A method for treating solid particle suspensions in water using a crystalline polymer of 2-acrylamido-2-methylpropanesulfonate sodium salt.

Abstract

This invention relates to a method for treating solid particle suspensions in water using a water-soluble polymer obtained from the crystalline form of ATBS.Na. This method is particularly useful for treating residues generated from the mining industry.

Description

[Technical Field]

[0001] The present invention relates to a method for treating solid particulate water suspensions, such as mining residues, using a water-soluble polymer obtained from the crystalline form of 2-acrylamido-2-methylpropanesulfonate sodium salt. The method includes the step of contacting the suspension with a water-soluble polymer obtained from the crystalline form of 2-acrylamido-2-methylpropanesulfonate sodium salt.

[0002] The method according to the present invention preferably comprises, in particular, adding the water-soluble polymer to a thicknesser containing the suspension to be processed, and / or adding the polymer during transport of the suspension to a deposition zone for dewatering and solidification of the suspension, and / or adding the polymer to the suspension and then performing mechanical processing such as centrifugation, pressing, or filtration. [Background technology]

[0003] Suspensions of solid particles in water include all types of sludge, residue, or waste material. The suspensions may originate from ore processing, such as industrial sludge or industrial waste, as well as all washing products and waste resulting from mining operations such as coal mines, diamond mines, phosphate mines, and metal mines (aluminum, platinum, iron, gold, copper, silver, etc.). The suspensions may also originate from sludge or extraction residues from oil sands processing. These solid particle suspensions generally contain organic and / or mineral particles such as clay, sediments, sand, metal oxides, and oil, and are mixed with water, for example.

[0004] The term "suspended matter" is used hereafter (including in the specification of this invention) and refers to a suspension of solid particles as described above.

[0005] The processing of these residues and other waste materials poses technical, environmental, and public order problems. The use of synthetic or natural polymers such as coagulants and flocculants to separate solids from liquids is a common practice.

[0006] Over a long period and even today, mineral sludges resulting from physical or chemical processing methods of ores have been stored in open basins, ponds, storage dams, or embankments in semi-liquid form. These large accumulations of sludge thus pose a real danger, especially when the dikes burst.

[0007] Since traditional storage measures are clearly dangerous, more national regulations have been issued that prohibit abandoning these areas. These regulations also require the obligation to rehabilitate these sites, namely, the treatment of soil and the consolidation of soils.

[0008] Therefore, the improvement of chemical and mechanical treatment of residues or sludges is a significant challenge.

[0009] In recent decades, various attempts have been made to increase the sedimentation rate of residues in order to efficiently recycle water and reduce the amount of residues. Major physical treatments include centrifugation, filtration, electrophoresis, and electrocoagulation. ​​​​​​Between 1979 and 1980, Alsthom Atlantique and SNF (U.S. Patent No. 4,347,140) developed a multi-stage flocculation system (super-flocculation) specifically designed to treat clay residue pools resulting from phosphate production in Florida.

[0012] The treatment of suspended solids was continuously studied: in 1986 according to the method described in document CA1273888, then in 1994 according to the method described in document WO96 / 05146, in 2000 according to the method described in document CA2407869, and in 2004 according to the method described in document CA1515581.

[0013] In reference CA2682542, the method involves adding polymers modified by copolymerization and / or branching. Furthermore, polymers with hydrophobic groups have been studied and shown to improve the treatment of suspensions.

[0014] Despite significant progress in recent years, there remains a need to develop polymers that increase the speed and amount of water released from suspended solids. Improving the physical properties of the resulting sludge is also a requirement. [Overview of the project]

[0015] ●Disclosure of the present invention The applicant has found and developed a method for treating solid particle suspensions in water using at least one water-soluble polymer obtained from the crystalline form of sodium 2-acrylamido-2-methylpropanesulfonate salt, referred to as ATBS.Na. This method makes it possible to meet the aforementioned needs.

[0016] Remarkably, the use of at least one water-soluble polymer obtained from the aforementioned crystalline form of ATBS.Na enables efficient processing of solid suspensions.

[0017] More precisely, the present invention involves contacting an aqueous suspension of solid particles with at least one water-soluble polymer of 2-acrylamido-2-methylpropanesulfonic acid (ATBS), wherein the 2-acrylamido-2-methylpropanesulfonic acid has 2θ angles (+ / -0.1°) of 11.7°, 12.2°, 13.2°, 13.5°, 15.6°, 16.8°, 17.8°, 18.5°, 19.1°, 20.6°, 21.4°, 23.3°, and 25.1° before polymerization. The present invention relates to a method for processing a suspension of solid particles in water, which is a crystalline form of sodium 2-acrylamido-2-methylpropanesulfonate (ATBS.Na) having an X-ray powder diffraction pattern that includes a group of peaks located at 45.8°, 26.9°, 29.1°, 29.5°, 31.0°, 33.0°, 33.6°, 34.4°, 35.2°, 35.9°, 37.1°, 38.4°, 39.6°, 41.1°, 42.9°, 45.1°, 46.0°, 47.2°, and 47.6°.

[0018] The presence of the crystalline form monomer of ATBS.Na in the monomer composition of the water-soluble polymer imparts specific properties to the water-soluble polymer, thereby enabling improved processing of solid particles in suspensions.

[0019] According to the present invention, the water-soluble polymer obtained from the crystalline form of ATBS.Na is: • Increasing the sludge concentration, for example, increasing the sludge concentration at the outlet of the sinking concentrator (thickener). • A dehydration step, and, if the suspension is discharged to the ground, a step of drying and solidifying the suspension, - Mechanically processing the aforementioned processed suspension. This includes improving the performance of suspension processing.

[0020] The improved performance of polymers obtained from the aforementioned crystalline form of ATBS.Na for processing suspended materials reduces the amount of product required, and therefore helps to reduce overall water consumption and emissions of greenhouse gases such as CO2.

[0021] Another object of the present invention relates to a method for agglomerating a suspension of solid particles in water, comprising contacting the suspension of solid particles in water with at least one water-soluble polymer obtained from the crystalline form of ATBS.Na. [Brief explanation of the drawing]

[0022] [Figure 1] Figure 1 shows the proton NMR spectrum of the 2-acrylamido-2-methylpropanesulfonic acid (ATBS) needle-shaped crystals obtained in Example 1. [Figure 2] Figure 2 shows the proton NMR spectrum of the crystalline 2-acrylamido-2-methylpropanesulfonate sodium salt (ATBS.Na) obtained in Example 2a. [Figure 3] Figure 3 shows the X-ray diffraction pattern of the ATBS crystal obtained in Example 1. [Figure 4] Figure 4 shows the X-ray diffraction pattern of the ATBS.Na crystal obtained in Example 2a. [Figure 5] Figure 5 shows the Fourier transform infrared spectrum of the ATBS crystal obtained in Example 1. [Figure 6] Figure 6 shows the Fourier transform infrared spectrum of the ATBS.Na crystal obtained in Example 2a. [Figure 7] Figure 7 shows the thermogram of the ATBS crystal obtained in Example 1. [Figure 8] Figure 8 shows the thermogram of the ATBS.Na crystal obtained in Example 2a. [Figure 9] Figure 9 shows an optical microscope image of the ATBS crystal obtained in Example 1. [Figure 10] Figure 10 shows an optical microscope image of the ATBS.Na crystal obtained in Example 2a. [Figure 11] Figure 11 shows an optical microscope image of the ATBS.Na crystal obtained in Example 2b. [Figure 12] Figure 12 shows an optical microscope image of the ATBS.Na crystal obtained in Example 2c. [Figure 13] Figure 13 shows a photograph of the ATBS.Na product obtained in solution according to Comparative Example 2b. [Figure 14] Figure 14 shows an optical microscope image of the crystal obtained in Comparative Example 2c. [Figure 15] Figure 15 shows an optical microscope image of the crystal obtained in Comparative Example 2d. [Figure 16] Figure 16 shows an optical microscope image of the crystal obtained in Comparative Example 2e. [Modes for carrying out the invention]

[0023] ●Description of the present invention The term "polymer" should be understood to mean a homopolymer or copolymer. The term "copolymer" should be understood to mean a polymer obtained from at least two different monomers. Therefore, it may be a copolymer of at least two monomers selected from anionic monomers, cationic monomers, nonionic monomers, zwitterionic monomers, hydrophobic monomers, and mixtures thereof. The term "hydrophilic monomer" refers to an octanol-water partition coefficient K of 1 or less. ow It should be understood that this means a monomer having a partition coefficient K ow This is determined at 25°C in a 1:1 volume octanol-water mixture with a pH of 6-8.

[0024] The terms "crystal" or "crystalline form" refer to solid materials in which their constituent elements (atoms, molecules, or ions, etc.) are arranged in a highly ordered microstructure, forming a crystalline lattice that extends in all directions. This does not include amorphous solids.

[0025] The term "hydrophobic monomer" refers to an octanol-water partition coefficient greater than 1 K ow It should be understood that this means a monomer having a partition coefficient K ow This is determined at 25°C in a 1:1 volume octanol-water mixture with a pH of 6-8.

[0026] Octanol-water partition coefficient K ow This represents the ratio (g / L) of monomer concentrations between the octanol phase and the aqueous phase. The partition coefficient is defined as follows:

number

[0027] According to the definition, a water-soluble polymer is dissolved in water at 25°C while stirring, in a volume of 50 g / L. -1 This polymer, when dissolved at a certain concentration, yields an aqueous solution free of insoluble particles.

[0028] "X and / or Y" should be understood to mean "X", "Y", or "X and Y".

[0029] The present invention also includes all possible combinations of the various embodiments disclosed, whether they are preferred embodiments or given as examples. Furthermore, where numerical ranges are indicated, boundary values ​​are included within those ranges. The disclosure also includes all combinations between the boundary values ​​of these numerical ranges. For example, the numerical range "1 to 20, preferably 5 to 15" implies the disclosure of the range "1 to 5", the range "1 to 15", the range "5 to 20", and the range "15 to 20", as well as the values ​​1, 5, 15, and 20.

[0030] ●Crystal form of sodium 2-acrylamido-2-methylpropanesulfonate The crystalline form of ATBS.Na has an X-ray powder diffraction pattern that includes a group of peaks located at 11.7°, 12.2°, 13.2°, 13.5°, 15.6°, 16.8°, 17.8°, 18.5°, 19.1°, 20.6°, 21.4°, 23.3°, 25.1°, 25.8°, 26.9°, 29.1°, 29.5°, 31.0°, 33.0°, 33.6°, 34.4°, 35.2°, 35.9°, 37.1°, 38.4°, 39.6°, 41.1°, 42.9°, 45.1°, 46.0°, 47.2°, and 47.6° in 2θ angles. The uncertainty of these peaks is generally on the order of + / -0.1°.

[0031] X-ray crystallography, radiation crystallography, or X-ray diffraction is an analytical technique used to study the structure of crystalline substances at the atomic scale. This is based on the physical phenomenon of X-ray diffraction. A diffractometer with a copper wire source can be used.

[0032] Powders formed from a specific crystal phase always show diffraction peaks in the same direction. Therefore, this diffraction pattern forms the true signature of the crystal phase. Thus, it is possible to determine the nature of each crystal phase within a mixture or pure substance.

[0033] This signature is specific to each crystalline organic or inorganic compound and is in the form of a list of peaks located at an angle of 2θ (two theta).

[0034] This technique is used to characterize substances, particularly to characterize the various crystal forms that can exist for the same chemical molecule.

[0035] The said crystal form of ATBS.Na has a Fourier transform infrared spectrum containing a group of peaks at 3576 cm -1 、3485 cm -1 、3310 cm -1 、3079 cm -1 、2975 cm -1 、1658 cm -1 、1629 cm -1 、1543 cm -1 、1403 cm -1 、1321 cm -1 、1301 cm -1 、1205 cm -1 、1187 cm -1 、1163 cm -1 、1046 cm -1 、980 cm -1 、629 cm -1 The uncertainty of these peaks is generally on the order of + / -8 cm -1 。

[0036] Infrared measurements are performed by Fourier transform, for example, using a Perkin Elmer Spectrum 100 spectrometer with a single-reflection ATR polarization accessory, at 8 cm. -1 This is done by Fourier transform with this level of precision.

[0037] Fourier transform infrared spectroscopy is the analysis of vibrations emitted, absorbed, or scattered by molecules. This technique is sensitive to so-called short-range interactions (the influence of a unit mesh on bonding). In most cases, the Fourier transform infrared spectra of different crystal systems are significantly different. Therefore, the Fourier transform infrared spectrum reflects the details of the crystalline structure of a compound.

[0038] Generally, unless otherwise specified, X-ray diffraction patterns and infrared spectra are obtained at 20°C and a pressure of 1 absolute atmosphere (101,325 Pa).

[0039] The crystalline form of ATBS.Na has a minimum ignition energy greater than 500 mJ, preferably greater than 1000 mJ (1 mJ = 10 -3 Jules).

[0040] Minimum ignition energy represents the minimum energy that must be supplied to a substance (compound) to ignite it. This energy can be electrical or thermal. Minimum ignition energy is essential information when considering the risk of explosion during substance handling (transport, storage, reaction, molding, etc.).

[0041] The minimum ignition energy depends on the properties of the powder (composition) and its polymer structure (particle size, crystal form, specific surface area). For solids, this energy is the minimum energy of an electrical spark that is likely to ignite a dust cloud. The higher the minimum ignition energy, the lower the risk the solid poses when it is used, handled, or stored.

[0042] The minimum ignition energy is measured according to the standard NF EN 13821. The aforementioned crystalline form of ATBS.Na exhibits four thermal phenomena at 49.8°C, 144.8°C, 169.8°C, and 254.3°C, as determined by differential scanning calorimetry. The uncertainty regarding the observation of these phenomena is generally on the order of 10°C, and preferably less than 5°C.

[0043] Thermal phenomena are measured by differential scanning calorimetry (DSC). This technique involves measuring the thermal fluctuations associated with the thermal denaturation of a compound when heated at a constant rate, for example, with a heating gradient of 10°C / min.

[0044] ● Method for producing the crystalline form of the sodium salt A method for producing the crystalline form of 2-acrylamido-2-methylpropanesulfonate sodium salt ATBS.Na includes at least the following steps in sequence: 1) To form an aqueous solution or aqueous suspension SA2, mix 2-acrylamido-2-methylpropanesulfonic acid ATBS with an aqueous solution SA1 and at least one sodium salt base, preferably for at least 1 minute; 2) Distill the aqueous solution or aqueous suspension SA2 at a pressure of 700 mbar or less in order to form suspension S1; 3) Separating the suspension S1 into solid and liquid components, and isolating the crystals of the suspension S1 obtained in the form of composition C1 at the end of step 2). The obtained crystals are the aforementioned crystalline form of ATBS.Na.

[0045] The "sodium salt base" in step 1) should be understood to mean at least one inorganic sodium salt Brønsted base, such as sodium hydroxide, sodium carbonate, sodium bicarbonate, or a mixture thereof.

[0046] The temperature and mixing time in step 1) can vary, in particular, as a function of the concentration of 2-acrylamido-2-methylpropanesulfonic acid, referred to as ATBS. Those skilled in the art know how to adapt the temperature variations and mixing time to optimize crystal formation.

[0047] The method for producing the crystalline form of ATBS sodium salt can be applied to any form of ATBS, such as a needle-shaped form or a hydrated form. The above manufacturing method may be carried out on ATBS of any purity.

[0048] Therefore, the method may be carried out downstream of any type of ATBS manufacturing method. The method may also be carried out on any form of ATBS already obtained, i.e., amorphous or crystalline.

[0049] ●Step 1 of the method for producing the crystalline form of ATBS sodium salt): ATBS is produced by the manufacturing method described above (acrylonitrile, fuming sulfuric acid, and isobutylene). ATBS may be in the form of a fine powder, or it may be molded in a controlled manner by methods such as compression, granulation, or extrusion.

[0050] ATBS may be added to aqueous solution SA1 before, after, or in parallel with the sodium salt base, and preferably in parallel with the sodium salt base. Preferably, the aqueous solution is water.

[0051] The sodium salt base may be added as an aqueous solution SA1. In this case, the aqueous solution of the sodium base may be partially or entirely aqueous solution SA1. Advantageously, the concentration of ATBS sodium salt in the aqueous solution or aqueous suspension SA2 is 1% by weight to the saturation concentration, preferably 10% by weight to the saturation concentration, more preferably 20% by weight to the saturation concentration, more preferably 30% by weight to the saturation concentration, more preferably 40% by weight to the saturation concentration, and even more preferably 50% by weight to the saturation concentration, based on the weight of the aqueous solution or aqueous suspension SA2.

[0052] ATBS and sodium salt base may be added all at once or in several stages. It is preferable that they be added in several stages. In some preferred embodiments, they are added all at once. When adding them in several stages, ATBS and sodium salt bases are added in fractions.

[0053] When ATBS and sodium salt base are added in partial amounts, there is no limit to the number of parts, but it is advantageous to have at least two parts, preferably at least three parts.

[0054] There are no restrictions on the order in which ATBS and sodium salt base are added. They may be added simultaneously (i.e., in parallel), sequentially (ATBS first, then sodium salt base, or vice versa), or alternately (first portion of ATBS, then first portion of sodium salt base, then second portion of ATBS, then second portion of sodium salt base, and so on), but they are preferably added simultaneously.

[0055] When added sequentially or alternately, the addition of the second compound (which may be ATBS or a sodium salt base) can begin before the addition of the first compound is complete.

[0056] The first portion F1 of ATBS advantageously accounts for 1 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and even more preferably 20 mol% or more of the total ATBS present in the aqueous solution or aqueous suspension SA2.

[0057] The second portion F2 of ATBS advantageously accounts for 1 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and even more preferably 20 mol% or more of the total ATBS present in the aqueous solution or aqueous suspension SA2.

[0058] The third portion F3 of ATBS is advantageously comprised of 1 mol% or more, preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and even more preferably 20 mol% or more, of the total ATBS present in the aqueous solution or aqueous suspension SA2.

[0059] In one particular embodiment, the method is carried out continuously, in which case ATBS and sodium salt base are added continuously. The amount of ATBS in the aqueous solution or aqueous suspension SA2 is advantageously 10 to 90% by weight, preferably 20 to 85% by weight, and more preferably 30 to 80% by weight, relative to the total weight of the aqueous solution or aqueous suspension SA2.

[0060] The mixing in step 1) (ATBS + sodium salt base) is preferably carried out at a temperature of 0 to 90°C, preferably 5 to 60°C, more preferably 10 to 40°C, to obtain an aqueous solution or aqueous suspension SA2.

[0061] In a particular embodiment, the aqueous solution or aqueous suspension SA2 may contain one or more organic solvents.

[0062] In some embodiments, the aqueous solution SA1 may contain one or more organic solvents. The amount of organic solvent may vary as a function of temperature and the amount of ATBS or sodium salt base. This amount is not limited as long as it does not prevent the acquisition of the crystalline form of ATBS.Na. Those skilled in the art will understand how to determine this limit, and this is a routine task. Generally, aqueous solutions or aqueous suspensions SA2 contain more water (by volume) than organic solvent.

[0063] One or more organic solvents are advantageously selected from the following compounds: • Organic acids, preferably carboxylic acids containing 1 to 8 carbon atoms; • Amides, which preferably contain 1 to 8 carbon atoms; • Alcohols, which preferably contain 1 to 8 carbon atoms; Ketones, which favorably contain 3 to 8 carbon atoms; Ethers, which preferably contain 2 to 8 carbon atoms; • Esters, which preferably contain 2 to 8 carbon atoms; Alkanes, which preferably contain 4 to 8 carbon atoms, and more preferably 5 to 6 carbon atoms; • Halogenated hydrocarbon compounds, which preferably contain 1 to 8 carbon atoms; Nitriles, which preferably contain 1 to 8 carbon atoms; or • A mixture of those.

[0064] When using an organic solvent in this invention, the temperature can be adjusted so that the mixture of solvent and water remains in a liquid state. These compounds may be linear or branched. They may be saturated or contain unsaturated bonds. Unsaturated bonds may be double or triple bonds. [ka] It corresponds to this.

[0065] The organic solvent is preferably selected from acrylonitrile, isopropanol, acrylic acid, acetic acid, or a mixture thereof. The organic solvent is preferably acrylonitrile. The organic solvent is generally liquid at the temperature at which steps 2) and 3) are performed. Furthermore, the organic solvent is advantageously partially miscible with water, and preferably completely miscible with water.

[0066] Organic solvents may be used, if necessary, to solubilize any impurities or by-products present with the ATBS used to form the aqueous solution or aqueous suspension SA2. However, the ATBS does not necessarily have to be soluble in the solvent.

[0067] In one preferred embodiment of the present invention, the aqueous solution or aqueous suspension SA2 does not contain an organic solvent. In one preferred embodiment of the present invention, the aqueous solution SA1 does not contain an organic solvent.

[0068] The permissible time for mixing the aqueous solution SA1, the sodium salt base, and the ATBS is preferably 1 minute or more, preferably 1 to 600 minutes, more preferably 5 to 400 minutes, and even more preferably 10 to 240 minutes.

[0069] The compounds in step 1) can be mixed using a variety of techniques. Examples include, but are not limited to, reactors with agitators, loop reactors, static mixers, microreactors, piston reactors, agitated filter dryers (e.g., agitated filter dryers from Nutsche), paddle mixers, twin-cone mixers, plow shear mixers, and disc mixers.

[0070] The pH in step 1) is advantageously controlled to be 6-14, preferably 8-14, more preferably 10-14, even more preferably 12-14, and even more preferably 13-14.

[0071] The amount of ATBS.Na in the aqueous solution SA2 or aqueous suspension SA2 is advantageously 10 to 90% by weight, preferably 20 to 90% by weight, preferably 30 to 90% by weight, preferably 50 to 90% by weight, preferably 20 to 85% by weight, and more preferably 30 to 80% by weight, relative to the total weight of the aqueous solution or aqueous suspension SA2.

[0072] ●Step 2 of the method for producing the crystalline form of ATBS sodium salt): The distillation of aqueous solutions or aqueous suspensions of SA2 is carried out at a pressure of 700 mbar or less. This is generally done in a vacuum distillation apparatus, which is typically an evaporator. Therefore, this distillation is also referred to as "vacuum distillation" herein.

[0073] When an aqueous solution or aqueous suspension SA2 is distilled, typically by passing it through an evaporator, crystals of ATBS.Na begin to form. The aqueous solution or aqueous suspension SA2 then coexists with ATBS, at least one sodium salt base, and crystalline solid particles of ATBS.Na.

[0074] The aqueous solution or aqueous suspension SA2 can be distilled using an evaporator. This may be a drip evaporator, a vacuum evaporator, a scraper-type thin-film evaporator, a short-pass evaporator, a forced-circulation evaporator, a spiral-tube evaporator, or a flash evaporator. It may also be a continuous-stirring reactor. Preferably, the distillation is carried out in a scraper-type thin-film evaporator, a short-pass evaporator, or a forced-circulation evaporator. More preferably, the distillation is carried out in a scraper-type thin-film evaporator.

[0075] Generally, an evaporator is a device that includes an inlet for the solution to be processed (aqueous solution or aqueous suspension SA2), an outlet for discharging the distilled solvent (water and organic solvent), and an outlet for discharging the suspension S1.

[0076] The residence time of the aqueous solution or aqueous suspension SA2 (preferably under vacuum) in the distillation apparatus, preferably an evaporator, in other words, the distillation time at a pressure of 700 mbar or less, is preferably 1 second to 600 seconds, preferably 3 seconds to 300 seconds, and more preferably 30 seconds to 100 seconds. The residence time corresponds to the time required to carry out step 2), i.e., the time required to prepare suspension S1 by distillation of the aqueous solution or aqueous suspension SA2. In other words, when using an evaporator, it is the residence time of ATBS (and / or the crystalline form of its sodium salt) between the inlet and outlet of the apparatus. This residence time depends on the amount of water (and organic solvent, if any), ATBS, and sodium salt base present in the aqueous solution or aqueous suspension SA2. Those skilled in the art will understand how to adapt the residence time to obtain the crystalline form of ATBS.Na depending on the amount of components in the aqueous solution or aqueous suspension SA2.

[0077] Distillation can be carried out in a vertical evaporator or a horizontal evaporator. Preferably, distillation is carried out in a vertical evaporator.

[0078] The aqueous solution or aqueous suspension SA2 can be circulated in a parallel or countercurrent flow relative to the vapor produced by evaporation. Preferably, the aqueous solution or aqueous suspension SA2 is circulated in a countercurrent flow relative to the vapor within the distillation apparatus. In other words, the aqueous solution or aqueous suspension SA2 is introduced into the distillation apparatus, preferably into an evaporator, in a parallel or countercurrent flow relative to the distilled solvent.

[0079] The aqueous solution or aqueous suspension SA2 may be circulated in series through one or more evaporators before obtaining the suspension S1. Preferably, the aqueous solution or aqueous suspension SA2 is circulated through a single evaporator.

[0080] The pressure during distillation is preferably between 1 and 700 mbar (1 mbar = 100 Pa). Preferably, the pressure during distillation is less than 700 mbar, more preferably less than 600 mbar, more preferably less than 500 mbar, more preferably less than 400 mbar, more preferably less than 300 mbar, more preferably less than 200 mbar, more preferably less than 100 mbar, and even more preferably less than 50 mbar, where preferably more than 1 mbar. Absolute pressure corresponds to pressure relative to zero pressure (vacuum).

[0081] Generally, the pressure during distillation is preferably 10-700 mbar, preferably 20-700 mbar, preferably 40-700 mbar, more preferably 50-600 mbar, more preferably 50-500 mbar, more preferably 50-400 mbar, more preferably 50-300 mbar, more preferably 100-700 mbar, more preferably 200-700 mbar, more preferably 500-700 mbar, and more preferably 40-100 mbar.

[0082] In a particular embodiment, step 2) includes step 2') (optional) to help evaporate the solvent. Step 2') consists of raising the temperature of the aqueous solution or aqueous suspension SA2, in other words, the distillation by step 2') is carried out under heating.

[0083] In some embodiments, in step 2), the aqueous solution or aqueous suspension SA2 is heated, preferably to a temperature of 5°C to 95°C, preferably greater than 10°C to 60°C, and more preferably greater than 20°C to 40°C.

[0084] Heating during distillation can be carried out by various techniques. Examples include, but are not limited to, heating with steam, heating with hot water, heating with electricity, heating by vapor compression, or heating using a heat pump. Therefore, the distillation apparatus may be a double-wall type in which a high-temperature heat transfer fluid circulates between two walls.

[0085] The aqueous solution or aqueous suspension SA2 is preferably heated to a temperature of over 5°C to 95°C, preferably over 10°C to 60°C, and more preferably over 20°C to 40°C. When heating the aqueous solution or aqueous suspension SA2, the temperature is advantageously higher than the temperature in step 1).

[0086] The temperature of the aqueous solution or aqueous suspension SA2 rises advantageously with a gradient of 0.1 to 10°C / hour, preferably 0.2 to 9°C / hour, more preferably 0.3 to 8°C / hour, and even more preferably 0.5 to 5°C / hour.

[0087] In some embodiments, the temperature of the aqueous solution or aqueous suspension SA2 rises advantageously in a gradient of 10 to 150°C / hour, preferably 30 to 110°C / hour, more preferably 50 to 100°C / hour, and even more preferably 60 to 90°C / hour.

[0088] The temperature rise does not have to be constant throughout the entire process. For example, the aqueous solution or aqueous suspension SA2 may be heated at a rate of 5°C / hour for the first 3 hours, and then at a rate of 10°C / hour until the final temperature is reached.

[0089] According to another particular embodiment of the present invention, step 2) may include, after step 2'), or instead of step 2'), step 2") (optional), which helps to increase the productivity and profitability of the method of the present invention by promoting the crystallization of ATBS to the crystalline form of its own sodium salt. Step 2") consists of lowering the temperature of the aqueous solution or aqueous suspension SA2.

[0090] The aqueous solution or aqueous suspension SA2 is advantageously cooled to a temperature of 5 to less than 95°C, preferably 10 to less than 60°C, more preferably 20 to less than 40°C, and even more preferably 10 to 40°C.

[0091] In some embodiments, step 2) further includes a cooling step. The cooling step is advantageously carried out at a temperature of 5°C to 95°C, preferably greater than 10°C to 60°C, and more preferably greater than 10°C to 40°C.

[0092] In some embodiments, the temperature in the cooling step decreases with a gradient of 0.1 to 8°C / hour, preferably 0.2 to 8°C / hour, more preferably 0.3 to 8°C / hour, and even more preferably 0.5 to 5°C / hour.

[0093] In some embodiments, the temperature of the cooling step is advantageously lower than the heating temperature of step 2) and / or step 1). In some embodiments, the cooling step is performed on an aqueous solution or aqueous suspension SA2 and / or a concentrated aqueous solution or aqueous suspension SA2 and / or suspension S1.

[0094] If the aqueous solution or aqueous suspension SA2 is cooled (step 2"), the temperature is advantageously lower than the temperature in step 2) and optionally lower than the temperature in step 2').

[0095] According to one preferred embodiment, the temperature in step 2) is the same as or lower than the temperature in step 1).

[0096] In some embodiments, no organic solvent or aqueous solution is added in step 2" to obtain ATBS.Na crystals. The temperature of the solution or aqueous suspension SA2 decreases advantageously at a gradient of 0.1 to 8°C / hour, preferably 0.2 to 8°C / hour, more preferably 0.3 to 8°C / hour, and even more preferably 0.5 to 5°C / hour.

[0097] The rate of temperature decrease does not have to be constant throughout the entire process. For example, the aqueous solution or aqueous suspension SA2 may be cooled at a rate of 5°C / hour for the first 3 hours, and then at a rate of 8°C / hour until it reaches the final temperature.

[0098] While the aqueous solution or aqueous suspension SA2 is being cooled, crystals and suspension S1 in the form of ATBS.Na are obtained.

[0099] In a particular embodiment, crystals of ATBS.Na obtained earlier may be added during this step to modify the formation of suspension S1, a process called crystal seeding, which allows for better control of the crystallization temperature, crystal size, particle size distribution, purity of the final product, and possibly the yield. Crystals of ATBS.Na favorably have an X-ray powder diffraction pattern that includes a group of peaks located at 11.7°, 12.2°, 13.2°, 13.5°, 15.6°, 16.8°, 17.8°, 18.5°, 19.1°, 20.6°, 21.4°, 23.3°, 25.1°, 25.8°, 26.9°, 29.1°, 29.5°, 31.0°, 33.0°, 33.6°, 34.4°, 35.2°, 35.9°, 37.1°, 38.4°, 39.6°, 41.1°, 42.9°, 45.1°, 46.0°, 47.2°, and 47.6° at a 2θ angle (+ / -0.1°).

[0100] According to a particular embodiment of the present invention, the solvent distilled in step 2) may be partially or completely reused to form the aqueous solution or aqueous suspension SA2 of step 1). In other words, the distilled solvent is advantageously reused in the aqueous solution or aqueous suspension SA2, at least partially.

[0101] According to another specific embodiment of the present invention, the distilled solvent may be partially or completely reused in an optional step 4) with or without a pretreatment step, generally for washing the ATBS.Na crystals obtained after step 3) of solid-liquid separation.

[0102] The resulting suspension S1 advantageously contains 30 to 90% by weight of ATBS.Na crystalline form relative to the total weight of the suspension S1, preferably 50 to 90% by weight of ATBS.Na crystalline form, more preferably 30 to 80% by weight of ATBS.Na crystalline form, and preferably 50 to 60% by weight of ATBS.Na crystalline form.

[0103] During step 2), the pH is advantageously greater than 10, preferably greater than 11, more preferably greater than 12, and even more preferably 13-14.

[0104] ●Step 3 of the method for producing the crystalline form of ATBS sodium salt): The ATBS.Na salt crystals contained in the suspension S1 obtained at the end of step 2) are isolated in the solid-liquid separation step and are in the form of composition C1.

[0105] The solid-liquid separation step can be carried out using various techniques. Examples include, but are not limited to, the use of centrifuges, decanters, filter presses, agitated filters, belt filters, disc filters, or rotary drum filters. Solid-liquid separation is preferably carried out using a centrifuge. Solid-liquid separation may also be carried out by gravity sedimentation.

[0106] Step 3) is advantageously carried out at a temperature of -20 to 40°C, preferably -5 to 30°C. After step 3) of solid-liquid separation, it is preferable not to dry the ATBS.Na crystals.

[0107] The isolated composition C1 has a crystalline content of ATBS.Na that is advantageously 40-99% by weight, preferably 60-99% by weight, more preferably 60-98% by weight, and even more preferably 80-99% by weight, relative to the weight of composition C1. The remainder of composition C1 may be water and / or solubilized ATBS sodium salt, and optionally the sodium salt base introduced in step 1).

[0108] At the end of step 3), the crystal is characterized as an ATBS.Na crystal. In one particular embodiment, all or part of the liquid phase obtained after solid-liquid separation is used in the aqueous solution or aqueous suspension SA2 of step 1).

[0109] During step 4), the pH is advantageously controlled to 6-14, preferably 8-14, more preferably 10-14, even more preferably 12-14, and even more preferably 13-14.

[0110] ●Step 4 of the method for producing the crystalline form of ATBS sodium salt): In the optional step 4), the composition C1 containing the crystal obtained at the end of step 3) is washed with a washing solution.

[0111] The washing solution may be water, an aqueous solution of a sodium salt base (which may be saturated or unsaturated), or a solution of ATBS.Na (which may be saturated or unsaturated) (preferably the crystalline form of ATBS.Na), and it is preferable that it be a saturated solution of the sodium salt of ATBS.

[0112] Examples of sodium salt solutions include solutions of sodium hydroxide, sodium carbonate, sodium bicarbonate, or mixtures thereof. The washing solution may contain one or more organic solvents.

[0113] The amount of organic solvent may vary as a function of temperature and the amount of ATBS.Na or sodium salt base. Advantageously, the cleaning solution does not contain organic solvents.

[0114] As already shown in Step 1), the organic solvent is advantageously selected from organic acids, amides, alcohols, ketones, ethers, esters, alkanes, halogenated hydrocarbon compounds, nitriles, or mixtures thereof. The organic solvent is preferably selected from acrylonitrile, isopropanol, acetic acid, or mixtures thereof. More preferably, the organic solvent is acrylonitrile.

[0115] In one particular embodiment, the composition C1 obtained at the end of step 3) is cleaned by spraying a cleaning solution onto the composition C1. In one particular embodiment, the composition C1 obtained at the end of step 3) is washed by suspending the composition C1 in a washing solution.

[0116] The weight ratio of the aqueous cleaning solution to composition C1 obtained at the end of step 3) is advantageously 0.05:1 to 10:1, and more preferably 0.1:1 to 5:1. This washing step is advantageously carried out at a temperature of -5 to 40°C, preferably 0 to 30°C. Those skilled in the art know how to adjust the temperature so as not to solubilize the ATBS.Na crystals.

[0117] The ATBS.Na crystals obtained at the end of this optional step 4) can be isolated from the washing solution in the form of composition C2 by the solid-liquid separation step.

[0118] The solid-liquid separation step can be carried out using various techniques. Examples include, but are not limited to, the use of vertical or horizontal centrifuges, decanters, filter presses, belt filters, disc filters, push filters, or rotary drum filters. Solid-liquid separation can also be carried out by gravity sedimentation.

[0119] In one particular embodiment, all or part of the recovered cleaning solution can be reused in step 4) with or without the pretreatment step.

[0120] In one particular embodiment, all or part of the recovered washing solution can be used in the aqueous solution or aqueous suspension SA2 in step 1), with or without the pretreatment step. The pH of the washing solution in step 5) is advantageously controlled to be between 6 and 14, preferably between 8 and 14.

[0121] ●Step 5 of the method for producing the crystalline form of ATBS sodium salt): In the optional step 5), the composition C1 obtained at the end of step 3) or the composition C2 obtained at the end of step 4) is dried.

[0122] The drying step can be carried out using a variety of techniques. Examples include, but are not limited to, the use of all convection drying techniques, conduction drying techniques, or radiation drying techniques (fluidized bed dryers, through-bed dryers, conveyor belt drying, microwaves, heated agitation filters, high-frequency radiation, infrared radiation, and spraying). The drying operation can be carried out under atmospheric pressure or vacuum. The drying step may be performed discontinuously (batch drying) or continuously.

[0123] ●Other steps in the method for producing the crystalline form of ATBS sodium salt: During the manufacturing process, i.e., between steps 1) to 5), and regardless of the step, at least one polymerization inhibitor may be introduced to prevent polymerization that may result in ATBS or a salt thereof. This inhibitor may be selected non-limitingly from hydroquinone, paramethoxyphenol, phenothiazine, 2,2,6,6-tetramethyl(piperidine-1-yl)oxyl, 4-hydroxy-2,2,6,6-tetramethyl(piperidine-1-yl)oxyl, phenylenediamine derivatives, or mixtures thereof.

[0124] The inhibitor is preferably paramethoxyphenol or 4-hydroxy-2,2,6,6-tetramethyl(piperidine-1-yl)oxyl. The amount of the inhibitor introduced relative to the amount of ATBS introduced in step 1) is advantageously 0.001% to 5% by weight, more preferably 0.01% to 1% by weight.

[0125] The inhibitor may be introduced during any one or more steps of this method. The amount added is preferably introduced during step 1). More preferably, the inhibitor is part of the aqueous solution or aqueous suspension SA2 introduced in step 1).

[0126] The manufacturing process (steps 1) to 5)) may be carried out continuously or discontinuously (batch production).

[0127] ●Composition of the water-soluble polymer The water-soluble polymer is obtained from the crystalline form of ATBS.Na, and is advantageously obtained from at least one other monomer selected from hydrophilic nonionic monomers and / or hydrophilic anionic monomers and / or hydrophilic cationic monomers and / or hydrophilic zwitterionic monomers and / or hydrophobic monomers and mixtures thereof. The water-soluble polymer may be a polymer of several distinct monomers or a homopolymer.

[0128] Advantageously, one or more hydrophilic nonionic monomers usable in the present invention include, in particular, acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N,N-dialkylacrylamide (e.g., N,N-dimethylacrylamide or N,N-diethylacrylamide), N,N-dialkylmethacrylamide, alkoxylated esters of acrylic acid, N-vinylpyrrolidone, N-methylol(meth)acrylamide, N-vinylcaprolactam, N-vinylformamide (NVF), N-vinylacetamide, N-vinylimidazole, N-vinyl The water-soluble vinyl monomer is selected from the group including lusuccinimide, acryloylmorpholine (ACMO), glycidyl methacrylate, vinyl acetate, glyceryl methacrylate, diacetone acrylamide, methacrylic anhydride, acrylonitrile, maleic anhydride, itaconamide, hydroxyalkyl (meth)acrylate, thioalkyl (meth)acrylate, isoprenol and its alkoxylated derivatives, hydroxyethyl (meth)acrylate and its alkoxylated derivatives, hydroxypropyl acrylate and its alkoxylated derivatives, and mixtures thereof. Among the nonionic monomers, the alkyl group is preferably C1-C5, more preferably C1-C3. The alkyl group is preferably a linear alkyl. Preferably, the hydrophilic nonionic monomer is acrylamide.

[0129] The water-soluble polymer preferably contains 1 to 99 mol%, more preferably 40 to 95 mol%, and more preferably 45 to 90 mol%, of one or more hydrophilic nonionic monomers.

[0130] Advantageously, apart from crystalline ATBS.Na, one or more hydrophilic anionic monomers usable in the present invention can be selected from a broad group. These monomers may have vinyl functional groups (preferably acrylic, maleic, fumaric, malonic, itaconic, or allyl functional groups), and may contain carboxylate groups, phosphonate groups, phosphate groups, sulfate groups, or sulfonate groups, or other anionic charged groups. Examples of suitable monomers include acrylic acid; methacrylic acid; dimethylacrylic acid; itaconic acid; C1-C3 hemiesters of itaconic acid; acryloyl chloride; crotonic acid; maleic acid; fumaric acid; 3-acrylamido-3-methylbutanoic acid; and strongly acidic monomers with sulfonic acid or phosphonic acid functional groups, such as vinyl sulfonic acid, vinyl phosphonic acid, allyl sulfonic acid, methallyl sulfonic acid, 2-methylidenepropane-1,3-disulfonic acid, 2-sulfoethyl methacrylate, sulfopropyl methacrylate, etc. Examples include bisphosphonate, allylphosphonic acid, ethylene glycol methacrylate phosphoric acid, 2-acrylamido-2-methylpropanesulfonic acid (ATBS), 2-acrylamido-2-methylpropanedisulfonic acid, 3-allyloxy-2-hydroxypropanesulfonic acid, diethylallylphosphonate, carboxyethyl acrylate; water-soluble salts of these monomers, e.g., alkali metal salts, alkaline earth metal salts, or ammonium salts thereof (different from the crystalline form ATBS.Na); and mixtures thereof. Preferably, one or more hydrophilic anionic monomers are acrylic acid and / or salts thereof.

[0131] The water-soluble polymer preferably contains 0.1 to 100 mol%, more preferably 1 to 99 mol%, more preferably 5 to 70 mol%, and even more preferably 10 to 50 mol%, of one or more hydrophilic anionic monomers (separate from the crystalline form of ATBS.Na). In this case, these percentages also include monomers of the crystalline form of ATBS.Na.

[0132] In a particular embodiment of the present invention, one or more anionic hydrophilic monomers may be chlorinated in addition to the crystalline form of ATBS.Na.

[0133] Chlorination refers to the -R of anionic monomers. a The proton of at least one acidic functional group of the (=O)-OH type (where R represents P, S, or C) is replaced with a metal cation or an ammonium cation, -R a This means that it forms a salt of the (=O)-OX type (where X is a metal cation or an organic cation). In other words, the non-salt form is the acid form of the monomer, for example, in the case of a carboxylic acid functional group, R b Corresponding to -C(=O)-OH, the salt form of the monomer is R b -C(=O)-O - X + (X + This corresponds to the form of an alkaline cation or an organic cation. The chlorination of the acid functional group of the branched water-soluble polymer may be partial or whole.

[0134] The salt form preferably corresponds to a salt of alkali metals (Li, Na, K, etc.), alkaline earth metals (Ca, Mg, etc.), or ammonium (e.g., ammonium ion or tertiary ammonium). The preferred salt is the sodium salt.

[0135] Chloridation may occur before, during, or after polymerization. In one particular embodiment of the present invention, the water-soluble polymer preferably comprises 1 to 100 mol%, preferably 20 to 100 mol%, more preferably 50 to 100 mol%, and even more preferably 80 to 100 mol%, of one or more anionic monomers in chloride form.

[0136] Advantageously, one or more hydrophilic cationic monomers usable in the present invention are selected from monomers derived from vinyl-type units (preferably acrylamide, acrylic, allyl, or maleic acid) having a phosphonium or quaternary ammonium functional group. Not particularly limited, Diallyldialkylammonium salts such as diallyldimethylammonium chloride (DADMAC); Acidified or quaternized salts of dialkylaminoalkyl(meth)acrylamides, for example, methacrylamide-propyltrimethylammonium chloride (MAPTAC), acrylamide-propyltrimethylammonium chloride (APTAC); Acidified or quaternized salts of dialkylaminoalkyl acrylates, such as quaternized or dimethylaminoethyl acrylate (DMAEA); Acidified or quaternized salts of dialkylaminoalkyl methacrylates, such as quaternized or dimethylaminoethyl methacrylate (DMAEMA); Acidified or quaternized salts of N,N-dimethylallylamine; Acidified or quaternized salts of diallylmethylamine; Acidified or quaternized salts of diallylamine; Vinylamines obtained by hydrolysis (with a base or acid) of an amide group -N(R2)-CO-R1 (where R1 and R2 are independently hydrogen atoms or an alkylated chain of 1 to 6 carbon atoms), for example, vinylamines obtained from the hydrolysis of vinylformamide; Vinylamines obtained by Hoffmann decomposition; and those mixtures The following can be cited. Advantageously, the alkyl group is C1 to C7, preferably C1 to C3, and may be linear, cyclic, saturated, or unsaturated. Preferably, it is quaternized dimethylaminoethyl acrylate.

[0137] Those skilled in the art know how to prepare quaternized monomers, which is done, for example, using an RX-type quaternizing agent (where R is an alkyl group and X is a halogen or sulfate). The term "quaternizing agent" refers to a molecule that can alkylate a tertiary amine.

[0138] The quaternizing agent may be selected from dialkyl sulfates or alkyl halides containing 1 to 6 carbon atoms. Preferably, the quaternizing agent is selected from methyl chloride, benzyl chloride, dimethyl sulfate, or diethyl sulfate. Furthermore, the present invention also encompasses DADMAC, APTAC, and MAPTAC monomers in which the counterion is sulfate, fluoride, bromide, or iodide instead of chloride.

[0139] The water-soluble polymer preferably contains 0 to 20 mol%, more preferably 0 to 6 mol%, of one or more hydrophilic cationic monomers. Advantageously, the hydrophilic zwitterionic monomer(s)(one or more) may be a derivative of a vinyl-type unit(s)(preferably acrylamide, acrylic, allyl, or maleic acid) having a quaternary amine functional group or an ammonium functional group and a carboxylic acid (or carboxylate) functional group, a sulfonic acid (or sulfonate) functional group, or a phosphoric acid (or phosphate) functional group. In particular, not limited to, Dimethylaminoethyl acrylate derivatives such as 2-((2-(acryloyloxy)ethyl)dimethylammonio)dimethylammonio)ethane-1-sulfonate, 3-((2-(acryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 4-((2-(acryloyloxy)ethyl)dimethylammonio)butane-1-sulfonate, and [2-(acryloyloxy)ethyl](dimethylammonio)acetate. Dimethylaminoethyl methacrylate derivatives such as 2-((2-(methacryloyloxy)ethyl)dimethylammonio)ethane-1-sulfonate, 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 4((2-(methacryloyloxy)ethyl)dimethylammonio)butane-1-sulfonate, and [2-(methacryloyloxy)ethyl](dimethylammonio)acetate. Dimethylaminopropylacrylamide derivatives such as 2-((3-acrylamidopropyl)dimethylammonio)ethane-1-sulfonate, 3-((3-acrylamidopropyl)dimethylammonio)propane-1-sulfonate, 4-((3-acrylamidopropyl)dimethylammonio)butane-1-sulfonate, and [3-(acryloyloxy)propyl](dimethylammonio)acetate. Dimethylaminopropylmethylacrylamide derivatives such as 2-((3-methacrylamidopropyl)dimethylammonio)ethane-1-sulfonate, 3-((3-methacrylamidopropyl)dimethylammonio)propane-1-sulfonate, 4-((3-methacrylamidopropyl)dimethylammonio)butane-1-sulfonate, and [3-(methacryloyloxy)propyl](dimethylammonio)acetate. and mixtures thereof We can list some examples.

[0140] Other hydrophilic zwitterionic monomers may also be used, in particular the hydrophilic zwitterionic monomer described by the applicant in International Patent Publication No. 2021 / 123599. The water-soluble polymer preferably contains 0 to 20 mol%, more preferably 0 to 10 mol%, of one or more hydrophilic zwitterionic monomers.

[0141] Distribution coefficient K greater than 1 ow Hydrophobic monomers having the following properties can also be used in the preparation of polymers according to the present invention. The hydrophobic monomer is preferably selected from the following list: (i) C4-C30 alkyl chains, or (ii) arylalkyl (C4-C30 alkyl, C4-C30 aryl) chains, or (iii) propoxylated chains, or (iv) ethoxylated chains, or (v) (meth)acrylic acid esters having ethoxylated and propoxylated chains; Alkylaryl sulfonates (C4-C30 alkyl, C4-C30 aryl); (i) C4-C30 alkyl chains, or (ii) arylalkyl (C4-C30 alkyl, C4-C30 aryl) chains, or (iii) propoxylated chains, or (iv) ethoxylated chains, or (v) monosubstituted or disubstituted (meth)acrylamide amides having ethoxylated and propoxylated chains; Anionic or cationic monomer derivatives of (meth)acrylamide or (meth)acrylic acid having hydrophobic chains; Vinylpyridine and A mixture of those. The hydrophobic monomer may contain a halogen atom, such as chlorine. Among these hydrophobic monomers: The alkyl group is preferably C4-C20, more preferably C4-C8. C6-C20 alkyl groups are preferably linear, while C4-C5 alkyl groups are preferably branched. The arylalkyl group is preferably C7-C25, more preferably C7-C15. The ethoxylated chain preferably contains 1 to 200, more preferably 6 to 100, and more preferably 10 to 40 -CH2-CH2-O- groups. The propoxylated chain preferably contains 1 to 50, more preferably 1 to 20, -CH2-CH2-CH2-O- groups.

[0142] Preferred hydrophobic monomers belonging to these classes include, for example: n-hexyl(meth)acrylate, n-octyl(meth)acrylate, octyl(meth)acrylamide, lauryl(meth)acrylate, lauryl(meth)acrylamide, myristyl(meth)acrylate, myristyl(meth)acrylamide, pentadecyl(meth)acrylate, pentadecyl(meth)acrylamide, cetyl(meth)acrylate, cetyl(meth)acrylamide, oleyl(meth)acrylate, oleyl(meth)acrylamide, erucyl(meth)acrylate, erucyl(meth)acrylamide, N-tert-butyl(meth)acrylamide, 2-ethylhexylacrylate, C4-C22 itaconic acid hemiesters, acidified or quaternized salts of C4-C22 dialkylaminoalkyl(meth)acrylates, acidified or quaternized salts of C4-C22 dialkylaminoalkyl(meth)acrylamides, vinylpyridine, acrylamide undecanoic acid, and mixtures thereof.

[0143] • Cationic allyl derivatives of formula (I) or (II): [ka] (In the formula, R is independently an alkyl chain containing 1 to 4 carbon atoms, R1 is an alkyl or arylalkyl chain containing 8 to 30 carbon atoms, and X is a halide selected from the group consisting of bromides, chlorides, iodides, fluorides, and any negatively charged counterions.) And, preferably, a (meth)acryloyl-type hydrophobic cationic derivative corresponding to formula (III): [ka] (In the formula, A represents O or N-R5 (preferably A represents N-R5), R2, R3, R4, R5, R6, and R7 are independently alkyl chains containing hydrogen or 1 to 4 carbon atoms, Q is an alkyl chain containing 1 to 20 carbon atoms, R8 is an alkyl or arylalkyl chain containing 8 to 30 carbon atoms, and X is a halide selected from the group consisting of bromides, chlorides, iodides, fluorides, and any negatively charged counterions.) These are some examples.

[0144] The water-soluble polymer preferably contains less than 5 mol% of hydrophobic monomer. If the water-soluble polymer contains a hydrophobic monomer, the hydrophobic monomer is present in an amount that allows the polymer to remain soluble in water.

[0145] Monomers with fluorescent properties can also be used in this invention. Monomers with fluorescent properties may be detected by any suitable method, for example, by fluorescence measurement using a fixed-wavelength fluorometer. Generally, monomers with fluorescent properties are detected at maximum excitation and maximum emission, which can be determined using a scanning fluorometer. Monomers having fluorescent properties are selected, for example, from the following monomers: sodium styrenesulfonate or potassium styrenesulfonate, styrenesulfonic acid, vinylimidazole and its derivatives, 9-vinylanthracene and its derivatives, N-9-xanthenylacrylamide and its derivatives, allyldibenzosverenol and its derivatives, tinconisine and its derivatives, quininone and its derivatives, cinconinone and its derivatives, N,N-dimethyl-N-[3-[N'-(4-methoxynaphthalimide)]]propyl-N-(2-hydroxy-3-allyloxy)propylammonium hydroxide, and mixtures thereof. Other fluorescent compounds can also be used if they are functionalized with an allyl double bond, a vinyl double bond, or an acrylic double bond, such as pyranine and its derivatives, coumarin and its derivatives, quinolaxin and its derivatives, pinacyanol and its derivatives, xanthidol and its derivatives, luminol and its derivatives, dabusil and its derivatives, 3-hydroxy-2-methylene-3-(1-naphthyl)propionic acid and its derivatives, rhodamine and its derivatives, N-dibenzoberylacrylamide and its derivatives, naphthalene derivatives, fluorescein and its derivatives, pyrene and its derivatives, carbostyryl and its derivatives, pyrazoline and its derivatives, and mixtures thereof.

[0146] In a preferred embodiment, the polymer does not contain monomers having fluorescent properties. In a particular embodiment of the present invention, the water-soluble polymer may comprise at least one cyclic monomer having hydrolytic functionality. Advantageously, one or more cyclic monomers having hydrolytic functionality are selected from cyclic ketene acetals, thionolactones, and mixtures thereof.

[0147] The cyclic ketene acetal is advantageously selected from 2-methylene-1,3-dioxepane (MDO), 5,6-benzo-2-methylene-1,3-dioxepane (BMDO), 2-methylene-4-phenyl-1,3-dioxolane (MPDL), 2-methylene-1,3,6-trioxocan (MTC), and mixtures thereof. Preferably, the cyclic ketene acetal is 2-methylene-1,3-dioxepane (MDO).

[0148] The thionolactone is advantageously selected from dibenzo[c,e]oxepin(7H)-5-thion (DOT), ε-thionocaprolactone, 3,3-dimethyl-2,3-dihydro-5H-benzo[e][1,4]dioxepin-5-thion (DBT), and mixtures thereof. Preferably, the thionolactone is 3,3-dimethyl-2,3-dihydro-5H-benzo[e][1,4]dioxepin-5-thion.

[0149] In a particular embodiment of the present invention, the water-soluble polymer may contain at least one group having an LCST. According to the general knowledge of those skilled in the art, a group having an LCST corresponds to a group whose water solubility, for a given concentration, is modified as a function of salt concentration above a certain temperature. This is a group that has a heating transition temperature that defines a lack of affinity with the solvent medium. This lack of affinity with the solvent results in opacity or loss of transparency, which can be due to precipitation, aggregation, gelation, or viscosity of the medium. The minimum transition temperature is known as the LCST (lower critical solution temperature). For each concentration of a group having an LCST, a heating transition temperature is observed. This is higher than the LCST, which is the minimum point on the curve. Below this temperature, the polymer is soluble in water. Above this temperature, the polymer loses its solubility in water.

[0150] In a particular embodiment of the present invention, the water-soluble polymer may contain at least one group having UCST. According to the general knowledge of those skilled in the art, a group having UCST corresponds to a group whose water solubility, for a given concentration, is modified as a function of salt concentration below a certain temperature. This is a group that has a cooling transition temperature that defines a lack of affinity with the solvent medium. This lack of affinity with the solvent results in opacity or loss of transparency, which can be due to precipitation, aggregation, gelation, or viscosity of the medium. The maximum transition temperature is known as UCST (upper critical solution temperature). For each concentration of a group having UCST, a cooling transition temperature is observed. This is lower than UCST, which is the maximum point on the curve. Above this temperature, the polymer is soluble in water; below this temperature, the polymer loses its solubility in water.

[0151] The amounts of various monomers (one or more) are adjusted by those skilled in the art so as not to exceed 100 mol% when preparing the water-soluble polymer.

[0152] ●Water-soluble polymer Advantageously, 50 mol% or more, preferably 70 to 100 mol%, of the 2-acrylamido-2-methylpropanesulfonic acid used to obtain the water-soluble polymer is the crystalline form of ATBS sodium salt before polymerization. More preferably, 100 mol% of the ATBS used is the crystalline form of ATBS sodium salt.

[0153] In one preferred embodiment of the present invention, the water-soluble polymer comprises only hydrophilic anionic monomers and hydrophilic nonionic monomers. In other words, the water-soluble polymer is preferably obtained from at least one hydrophilic anionic monomer and at least one hydrophilic nonionic monomer.

[0154] In a particular embodiment of the present invention, the water-soluble polymer contains 0.1 to 100 mol%, preferably 2 to 60 mol%, and more preferably 3 to 50 mol%, of ATBS, wherein 50 mol% or more of the ATBS used is the crystalline form of ATBS sodium salt, and preferably 70 to 100 mol% of the ATBS used is the crystalline form of ATBS sodium salt. More preferably, 100 mol% of the ATBS used is the crystalline form of ATBS sodium salt.

[0155] In a particular embodiment of the present invention, the water-soluble polymer contains 1 to 99 mol%, preferably 40 to 95 mol%, more preferably 45 to 90 mol%, of a hydrophilic nonionic monomer, and 1 to 99 mol%, more preferably 5 to 70 mol%, more preferably 3 to 50 mol%, of ATBS, wherein 50 mol% or more of the ATBS used is the crystalline form of ATBS sodium salt before polymerization, and preferably 70 to 100 mol% of the ATBS used is the crystalline form of ATBS sodium salt before polymerization. More preferably, 100 mol% of the ATBS used is the crystalline form of ATBS sodium salt.

[0156] In one preferred embodiment of the present invention, the water-soluble polymer is an ATBS-based polymer, wherein 50 mol% or more of the ATBS used is the crystalline form of ATBS sodium salt.

[0157] Preferably, the water-soluble polymer is a polymer comprising acrylamide, acrylic acid, and ATBS, wherein 50 mol% or more of the ATBS used is the crystalline form of ATBS sodium salt.

[0158] The water-soluble polymer may be partially or entirely post-hydrolyzed. According to the present invention, the water-soluble polymer may have a linear, branched, crosslinked, star-shaped, or comb-shaped structure. This structure can be obtained, according to the general knowledge of those skilled in the art, by, for example, by selecting an initiator, a transfer agent, polymerization techniques such as RAFT (reversible addition-cleavage chain transfer), NMP (nitroxide-mediated polymerization), or ATRP (atomic transfer radical polymerization), incorporating structural monomers, or selecting their concentrations.

[0159] The water-soluble polymer may be further composed of branching agents. The structured polymer is a nonlinear polymer having side chains such that when dissolved in water, the polymer exhibits a high degree of entanglement, resulting in a very high low gradient viscosity.

[0160] The branching agent is advantageously selected from the following: The structural agent can be selected from the group including polyethylene unsaturated monomers such as vinyl functional groups (having at least two unsaturated functional groups), particularly allyl functional groups or acrylic functional groups, for example, methylenebisacrylamide (MBA), triallylamine, tetraallylammonium chloride, or 1,2-dihydroxyethylenebis-(N-acrylamide). • A monomer having at least two epoxy functional groups, • A monomer having at least one unsaturated functional group and one epoxy functional group. Macroinitiators such as polyperoxides and polyazoids, and transfer agents such as polymer mercaptan polymers and polyols. ·Functionalized polysaccharides, • Water-soluble metal complex consisting of the following: *For example and not limited to, metals having a valency of more than 3, such as aluminum, boron, zirconium, or titanium, and * Ligand having a hydroxyl functional group.

[0161] The amount of branching agent in the water-soluble polymer is advantageously less than 40,000 ppm, preferably less than 10,000 ppm, and more preferably less than 5,000 ppm, relative to the total weight of the monomers of the water-soluble polymer.

[0162] In one particular embodiment, the amount of branching agent is 0.1 ppm or more, preferably 1 ppm or more, relative to the total weight of the monomers of the water-soluble polymer. If the water-soluble polymer contains a branching agent, the polymer remains soluble in water. Those skilled in the art know how to adjust the amount of branching agent, and possibly the amount of transfer agent, required to obtain this result.

[0163] In a preferred embodiment of the present invention, the water-soluble polymer does not contain a branching agent. In a particular embodiment of the present invention, the water-soluble polymer includes a transfer agent. The transport agents are advantageously methanol; isopropyl alcohol; sodium hypophosphate; calcium hypophosphate; magnesium hypophosphate; potassium hypophosphate; ammonium hypophosphate; formic acid; sodium formate; calcium formate; magnesium formate; potassium formate; ammonium formate; 2-mercaptoethanol; 3-mercaptopropanol; dithiopropylene glycol; thioglycerol; thioglycolic acid; thiohydroacrylic acid; thiolactic acid; thiomalic acid; cysteine; aminoethanethiol; thioglycolate; allyl phosphite; allyl mercaptan such as n-dodecyl mercaptan; sodium methallyl sulfonate; methallyl sulfonate The following are selected from: calcium phosphate; magnesium methallyl sulfonate; potassium methallyl sulfonate; ammonium methallyl sulfonate; alkyl phosphates such as trialkyl (C12-C15) phosphite, dioleyl-hydrogen phosphite, and dibutyl phosphite; dialkyldithiophosphates such as dioctyl phosphonate; tertiary nonyl mercaptan; 2-ethylhexyl thioglycolate; n-octyl mercaptan; n-dodecyl mercaptan; tertiary dodecyl mercaptan; isooctyl thioglycolate; 2-ethylhexyl thioglycolate; 2-ethylhexyl mercaptoacetate; polythiols; and mixtures thereof. Preferably, the transfer agent is sodium hypophosphate or sodium formate.

[0164] The amount of the transfer agent in the water-soluble polymer is advantageously 0 to 100,000 ppm, preferably 0 to 10,000 ppm, more preferably 0 to 1,000 ppm, and even more preferably 0 to 100 ppm, relative to the total weight of the monomers of the polymer. When present, the transfer agent accounts for 0.1 ppm or more, and preferably 1 ppm or more, relative to the total weight of the monomers of the water-soluble polymer.

[0165] In a particular embodiment of the present invention, the water-soluble polymer does not contain a transfer agent. Generally speaking, the water-soluble polymer does not require the development of a specific polymerization method. In fact, the water-soluble polymer may be obtained using any polymerization technique well known to those skilled in the art. These include solution polymerization; gel polymerization; precipitation polymerization; emulsion polymerization (aqueous or reversed phase); suspension polymerization; reaction extrusion polymerization; water-in-water polymerization; or micelle polymerization.

[0166] Polymerization is generally radical polymerization, preferably radical polymerization by reverse-phase emulsion polymerization or gel polymerization. Radical polymerization includes free radical polymerization using UV initiators, azo initiators, redox initiators, or thermal initiators, as well as controlled radical polymerization (CRP) or matrix polymerization techniques.

[0167] Controlled radical polymerization techniques include, but are not limited to, iodine transfer polymerization (ITP), nitroxide-mediated polymerization (NMP), atom transfer radical polymerization (ATRP), reversible addition-cleavage-chain transfer (RAFT) polymerization (which includes MADIX (polymer design by xanthate exchange) technology), various variations of organometallic radical polymerization (OMRP), and organic heteroatom-mediated radical polymerization (OHRP).

[0168] As already shown, the water-soluble polymer may be post-hydrolyzed. Post-hydrolysis is a hydrolysis reaction of a polymer after it has been formed by the polymerization of monomers. This step involves reacting the hydrolyzable functional groups of the monomers, preferably nonionic functional groups, and more preferably amide or ester functional groups, with a hydrolyzing agent. This hydrolyzing agent may be an enzyme, an ion exchange resin, or a Brønsted acid (e.g., a hydrohalic acid) or a Brønsted base (e.g., an alkali hydroxide or alkaline earth hydroxide). Preferably, the hydrolyzing agent is a Brønsted base. During this step of post-hydrolysis of the water-soluble polymer, the number of carboxylic acid functional groups increases. In fact, the reaction between the base and the amide or ester functional groups present in the water-soluble polymer produces carboxylate groups.

[0169] The water-soluble polymer may be in liquid, gel, or solid form if its preparation involves a drying step such as spray drying, drum drying, radiation drying such as microwave drying, or drying in a fluidized bed.

[0170] The water-soluble polymer is advantageously 0.5 × 10 6 g / mol or more, preferably 0.5 × 10⁻⁶ 6 ~40×10 6 g / mol, comfortable 5 × 10 6 ~30×10 6 It has a molecular weight of g / mol. Molecular weight is defined as weight-average molecular weight. In certain embodiments, the water-soluble polymer may have a molecular weight of 5,000 to 100,000 g / mol, or 100,000 to 500,000 g / mol.

[0171] The molecular weight is determined by the intrinsic viscosity of the polymer. Intrinsic viscosity can be measured by methods known to those skilled in the art, and can be calculated from the reduced viscosity values ​​for various polymer concentrations by a graphing method consisting of plotting the reduced viscosity value (y-axis) against the concentration (x-axis) and extrapolating the curve to the 0 concentration. The intrinsic viscosity value is plotted on the y-axis or using the least squares method. The molecular weight can then be determined using the Mark-Houwink equation:

[0172] [η]=KM α [η] represents the intrinsic viscosity of the polymer as determined by the solution viscosity method. K represents the experimental constant. M represents the molecular weight of the polymer. α represents the Mark-Houwink coefficient. K and α depend on the specific polymer-solvent system.

[0173] ● Method for processing suspended solid particles in water Surprisingly, the applicant has found that using a water-soluble polymer obtained from the aforementioned crystalline form of ATBS.Na is: • Increasing the sludge concentration, for example, increasing the sludge concentration at the outlet of the sinking concentrator (thickener). • A dehydration step, and, if the suspension is released onto the ground, a step of drying and solidifying the suspension, - Mechanically processing the aforementioned processed suspension. We discovered that it improves the performance of suspension processing, including [the substance].

[0174] Accordingly, the present invention relates to a method for processing a suspension of solid particles in water, comprising contacting the suspension of solid particles in water with at least one water-soluble polymer obtained from the crystalline form of ATBS.Na.

[0175] The present invention comprises contacting a suspension of solid particles in water with at least one water-soluble polymer, wherein the polymer has 2θ angles (+ / -0.1°) of 11.7°, 12.2°, 13.2°, 13.5°, 15.6°, 16.8°, 17.8°, 18.5°, 19.1°, 20.6°, 21.4°, 23.3°, 25.1°, and 25.8°. It is prepared from the aforementioned crystalline form of ATBS.Na having an X-ray powder diffraction pattern that includes a group of peaks located at 26.9°, 29.1°, 29.5°, 31.0°, 33.0°, 33.6°, 34.4°, 35.2°, 35.9°, 37.1°, 38.4°, 39.6°, 41.1°, 42.9°, 45.1°, 46.0°, 47.2°, and 47.6°. Therefore, this method includes mixing the suspension with the water-soluble polymer.

[0176] Such processing can be carried out in a thicknesser, which is a holding zone that is generally several meters in diameter and has the shape of a cylindrical section with a conical bottom into which particles can settle. According to one particular embodiment, the aqueous suspension is transported to the thicknesser by a pipeline, and the water-soluble polymer is added into the pipeline.

[0177] In one embodiment, the water-soluble polymer is added to a sedimentation concentrator that already contains the suspension to be treated. In a typical mineral treatment operation, the suspension is often concentrated in the sedimentation concentrator. This results in a high-concentration sludge at the bottom of the sedimentation concentrator and an aqueous fluid (called liquor) released from the treated suspension, which is present at the top of the sedimentation concentrator by overflow. Adding the water-soluble polymer increases the concentration of the sludge and increases the clarity of the liquor.

[0178] In one embodiment, the water-soluble polymer is added to a suspension of particles while the suspension is being transported through piping to a deposit zone. Preferably, the water-soluble polymer is added in the piping transporting the suspension to the deposit zone. The treated suspension is spread in this deposit zone, dewatered, and solidified. This deposit zone may be undefined, for example, an undefined area of ​​the ground, or it may be defined, for example, a watershed or a cell.

[0179] One example of these treatments performed while the suspension is being transported is to spread the suspension treated with the water-soluble polymer on the ground to dehydrate and solidify it, and then spread a second layer of the treated suspension on top of this first solidified layer.

[0180] Another example is to continuously spread the water-soluble polymer-treated suspension so that it continuously falls onto the suspension previously discharged into the deposition zone, forming a mass of treated material from which water is drawn.

[0181] In one particular embodiment, the water-soluble polymer is added to the suspension, and then subjected to mechanical treatment such as centrifugation, pressing, or filtration.

[0182] The water-soluble polymer can also be added simultaneously to different stages of the suspension processing process, for example, into the pipeline transporting the suspension to the sedimentation concentrator and into the slurry exiting the sedimentation concentrator. The slurry is then transported to a deposition zone or a mechanical processing unit.

[0183] The water-soluble polymer may be added to the aqueous suspension to be treated in liquid form or in solid form. The water-soluble polymer may also be added in the form of an emulsion (preferably a water-in-oil emulsion), an aqueous or oily multiphase particulate suspension, or a powder. Preferably, the polymer is added in the form of an aqueous solution obtained from a concentrated form of the polymer, such as a powder, a water-in-oil emulsion, or an aqueous or oily multiphase particulate suspension.

[0184] In one particular embodiment, the aqueous multiphase particulate suspension is preferably, • 15-60% by mass of at least one water-soluble polymer in the form of solid particles with an average particle size of 5-500 μm; • 15-45% by mass of at least one alkali metal salt and / or at least one alkaline earth metal salt; • At least one viscosifying agent other than the aforementioned water-soluble polymer; • Water at least 10% by mass Including, The aforementioned suspension has a Brookfield viscosity of 500 to 20,000 cps at 20°C, and, The aforementioned suspension has a density of 1.1 to 2 kg·L. -1 That is the case.

[0185] In one particular embodiment, the oily multiphase particulate suspension is preferably, • 15-60% by mass of at least one water-soluble polymer in the form of solid particles with an average particle size of 5-500 μm; • At least one viscosifying agent other than the aforementioned water-soluble polymer; • Oil content of 10% or more by mass Including, The aforementioned suspension has a Brookfield viscosity of 500 to 20,000 cps at 20°C, and, The aforementioned suspension has a density of 0.6 to 1.4 kg·L. -1 That is the case.

[0186] Brookfield viscosity is measured using a Brookfield apparatus equipped with an LV module, which can rotate at a speed of, for example, 30 rpm, and the measurement is preferably performed at 20°C. The density is measured at 20°C and a pressure of 1 atm, or 101,325 Pa.

[0187] If the water-soluble polymer is in solid form, the water-soluble polymer can be partially or completely dissolved in water using a polymer preparation unit such as a polymer slicing unit (PSU) disclosed in EP2203245.

[0188] In one particular embodiment, the water-soluble polymer is added to the suspension in combination with at least one other synthetic or natural polymer. These polymers may be added simultaneously or separately (before or after the addition of the water-soluble polymer is complete). The other polymer may be water-soluble or water-swellable. The other polymer may be a dispersant, a coagulant, or a flocculant.

[0189] In one particular embodiment, the water-soluble polymer is added to the suspension in combination with a salt, such as a calcium and / or magnesium salt. The water-soluble polymer and the salt may be added simultaneously or separately. The salt may be an inorganic or organic salt. Suitable salts include calcium chloride, calcium acetate, calcium sulfate, calcium nitrate, calcium hydroxide, calcium carbonate, magnesium chloride, magnesium acetate, magnesium sulfate, magnesium nitrate, magnesium hydroxide, magnesium carbonate, calcium formate, calcium gluconate, calcium propionate, tricalcium phosphate, and calcium succinate.

[0190] The amount of water-soluble polymer added to the aqueous suspension is advantageously 50 to 5,000 g per ton (dry weight) of solid particles of the suspension, preferably 250 to 2,000 g / t, and more preferably 500 to 1,500 g / t. The amount depends on the properties and composition of the suspension being treated. Those skilled in the art will know how to adjust this amount and will consider such adjustments to be routine matter.

[0191] According to the present invention, the method can be used to efficiently process suspensions of solid particles, more specifically mineral particles.

[0192] The suspended solid particles in water include all types of sludge, residue, or waste materials. More specifically, the suspensions are those resulting from mineral extraction and are in the form of suspended mineral particles. These may be, for example, mining sludge or industrial waste, as well as all washing products and wastes resulting from mining operations such as coal mines, diamond mines, phosphate mines, and metal mines (aluminum, platinum, iron, gold, copper, silver, etc.). The suspensions also include those resulting from oil sands extraction, such as sludge or extraction residues derived from the processing of oil sands. These suspensions generally contain organic and / or mineral particles such as clay, sediments, sand, metal oxides, oil, etc., and are mixed with water, for example.

[0193] Generally, the suspension of solid particles is concentrated to contain 5% to 60% by weight of solid particles, and preferably 20% to 50% by weight of solid particles, relative to the total weight of the suspension.

[0194] The method according to the present invention may also be useful for processing the residue resulting from oil sands extraction, which is called fine or fine tailings, that is, residue containing a large amount of clay, and may also be useful for processing the fine residue known as mature fine tailings (MFT), that is, the same fine residue after several years of sedimentation, which contains a larger amount of clay. The method according to the present invention may also be used for processing so-called "fresh" residue, that is, residue resulting directly from the operation of separating bitumen from soil from which bitumen is extracted.

[0195] ● Method for agglomerating suspended solid particles in water The present invention also relates to angles of 11.7°, 12.2°, 13.2°, 13.5°, 15.6°, 16.8°, 17.8°, 18.5°, 19.1°, 20.6°, 21.4°, 23.3°, 25.1°, 25.8°, 26.9°, 29.1°, 29.5°, 31.0°, 33.0°, 33.6°, 34.4°, 35.2°, 35.9° at 2θ angles (+ / -47.6°). The present invention also relates to a method for agglomerating a suspension of solid particles in water, comprising contacting the suspension with a suspension of solid particles in water with at least one water-soluble polymer obtained from the crystalline form of ATBS.Na having an X-ray powder diffraction pattern including a group of peaks located at 37.1°, 38.4°, 39.6°, 41.1°, 42.9°, 45.1°, 46.0°, 47.2°, and 47.6°.

[0196] All of the above embodiments of methods for processing suspended solid particles in water are also applicable to methods for agglomerating suspended solid particles in water.

[0197] The following examples are provided solely for illustrative purposes of the subject matter of the present invention and are not intended to limit the invention in any way.

[0198] ▲Example ●Example 1: Synthesis of 2-acrylamido-2-methylpropanesulfonic acid E1 (ATBS) 1522 g of acrylonitrile containing 0.4 wt% water and 180 g of fuming sulfuric acid (104% H2SO4, 18% fuming sulfuric acid) are added to a 2000 ml reactor with a double jacket and stirring. The mixture is stirred for 1 hour and then cooled by the reactor jacket, which maintains the temperature of the sulfonated mixture at -20°C.

[0199] 97 g of isobutylene was added to the above sulfonated mixture at a rate of 1.6 g / min.

[0200] When isobutylene was introduced, the temperature of the mixture was controlled to 45°C. 2-acrylamido-2-methylpropanesulfonic acid particles precipitated from the mixture, with a solid content of approximately 20% by weight. This reaction mixture was filtered through a Buchner filter and dried under vacuum at 50°C. The resulting solid was 2-acrylamido-2-methylpropanesulfonic acid in the form of a very fine white powder. Optical microscopy observation (Figure 9) shows that the ATBS crystals have a needle-like morphology.

[0201] ●Example 2a: Formation of the crystalline form of the sodium salt (ATBS.Na)E2a of 2-acrylamido-2-methylpropanesulfonic acid according to the present invention Add 439 g of a 22% (by weight in water) sodium hydroxide solution to a double-jacketed 1000 ml reactor with stirring. Add 452 g of ATBS from Example 1 to the mixture.

[0202] The mixture is stirred at 10°C for 30 minutes to form an aqueous solution SA2. The aqueous solution SA2 is heated to a temperature of 40°C for 20 minutes under a vacuum of 50 mbar, then the temperature is maintained under a vacuum of 50 mbar for 30 minutes and cooled to a temperature of 10°C. The cooling time from 40°C to 10°C is 6 hours. A suspension S1 of crystalline sodium salt of 2-acrylamido-2-methylpropanesulfonic acid is obtained. This suspension S1 is filtered using a Robatel vertical centrifuge. A solid of composition C1 containing 80% by weight of crystalline ATBS.Na E2a is obtained.

[0203] Optical microscope observation (Figure 10) shows that the crystals of ATBS.Na E2a have columnar and platelet forms. The crystals of E2a show an X-ray diffraction pattern having the following characteristic peaks: At 2θ angles (+ / -0.1°): 11.70°; 12.20°; 13.2°; 13.5°; 15.60°; 16.80°; 17.80°; 18.5°; 19.1°; 20.6°; 21.40°; 23.3°; 25.1°; 25.8°; 26.9°; 29.10°; 29.50°; 31.0°; 33°; 33.6°; 34.4°; 35.2°; 35.9°; 37.1°; 38.4°; 39.6°; 41.10°; 42.90°; 45.10°; 46.0°; 47.2°; 47.6°

[0204] ● Example 2b: Formation of the crystalline form of ATBS.Na according to the present invention The crystals of ATBS.Na are prepared according to the procedure described in Example 2a, except that SA2 is distilled at 700 mbar.

[0205] Optical microscope observation (Figure 11) shows that the crystals obtained under these conditions are the same as the crystals of ATBS.Na prepared in Example 2a.

[0206] ● Example 2c: Formation of the crystalline form of ATBS.Na according to the present invention The crystals of ATBS.Na are prepared according to the procedure described in Example 2a, except that the cooling time is shortened to 3 hours and 45 minutes. Optical microscope observation (Figure 12) shows that the crystals obtained under these conditions are the same as the crystals of ATBS.Na prepared in Example 2a.

[0207] ● Comparative Example 2a: Preparation of crystals of ATBS.Na at atmospheric pressure (1 bar) (not obtained) The reaction is carried out according to the procedure described in Example 2a, except that SA2 is distilled at atmospheric pressure. At the end of the cooling step, a suspension S1 cannot be formed from the aqueous solution SA2, and a filtration operation or a centrifugation operation for isolating the crystals of the ATBS sodium salt cannot be performed.

[0208] ● Comparative Example 2b: Preparation of crystals of ATBS.Na (not obtained) The reaction was carried out according to the conditions described in Example 27 of patent application US6331647. 124 g of sodium hydroxide and 0.13 g of hydroquinone monomethyl ether are added with stirring to a 5000 ml double-jacketed reactor containing 400 g of water. The medium is stirred until all of the sodium hydroxide has dissolved.

[0209] 632 g of ATBS of Example 1 are added to the above mixture. The mixture is stirred at 10 °C for 30 minutes to form an aqueous solution of the sodium salt of 2-acrylamido-2-methylpropanesulfonic acid.

[0210] The resulting aqueous solution is filtered in a 3000 ml reactor equipped for distillation and containing an air purge tube. The contents are heated and stirred while blowing air under the surface at a rate of 0.5 cubic feet per hour. The contents are heated to 50 °C under a vacuum of 933 mbar (about 700 mmHg). As water is removed, a yellowish honey-like product is formed. Then this product is transferred to a Robatel vertical centrifuge, but no solids are recovered. Since no solids were obtained, optical microscope observation was impossible (Figure 13).

[0211] ● Comparative Example 2c: Preparation of ATBS.Na CE2c The reaction was carried out according to the conditions described in Example 3 of patent application WO2013 / 079507. According to Example 1 of WO2013 / 079507, 100 g of an ATBS.Na solution (16.77% by weight) is obtained.

[0212] While introducing air into the ATBS.Na solution, 50 g of solvent is removed from the ATBS.Na solution under reduced pressure and at room temperature. A solid of ATBS.Na CE2c is formed, which is filtered, washed with acrylonitrile / methanol, and then dried overnight at 50°C.

[0213] Optical microscope observation (Figure 15) shows that the dried solid of ATBS.Na CE2c does not correspond to the ATBS.Na crystals according to the present invention.

[0214] ●Comparative Example 2d: Preparation of crystalline ATBS.Na CE2d The reaction is carried out according to the procedure described in Example 2a, except that SA2 is distilled at 720 mbar. A solid of composition C1 containing 80% by weight of ATBS.Na CE2d crystals is obtained.

[0215] Optical microscopy observation (Figure 15) shows that the crystals of ATBS.Na CE2d do not correspond to the crystals of ATBS.Na according to the present invention.

[0216] ●Comparative Example 2e: Preparation of ATBS.Na CE2e crystals The reaction is carried out according to the procedure described in Example 2a, except that the cooling time is 3 hours and 20 minutes. A solid of composition C1 containing 80% by weight of ATBS.Na CE2e crystals is obtained.

[0217] Optical microscopy observation (Figure 16) shows that the ATBS.Na CE2e crystals do not correspond to the ATBS.Na crystals according to the present invention.

[0218] ●Example 3: NMR analysis of ATBS and ATBS.Na E2a ATBS and ATBS.Na E2a are analyzed by proton nuclear magnetic resonance (NMR). The sample is dissolved in D2O. The NMR spectrometer is a Bruker model with a frequency of 400 MHz, and 5 mmBBO BB- 1 H is attached.

[0219] The two proton spectra (Figures 1 and 2) are similar, and the peak assignments are consistent with the molecular structure of ATBS or its sodium salt.

[0220] ●Example 4: Analysis of ATBS and ATBS.Na E2a by X-ray diffraction ATBS and ATBS.Na E2a are pre-ground to prepare powders, which are then analyzed by X-ray diffraction over an angular range of 10 to 90°. The instrument used is a Rigaku MiniFlex II diffractometer equipped with a copper source.

[0221] The crystal of ATBS.Na E2a (Figure 4) shows an X-ray diffraction pattern with the following characteristic peaks: At an angle of 2θ (+ / -0.1°), the angles are 11.7°, 12.2°, 13.2°, 13.5°, 15.6°, 16.8°, 17.8°, 18.5°, 19.1°, 20.6°, 21.4°, 23.3°, 25.1°, 25.8°, 26.9°, 29.1°, 29.5°, 31.0°, 33.0°, 33.6°, 34.4°, 35.2°, 35.9°, 37.1°, 38.4°, 39.6°, 41.1°, 42.9°, 45.1°, 46.0°, 47.2°, and 47.6°. The X-ray diffraction patterns of ATBS in Example 1 (Figure 3) do not have the same group of peaks.

[0222] ●Example 5: Fourier transform infrared measurement of ATBS and ATBS.Na E2a The instrument used for Fourier transform infrared measurements is a Perkin Elmer Spectrum 100 with a single reflection ATR polarization accessory, and has an accuracy of 8 cm. -1 That is the case.

[0223] ATBS and ATBS.Na E2a are sieved to a 100 μm particle size. The particles remaining on the sieve are dried and placed in a 60°C oven for at least 4 hours. Place several hundred milligrams of solid material onto the diamond of the ATR accessory and apply pressure manually using the accessory.

[0224] The following bands (Figure 6) are characteristic of the crystalline form of ATBS.Na E2a: 3576 cm -1 , 3485 cm -1 , 3310 cm -1 , 3079 cm -1 , 2975 cm -1 , 1658 cm -1 , 1629 cm -1 , 1543 cm -1 [[ID=1十八]], 1403 cm -1 , 1321 cm -1 , 1301 cm -1 , 1205 cm -1 , 1187 cm -1 , 1163 cm -1 , 1046 cm -1 , 980 cm -1 , 629 cm -1 . The infrared spectrum of ATBS in Example 1 (Figure 5) does not have the same peak group.

[0225] ● Example 6: Differential Scanning Calorimetry (DSC) of ATBS and ATBS.Na E2a The apparatus used is a Mettler DSC3. ATBS and ATBS.Na E2a are analyzed under a nitrogen flow with a heating gradient of 10 °C / min. The initial temperature is 30 °C, and the product is heated to 350 °C.

[0226] The thermogram of ATBS in Example 1 (Figure 7) shows a thermal effect at a temperature of 195.15 °C, generally considered to be the melting / decomposition point of ATBS, followed by two exothermic decomposition phenomena at 212.8 °C and 288.4 °C.

[0227] The thermogram of the crystals of ATBS.Na E2a (Figure 8) shows four thermal phenomena at 49.8 °C, 144.8 °C, 169.8 °C, and 254.3 °C.

[0228] ● Example 7: Synthesis of Polymers of ATBS and Polymers of ATBS.Na Water-soluble polymers of various monomer compositions are obtained by reaction in a 1.5 L reactor equipped with a mechanical stirrer, thermometer, and nitrogen inlet. The monomers are introduced into the reactor in the presence of distilled water. [When ATBS (Example 1) is used, an appropriate amount of sodium hydroxide is added to neutralize exactly 100% of the acid monomer (ATBS).] The total concentration of monomers in this reaction mixture is 25% by weight. The previously prepared ATBS and ATBS.Na crystals are used.

[0229] The resulting mixture is homogenized, then cooled and degassed under a nitrogen stream. Polymerization is then initiated using a redox system of sodium hypophosphite and tert-butyl hydroperoxide. The resulting gel is then ground and dried in a drying oven to obtain the polymer as a powder.

[0230] All of the obtained polymers are water-soluble polymers, 10 × 10 6 ~12×10 6 They have a high molecular weight of g / mol, and their composition is given in Table 1.

[0231] Table 1: Polymers PB1-PB6 of the present invention and comparative polymer PA a~f 1 and PA a~f Composition of 2c~e [Table 1] inv = present invention; CE = comparative example; AM = acrylamide; AA = acrylic acid; DADMAC = diallyldimethylammonium chloride; DMEA = 2-dimethylaminoethyl acrylate

[0232] The polymer is dissolved in tap water to obtain an aqueous solution in which the polymer concentration is 0.4% by weight relative to the total weight of the solution. These solutions are mechanically stirred at 500 rpm until the polymer is completely solubilized and a clear, homogeneous solution is obtained.

[0233] ●Example 8: Treatment of coal mining effluent A series of coagulation tests will be conducted on coal mine wastewater with a solid content concentration of 18.2% by weight. Each solution is added to 200 g of coal mine wastewater in an amount corresponding to a polymer dosage of 280 g of polymer per ton of dry coal mine wastewater, and then thoroughly mixed by hand until flocculation and optimal water release are observed.

[0234] The results are expressed as NWR (Net Water Release), which corresponds to the total amount of water recovered after 1 hour of the coagulation test minus the amount of water released when the polymer aqueous solution was incorporated into the suspension. The same NWR is calculated after 24 hours, which gives a good idea of ​​the maximum water release.

[0235] The results are shown in Table 2. Table 2: Polymers PB1-PB5 of the present invention and comparative polymer PA a~e 1 and PA a~e Results of net water release using 2c~e [Table 2]

[0236] The results of this experiment clearly demonstrate that the use of crystalline ATBS sodium salt according to the present invention provides a more effective polymer for flocculating coal mine wastewater.

[0237] ●Example 9: Treatment of red mud discharged from the Bayer process Following the protocol described in Example 26, another series of tests were performed on red mud with a solid content of 22.8% by weight obtained from the Bayer process, using 740 g of polymer per ton of dried red mud. The results are shown in Table 3.

[0238] Table 3: Polymers PB1-PB6 of the present invention and comparative polymer PA a~f 1 and PA a~f Results of net water release using 2c~e [Table 3]

[0239] The results of this experiment clearly demonstrate that the use of the crystalline form of ATBS.Na in the present invention produces a more effective polymer for agglomerating red clay discharged from the Bayer process.

Claims

1. The method involves contacting a suspension of solid particles in water with at least one water-soluble polymer of 2-acrylamido-2-methylpropanesulfonic acid (ATBS), wherein, before polymerization, the ATBS has 2θ angles (+ / -0.1°) of 11.7°, 12.2°, 13.2°, 13.5°, 15.6°, 16.8°, 17.8°, 18.5°, 19.1°, 20.6°, 21.4°, 23.3°, and 25.1°. A method for processing a suspension of solid particles in water containing sodium 2-acrylamido-2-methylpropanesulfonate salt (ATBS.Na), which has an X-ray powder diffraction pattern including a group of peaks located at 45.8°, 26.9°, 29.1°, 29.5°, 31.0°, 33.0°, 33.6°, 34.4°, 35.2°, 35.9°, 37.1°, 38.4°, 39.6°, 41.1°, 42.9°, 45.1°, 46.0°, 47.2°, and 47.6°.

2. The method according to claim 1, characterized in that 50 mol% or more of the ATBS in the water-soluble polymer is the crystalline form of ATBS.Na before polymerization.

3. The method according to claim 1 or claim 2, characterized in that the water-soluble polymer is derived from the crystalline form of ATBS.Na and is a polymer derived from at least one hydrophilic monomer selected from nonionic monomers, anionic monomers, cationic monomers, zwitterionic monomers, and mixtures thereof.

4. The method according to claim 3, wherein the nonionic hydrophilic monomer is selected from acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethacrylamide, N,N-dialkylacrylamide, N,N-dialkylmethacrylamide, alkoxylated esters of acrylic acid, N-vinylpyrrolidone, N-methylol(meth)acrylamide, N-vinylcaprolactam, N-vinylformamide, N-vinylacetamide, N-vinylimidazole, N-vinylsuccinimide, acryloylmorpholine, glycidyl methacrylate, vinyl acetate, glyceryl methacrylate, diacetone acrylamide, methacrylic anhydride, acrylonitrile, maleic anhydride, itaconamide, hydroxyalkyl(meth)acrylate, thioalkyl(meth)acrylate, isoprenol and its alkoxylated derivatives, hydroxyethyl(meth)acrylate and its alkoxylated derivatives, hydroxypropyl acrylate and its alkoxylated derivatives, and mixtures thereof, wherein the alkyl group is C1 to C5.

5. The method according to any one of claims 1 to 4, wherein the water-soluble polymer comprises 1 to 99 mol% of a nonionic monomer and 1 to 99 mol% of ATBS, wherein 50 mol% or more of the ATBS is the crystalline form of ATBS.Na before polymerization.

6. The method according to any one of claims 1 to 5, characterized in that the water-soluble polymer is a polymer based on acrylamide and ATBS, wherein 50 mol% or more of the ATBS is a polymer in the crystalline form of ATBS.Na before polymerization, or a polymer consisting of acrylamide, acrylic acid, and ATBS, wherein 50 mol% or more of the ATBS is a polymer in the crystalline form of ATBS.Na before polymerization.

7. The aforementioned water-soluble polymer is 0.5 × 10 ６ ~40 x 10 ６ The method according to any one of claims 1 to 6, characterized in that it has an average molecular weight of g / mol.

8. The method according to any one of claims 1 to 7, characterized in that the amount of water-soluble polymer added to the aqueous suspension is 50 to 5,000 g per ton (dry weight) of solid particles of the suspension.

9. The method according to any one of claims 1 to 8, characterized in that the aqueous suspension of solid particles is derived from ore extraction and consists of a suspension of mineral particles.

10. The method according to any one of claims 1 to 9, characterized in that the aqueous suspension of solid particles contains 5% to 60% by weight of solid particles.

11. The method according to any one of claims 1 to 10, characterized in that the aqueous suspension is transported to a deposition zone by piping, and the water-soluble polymer is added into the piping.

Images