. was recorded. Then a small amount (approx. 0.5 wt %) Hozol was added to the samples, after which they were thoroughly mixed by hand for 2 min and left for 30 min. The test was repeated and another small amount of Hozol was added. This procedure was continued until no flow was possible anymore from the cups. The amount of Hozol that was added to the sample at the occasions the flowability qualification changed is recorded in the following table.

TABLE-US-00006 TABLE 4 Classification of the flowability as function of the added amount of Hozol HOZOL amount [wt %] Cup Morton no. Classification TS-M100 A30F dendritic Microzo 1 very good 0.00 0.00 0.00 2 good 0.52 0.46 3 satisfactory 1.42 4 just sufficient 1.34 1.63 5 insufficient 2.21 2.27 0.54 no flow bad >2.21 >2.27 >0.54 0.00

[0082] The Morton Dendritic salt showed a very good flowability as long as no Hozol was added. After the first addition of Hozol (0.54 wt %), flow from the widest cup was not possible anymore. The flowability of Microzo salt was already bad when no Hozol was added. On the other hand, the salt compositions mentioned under (a) and (b) above were able to absorb a certain amount of Hozol before the flowability gradually decreased. At approx. 1.5 wt % the flowability turned to insufficient. See also FIG. 1.

EXAMPLE 3

[0083] The preparation of the salt compositions according to the present invention which were used in this example was done in 5 consecutive steps. In the first step the raw materials NaCl (Suprasel Fine ex Akzo Nobel) and KCl (ex K+S Kali GmbH) were milled on an Alpine 160 UPZ pin mill operated at 7125 rpm to a d50, NaCl=42.3 m and d50, KCl=52.6 m. From these milled raw materials, four product mixes of each 2000 g were prepared in the second step. These mixtures consisted of: [0084] (a) 100% NaCl [0085] (b) 80% NaCl/20% KCl [0086] (c) 20% NaCl/80% KCl [0087] (d) 100% KCl

[0088] From these mixtures tablets of each 50 g were prepared on a Herzog HTP-40 tablet press using a 1.0 t/cm2 compaction pressure. In the fourth step these tablets were first broken diametrically and then further crushed on a Frewitt GLA-ORV rubbing sieve using a 6 mm, 3.15 mm and finally a 1 mm screen. The resulting product was sieved on a 90 m, 280 m and a 710 m screen.

[0089] Based on the tablet dimensions and the true density of the raw materials, the porosity of the tablets could be calculated.

[0090] Besides above mentioned samples also regular Suprasel Fine ex Akzo Nobel and regular KCl ex K+S Kali GmbH were included in the tests.

[0091] The flowability of the salts was determined using the Degussa test. For a description of this test, see Example 2. First the blank salts were subjected to the test. Subsequently approx. 0.5 wt % Hozol was added and thoroughly mixed in by hand. A period of 30 min was used to ensure proper distribution of the Hozol. Then the test was repeated. Subsequently the amount of Hozol was increased in steps of approx. 0.25 wt % until the sample did not pour out of the widest cup anymore. The results are given in table 5 and FIG. 2.

TABLE-US-00007 TABLE 5 Classification of the flowability as function of the added amount of Hozol HOZOL amount [wt %] Cup regular regular no. Classification 100/0 80/20 20/80 0/100 NaCl KCl 1 very good 0.00 0.00 0.00 0.00 0.00 0.24 2 good 4.5 4.07 3.21 2.53 0.5 3 satisfactory 6.27 4.79 3.45 3.0 4 just sufficient 6.5 5.57 3.72 3.28 5 insufficient 6.76 6.08 4.25 3.74 no flow bad >6.76 >6.08 >4.25 >3.74 >0.24 >0.5

[0092] The addition of Hozol to regular Suprasel Fine had a huge impact on the flowability. Where the blank salt flowed very well, the addition of only 0.24 wt % Hozol hindered the spontaneous flow from even the widest cup. Regular KCl could handle 0.5 wt % before spontaneous flow was hindered.

[0093] The formulations prepared according to the present invention clearly could handle a much larger amount of Hozol. The product prepared according to the present invention based on 100% KCl kept at least a just sufficient classification when 3.3 wt % Hozol was added. The 100% NaCl product prepared according to the present invention could cope with 6.5 wt % before it lost its just sufficient classification.

EXAMPLE 4

[0094] Another way to evaluate the flow behavior of a particulate solid is by running a flow function test on a ring shear tester. This test is a simulation of particulate solids flowing from a vessel through an orifice. The test was executed with a Brookfield Powder Flow Tester, model PFT manufactured by Brookfield Engineering Laboratories, Middleboro, Mass., USA. The Powder Flow Tester was equipped with a standard ring shaped trough with an outer diameter of 156.5 mm and in inner diameter of 97 mm. After filling the trough, the test is started. At 5 different consolidation stresses, which represent a fill level of a vessel, the unconfined failure strengths were measured. This is the stress at which the particulate solid yields and flows. The values of each measuring point are plotted in a curve as unconfined failure strength (C) versus major principal consolidation stress (1).

[0095] In this plot, 5 regions can be identified with the following classification:

[0096] 0C/1<0.1: Free flowing

[0097] 0.1C/1<:Easy flowing 0.25

[0098] 0.25C/1<:Cohesive 0.5

[0099] 0.5C/1<:Very

[0100] 1.0 cohesive

[0101] C/1>1.0:Non flowing

[0102] The same salt products as described in Example 3 were subjected to this test. Starting from the blank salts, also mixtures with 2%, 4% and 6% Hozol were tested. Additionally also regular NaCl (Suprasel Fine ex AkzoNobel) and KCl (ex K+S Kali GmbH were tested. The results are plotted in the FIGS. 3a, b, c, d, respectively.

[0103] FIG. 3a shows the flow functions when no Hozol was added. All salts behaved as free flowing solids. Then 2% Hozol is added and mixed in thoroughly. FIG. 3b plot shows the flow behavior of these samples.

[0104] It is clear that both regular salts, NaCl and KCl, had a worse performance and could be classified as very cohesive at low consolidation stresses. At higher stresses this behavior improved somewhat.

[0105] The behavior of the salts prepared according to the present invention upon the addition of Hozol was much better. Even at low stresses the solids behaved as easy flowing at 2% Hozol addition. At 4% addition the salts prepared according to the present invention containing 100% or 80% NaCl behaved cohesive at low stresses, but turned into easy flowing already at 1 kPa consolidation stress. At 6% Hozol addition, the flow behavior further worsened, but even then the 100% NaCl prepared according to the present invention still exhibited free flowing behavior over the whole tested range of consolidation stresses.

EXAMPLE 5

[0106] NaCl (Suprasel Fine ex Akzo Nobel) and KCl (ex K+S Kali GmbH) were milled on an Alpine 160 UPZ pin mill (d50, NaCl=42.3 m, d50, KCl=52.6 m) and thoroughly mixed in a 50/50wt % ratio. From this mixture tablets of each 50 g were prepared on a Herzog HTP-40 tablet press using various compaction pressures:

[0107] (a) 0.75 t/cm2

[0108] (b) 0.88 t/cm2

[0109] (c) 1.0 t/cm2

[0110] (d) 1.25 t/cm2

[0111] Based on the tablet dimensions and the true density of the raw materials, the porosity of the tablets could be calculated. These tablets were first broken diametrically and then further crushed on a Frewitt GLA-ORV rubbing sieving using a 6 mm, 3.15 mm and finally a 1 mm screen. The resulting product was sieved on a 90 m, 280 m and a 710 m screen.

[0112] From the grains in the fraction 250-710 m the flowability was measured as a function of the amount of added Hozol ex Contined. The Degussa test is used for this. First the blank salts were subjected to the test. Then approx. 2.0 wt % Hozol was added and thoroughly mixed in by hand. A period of 30 min was used to ensure proper distribution of the Hozol. Then the test was repeated. Next, the amount of Hozol was increased in steps of approx. 0.25-0.5 wt % until the sample did not pour out of the widest cup anymore. The results are given in table 6 and FIG. 4.

TABLE-US-00008 TABLE 6 Classification of the flowability as function of the added amount of Hozol HOZOL amount [wt %] Cup 0.75 0.88 1.0 1.25 no. Classification t/cm.sup.2 t/cm.sup.2 t/cm.sup.2 t/cm.sup.2 1 very good 0.00 0.00 0.00 0.00 2 good 3.5 3.04 3.07 2.02 3 satisfactory 4.73 4.22 3.97 3.02 4 just sufficient 5.92 4.72 4.23 3.33 5 insufficient 6.55 5.18 4.66 3.84 no flow bad >6.55 >5.18 >4.66 >3.84

[0113] It is shown that the amount of Hozol that can be absorbed depends on the compaction force that was applied. But even at 1.25 t/cm.sup.2, the highest force, more than 3% Hozol could be added to the salt composition before the flowability became insufficient.

EXAMPLE 6

[0114] A comparison has been made between sodium chloride crystals with and without Hozol as the agent and a product according to the present invention, with and without Hozol. The results are depicted in FIGS. 5a-d.

[0115] Picture 5a and 5b show NaCl (Suprasel Fine ex AkzoNobel) before and after the addition of 2 wt % Hozol. Where the blank NaCl sample consists of loose, single crystals, it is a lumpy mass after the addition of Hozol, wherein the crystals tick together.

[0116] Picture 5c and 5d show that before and after the addition of Hozol to NaCl prepared according to the method as described in Example 3, the grains do not stick to each other. The oil is well absorbed leaving the grains as single particles.